Merge branch 'moving-to-lmdb'

meilidb-core/Cargo.toml

@@ -1,34 +1,55 @@
 [package]
 name = "meilidb-core"
 version = "0.1.0"
-authors = ["Kerollmops <renault.cle@gmail.com>"]
+authors = ["Kerollmops <clement@meilisearch.com>"]
 edition = "2018"
 
 [dependencies]
-byteorder = "1.3.1"
+arc-swap = "0.4.3"
+bincode = "1.1.4"
+byteorder = "1.3.2"
+crossbeam-channel = "0.3.9"
 deunicode = "1.0.0"
-hashbrown = "0.6.0"
-lazy_static = "1.2.0"
-log = "0.4.6"
+env_logger = "0.7.0"
+hashbrown = { version = "0.6.0", features = ["serde"] }
+lmdb-rkv = "0.12.3"
+log = "0.4.8"
+meilidb-schema = { path = "../meilidb-schema", version = "0.1.0" }
 meilidb-tokenizer = { path = "../meilidb-tokenizer", version = "0.1.0" }
-rayon = "1.2.0"
+once_cell = "1.2.0"
+ordered-float = { version = "1.0.2", features = ["serde"] }
+rkv = "0.10.2"
 sdset = "0.3.2"
-serde = { version = "1.0.88", features = ["derive"] }
+serde = { version = "1.0.99", features = ["derive"] }
+serde_json = "1.0.40"
+siphasher = "0.3.0"
 slice-group-by = "0.2.6"
 zerocopy = "0.2.8"
 
-[dependencies.fst]
-git = "https://github.com/Kerollmops/fst.git"
-branch = "arc-byte-slice"
+[dependencies.rmp-serde]
+git = "https://github.com/3Hren/msgpack-rust.git"
+rev = "40b3d48"
+
+[dependencies.rmpv]
+git = "https://github.com/3Hren/msgpack-rust.git"
+rev = "40b3d48"
+features = ["with-serde"]
 
 [dependencies.levenshtein_automata]
 git = "https://github.com/Kerollmops/levenshtein-automata.git"
 branch = "arc-byte-slice"
 features = ["fst_automaton"]
 
+[dependencies.fst]
+git = "https://github.com/Kerollmops/fst.git"
+branch = "arc-byte-slice"
+
 [dev-dependencies]
 assert_matches = "1.3"
-
-[features]
-i128 = ["byteorder/i128"]
-nightly = ["hashbrown/nightly", "slice-group-by/nightly"]
+csv = "1.0.7"
+indexmap = { version = "1.2.0", features = ["serde-1"] }
+rustyline = { version = "5.0.0", default-features = false }
+structopt = "0.3.2"
+tempfile = "3.1.0"
+termcolor = "1.0.4"
+toml = "0.5.3"

meilidb-core/examples/from_file.rs

@@ -0,0 +1,371 @@
+use std::collections::btree_map::{BTreeMap, Entry};
+use std::collections::HashSet;
+use std::error::Error;
+use std::io::Write;
+use std::iter::FromIterator;
+use std::path::{Path, PathBuf};
+use std::time::{Instant, Duration};
+use std::{fs, io, sync::mpsc};
+
+use rustyline::{Editor, Config};
+use serde::{Serialize, Deserialize};
+use structopt::StructOpt;
+use termcolor::{Color, ColorChoice, ColorSpec, StandardStream, WriteColor};
+
+use meilidb_core::{Highlight, Database, UpdateResult, BoxUpdateFn};
+use meilidb_schema::SchemaAttr;
+
+const INDEX_NAME: &str = "default";
+
+#[derive(Debug, StructOpt)]
+struct IndexCommand {
+    /// The destination where the database must be created.
+    #[structopt(parse(from_os_str))]
+    database_path: PathBuf,
+
+    /// The csv file to index.
+    #[structopt(parse(from_os_str))]
+    csv_data_path: PathBuf,
+
+    /// The path to the schema.
+    #[structopt(long, parse(from_os_str))]
+    schema: PathBuf,
+
+    #[structopt(long)]
+    update_group_size: Option<usize>,
+}
+
+#[derive(Debug, StructOpt)]
+struct SearchCommand {
+    /// The destination where the database must be created.
+    #[structopt(parse(from_os_str))]
+    database_path: PathBuf,
+
+    /// Timeout after which the search will return results.
+    #[structopt(long)]
+    fetch_timeout_ms: Option<u64>,
+
+    /// The number of returned results
+    #[structopt(short, long, default_value = "10")]
+    number_results: usize,
+
+    /// The number of characters before and after the first match
+    #[structopt(short = "C", long, default_value = "35")]
+    char_context: usize,
+
+    /// A filter string that can be `!adult` or `adult` to
+    /// filter documents on this specfied field
+    #[structopt(short, long)]
+    filter: Option<String>,
+
+    /// Fields that must be displayed.
+    displayed_fields: Vec<String>,
+}
+
+#[derive(Debug, StructOpt)]
+enum Command {
+    Index(IndexCommand),
+    Search(SearchCommand),
+}
+
+impl Command {
+    fn path(&self) -> &Path {
+        match self {
+            Command::Index(command) => &command.database_path,
+            Command::Search(command) => &command.database_path,
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize)]
+#[serde(transparent)]
+struct Document(indexmap::IndexMap<String, String>);
+
+fn index_command(command: IndexCommand, database: Database) -> Result<(), Box<dyn Error>> {
+    let start = Instant::now();
+
+    let (sender, receiver) = mpsc::sync_channel(100);
+    let update_fn = move |update: UpdateResult| sender.send(update.update_id).unwrap();
+    let index = database.open_index(INDEX_NAME, Some(Box::new(update_fn)))?;
+    let rkv = database.rkv.read().unwrap();
+
+    let schema = {
+        let string = fs::read_to_string(&command.schema)?;
+        toml::from_str(&string).unwrap()
+    };
+
+    let writer = rkv.write().unwrap();
+    match index.main.schema(&writer)? {
+        Some(current_schema) => {
+            if current_schema != schema {
+                return Err(meilidb_core::Error::SchemaDiffer.into())
+            }
+            writer.abort();
+        },
+        None => index.schema_update(writer, schema)?,
+    }
+
+    let mut rdr = csv::Reader::from_path(command.csv_data_path)?;
+    let mut raw_record = csv::StringRecord::new();
+    let headers = rdr.headers()?.clone();
+
+    let mut max_update_id = 0;
+    let mut i = 0;
+    let mut end_of_file = false;
+
+    while !end_of_file {
+        let mut additions = index.documents_addition();
+
+        loop {
+            end_of_file = !rdr.read_record(&mut raw_record)?;
+            if end_of_file { break }
+
+            let document: Document = match raw_record.deserialize(Some(&headers)) {
+                Ok(document) => document,
+                Err(e) => {
+                    eprintln!("{:?}", e);
+                    continue;
+                }
+            };
+
+            additions.update_document(document);
+
+            print!("\rindexing document {}", i);
+            i += 1;
+
+            if let Some(group_size) = command.update_group_size {
+                if i % group_size == 0 { break }
+            }
+        }
+
+        println!();
+
+        let writer = rkv.write().unwrap();
+        println!("committing update...");
+        let update_id = additions.finalize(writer)?;
+        max_update_id = max_update_id.max(update_id);
+        println!("committed update {}", update_id);
+    }
+
+    println!("Waiting for update {}", max_update_id);
+    for id in receiver {
+        if id == max_update_id { break }
+    }
+
+    println!("database created in {:.2?} at: {:?}", start.elapsed(), command.database_path);
+
+    Ok(())
+}
+
+fn display_highlights(text: &str, ranges: &[usize]) -> io::Result<()> {
+    let mut stdout = StandardStream::stdout(ColorChoice::Always);
+    let mut highlighted = false;
+
+    for range in ranges.windows(2) {
+        let [start, end] = match range { [start, end] => [*start, *end], _ => unreachable!() };
+        if highlighted {
+            stdout.set_color(ColorSpec::new().set_fg(Some(Color::Yellow)))?;
+        }
+        write!(&mut stdout, "{}", &text[start..end])?;
+        stdout.reset()?;
+        highlighted = !highlighted;
+    }
+
+    Ok(())
+}
+
+fn char_to_byte_range(index: usize, length: usize, text: &str) -> (usize, usize) {
+    let mut byte_index = 0;
+    let mut byte_length = 0;
+
+    for (n, (i, c)) in text.char_indices().enumerate() {
+        if n == index {
+            byte_index = i;
+        }
+
+        if n + 1 == index + length {
+            byte_length = i - byte_index + c.len_utf8();
+            break;
+        }
+    }
+
+    (byte_index, byte_length)
+}
+
+fn create_highlight_areas(text: &str, highlights: &[Highlight]) -> Vec<usize> {
+    let mut byte_indexes = BTreeMap::new();
+
+    for highlight in highlights {
+        let char_index = highlight.char_index as usize;
+        let char_length = highlight.char_length as usize;
+        let (byte_index, byte_length) = char_to_byte_range(char_index, char_length, text);
+
+        match byte_indexes.entry(byte_index) {
+            Entry::Vacant(entry) => { entry.insert(byte_length); },
+            Entry::Occupied(mut entry) => {
+                if *entry.get() < byte_length {
+                    entry.insert(byte_length);
+                }
+            },
+        }
+    }
+
+    let mut title_areas = Vec::new();
+    title_areas.push(0);
+    for (byte_index, length) in byte_indexes {
+        title_areas.push(byte_index);
+        title_areas.push(byte_index + length);
+    }
+    title_areas.push(text.len());
+    title_areas.sort_unstable();
+    title_areas
+}
+
+/// note: matches must have been sorted by `char_index` and `char_length` before being passed.
+///
+/// ```no_run
+/// matches.sort_unstable_by_key(|m| (m.char_index, m.char_length));
+///
+/// let matches = matches.matches.iter().filter(|m| SchemaAttr::new(m.attribute) == attr).cloned();
+///
+/// let (text, matches) = crop_text(&text, matches, 35);
+/// ```
+fn crop_text(
+    text: &str,
+    highlights: impl IntoIterator<Item=Highlight>,
+    context: usize,
+) -> (String, Vec<Highlight>)
+{
+    let mut highlights = highlights.into_iter().peekable();
+
+    let char_index = highlights.peek().map(|m| m.char_index as usize).unwrap_or(0);
+    let start = char_index.saturating_sub(context);
+    let text = text.chars().skip(start).take(context * 2).collect();
+
+    let highlights = highlights
+        .take_while(|m| {
+            (m.char_index as usize) + (m.char_length as usize) <= start + (context * 2)
+        })
+        .map(|highlight| {
+            Highlight { char_index: highlight.char_index - start as u16, ..highlight }
+        })
+        .collect();
+
+    (text, highlights)
+}
+
+fn search_command(command: SearchCommand, database: Database) -> Result<(), Box<dyn Error>> {
+    let rkv = database.rkv.read().unwrap();
+    let update_fn = None as Option::<BoxUpdateFn>;
+    let index = database.open_index(INDEX_NAME, update_fn)?;
+    let reader = rkv.read().unwrap();
+
+    let schema = index.main.schema(&reader)?;
+    let schema = schema.ok_or(meilidb_core::Error::SchemaMissing)?;
+
+    let fields = command.displayed_fields.iter().map(String::as_str);
+    let fields = HashSet::from_iter(fields);
+
+    let config = Config::builder().auto_add_history(true).build();
+    let mut readline = Editor::<()>::with_config(config);
+    let _ = readline.load_history("query-history.txt");
+
+    for result in readline.iter("Searching for: ") {
+        match result {
+            Ok(query) => {
+                let start_total = Instant::now();
+
+                let documents = match command.filter {
+                    Some(ref filter) => {
+                        let filter = filter.as_str();
+                        let (positive, filter) = if filter.chars().next() == Some('!') {
+                            (false, &filter[1..])
+                        } else {
+                            (true, filter)
+                        };
+
+                        let attr = schema.attribute(&filter).expect("Could not find filtered attribute");
+
+                        let builder = index.query_builder();
+                        let builder = builder.with_filter(|document_id| {
+                            let string: String = index.document_attribute(&reader, document_id, attr).unwrap().unwrap();
+                            (string == "true") == positive
+                        });
+                        builder.query(&reader, &query, 0..command.number_results)?
+                    },
+                    None => {
+                        let builder = index.query_builder();
+                        builder.query(&reader, &query, 0..command.number_results)?
+                    }
+                };
+
+                let mut retrieve_duration = Duration::default();
+
+                let number_of_documents = documents.len();
+                for mut doc in documents {
+
+                    doc.highlights.sort_unstable_by_key(|m| (m.char_index, m.char_length));
+
+                    let start_retrieve = Instant::now();
+                    let result = index.document::<Document, _>(&reader, Some(&fields), doc.id);
+                    retrieve_duration += start_retrieve.elapsed();
+
+                    match result {
+                        Ok(Some(document)) => {
+                            println!("raw-id: {:?}", doc.id);
+                            for (name, text) in document.0 {
+                                print!("{}: ", name);
+
+                                let attr = schema.attribute(&name).unwrap();
+                                let highlights = doc.highlights.iter()
+                                                .filter(|m| SchemaAttr::new(m.attribute) == attr)
+                                                .cloned();
+                                let (text, highlights) = crop_text(&text, highlights, command.char_context);
+                                let areas = create_highlight_areas(&text, &highlights);
+                                display_highlights(&text, &areas)?;
+                                println!();
+                            }
+                        },
+                        Ok(None) => eprintln!("missing document"),
+                        Err(e) => eprintln!("{}", e),
+                    }
+
+                    let mut matching_attributes = HashSet::new();
+                    for highlight in doc.highlights {
+                        let attr = SchemaAttr::new(highlight.attribute);
+                        let name = schema.attribute_name(attr);
+                        matching_attributes.insert(name);
+                    }
+
+                    let matching_attributes = Vec::from_iter(matching_attributes);
+                    println!("matching in: {:?}", matching_attributes);
+
+                    println!();
+                }
+
+                eprintln!("whole documents fields retrieve took {:.2?}", retrieve_duration);
+                eprintln!("===== Found {} results in {:.2?} =====", number_of_documents, start_total.elapsed());
+            },
+            Err(err) => {
+                println!("Error: {:?}", err);
+                break
+            }
+        }
+    }
+
+    readline.save_history("query-history.txt").unwrap();
+
+    Ok(())
+}
+
+fn main() -> Result<(), Box<dyn Error>> {
+    env_logger::init();
+
+    let opt = Command::from_args();
+    let database = Database::open_or_create(opt.path())?;
+
+    match opt {
+        Command::Index(command) => index_command(command, database),
+        Command::Search(command) => search_command(command, database),
+    }
+}

meilidb-core/src/automaton.rs

@@ -1,44 +0,0 @@
-use lazy_static::lazy_static;
-use levenshtein_automata::{
-    LevenshteinAutomatonBuilder as LevBuilder,
-    DFA,
-};
-
-lazy_static! {
-    static ref LEVDIST0: LevBuilder = LevBuilder::new(0, false);
-    static ref LEVDIST1: LevBuilder = LevBuilder::new(1, false);
-    static ref LEVDIST2: LevBuilder = LevBuilder::new(2, false);
-}
-
-#[derive(Copy, Clone)]
-enum PrefixSetting {
-    Prefix,
-    NoPrefix,
-}
-
-fn build_dfa_with_setting(query: &str, setting: PrefixSetting) -> DFA {
-    use self::PrefixSetting::{Prefix, NoPrefix};
-
-    match query.len() {
-        0 ..= 4 => match setting {
-            Prefix   => LEVDIST0.build_prefix_dfa(query),
-            NoPrefix => LEVDIST0.build_dfa(query),
-        },
-        5 ..= 8 => match setting {
-            Prefix   => LEVDIST1.build_prefix_dfa(query),
-            NoPrefix => LEVDIST1.build_dfa(query),
-        },
-        _ => match setting {
-            Prefix   => LEVDIST2.build_prefix_dfa(query),
-            NoPrefix => LEVDIST2.build_dfa(query),
-        },
-    }
-}
-
-pub fn build_prefix_dfa(query: &str) -> DFA {
-    build_dfa_with_setting(query, PrefixSetting::Prefix)
-}
-
-pub fn build_dfa(query: &str) -> DFA {
-    build_dfa_with_setting(query, PrefixSetting::NoPrefix)
-}

meilidb-core/src/automaton/dfa.rs

@@ -0,0 +1,51 @@
+use once_cell::sync::OnceCell;
+use levenshtein_automata::{
+    LevenshteinAutomatonBuilder as LevBuilder,
+    DFA,
+};
+
+static LEVDIST0: OnceCell<LevBuilder> = OnceCell::new();
+static LEVDIST1: OnceCell<LevBuilder> = OnceCell::new();
+static LEVDIST2: OnceCell<LevBuilder> = OnceCell::new();
+
+#[derive(Copy, Clone)]
+enum PrefixSetting {
+    Prefix,
+    NoPrefix,
+}
+
+fn build_dfa_with_setting(query: &str, setting: PrefixSetting) -> DFA {
+    use PrefixSetting::{Prefix, NoPrefix};
+
+    match query.len() {
+        0 ..= 4 => {
+            let builder = LEVDIST0.get_or_init(|| LevBuilder::new(0, false));
+            match setting {
+                Prefix   => builder.build_prefix_dfa(query),
+                NoPrefix => builder.build_dfa(query),
+            }
+        },
+        5 ..= 8 => {
+            let builder = LEVDIST1.get_or_init(|| LevBuilder::new(1, false));
+            match setting {
+                Prefix   => builder.build_prefix_dfa(query),
+                NoPrefix => builder.build_dfa(query),
+            }
+        },
+        _ => {
+            let builder = LEVDIST2.get_or_init(|| LevBuilder::new(2, false));
+            match setting {
+                Prefix   => builder.build_prefix_dfa(query),
+                NoPrefix => builder.build_dfa(query),
+            }
+        },
+    }
+}
+
+pub fn build_prefix_dfa(query: &str) -> DFA {
+    build_dfa_with_setting(query, PrefixSetting::Prefix)
+}
+
+pub fn build_dfa(query: &str) -> DFA {
+    build_dfa_with_setting(query, PrefixSetting::NoPrefix)
+}

meilidb-core/src/automaton/mod.rs

@@ -0,0 +1,219 @@
+mod dfa;
+mod query_enhancer;
+
+use std::cmp::Reverse;
+use std::vec;
+
+use fst::{IntoStreamer, Streamer};
+use levenshtein_automata::DFA;
+use meilidb_tokenizer::{split_query_string, is_cjk};
+
+use crate::store;
+use crate::error::MResult;
+
+use self::dfa::{build_dfa, build_prefix_dfa};
+use self::query_enhancer::QueryEnhancerBuilder;
+pub use self::query_enhancer::QueryEnhancer;
+
+const NGRAMS: usize = 3;
+
+pub struct AutomatonProducer {
+    automatons: Vec<Vec<Automaton>>,
+}
+
+impl AutomatonProducer {
+    pub fn new(
+        reader: &impl rkv::Readable,
+        query: &str,
+        main_store: store::Main,
+        synonyms_store: store::Synonyms,
+    ) -> MResult<(AutomatonProducer, QueryEnhancer)>
+    {
+        let (automatons, query_enhancer) = generate_automatons(
+            reader,
+            query,
+            main_store,
+            synonyms_store,
+        )?;
+
+        Ok((AutomatonProducer { automatons }, query_enhancer))
+    }
+
+    pub fn into_iter(self) -> vec::IntoIter<Vec<Automaton>> {
+        self.automatons.into_iter()
+    }
+}
+
+#[derive(Debug)]
+pub struct Automaton {
+    pub index: usize,
+    pub ngram: usize,
+    pub query_len: usize,
+    pub is_exact: bool,
+    pub is_prefix: bool,
+    pub query: String,
+}
+
+impl Automaton {
+    pub fn dfa(&self) -> DFA {
+        if self.is_prefix {
+            build_prefix_dfa(&self.query)
+        } else {
+            build_dfa(&self.query)
+        }
+    }
+
+    fn exact(index: usize, ngram: usize, query: &str) -> Automaton {
+        Automaton {
+            index,
+            ngram,
+            query_len: query.len(),
+            is_exact: true,
+            is_prefix: false,
+            query: query.to_string(),
+        }
+    }
+
+    fn prefix_exact(index: usize, ngram: usize, query: &str) -> Automaton {
+        Automaton {
+            index,
+            ngram,
+            query_len: query.len(),
+            is_exact: true,
+            is_prefix: true,
+            query: query.to_string(),
+        }
+    }
+
+    fn non_exact(index: usize, ngram: usize, query: &str) -> Automaton {
+        Automaton {
+            index,
+            ngram,
+            query_len: query.len(),
+            is_exact: false,
+            is_prefix: false,
+            query: query.to_string(),
+        }
+    }
+}
+
+pub fn normalize_str(string: &str) -> String {
+    let mut string = string.to_lowercase();
+
+    if !string.contains(is_cjk) {
+        string = deunicode::deunicode_with_tofu(&string, "");
+    }
+
+    string
+}
+
+fn generate_automatons(
+    reader: &impl rkv::Readable,
+    query: &str,
+    main_store: store::Main,
+    synonym_store: store::Synonyms,
+) -> MResult<(Vec<Vec<Automaton>>, QueryEnhancer)>
+{
+    let has_end_whitespace = query.chars().last().map_or(false, char::is_whitespace);
+    let query_words: Vec<_> = split_query_string(query).map(str::to_lowercase).collect();
+    let synonyms = match main_store.synonyms_fst(reader)? {
+        Some(synonym) => synonym,
+        None => fst::Set::default(),
+    };
+
+    let mut automaton_index = 0;
+    let mut automatons = Vec::new();
+    let mut enhancer_builder = QueryEnhancerBuilder::new(&query_words);
+
+    // We must not declare the original words to the query enhancer
+    // *but* we need to push them in the automatons list first
+    let mut original_automatons = Vec::new();
+    let mut original_words = query_words.iter().peekable();
+    while let Some(word) = original_words.next() {
+
+        let has_following_word = original_words.peek().is_some();
+        let not_prefix_dfa = has_following_word || has_end_whitespace || word.chars().all(is_cjk);
+
+        let automaton = if not_prefix_dfa {
+            Automaton::exact(automaton_index, 1, word)
+        } else {
+            Automaton::prefix_exact(automaton_index, 1, word)
+        };
+        automaton_index += 1;
+        original_automatons.push(automaton);
+    }
+
+    automatons.push(original_automatons);
+
+    for n in 1..=NGRAMS {
+        let mut ngrams = query_words.windows(n).enumerate().peekable();
+        while let Some((query_index, ngram_slice)) = ngrams.next() {
+
+            let query_range = query_index..query_index + n;
+            let ngram_nb_words = ngram_slice.len();
+            let ngram = ngram_slice.join(" ");
+
+            let has_following_word = ngrams.peek().is_some();
+            let not_prefix_dfa = has_following_word || has_end_whitespace || ngram.chars().all(is_cjk);
+
+            // automaton of synonyms of the ngrams
+            let normalized = normalize_str(&ngram);
+            let lev = if not_prefix_dfa { build_dfa(&normalized) } else { build_prefix_dfa(&normalized) };
+
+            let mut stream = synonyms.search(&lev).into_stream();
+            while let Some(base) = stream.next() {
+
+                // only trigger alternatives when the last word has been typed
+                // i.e. "new " do not but "new yo" triggers alternatives to "new york"
+                let base = std::str::from_utf8(base).unwrap();
+                let base_nb_words = split_query_string(base).count();
+                if ngram_nb_words != base_nb_words { continue }
+
+                if let Some(synonyms) = synonym_store.synonyms(reader, base.as_bytes())? {
+
+                    let mut stream = synonyms.into_stream();
+                    while let Some(synonyms) = stream.next() {
+                        let synonyms = std::str::from_utf8(synonyms).unwrap();
+                        let synonyms_words: Vec<_> = split_query_string(synonyms).collect();
+                        let nb_synonym_words = synonyms_words.len();
+
+                        let real_query_index = automaton_index;
+                        enhancer_builder.declare(query_range.clone(), real_query_index, &synonyms_words);
+
+                        for synonym in synonyms_words {
+                            let automaton = if nb_synonym_words == 1 {
+                                Automaton::exact(automaton_index, n, synonym)
+                            } else {
+                                Automaton::non_exact(automaton_index, n, synonym)
+                            };
+                            automaton_index += 1;
+                            automatons.push(vec![automaton]);
+                        }
+                    }
+                }
+            }
+
+            if n != 1 {
+                // automaton of concatenation of query words
+                let concat = ngram_slice.concat();
+                let normalized = normalize_str(&concat);
+
+                let real_query_index = automaton_index;
+                enhancer_builder.declare(query_range.clone(), real_query_index, &[&normalized]);
+
+                let automaton = Automaton::exact(automaton_index, n, &normalized);
+                automaton_index += 1;
+                automatons.push(vec![automaton]);
+            }
+        }
+    }
+
+    // order automatons, the most important first,
+    // we keep the original automatons at the front.
+    automatons[1..].sort_unstable_by_key(|a| {
+        let a = a.first().unwrap();
+        (Reverse(a.is_exact), Reverse(a.ngram))
+    });
+
+    Ok((automatons, enhancer_builder.build()))
+}

meilidb-core/src/automaton/query_enhancer.rs

@@ -0,0 +1,398 @@
+use std::ops::Range;
+use std::cmp::Ordering::{Less, Greater, Equal};
+
+/// Return `true` if the specified range can accept the given replacements words.
+/// Returns `false` if the replacements words are already present in the original query
+/// or if there is fewer replacement words than the range to replace.
+//
+//
+// ## Ignored because already present in original
+//
+//     new york city subway
+//     -------- ^^^^
+//   /          \
+//  [new york city]
+//
+//
+// ## Ignored because smaller than the original
+//
+//   new york city subway
+//   -------------
+//   \          /
+//    [new york]
+//
+//
+// ## Accepted because bigger than the original
+//
+//        NYC subway
+//        ---
+//       /   \
+//      /     \
+//     /       \
+//    /         \
+//   /           \
+//  [new york city]
+//
+fn rewrite_range_with<S, T>(query: &[S], range: Range<usize>, words: &[T]) -> bool
+where S: AsRef<str>,
+      T: AsRef<str>,
+{
+    if words.len() <= range.len() {
+        // there is fewer or equal replacement words
+        // than there is already in the replaced range
+        return false
+    }
+
+    // retrieve the part to rewrite but with the length
+    // of the replacement part
+    let original = query.iter().skip(range.start).take(words.len());
+
+    // check if the original query doesn't already contain
+    // the replacement words
+    !original.map(AsRef::as_ref).eq(words.iter().map(AsRef::as_ref))
+}
+
+type Origin = usize;
+type RealLength = usize;
+
+struct FakeIntervalTree {
+    intervals: Vec<(Range<usize>, (Origin, RealLength))>,
+}
+
+impl FakeIntervalTree {
+    fn new(mut intervals: Vec<(Range<usize>, (Origin, RealLength))>) -> FakeIntervalTree {
+        intervals.sort_unstable_by_key(|(r, _)| (r.start, r.end));
+        FakeIntervalTree { intervals }
+    }
+
+    fn query(&self, point: usize) -> Option<(Range<usize>, (Origin, RealLength))> {
+        let element = self.intervals.binary_search_by(|(r, _)| {
+            if point >= r.start {
+                if point < r.end { Equal } else { Less }
+            } else { Greater }
+        });
+
+        let n = match element { Ok(n) => n, Err(n) => n };
+
+        match self.intervals.get(n) {
+            Some((range, value)) if range.contains(&point) => Some((range.clone(), *value)),
+            _otherwise => None,
+        }
+    }
+}
+
+pub struct QueryEnhancerBuilder<'a, S> {
+    query: &'a [S],
+    origins: Vec<usize>,
+    real_to_origin: Vec<(Range<usize>, (Origin, RealLength))>,
+}
+
+impl<S: AsRef<str>> QueryEnhancerBuilder<'_, S> {
+    pub fn new(query: &[S]) -> QueryEnhancerBuilder<S> {
+        // we initialize origins query indices based on their positions
+        let origins: Vec<_> = (0..query.len() + 1).collect();
+        let real_to_origin = origins.iter().map(|&o| (o..o+1, (o, 1))).collect();
+
+        QueryEnhancerBuilder { query, origins, real_to_origin }
+    }
+
+    /// Update the final real to origin query indices mapping.
+    ///
+    /// `range` is the original words range that this `replacement` words replace
+    /// and `real` is the first real query index of these replacement words.
+    pub fn declare<T>(&mut self, range: Range<usize>, real: usize, replacement: &[T])
+    where T: AsRef<str>,
+    {
+        // check if the range of original words
+        // can be rewritten with the replacement words
+        if rewrite_range_with(self.query, range.clone(), replacement) {
+
+            // this range can be replaced so we need to
+            // modify the origins accordingly
+            let offset = replacement.len() - range.len();
+
+            let previous_padding = self.origins[range.end - 1];
+            let current_offset = (self.origins[range.end] - 1) - previous_padding;
+            let diff = offset.saturating_sub(current_offset);
+            self.origins[range.end] += diff;
+
+            for r in &mut self.origins[range.end + 1..] {
+                *r += diff;
+            }
+        }
+
+        // we need to store the real number and origins relations
+        // this way it will be possible to know by how many
+        // we need to pad real query indices
+        let real_range = real..real + replacement.len().max(range.len());
+        let real_length = replacement.len();
+        self.real_to_origin.push((real_range, (range.start, real_length)));
+    }
+
+    pub fn build(self) -> QueryEnhancer {
+        QueryEnhancer {
+            origins: self.origins,
+            real_to_origin: FakeIntervalTree::new(self.real_to_origin),
+        }
+    }
+}
+
+pub struct QueryEnhancer {
+    origins: Vec<usize>,
+    real_to_origin: FakeIntervalTree,
+}
+
+impl QueryEnhancer {
+    /// Returns the query indices to use to replace this real query index.
+    pub fn replacement(&self, real: u32) -> Range<u32> {
+        let real = real as usize;
+
+        // query the fake interval tree with the real query index
+        let (range, (origin, real_length)) =
+            self.real_to_origin
+                .query(real)
+                .expect("real has never been declared");
+
+        // if `real` is the end bound of the range
+        if (range.start + real_length - 1) == real {
+            let mut count = range.len();
+            let mut new_origin = origin;
+            for (i, slice) in self.origins[new_origin..].windows(2).enumerate() {
+                let len = slice[1] - slice[0];
+                count = count.saturating_sub(len);
+                if count == 0 { new_origin = origin + i; break }
+            }
+
+            let n = real - range.start;
+            let start = self.origins[origin];
+            let end = self.origins[new_origin + 1];
+            let remaining = (end - start) - n;
+
+            Range { start: (start + n) as u32, end: (start + n + remaining) as u32 }
+
+        } else {
+            // just return the origin along with
+            // the real position of the word
+            let n = real as usize - range.start;
+            let origin = self.origins[origin];
+
+            Range { start: (origin + n) as u32, end: (origin + n + 1) as u32 }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn original_unmodified() {
+        let query = ["new", "york", "city", "subway"];
+        //             0       1       2        3
+        let mut builder = QueryEnhancerBuilder::new(&query);
+
+        // new york = new york city
+        builder.declare(0..2, 4, &["new", "york", "city"]);
+        //                    ^      4       5       6
+
+        let enhancer = builder.build();
+
+        assert_eq!(enhancer.replacement(0), 0..1); // new
+        assert_eq!(enhancer.replacement(1), 1..2); // york
+        assert_eq!(enhancer.replacement(2), 2..3); // city
+        assert_eq!(enhancer.replacement(3), 3..4); // subway
+        assert_eq!(enhancer.replacement(4), 0..1); // new
+        assert_eq!(enhancer.replacement(5), 1..2); // york
+        assert_eq!(enhancer.replacement(6), 2..3); // city
+    }
+
+    #[test]
+    fn simple_growing() {
+        let query = ["new", "york", "subway"];
+        //             0       1        2
+        let mut builder = QueryEnhancerBuilder::new(&query);
+
+        // new york = new york city
+        builder.declare(0..2, 3, &["new", "york", "city"]);
+        //                    ^      3       4       5
+
+        let enhancer = builder.build();
+
+        assert_eq!(enhancer.replacement(0), 0..1); // new
+        assert_eq!(enhancer.replacement(1), 1..3); // york
+        assert_eq!(enhancer.replacement(2), 3..4); // subway
+        assert_eq!(enhancer.replacement(3), 0..1); // new
+        assert_eq!(enhancer.replacement(4), 1..2); // york
+        assert_eq!(enhancer.replacement(5), 2..3); // city
+    }
+
+    #[test]
+    fn same_place_growings() {
+        let query = ["NY", "subway"];
+        //             0       1
+        let mut builder = QueryEnhancerBuilder::new(&query);
+
+        // NY = new york
+        builder.declare(0..1, 2, &["new", "york"]);
+        //                    ^      2       3
+
+        // NY = new york city
+        builder.declare(0..1, 4, &["new", "york", "city"]);
+        //                    ^      4       5       6
+
+        // NY = NYC
+        builder.declare(0..1, 7, &["NYC"]);
+        //                    ^      7
+
+        // NY = new york city
+        builder.declare(0..1, 8, &["new", "york", "city"]);
+        //                    ^      8       9      10
+
+        // subway = underground train
+        builder.declare(1..2, 11, &["underground", "train"]);
+        //                    ^          11          12
+
+        let enhancer = builder.build();
+
+        assert_eq!(enhancer.replacement(0), 0..3); // NY
+        assert_eq!(enhancer.replacement(1), 3..5); // subway
+        assert_eq!(enhancer.replacement(2), 0..1); // new
+        assert_eq!(enhancer.replacement(3), 1..3); // york
+        assert_eq!(enhancer.replacement(4), 0..1); // new
+        assert_eq!(enhancer.replacement(5), 1..2); // york
+        assert_eq!(enhancer.replacement(6), 2..3); // city
+        assert_eq!(enhancer.replacement(7), 0..3); // NYC
+        assert_eq!(enhancer.replacement(8), 0..1); // new
+        assert_eq!(enhancer.replacement(9), 1..2); // york
+        assert_eq!(enhancer.replacement(10), 2..3); // city
+        assert_eq!(enhancer.replacement(11), 3..4); // underground
+        assert_eq!(enhancer.replacement(12), 4..5); // train
+    }
+
+    #[test]
+    fn bigger_growing() {
+        let query = ["NYC", "subway"];
+        //             0        1
+        let mut builder = QueryEnhancerBuilder::new(&query);
+
+        // NYC = new york city
+        builder.declare(0..1, 2, &["new", "york", "city"]);
+        //                    ^      2       3       4
+
+        let enhancer = builder.build();
+
+        assert_eq!(enhancer.replacement(0), 0..3); // NYC
+        assert_eq!(enhancer.replacement(1), 3..4); // subway
+        assert_eq!(enhancer.replacement(2), 0..1); // new
+        assert_eq!(enhancer.replacement(3), 1..2); // york
+        assert_eq!(enhancer.replacement(4), 2..3); // city
+    }
+
+    #[test]
+    fn middle_query_growing() {
+        let query = ["great", "awesome", "NYC", "subway"];
+        //              0         1        2        3
+        let mut builder = QueryEnhancerBuilder::new(&query);
+
+        // NYC = new york city
+        builder.declare(2..3, 4, &["new", "york", "city"]);
+        //                    ^      4       5       6
+
+        let enhancer = builder.build();
+
+        assert_eq!(enhancer.replacement(0), 0..1); // great
+        assert_eq!(enhancer.replacement(1), 1..2); // awesome
+        assert_eq!(enhancer.replacement(2), 2..5); // NYC
+        assert_eq!(enhancer.replacement(3), 5..6); // subway
+        assert_eq!(enhancer.replacement(4), 2..3); // new
+        assert_eq!(enhancer.replacement(5), 3..4); // york
+        assert_eq!(enhancer.replacement(6), 4..5); // city
+    }
+
+    #[test]
+    fn end_query_growing() {
+        let query = ["NYC", "subway"];
+        //             0        1
+        let mut builder = QueryEnhancerBuilder::new(&query);
+
+        // NYC = new york city
+        builder.declare(1..2, 2, &["underground", "train"]);
+        //                    ^         2            3
+
+        let enhancer = builder.build();
+
+        assert_eq!(enhancer.replacement(0), 0..1); // NYC
+        assert_eq!(enhancer.replacement(1), 1..3); // subway
+        assert_eq!(enhancer.replacement(2), 1..2); // underground
+        assert_eq!(enhancer.replacement(3), 2..3); // train
+    }
+
+    #[test]
+    fn multiple_growings() {
+        let query = ["great", "awesome", "NYC", "subway"];
+        //              0         1        2        3
+        let mut builder = QueryEnhancerBuilder::new(&query);
+
+        // NYC = new york city
+        builder.declare(2..3, 4, &["new", "york", "city"]);
+        //                    ^      4       5       6
+
+        // subway = underground train
+        builder.declare(3..4, 7, &["underground", "train"]);
+        //                    ^          7           8
+
+        let enhancer = builder.build();
+
+        assert_eq!(enhancer.replacement(0), 0..1); // great
+        assert_eq!(enhancer.replacement(1), 1..2); // awesome
+        assert_eq!(enhancer.replacement(2), 2..5); // NYC
+        assert_eq!(enhancer.replacement(3), 5..7); // subway
+        assert_eq!(enhancer.replacement(4), 2..3); // new
+        assert_eq!(enhancer.replacement(5), 3..4); // york
+        assert_eq!(enhancer.replacement(6), 4..5); // city
+        assert_eq!(enhancer.replacement(7), 5..6); // underground
+        assert_eq!(enhancer.replacement(8), 6..7); // train
+    }
+
+    #[test]
+    fn multiple_probable_growings() {
+        let query = ["great", "awesome", "NYC", "subway"];
+        //              0         1        2        3
+        let mut builder = QueryEnhancerBuilder::new(&query);
+
+        // NYC = new york city
+        builder.declare(2..3, 4, &["new", "york", "city"]);
+        //                    ^      4       5       6
+
+        // subway = underground train
+        builder.declare(3..4, 7, &["underground", "train"]);
+        //                    ^          7           8
+
+        // great awesome = good
+        builder.declare(0..2, 9, &["good"]);
+        //                    ^       9
+
+        // awesome NYC = NY
+        builder.declare(1..3, 10, &["NY"]);
+        //                    ^^     10
+
+        // NYC subway = metro
+        builder.declare(2..4, 11, &["metro"]);
+        //                    ^^      11
+
+        let enhancer = builder.build();
+
+        assert_eq!(enhancer.replacement(0),  0..1); // great
+        assert_eq!(enhancer.replacement(1),  1..2); // awesome
+        assert_eq!(enhancer.replacement(2),  2..5); // NYC
+        assert_eq!(enhancer.replacement(3),  5..7); // subway
+        assert_eq!(enhancer.replacement(4),  2..3); // new
+        assert_eq!(enhancer.replacement(5),  3..4); // york
+        assert_eq!(enhancer.replacement(6),  4..5); // city
+        assert_eq!(enhancer.replacement(7),  5..6); // underground
+        assert_eq!(enhancer.replacement(8),  6..7); // train
+        assert_eq!(enhancer.replacement(9),  0..2); // good
+        assert_eq!(enhancer.replacement(10), 1..5); // NY
+        assert_eq!(enhancer.replacement(11), 2..5); // metro
+    }
+}

meilidb-core/src/criterion/document_id.rs

@@ -10,7 +10,7 @@ impl Criterion for DocumentId {
         lhs.id.cmp(&rhs.id)
     }
 
-    fn name(&self) -> &'static str {
+    fn name(&self) -> &str {
         "DocumentId"
     }
 }

meilidb-core/src/criterion/exact.rs

@@ -37,7 +37,7 @@ impl Criterion for Exact {
         lhs.cmp(&rhs).reverse()
     }
 
-    fn name(&self) -> &'static str {
+    fn name(&self) -> &str {
         "Exact"
     }
 }

meilidb-core/src/criterion/mod.rs

@@ -4,6 +4,7 @@ mod words_proximity;
 mod sum_of_words_attribute;
 mod sum_of_words_position;
 mod exact;
+mod sort_by_attr;
 mod document_id;
 
 use std::cmp::Ordering;
@@ -16,13 +17,14 @@ pub use self::{
     sum_of_words_attribute::SumOfWordsAttribute,
     sum_of_words_position::SumOfWordsPosition,
     exact::Exact,
+    sort_by_attr::SortByAttr,
     document_id::DocumentId,
 };
 
 pub trait Criterion: Send + Sync {
     fn evaluate(&self, lhs: &RawDocument, rhs: &RawDocument) -> Ordering;
 
-    fn name(&self) -> &'static str;
+    fn name(&self) -> &str;
 
     #[inline]
     fn eq(&self, lhs: &RawDocument, rhs: &RawDocument) -> bool {
@@ -35,7 +37,7 @@ impl<'a, T: Criterion + ?Sized + Send + Sync> Criterion for &'a T {
         (**self).evaluate(lhs, rhs)
     }
 
-    fn name(&self) -> &'static str {
+    fn name(&self) -> &str {
         (**self).name()
     }
 
@@ -49,7 +51,7 @@ impl<T: Criterion + ?Sized> Criterion for Box<T> {
         (**self).evaluate(lhs, rhs)
     }
 
-    fn name(&self) -> &'static str {
+    fn name(&self) -> &str {
         (**self).name()
     }
 

meilidb-core/src/criterion/number_of_words.rs

@@ -25,7 +25,7 @@ impl Criterion for NumberOfWords {
         lhs.cmp(&rhs).reverse()
     }
 
-    fn name(&self) -> &'static str {
+    fn name(&self) -> &str {
         "NumberOfWords"
     }
 }

meilidb-core/src/criterion/sort_by_attr.rs

@@ -0,0 +1,125 @@
+use std::cmp::Ordering;
+use std::error::Error;
+use std::fmt;
+
+use meilidb_schema::{Schema, SchemaAttr};
+use crate::criterion::Criterion;
+use crate::{RawDocument, RankedMap};
+
+/// An helper struct that permit to sort documents by
+/// some of their stored attributes.
+///
+/// # Note
+///
+/// If a document cannot be deserialized it will be considered [`None`][].
+///
+/// Deserialized documents are compared like `Some(doc0).cmp(&Some(doc1))`,
+/// so you must check the [`Ord`] of `Option` implementation.
+///
+/// [`None`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.None
+/// [`Ord`]: https://doc.rust-lang.org/std/option/enum.Option.html#impl-Ord
+///
+/// # Example
+///
+/// ```ignore
+/// use serde_derive::Deserialize;
+/// use meilidb::rank::criterion::*;
+///
+/// let custom_ranking = SortByAttr::lower_is_better(&ranked_map, &schema, "published_at")?;
+///
+/// let builder = CriteriaBuilder::with_capacity(8)
+///        .add(SumOfTypos)
+///        .add(NumberOfWords)
+///        .add(WordsProximity)
+///        .add(SumOfWordsAttribute)
+///        .add(SumOfWordsPosition)
+///        .add(Exact)
+///        .add(custom_ranking)
+///        .add(DocumentId);
+///
+/// let criterion = builder.build();
+///
+/// ```
+pub struct SortByAttr<'a> {
+    ranked_map: &'a RankedMap,
+    attr: SchemaAttr,
+    reversed: bool,
+}
+
+impl<'a> SortByAttr<'a> {
+    pub fn lower_is_better(
+        ranked_map: &'a RankedMap,
+        schema: &Schema,
+        attr_name: &str,
+    ) -> Result<SortByAttr<'a>, SortByAttrError>
+    {
+        SortByAttr::new(ranked_map, schema, attr_name, false)
+    }
+
+    pub fn higher_is_better(
+        ranked_map: &'a RankedMap,
+        schema: &Schema,
+        attr_name: &str,
+    ) -> Result<SortByAttr<'a>, SortByAttrError>
+    {
+        SortByAttr::new(ranked_map, schema, attr_name, true)
+    }
+
+    fn new(
+        ranked_map: &'a RankedMap,
+        schema: &Schema,
+        attr_name: &str,
+        reversed: bool,
+    ) -> Result<SortByAttr<'a>, SortByAttrError>
+    {
+        let attr = match schema.attribute(attr_name) {
+            Some(attr) => attr,
+            None => return Err(SortByAttrError::AttributeNotFound),
+        };
+
+        if !schema.props(attr).is_ranked() {
+            return Err(SortByAttrError::AttributeNotRegisteredForRanking);
+        }
+
+        Ok(SortByAttr { ranked_map, attr, reversed })
+    }
+}
+
+impl<'a> Criterion for SortByAttr<'a> {
+    fn evaluate(&self, lhs: &RawDocument, rhs: &RawDocument) -> Ordering {
+        let lhs = self.ranked_map.get(lhs.id, self.attr);
+        let rhs = self.ranked_map.get(rhs.id, self.attr);
+
+        match (lhs, rhs) {
+            (Some(lhs), Some(rhs)) => {
+                let order = lhs.cmp(&rhs);
+                if self.reversed { order.reverse() } else { order }
+            },
+            (None,    Some(_)) => Ordering::Greater,
+            (Some(_), None)    => Ordering::Less,
+            (None,    None)    => Ordering::Equal,
+        }
+    }
+
+    fn name(&self) -> &str {
+        "SortByAttr"
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum SortByAttrError {
+    AttributeNotFound,
+    AttributeNotRegisteredForRanking,
+}
+
+impl fmt::Display for SortByAttrError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        use SortByAttrError::*;
+        match self {
+            AttributeNotFound => f.write_str("attribute not found in the schema"),
+            AttributeNotRegisteredForRanking => f.write_str("attribute not registered for ranking"),
+        }
+    }
+}
+
+impl Error for SortByAttrError { }

meilidb-core/src/criterion/sum_of_typos.rs

@@ -54,7 +54,7 @@ impl Criterion for SumOfTypos {
         lhs.cmp(&rhs).reverse()
     }
 
-    fn name(&self) -> &'static str {
+    fn name(&self) -> &str {
         "SumOfTypos"
     }
 }

meilidb-core/src/criterion/sum_of_words_attribute.rs

@@ -36,7 +36,7 @@ impl Criterion for SumOfWordsAttribute {
         lhs.cmp(&rhs)
     }
 
-    fn name(&self) -> &'static str {
+    fn name(&self) -> &str {
         "SumOfWordsAttribute"
     }
 }

meilidb-core/src/criterion/sum_of_words_position.rs

@@ -36,7 +36,7 @@ impl Criterion for SumOfWordsPosition {
         lhs.cmp(&rhs)
     }
 
-    fn name(&self) -> &'static str {
+    fn name(&self) -> &str {
         "SumOfWordsPosition"
     }
 }

meilidb-core/src/criterion/words_proximity.rs

@@ -99,7 +99,7 @@ impl Criterion for WordsProximity {
         lhs.cmp(&rhs)
     }
 
-    fn name(&self) -> &'static str {
+    fn name(&self) -> &str {
         "WordsProximity"
     }
 }

meilidb-core/src/database.rs

@@ -0,0 +1,177 @@
+use std::collections::HashMap;
+use std::path::Path;
+use std::sync::{Arc, RwLock};
+use std::{fs, thread};
+
+use crossbeam_channel::Receiver;
+use log::{debug, error};
+
+use crate::{store, update, Index, MResult};
+
+pub type BoxUpdateFn = Box<dyn Fn(update::UpdateResult) + Send + Sync + 'static>;
+type ArcSwapFn = arc_swap::ArcSwapOption<BoxUpdateFn>;
+
+pub struct Database {
+    pub rkv: Arc<RwLock<rkv::Rkv>>,
+    main_store: rkv::SingleStore,
+    indexes_store: rkv::SingleStore,
+    indexes: RwLock<HashMap<String, (Index, Arc<ArcSwapFn>, thread::JoinHandle<()>)>>,
+}
+
+fn update_awaiter(
+    receiver: Receiver<()>,
+    rkv: Arc<RwLock<rkv::Rkv>>,
+    update_fn: Arc<ArcSwapFn>,
+    index: Index,
+)
+{
+    for () in receiver {
+        // consume all updates in order (oldest first)
+        loop {
+            let rkv = match rkv.read() {
+                Ok(rkv) => rkv,
+                Err(e) => { error!("rkv RwLock read failed: {}", e); break }
+            };
+
+            let mut writer = match rkv.write() {
+                Ok(writer) => writer,
+                Err(e) => { error!("LMDB writer transaction begin failed: {}", e); break }
+            };
+
+            match update::update_task(&mut writer, index.clone()) {
+                Ok(Some(status)) => {
+                    if let Err(e) = writer.commit() { error!("update transaction failed: {}", e) }
+
+                    if let Some(ref callback) = *update_fn.load() {
+                        (callback)(status);
+                    }
+                },
+                // no more updates to handle for now
+                Ok(None) => { debug!("no more updates"); writer.abort(); break },
+                Err(e) => { error!("update task failed: {}", e); writer.abort() },
+            }
+        }
+    }
+}
+
+impl Database {
+    pub fn open_or_create(path: impl AsRef<Path>) -> MResult<Database> {
+        let manager = rkv::Manager::singleton();
+        let mut rkv_write = manager.write().unwrap();
+
+        fs::create_dir_all(path.as_ref())?;
+
+        let rkv = rkv_write
+            .get_or_create(path.as_ref(), |path| {
+                let mut builder = rkv::Rkv::environment_builder();
+                builder.set_max_dbs(3000).set_map_size(10 * 1024 * 1024 * 1024); // 10GB
+                rkv::Rkv::from_env(path, builder)
+            })?;
+
+        drop(rkv_write);
+
+        let rkv_read = rkv.read().unwrap();
+        let create_options = rkv::store::Options::create();
+        let main_store = rkv_read.open_single("main", create_options)?;
+        let indexes_store = rkv_read.open_single("indexes", create_options)?;
+
+        // list all indexes that needs to be opened
+        let mut must_open = Vec::new();
+        let reader = rkv_read.read()?;
+        for result in indexes_store.iter_start(&reader)? {
+            let (key, _) = result?;
+            if let Ok(index_name) = std::str::from_utf8(key) {
+                must_open.push(index_name.to_owned());
+            }
+        }
+
+        drop(reader);
+
+        // open the previously aggregated indexes
+        let mut indexes = HashMap::new();
+        for index_name in must_open {
+
+            let (sender, receiver) = crossbeam_channel::bounded(100);
+            let index = store::open(&rkv_read, &index_name, sender.clone())?;
+            let update_fn = Arc::new(ArcSwapFn::empty());
+
+            let rkv_clone = rkv.clone();
+            let index_clone = index.clone();
+            let update_fn_clone = update_fn.clone();
+
+            let handle = thread::spawn(move || {
+                update_awaiter(receiver, rkv_clone, update_fn_clone, index_clone)
+            });
+
+            // send an update notification to make sure that
+            // possible previous boot updates are consumed
+            sender.send(()).unwrap();
+
+            let result = indexes.insert(index_name, (index, update_fn, handle));
+            assert!(result.is_none(), "The index should not have been already open");
+        }
+
+        drop(rkv_read);
+
+        Ok(Database { rkv, main_store, indexes_store, indexes: RwLock::new(indexes) })
+    }
+
+    pub fn open_index(
+        &self,
+        name: impl Into<String>,
+        update_fn: Option<BoxUpdateFn>,
+    ) -> MResult<Index>
+    {
+        let indexes_lock = self.indexes.read().unwrap();
+        let name = name.into();
+
+        match indexes_lock.get(&name) {
+            Some((index, old_update_fn, _)) => {
+                old_update_fn.swap(update_fn.map(Arc::new));
+                Ok(index.clone())
+            },
+            None => {
+                drop(indexes_lock);
+
+                let rkv_lock = self.rkv.read().unwrap();
+                let (sender, receiver) = crossbeam_channel::bounded(100);
+                let index = store::create(&rkv_lock, &name, sender)?;
+
+                let mut writer = rkv_lock.write()?;
+                let value = rkv::Value::Blob(&[]);
+                self.indexes_store.put(&mut writer, &name, &value)?;
+
+                {
+                    let mut indexes_write = self.indexes.write().unwrap();
+                    indexes_write.entry(name).or_insert_with(|| {
+                        let rkv_clone = self.rkv.clone();
+                        let index_clone = index.clone();
+
+                        let update_fn = update_fn.map(Arc::new);
+                        let update_fn = Arc::new(ArcSwapFn::new(update_fn));
+                        let update_fn_clone = update_fn.clone();
+
+                        let handle = thread::spawn(move || {
+                            update_awaiter(receiver, rkv_clone, update_fn_clone, index_clone)
+                        });
+
+                        (index.clone(), update_fn, handle)
+                    });
+                }
+
+                writer.commit()?;
+
+                Ok(index)
+            },
+        }
+    }
+
+    pub fn indexes_names(&self) -> MResult<Vec<String>> {
+        let indexes = self.indexes.read().unwrap();
+        Ok(indexes.keys().cloned().collect())
+    }
+
+    pub fn main_store(&self) -> rkv::SingleStore {
+        self.main_store
+    }
+}

meilidb-core/src/error.rs

@@ -0,0 +1,112 @@
+use std::{error, fmt, io};
+use crate::serde::{SerializerError, DeserializerError};
+
+pub type MResult<T> = Result<T, Error>;
+
+#[derive(Debug)]
+pub enum Error {
+    Io(io::Error),
+    SchemaDiffer,
+    SchemaMissing,
+    WordIndexMissing,
+    MissingDocumentId,
+    Rkv(rkv::StoreError),
+    Fst(fst::Error),
+    RmpDecode(rmp_serde::decode::Error),
+    RmpEncode(rmp_serde::encode::Error),
+    Bincode(bincode::Error),
+    Serializer(SerializerError),
+    Deserializer(DeserializerError),
+    UnsupportedOperation(UnsupportedOperation),
+}
+
+impl From<io::Error> for Error {
+    fn from(error: io::Error) -> Error {
+        Error::Io(error)
+    }
+}
+
+impl From<rkv::StoreError> for Error {
+    fn from(error: rkv::StoreError) -> Error {
+        Error::Rkv(error)
+    }
+}
+
+impl From<fst::Error> for Error {
+    fn from(error: fst::Error) -> Error {
+        Error::Fst(error)
+    }
+}
+
+impl From<rmp_serde::decode::Error> for Error {
+    fn from(error: rmp_serde::decode::Error) -> Error {
+        Error::RmpDecode(error)
+    }
+}
+
+impl From<rmp_serde::encode::Error> for Error {
+    fn from(error: rmp_serde::encode::Error) -> Error {
+        Error::RmpEncode(error)
+    }
+}
+
+impl From<bincode::Error> for Error {
+    fn from(error: bincode::Error) -> Error {
+        Error::Bincode(error)
+    }
+}
+
+impl From<SerializerError> for Error {
+    fn from(error: SerializerError) -> Error {
+        Error::Serializer(error)
+    }
+}
+
+impl From<DeserializerError> for Error {
+    fn from(error: DeserializerError) -> Error {
+        Error::Deserializer(error)
+    }
+}
+
+impl From<UnsupportedOperation> for Error {
+    fn from(op: UnsupportedOperation) -> Error {
+        Error::UnsupportedOperation(op)
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        use self::Error::*;
+        match self {
+            Io(e) => write!(f, "{}", e),
+            SchemaDiffer => write!(f, "schemas differ"),
+            SchemaMissing => write!(f, "this index does not have a schema"),
+            WordIndexMissing => write!(f, "this index does not have a word index"),
+            MissingDocumentId => write!(f, "document id is missing"),
+            Rkv(e) => write!(f, "rkv error; {}", e),
+            Fst(e) => write!(f, "fst error; {}", e),
+            RmpDecode(e) => write!(f, "rmp decode error; {}", e),
+            RmpEncode(e) => write!(f, "rmp encode error; {}", e),
+            Bincode(e) => write!(f, "bincode error; {}", e),
+            Serializer(e) => write!(f, "serializer error; {}", e),
+            Deserializer(e) => write!(f, "deserializer error; {}", e),
+            UnsupportedOperation(op) => write!(f, "unsupported operation; {}", op),
+        }
+    }
+}
+
+impl error::Error for Error { }
+
+#[derive(Debug)]
+pub enum UnsupportedOperation {
+    SchemaAlreadyExists,
+}
+
+impl fmt::Display for UnsupportedOperation {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        use self::UnsupportedOperation::*;
+        match self {
+            SchemaAlreadyExists => write!(f, "Cannot update index which already have a schema"),
+        }
+    }
+}

meilidb-core/src/lib.rs

@@ -1,25 +1,31 @@
-#![feature(checked_duration_since)]
-
 #[cfg(test)]
 #[macro_use] extern crate assert_matches;
 
 mod automaton;
+mod database;
 mod distinct_map;
+mod error;
+mod number;
 mod query_builder;
-mod query_enhancer;
+mod ranked_map;
 mod raw_document;
 mod reordered_attrs;
-mod store;
+mod update;
 pub mod criterion;
+pub mod raw_indexer;
+pub mod serde;
+pub mod store;
 
-use serde::{Serialize, Deserialize};
-use zerocopy::{AsBytes, FromBytes};
-
-use self::raw_document::raw_documents_from;
-
-pub use self::query_builder::{QueryBuilder, DistinctQueryBuilder, normalize_str};
+pub use self::database::{Database, BoxUpdateFn};
+pub use self::error::{Error, MResult};
+pub use self::number::{Number, ParseNumberError};
+pub use self::ranked_map::RankedMap;
 pub use self::raw_document::RawDocument;
-pub use self::store::Store;
+pub use self::store::Index;
+pub use self::update::{UpdateStatus, UpdateResult};
+
+use zerocopy::{AsBytes, FromBytes};
+use ::serde::{Serialize, Deserialize};
 
 /// Represent an internally generated document unique identifier.
 ///

meilidb-core/src/number.rs

@@ -0,0 +1,55 @@
+use std::num::{ParseIntError, ParseFloatError};
+use std::str::FromStr;
+use std::fmt;
+
+use ordered_float::OrderedFloat;
+use serde::{Serialize, Deserialize};
+
+#[derive(Serialize, Deserialize)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum Number {
+    Unsigned(u64),
+    Signed(i64),
+    Float(OrderedFloat<f64>),
+}
+
+impl FromStr for Number {
+    type Err = ParseNumberError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let uint_error = match u64::from_str(s) {
+            Ok(unsigned) => return Ok(Number::Unsigned(unsigned)),
+            Err(error) => error,
+        };
+
+        let int_error = match i64::from_str(s) {
+            Ok(signed) => return Ok(Number::Signed(signed)),
+            Err(error) => error,
+        };
+
+        let float_error = match f64::from_str(s) {
+            Ok(float) => return Ok(Number::Float(OrderedFloat(float))),
+            Err(error) => error,
+        };
+
+        Err(ParseNumberError { uint_error, int_error, float_error })
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct ParseNumberError {
+    uint_error: ParseIntError,
+    int_error: ParseIntError,
+    float_error: ParseFloatError,
+}
+
+impl fmt::Display for ParseNumberError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        if self.uint_error == self.int_error {
+            write!(f, "can not parse number: {}, {}", self.uint_error, self.float_error)
+        } else {
+            write!(f, "can not parse number: {}, {}, {}",
+                self.uint_error, self.int_error, self.float_error)
+        }
+    }
+}

meilidb-core/src/ranked_map.rs

@@ -0,0 +1,35 @@
+use std::io::{Read, Write};
+
+use hashbrown::HashMap;
+use meilidb_schema::SchemaAttr;
+
+use crate::{DocumentId, Number};
+
+#[derive(Debug, Default, Clone, PartialEq, Eq)]
+pub struct RankedMap(HashMap<(DocumentId, SchemaAttr), Number>);
+
+impl RankedMap {
+    pub fn len(&self) -> usize {
+        self.0.len()
+    }
+
+    pub fn insert(&mut self, document: DocumentId, attribute: SchemaAttr, number: Number) {
+        self.0.insert((document, attribute), number);
+    }
+
+    pub fn remove(&mut self, document: DocumentId, attribute: SchemaAttr) {
+        self.0.remove(&(document, attribute));
+    }
+
+    pub fn get(&self, document: DocumentId, attribute: SchemaAttr) -> Option<Number> {
+        self.0.get(&(document, attribute)).cloned()
+    }
+
+    pub fn read_from_bin<R: Read>(reader: R) -> bincode::Result<RankedMap> {
+        bincode::deserialize_from(reader).map(RankedMap)
+    }
+
+    pub fn write_to_bin<W: Write>(&self, writer: W) -> bincode::Result<()> {
+        bincode::serialize_into(writer, &self.0)
+    }
+}

meilidb-core/src/raw_indexer.rs

@@ -0,0 +1,208 @@
+use std::collections::{BTreeMap, HashMap};
+use std::convert::TryFrom;
+
+use deunicode::deunicode_with_tofu;
+use crate::{DocumentId, DocIndex};
+use meilidb_schema::SchemaAttr;
+use meilidb_tokenizer::{is_cjk, Tokenizer, SeqTokenizer, Token};
+use sdset::SetBuf;
+
+type Word = Vec<u8>; // TODO make it be a SmallVec
+
+pub struct RawIndexer {
+    word_limit: usize, // the maximum number of indexed words
+    words_doc_indexes: BTreeMap<Word, Vec<DocIndex>>,
+    docs_words: HashMap<DocumentId, Vec<Word>>,
+}
+
+pub struct Indexed {
+    pub words_doc_indexes: BTreeMap<Word, SetBuf<DocIndex>>,
+    pub docs_words: HashMap<DocumentId, fst::Set>,
+}
+
+impl RawIndexer {
+    pub fn new() -> RawIndexer {
+        RawIndexer::with_word_limit(1000)
+    }
+
+    pub fn with_word_limit(limit: usize) -> RawIndexer {
+        RawIndexer {
+            word_limit: limit,
+            words_doc_indexes: BTreeMap::new(),
+            docs_words: HashMap::new(),
+        }
+    }
+
+    pub fn index_text(&mut self, id: DocumentId, attr: SchemaAttr, text: &str) {
+        let lowercase_text = text.to_lowercase();
+        let deunicoded = deunicode_with_tofu(&lowercase_text, "");
+
+        // TODO compute the deunicoded version after the cjk check
+        let next = if !lowercase_text.contains(is_cjk) && lowercase_text != deunicoded {
+            Some(deunicoded)
+        } else {
+            None
+        };
+        let iter = Some(lowercase_text).into_iter().chain(next);
+
+        for text in iter {
+            for token in Tokenizer::new(&text) {
+                let must_continue = index_token(
+                    token,
+                    id,
+                    attr,
+                    self.word_limit,
+                    &mut self.words_doc_indexes,
+                    &mut self.docs_words,
+                );
+
+                if !must_continue { break }
+            }
+        }
+    }
+
+    pub fn index_text_seq<'a, I, IT>(&mut self, id: DocumentId, attr: SchemaAttr, iter: I)
+    where I: IntoIterator<Item=&'a str, IntoIter=IT>,
+          IT: Iterator<Item = &'a str> + Clone,
+    {
+        // TODO serialize this to one call to the SeqTokenizer loop
+
+        let lowercased: Vec<_> = iter.into_iter().map(str::to_lowercase).collect();
+        let iter = lowercased.iter().map(|t| t.as_str());
+
+        for token in SeqTokenizer::new(iter) {
+            let must_continue = index_token(
+                token,
+                id,
+                attr,
+                self.word_limit,
+                &mut self.words_doc_indexes,
+                &mut self.docs_words,
+            );
+
+            if !must_continue { break }
+        }
+
+        let deunicoded: Vec<_> = lowercased.into_iter().map(|lowercase_text| {
+            if lowercase_text.contains(is_cjk) { return lowercase_text }
+            let deunicoded = deunicode_with_tofu(&lowercase_text, "");
+            if lowercase_text != deunicoded { deunicoded } else { lowercase_text }
+        }).collect();
+        let iter = deunicoded.iter().map(|t| t.as_str());
+
+        for token in SeqTokenizer::new(iter) {
+            let must_continue = index_token(
+                token,
+                id,
+                attr,
+                self.word_limit,
+                &mut self.words_doc_indexes,
+                &mut self.docs_words,
+            );
+
+            if !must_continue { break }
+        }
+    }
+
+    pub fn build(self) -> Indexed {
+        let words_doc_indexes = self.words_doc_indexes
+            .into_iter()
+            .map(|(word, indexes)| (word, SetBuf::from_dirty(indexes)))
+            .collect();
+
+        let docs_words = self.docs_words
+            .into_iter()
+            .map(|(id, mut words)| {
+                words.sort_unstable();
+                words.dedup();
+                (id, fst::Set::from_iter(words).unwrap())
+            })
+            .collect();
+
+        Indexed { words_doc_indexes, docs_words }
+    }
+}
+
+fn index_token(
+    token: Token,
+    id: DocumentId,
+    attr: SchemaAttr,
+    word_limit: usize,
+    words_doc_indexes: &mut BTreeMap<Word, Vec<DocIndex>>,
+    docs_words: &mut HashMap<DocumentId, Vec<Word>>,
+) -> bool
+{
+    if token.word_index >= word_limit { return false }
+
+    match token_to_docindex(id, attr, token) {
+        Some(docindex) => {
+            let word = Vec::from(token.word);
+            words_doc_indexes.entry(word.clone()).or_insert_with(Vec::new).push(docindex);
+            docs_words.entry(id).or_insert_with(Vec::new).push(word);
+        },
+        None => return false,
+    }
+
+    true
+}
+
+fn token_to_docindex(id: DocumentId, attr: SchemaAttr, token: Token) -> Option<DocIndex> {
+    let word_index = u16::try_from(token.word_index).ok()?;
+    let char_index = u16::try_from(token.char_index).ok()?;
+    let char_length = u16::try_from(token.word.chars().count()).ok()?;
+
+    let docindex = DocIndex {
+        document_id: id,
+        attribute: attr.0,
+        word_index,
+        char_index,
+        char_length,
+    };
+
+    Some(docindex)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn strange_apostrophe() {
+        let mut indexer = RawIndexer::new();
+
+        let docid = DocumentId(0);
+        let attr = SchemaAttr(0);
+        let text = "Zut, l’aspirateur, j’ai oublié de l’éteindre !";
+        indexer.index_text(docid, attr, text);
+
+        let Indexed { words_doc_indexes, .. } = indexer.build();
+
+        assert!(words_doc_indexes.get(&b"l"[..]).is_some());
+        assert!(words_doc_indexes.get(&b"aspirateur"[..]).is_some());
+        assert!(words_doc_indexes.get(&b"ai"[..]).is_some());
+        assert!(words_doc_indexes.get(&b"eteindre"[..]).is_some());
+
+        // with the ugly apostrophe...
+        assert!(words_doc_indexes.get(&"l’éteindre".to_owned().into_bytes()).is_some());
+    }
+
+    #[test]
+    fn strange_apostrophe_in_sequence() {
+        let mut indexer = RawIndexer::new();
+
+        let docid = DocumentId(0);
+        let attr = SchemaAttr(0);
+        let text = vec!["Zut, l’aspirateur, j’ai oublié de l’éteindre !"];
+        indexer.index_text_seq(docid, attr, text);
+
+        let Indexed { words_doc_indexes, .. } = indexer.build();
+
+        assert!(words_doc_indexes.get(&b"l"[..]).is_some());
+        assert!(words_doc_indexes.get(&b"aspirateur"[..]).is_some());
+        assert!(words_doc_indexes.get(&b"ai"[..]).is_some());
+        assert!(words_doc_indexes.get(&b"eteindre"[..]).is_some());
+
+        // with the ugly apostrophe...
+        assert!(words_doc_indexes.get(&"l’éteindre".to_owned().into_bytes()).is_some());
+    }
+}

meilidb-core/src/serde/convert_to_number.rs

@@ -0,0 +1,180 @@
+use std::str::FromStr;
+
+use ordered_float::OrderedFloat;
+use serde::ser;
+use serde::Serialize;
+
+use super::SerializerError;
+use crate::Number;
+
+pub struct ConvertToNumber;
+
+impl ser::Serializer for ConvertToNumber {
+    type Ok = Number;
+    type Error = SerializerError;
+    type SerializeSeq = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeTuple = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeTupleStruct = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeTupleVariant = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeMap = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeStruct = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeStructVariant = ser::Impossible<Self::Ok, Self::Error>;
+
+    fn serialize_bool(self, value: bool) -> Result<Self::Ok, Self::Error> {
+        Ok(Number::Unsigned(u64::from(value)))
+    }
+
+    fn serialize_char(self, _value: char) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnrankableType { type_name: "char" })
+    }
+
+    fn serialize_i8(self, value: i8) -> Result<Self::Ok, Self::Error> {
+        Ok(Number::Signed(i64::from(value)))
+    }
+
+    fn serialize_i16(self, value: i16) -> Result<Self::Ok, Self::Error> {
+        Ok(Number::Signed(i64::from(value)))
+    }
+
+    fn serialize_i32(self, value: i32) -> Result<Self::Ok, Self::Error> {
+        Ok(Number::Signed(i64::from(value)))
+    }
+
+    fn serialize_i64(self, value: i64) -> Result<Self::Ok, Self::Error> {
+        Ok(Number::Signed(value))
+    }
+
+    fn serialize_u8(self, value: u8) -> Result<Self::Ok, Self::Error> {
+        Ok(Number::Unsigned(u64::from(value)))
+    }
+
+    fn serialize_u16(self, value: u16) -> Result<Self::Ok, Self::Error> {
+        Ok(Number::Unsigned(u64::from(value)))
+    }
+
+    fn serialize_u32(self, value: u32) -> Result<Self::Ok, Self::Error> {
+        Ok(Number::Unsigned(u64::from(value)))
+    }
+
+    fn serialize_u64(self, value: u64) -> Result<Self::Ok, Self::Error> {
+        Ok(Number::Unsigned(value))
+    }
+
+    fn serialize_f32(self, value: f32) -> Result<Self::Ok, Self::Error> {
+        Ok(Number::Float(OrderedFloat(f64::from(value))))
+    }
+
+    fn serialize_f64(self, value: f64) -> Result<Self::Ok, Self::Error> {
+        Ok(Number::Float(OrderedFloat(value)))
+    }
+
+    fn serialize_str(self, value: &str) -> Result<Self::Ok, Self::Error> {
+        Ok(Number::from_str(value)?)
+    }
+
+    fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnrankableType { type_name: "&[u8]" })
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnrankableType { type_name: "Option" })
+    }
+
+    fn serialize_some<T: ?Sized>(self, _value: &T) -> Result<Self::Ok, Self::Error>
+    where T: Serialize,
+    {
+        Err(SerializerError::UnrankableType { type_name: "Option" })
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnrankableType { type_name: "()" })
+    }
+
+    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnrankableType { type_name: "unit struct" })
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str
+    ) -> Result<Self::Ok, Self::Error>
+    {
+        Err(SerializerError::UnrankableType { type_name: "unit variant" })
+    }
+
+    fn serialize_newtype_struct<T: ?Sized>(
+        self,
+        _name: &'static str,
+        value: &T
+    ) -> Result<Self::Ok, Self::Error>
+    where T: Serialize,
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized>(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _value: &T
+    ) -> Result<Self::Ok, Self::Error>
+    where T: Serialize,
+    {
+        Err(SerializerError::UnrankableType { type_name: "newtype variant" })
+    }
+
+    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
+        Err(SerializerError::UnrankableType { type_name: "sequence" })
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
+        Err(SerializerError::UnrankableType { type_name: "tuple" })
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeTupleStruct, Self::Error>
+    {
+        Err(SerializerError::UnrankableType { type_name: "tuple struct" })
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeTupleVariant, Self::Error>
+    {
+        Err(SerializerError::UnrankableType { type_name: "tuple variant" })
+    }
+
+    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
+        Err(SerializerError::UnrankableType { type_name: "map" })
+    }
+
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStruct, Self::Error>
+    {
+        Err(SerializerError::UnrankableType { type_name: "struct" })
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStructVariant, Self::Error>
+    {
+        Err(SerializerError::UnrankableType { type_name: "struct variant" })
+    }
+}

meilidb-core/src/serde/convert_to_string.rs

@@ -0,0 +1,176 @@
+use serde::Serialize;
+use serde::ser;
+
+use super::SerializerError;
+
+pub struct ConvertToString;
+
+impl ser::Serializer for ConvertToString {
+    type Ok = String;
+    type Error = SerializerError;
+    type SerializeSeq = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeTuple = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeTupleStruct = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeTupleVariant = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeMap = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeStruct = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeStructVariant = ser::Impossible<Self::Ok, Self::Error>;
+
+    fn serialize_bool(self, _value: bool) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "boolean" })
+    }
+
+    fn serialize_char(self, value: char) -> Result<Self::Ok, Self::Error> {
+        Ok(value.to_string())
+    }
+
+    fn serialize_i8(self, value: i8) -> Result<Self::Ok, Self::Error> {
+        Ok(value.to_string())
+    }
+
+    fn serialize_i16(self, value: i16) -> Result<Self::Ok, Self::Error> {
+        Ok(value.to_string())
+    }
+
+    fn serialize_i32(self, value: i32) -> Result<Self::Ok, Self::Error> {
+        Ok(value.to_string())
+    }
+
+    fn serialize_i64(self, value: i64) -> Result<Self::Ok, Self::Error> {
+        Ok(value.to_string())
+    }
+
+    fn serialize_u8(self, value: u8) -> Result<Self::Ok, Self::Error> {
+        Ok(value.to_string())
+    }
+
+    fn serialize_u16(self, value: u16) -> Result<Self::Ok, Self::Error> {
+        Ok(value.to_string())
+    }
+
+    fn serialize_u32(self, value: u32) -> Result<Self::Ok, Self::Error> {
+        Ok(value.to_string())
+    }
+
+    fn serialize_u64(self, value: u64) -> Result<Self::Ok, Self::Error> {
+        Ok(value.to_string())
+    }
+
+    fn serialize_f32(self, value: f32) -> Result<Self::Ok, Self::Error> {
+        Ok(value.to_string())
+    }
+
+    fn serialize_f64(self, value: f64) -> Result<Self::Ok, Self::Error> {
+        Ok(value.to_string())
+    }
+
+    fn serialize_str(self, value: &str) -> Result<Self::Ok, Self::Error> {
+        Ok(value.to_string())
+    }
+
+    fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "&[u8]" })
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "Option" })
+    }
+
+    fn serialize_some<T: ?Sized>(self, _value: &T) -> Result<Self::Ok, Self::Error>
+    where T: Serialize,
+    {
+        Err(SerializerError::UnserializableType { type_name: "Option" })
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "()" })
+    }
+
+    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "unit struct" })
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str
+    ) -> Result<Self::Ok, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { type_name: "unit variant" })
+    }
+
+    fn serialize_newtype_struct<T: ?Sized>(
+        self,
+        _name: &'static str,
+        value: &T
+    ) -> Result<Self::Ok, Self::Error>
+    where T: Serialize,
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized>(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _value: &T
+    ) -> Result<Self::Ok, Self::Error>
+    where T: Serialize,
+    {
+        Err(SerializerError::UnserializableType { type_name: "newtype variant" })
+    }
+
+    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "sequence" })
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "tuple" })
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeTupleStruct, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { type_name: "tuple struct" })
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeTupleVariant, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { type_name: "tuple variant" })
+    }
+
+    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "map" })
+    }
+
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStruct, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { type_name: "struct" })
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStructVariant, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { type_name: "struct variant" })
+    }
+}

meilidb-core/src/serde/deserializer.rs

@@ -0,0 +1,142 @@
+use std::collections::HashSet;
+use std::io::Cursor;
+use std::{fmt, error::Error};
+
+use meilidb_schema::{Schema, SchemaAttr};
+use rmp_serde::decode::{Deserializer as RmpDeserializer, ReadReader};
+use rmp_serde::decode::{Error as RmpError};
+use serde::{de, forward_to_deserialize_any};
+
+use crate::store::DocumentsFields;
+use crate::DocumentId;
+
+#[derive(Debug)]
+pub enum DeserializerError {
+    RmpError(RmpError),
+    RkvError(rkv::StoreError),
+    Custom(String),
+}
+
+impl de::Error for DeserializerError {
+    fn custom<T: fmt::Display>(msg: T) -> Self {
+        DeserializerError::Custom(msg.to_string())
+    }
+}
+
+impl fmt::Display for DeserializerError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            DeserializerError::RmpError(e) => write!(f, "rmp serde related error: {}", e),
+            DeserializerError::RkvError(e) => write!(f, "rkv related error: {}", e),
+            DeserializerError::Custom(s) => f.write_str(s),
+        }
+    }
+}
+
+impl Error for DeserializerError {}
+
+impl From<RmpError> for DeserializerError {
+    fn from(error: RmpError) -> DeserializerError {
+        DeserializerError::RmpError(error)
+    }
+}
+
+impl From<rkv::StoreError> for DeserializerError {
+    fn from(error: rkv::StoreError) -> DeserializerError {
+        DeserializerError::RkvError(error)
+    }
+}
+
+pub struct Deserializer<'a, R> {
+    pub document_id: DocumentId,
+    pub reader: &'a R,
+    pub documents_fields: DocumentsFields,
+    pub schema: &'a Schema,
+    pub attributes: Option<&'a HashSet<SchemaAttr>>,
+}
+
+impl<'de, 'a, 'b, R: 'a> de::Deserializer<'de> for &'b mut Deserializer<'a, R>
+where R: rkv::Readable,
+{
+    type Error = DeserializerError;
+
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where V: de::Visitor<'de>
+    {
+        self.deserialize_map(visitor)
+    }
+
+    forward_to_deserialize_any! {
+        bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
+        bytes byte_buf option unit unit_struct newtype_struct seq tuple
+        tuple_struct struct enum identifier ignored_any
+    }
+
+    fn deserialize_map<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where V: de::Visitor<'de>
+    {
+        let mut error = None;
+
+        let iter = self.documents_fields
+            .document_fields(self.reader, self.document_id)?
+            .filter_map(|result| {
+                let (attr, value) = match result {
+                    Ok(value) => value,
+                    Err(e) => { error = Some(e); return None },
+                };
+
+                let is_displayed = self.schema.props(attr).is_displayed();
+                if is_displayed && self.attributes.map_or(true, |f| f.contains(&attr)) {
+                    let attribute_name = self.schema.attribute_name(attr);
+                    Some((attribute_name, Value::new(value)))
+                } else {
+                    None
+                }
+            });
+
+        let map_deserializer = de::value::MapDeserializer::new(iter);
+        let result = visitor.visit_map(map_deserializer).map_err(DeserializerError::from);
+
+        match error.take() {
+            Some(error) => Err(error.into()),
+            None => result,
+        }
+    }
+}
+
+struct Value<A>(RmpDeserializer<ReadReader<Cursor<A>>>) where A: AsRef<[u8]>;
+
+impl<A> Value<A> where A: AsRef<[u8]>
+{
+    fn new(value: A) -> Value<A> {
+        Value(RmpDeserializer::new(Cursor::new(value)))
+    }
+}
+
+impl<'de, A> de::IntoDeserializer<'de, RmpError> for Value<A>
+where A: AsRef<[u8]>,
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self::Deserializer {
+        self
+    }
+}
+
+impl<'de, 'a, A> de::Deserializer<'de> for Value<A>
+where A: AsRef<[u8]>,
+{
+    type Error = RmpError;
+
+    fn deserialize_any<V>(mut self, visitor: V) -> Result<V::Value, Self::Error>
+    where V: de::Visitor<'de>
+    {
+        self.0.deserialize_any(visitor)
+    }
+
+    forward_to_deserialize_any! {
+        bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
+        bytes byte_buf option unit unit_struct newtype_struct seq tuple
+        tuple_struct map struct enum identifier ignored_any
+    }
+}

meilidb-core/src/serde/extract_document_id.rs

@@ -0,0 +1,273 @@
+use std::hash::{Hash, Hasher};
+
+use crate::DocumentId;
+use serde::{ser, Serialize};
+use serde_json::Value;
+use siphasher::sip::SipHasher;
+
+use super::{SerializerError, ConvertToString};
+
+pub fn extract_document_id<D>(
+    identifier: &str,
+    document: &D,
+) -> Result<Option<DocumentId>, SerializerError>
+where D: serde::Serialize,
+{
+    let serializer = ExtractDocumentId { identifier };
+    document.serialize(serializer)
+}
+
+pub fn value_to_string(value: &Value) -> Option<String> {
+    match value {
+        Value::Null => None,
+        Value::Bool(_) => None,
+        Value::Number(value) => Some(value.to_string()),
+        Value::String(value) => Some(value.to_string()),
+        Value::Array(_) => None,
+        Value::Object(_) => None,
+    }
+}
+
+pub fn compute_document_id<H: Hash>(t: H) -> DocumentId {
+    let mut s = SipHasher::new();
+    t.hash(&mut s);
+    let hash = s.finish();
+    DocumentId(hash)
+}
+
+struct ExtractDocumentId<'a> {
+    identifier: &'a str,
+}
+
+impl<'a> ser::Serializer for ExtractDocumentId<'a> {
+    type Ok = Option<DocumentId>;
+    type Error = SerializerError;
+    type SerializeSeq = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeTuple = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeTupleStruct = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeTupleVariant = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeMap = ExtractDocumentIdMapSerializer<'a>;
+    type SerializeStruct = ExtractDocumentIdStructSerializer<'a>;
+    type SerializeStructVariant = ser::Impossible<Self::Ok, Self::Error>;
+
+    forward_to_unserializable_type! {
+        bool => serialize_bool,
+        char => serialize_char,
+
+        i8  => serialize_i8,
+        i16 => serialize_i16,
+        i32 => serialize_i32,
+        i64 => serialize_i64,
+
+        u8  => serialize_u8,
+        u16 => serialize_u16,
+        u32 => serialize_u32,
+        u64 => serialize_u64,
+
+        f32 => serialize_f32,
+        f64 => serialize_f64,
+    }
+
+    fn serialize_str(self, _value: &str) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "str" })
+    }
+
+    fn serialize_bytes(self, _value: &[u8]) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "&[u8]" })
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "Option" })
+    }
+
+    fn serialize_some<T: ?Sized>(self, _value: &T) -> Result<Self::Ok, Self::Error>
+    where T: Serialize,
+    {
+        Err(SerializerError::UnserializableType { type_name: "Option" })
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "()" })
+    }
+
+    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "unit struct" })
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str
+    ) -> Result<Self::Ok, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { type_name: "unit variant" })
+    }
+
+    fn serialize_newtype_struct<T: ?Sized>(
+        self,
+        _name: &'static str,
+        value: &T
+    ) -> Result<Self::Ok, Self::Error>
+    where T: Serialize,
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized>(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _value: &T
+    ) -> Result<Self::Ok, Self::Error>
+    where T: Serialize,
+    {
+        Err(SerializerError::UnserializableType { type_name: "newtype variant" })
+    }
+
+    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "sequence" })
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "tuple" })
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeTupleStruct, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { type_name: "tuple struct" })
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeTupleVariant, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { type_name: "tuple variant" })
+    }
+
+    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
+        let serializer = ExtractDocumentIdMapSerializer {
+            identifier: self.identifier,
+            document_id: None,
+            current_key_name: None,
+        };
+
+        Ok(serializer)
+    }
+
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStruct, Self::Error>
+    {
+        let serializer = ExtractDocumentIdStructSerializer {
+            identifier: self.identifier,
+            document_id: None,
+        };
+
+        Ok(serializer)
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStructVariant, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { type_name: "struct variant" })
+    }
+}
+
+pub struct ExtractDocumentIdMapSerializer<'a> {
+    identifier: &'a str,
+    document_id: Option<DocumentId>,
+    current_key_name: Option<String>,
+}
+
+impl<'a> ser::SerializeMap for ExtractDocumentIdMapSerializer<'a> {
+    type Ok = Option<DocumentId>;
+    type Error = SerializerError;
+
+    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
+    where T: Serialize,
+    {
+        let key = key.serialize(ConvertToString)?;
+        self.current_key_name = Some(key);
+        Ok(())
+    }
+
+    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    where T: Serialize,
+    {
+        let key = self.current_key_name.take().unwrap();
+        self.serialize_entry(&key, value)
+    }
+
+    fn serialize_entry<K: ?Sized, V: ?Sized>(
+        &mut self,
+        key: &K,
+        value: &V
+    ) -> Result<(), Self::Error>
+    where K: Serialize, V: Serialize,
+    {
+        let key = key.serialize(ConvertToString)?;
+
+        if self.identifier == key {
+            let value = serde_json::to_string(value).and_then(|s| serde_json::from_str(&s))?;
+            match value_to_string(&value).map(|s| compute_document_id(&s)) {
+                Some(document_id) => self.document_id = Some(document_id),
+                None => return Err(SerializerError::InvalidDocumentIdType),
+            }
+        }
+
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok, Self::Error> {
+        Ok(self.document_id)
+    }
+}
+
+pub struct ExtractDocumentIdStructSerializer<'a> {
+    identifier: &'a str,
+    document_id: Option<DocumentId>,
+}
+
+impl<'a> ser::SerializeStruct for ExtractDocumentIdStructSerializer<'a> {
+    type Ok = Option<DocumentId>;
+    type Error = SerializerError;
+
+    fn serialize_field<T: ?Sized>(
+        &mut self,
+        key: &'static str,
+        value: &T
+    ) -> Result<(), Self::Error>
+    where T: Serialize,
+    {
+        if self.identifier == key {
+            let value = serde_json::to_string(value).and_then(|s| serde_json::from_str(&s))?;
+            match value_to_string(&value).map(compute_document_id) {
+                Some(document_id) => self.document_id = Some(document_id),
+                None => return Err(SerializerError::InvalidDocumentIdType),
+            }
+        }
+
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok, Self::Error> {
+        Ok(self.document_id)
+    }
+}

meilidb-core/src/serde/indexer.rs

@@ -0,0 +1,336 @@
+use meilidb_schema::SchemaAttr;
+use serde::ser;
+use serde::Serialize;
+
+use crate::DocumentId;
+use crate::raw_indexer::RawIndexer;
+use super::{SerializerError, ConvertToString};
+
+pub struct Indexer<'a> {
+    pub attribute: SchemaAttr,
+    pub indexer: &'a mut RawIndexer,
+    pub document_id: DocumentId,
+}
+
+impl<'a> ser::Serializer for Indexer<'a> {
+    type Ok = ();
+    type Error = SerializerError;
+    type SerializeSeq = SeqIndexer<'a>;
+    type SerializeTuple = TupleIndexer<'a>;
+    type SerializeTupleStruct = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeTupleVariant = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeMap = MapIndexer<'a>;
+    type SerializeStruct = StructSerializer<'a>;
+    type SerializeStructVariant = ser::Impossible<Self::Ok, Self::Error>;
+
+    fn serialize_bool(self, _value: bool) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnindexableType { type_name: "boolean" })
+    }
+
+    fn serialize_char(self, value: char) -> Result<Self::Ok, Self::Error> {
+        let text = value.serialize(ConvertToString)?;
+        self.serialize_str(&text)
+    }
+
+    fn serialize_i8(self, value: i8) -> Result<Self::Ok, Self::Error> {
+        let text = value.serialize(ConvertToString)?;
+        self.serialize_str(&text)
+    }
+
+    fn serialize_i16(self, value: i16) -> Result<Self::Ok, Self::Error> {
+        let text = value.serialize(ConvertToString)?;
+        self.serialize_str(&text)
+    }
+
+    fn serialize_i32(self, value: i32) -> Result<Self::Ok, Self::Error> {
+        let text = value.serialize(ConvertToString)?;
+        self.serialize_str(&text)
+    }
+
+    fn serialize_i64(self, value: i64) -> Result<Self::Ok, Self::Error> {
+        let text = value.serialize(ConvertToString)?;
+        self.serialize_str(&text)
+    }
+
+    fn serialize_u8(self, value: u8) -> Result<Self::Ok, Self::Error> {
+        let text = value.serialize(ConvertToString)?;
+        self.serialize_str(&text)
+    }
+
+    fn serialize_u16(self, value: u16) -> Result<Self::Ok, Self::Error> {
+        let text = value.serialize(ConvertToString)?;
+        self.serialize_str(&text)
+    }
+
+    fn serialize_u32(self, value: u32) -> Result<Self::Ok, Self::Error> {
+        let text = value.serialize(ConvertToString)?;
+        self.serialize_str(&text)
+    }
+
+    fn serialize_u64(self, value: u64) -> Result<Self::Ok, Self::Error> {
+        let text = value.serialize(ConvertToString)?;
+        self.serialize_str(&text)
+    }
+
+    fn serialize_f32(self, value: f32) -> Result<Self::Ok, Self::Error> {
+        let text = value.serialize(ConvertToString)?;
+        self.serialize_str(&text)
+    }
+
+    fn serialize_f64(self, value: f64) -> Result<Self::Ok, Self::Error> {
+        let text = value.serialize(ConvertToString)?;
+        self.serialize_str(&text)
+    }
+
+    fn serialize_str(self, text: &str) -> Result<Self::Ok, Self::Error> {
+        self.indexer.index_text(self.document_id, self.attribute, text);
+        Ok(())
+    }
+
+    fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnindexableType { type_name: "&[u8]" })
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnindexableType { type_name: "Option" })
+    }
+
+    fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
+    where T: ser::Serialize,
+    {
+        let text = value.serialize(ConvertToString)?;
+        self.indexer.index_text(self.document_id, self.attribute, &text);
+        Ok(())
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnindexableType { type_name: "()" })
+    }
+
+    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnindexableType { type_name: "unit struct" })
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str
+    ) -> Result<Self::Ok, Self::Error>
+    {
+        Err(SerializerError::UnindexableType { type_name: "unit variant" })
+    }
+
+    fn serialize_newtype_struct<T: ?Sized>(
+        self,
+        _name: &'static str,
+        value: &T
+    ) -> Result<Self::Ok, Self::Error>
+    where T: ser::Serialize,
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized>(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _value: &T
+    ) -> Result<Self::Ok, Self::Error>
+    where T: ser::Serialize,
+    {
+        Err(SerializerError::UnindexableType { type_name: "newtype variant" })
+    }
+
+    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
+        let indexer = SeqIndexer {
+            attribute: self.attribute,
+            document_id: self.document_id,
+            indexer: self.indexer,
+            texts: Vec::new(),
+        };
+
+        Ok(indexer)
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
+        let indexer = TupleIndexer {
+            attribute: self.attribute,
+            document_id: self.document_id,
+            indexer: self.indexer,
+            texts: Vec::new(),
+        };
+
+        Ok(indexer)
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeTupleStruct, Self::Error>
+    {
+        Err(SerializerError::UnindexableType { type_name: "tuple struct" })
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeTupleVariant, Self::Error>
+    {
+        Err(SerializerError::UnindexableType { type_name: "tuple variant" })
+    }
+
+    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
+        let indexer = MapIndexer {
+            attribute: self.attribute,
+            document_id: self.document_id,
+            indexer: self.indexer,
+            texts: Vec::new(),
+        };
+
+        Ok(indexer)
+    }
+
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStruct, Self::Error>
+    {
+        Err(SerializerError::UnindexableType { type_name: "struct" })
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStructVariant, Self::Error>
+    {
+        Err(SerializerError::UnindexableType { type_name: "struct variant" })
+    }
+}
+
+pub struct SeqIndexer<'a> {
+    attribute: SchemaAttr,
+    document_id: DocumentId,
+    indexer: &'a mut RawIndexer,
+    texts: Vec<String>,
+}
+
+impl<'a> ser::SerializeSeq for SeqIndexer<'a> {
+    type Ok = ();
+    type Error = SerializerError;
+
+    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    where T: ser::Serialize
+    {
+        let text = value.serialize(ConvertToString)?;
+        self.texts.push(text);
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok, Self::Error> {
+        let texts = self.texts.iter().map(String::as_str);
+        self.indexer.index_text_seq(self.document_id, self.attribute, texts);
+        Ok(())
+    }
+}
+
+pub struct MapIndexer<'a> {
+    attribute: SchemaAttr,
+    document_id: DocumentId,
+    indexer: &'a mut RawIndexer,
+    texts: Vec<String>,
+}
+
+impl<'a> ser::SerializeMap for MapIndexer<'a> {
+    type Ok = ();
+    type Error = SerializerError;
+
+    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
+    where T: ser::Serialize,
+    {
+        let text = key.serialize(ConvertToString)?;
+        self.texts.push(text);
+        Ok(())
+    }
+
+    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    where T: ser::Serialize,
+    {
+        let text = value.serialize(ConvertToString)?;
+        self.texts.push(text);
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok, Self::Error> {
+        let texts = self.texts.iter().map(String::as_str);
+        self.indexer.index_text_seq(self.document_id, self.attribute, texts);
+        Ok(())
+    }
+}
+
+pub struct StructSerializer<'a> {
+    attribute: SchemaAttr,
+    document_id: DocumentId,
+    indexer: &'a mut RawIndexer,
+    texts: Vec<String>,
+}
+
+impl<'a> ser::SerializeStruct for StructSerializer<'a> {
+    type Ok = ();
+    type Error = SerializerError;
+
+    fn serialize_field<T: ?Sized>(
+        &mut self,
+        key: &'static str,
+        value: &T,
+    ) -> Result<(), Self::Error>
+    where T: ser::Serialize,
+    {
+        let key_text = key.to_owned();
+        let value_text = value.serialize(ConvertToString)?;
+        self.texts.push(key_text);
+        self.texts.push(value_text);
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok, Self::Error> {
+        let texts = self.texts.iter().map(String::as_str);
+        self.indexer.index_text_seq(self.document_id, self.attribute, texts);
+        Ok(())
+    }
+}
+
+pub struct TupleIndexer<'a> {
+    attribute: SchemaAttr,
+    document_id: DocumentId,
+    indexer: &'a mut RawIndexer,
+    texts: Vec<String>,
+}
+
+impl<'a> ser::SerializeTuple for TupleIndexer<'a> {
+    type Ok = ();
+    type Error = SerializerError;
+
+    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    where T: Serialize
+    {
+        let text = value.serialize(ConvertToString)?;
+        self.texts.push(text);
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok, Self::Error> {
+        let texts = self.texts.iter().map(String::as_str);
+        self.indexer.index_text_seq(self.document_id, self.attribute, texts);
+        Ok(())
+    }
+}

meilidb-core/src/serde/mod.rs

@@ -0,0 +1,130 @@
+macro_rules! forward_to_unserializable_type {
+    ($($ty:ident => $se_method:ident,)*) => {
+        $(
+            fn $se_method(self, _v: $ty) -> Result<Self::Ok, Self::Error> {
+                Err(SerializerError::UnserializableType { type_name: "$ty" })
+            }
+        )*
+    }
+}
+
+mod convert_to_number;
+mod convert_to_string;
+mod deserializer;
+mod extract_document_id;
+mod indexer;
+mod serializer;
+
+pub use self::deserializer::{Deserializer, DeserializerError};
+pub use self::extract_document_id::{extract_document_id, compute_document_id, value_to_string};
+pub use self::convert_to_string::ConvertToString;
+pub use self::convert_to_number::ConvertToNumber;
+pub use self::indexer::Indexer;
+pub use self::serializer::Serializer;
+
+use std::collections::BTreeMap;
+use std::{fmt, error::Error};
+
+use meilidb_schema::SchemaAttr;
+use rmp_serde::encode::Error as RmpError;
+use serde_json::Error as SerdeJsonError;
+use serde::ser;
+
+use crate::{DocumentId, ParseNumberError};
+
+#[derive(Debug)]
+pub enum SerializerError {
+    DocumentIdNotFound,
+    InvalidDocumentIdType,
+    RmpError(RmpError),
+    RkvError(rkv::StoreError),
+    SerdeJsonError(SerdeJsonError),
+    ParseNumberError(ParseNumberError),
+    UnserializableType { type_name: &'static str },
+    UnindexableType { type_name: &'static str },
+    UnrankableType { type_name: &'static str },
+    Custom(String),
+}
+
+impl ser::Error for SerializerError {
+    fn custom<T: fmt::Display>(msg: T) -> Self {
+        SerializerError::Custom(msg.to_string())
+    }
+}
+
+impl fmt::Display for SerializerError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            SerializerError::DocumentIdNotFound => {
+                write!(f, "serialized document does not have an id according to the schema")
+            },
+            SerializerError::InvalidDocumentIdType => {
+                write!(f, "document identifier can only be of type string or number")
+            },
+            SerializerError::RmpError(e) => write!(f, "rmp serde related error: {}", e),
+            SerializerError::RkvError(e) => write!(f, "rkv related error: {}", e),
+            SerializerError::SerdeJsonError(e) => write!(f, "serde json error: {}", e),
+            SerializerError::ParseNumberError(e) => {
+                write!(f, "error while trying to parse a number: {}", e)
+            },
+            SerializerError::UnserializableType { type_name } => {
+                write!(f, "{} is not a serializable type", type_name)
+            },
+            SerializerError::UnindexableType { type_name } => {
+                write!(f, "{} is not an indexable type", type_name)
+            },
+            SerializerError::UnrankableType { type_name } => {
+                write!(f, "{} types can not be used for ranking", type_name)
+            },
+            SerializerError::Custom(s) => f.write_str(s),
+        }
+    }
+}
+
+impl Error for SerializerError {}
+
+impl From<String> for SerializerError {
+    fn from(value: String) -> SerializerError {
+        SerializerError::Custom(value)
+    }
+}
+
+impl From<RmpError> for SerializerError {
+    fn from(error: RmpError) -> SerializerError {
+        SerializerError::RmpError(error)
+    }
+}
+
+impl From<SerdeJsonError> for SerializerError {
+    fn from(error: SerdeJsonError) -> SerializerError {
+        SerializerError::SerdeJsonError(error)
+    }
+}
+
+impl From<rkv::StoreError> for SerializerError {
+    fn from(error: rkv::StoreError) -> SerializerError {
+        SerializerError::RkvError(error)
+    }
+}
+
+impl From<ParseNumberError> for SerializerError {
+    fn from(error: ParseNumberError) -> SerializerError {
+        SerializerError::ParseNumberError(error)
+    }
+}
+
+pub struct RamDocumentStore(BTreeMap<(DocumentId, SchemaAttr), Vec<u8>>);
+
+impl RamDocumentStore {
+    pub fn new() -> RamDocumentStore {
+        RamDocumentStore(BTreeMap::new())
+    }
+
+    pub fn set_document_field(&mut self, id: DocumentId, attr: SchemaAttr, value: Vec<u8>) {
+        self.0.insert((id, attr), value);
+    }
+
+    pub fn into_inner(self) -> BTreeMap<(DocumentId, SchemaAttr), Vec<u8>> {
+        self.0
+    }
+}

meilidb-core/src/serde/serializer.rs

@@ -0,0 +1,288 @@
+use meilidb_schema::Schema;
+use serde::ser;
+
+use crate::{DocumentId, RankedMap};
+use crate::raw_indexer::RawIndexer;
+use crate::serde::RamDocumentStore;
+
+use super::{SerializerError, ConvertToString, ConvertToNumber, Indexer};
+
+pub struct Serializer<'a> {
+    pub schema: &'a Schema,
+    pub document_store: &'a mut RamDocumentStore,
+    pub indexer: &'a mut RawIndexer,
+    pub ranked_map: &'a mut RankedMap,
+    pub document_id: DocumentId,
+}
+
+impl<'a> ser::Serializer for Serializer<'a> {
+    type Ok = ();
+    type Error = SerializerError;
+    type SerializeSeq = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeTuple = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeTupleStruct = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeTupleVariant = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeMap = MapSerializer<'a>;
+    type SerializeStruct = StructSerializer<'a>;
+    type SerializeStructVariant = ser::Impossible<Self::Ok, Self::Error>;
+
+    forward_to_unserializable_type! {
+        bool => serialize_bool,
+        char => serialize_char,
+
+        i8  => serialize_i8,
+        i16 => serialize_i16,
+        i32 => serialize_i32,
+        i64 => serialize_i64,
+
+        u8  => serialize_u8,
+        u16 => serialize_u16,
+        u32 => serialize_u32,
+        u64 => serialize_u64,
+
+        f32 => serialize_f32,
+        f64 => serialize_f64,
+    }
+
+    fn serialize_str(self, _v: &str) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "str" })
+    }
+
+    fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "&[u8]" })
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "Option" })
+    }
+
+    fn serialize_some<T: ?Sized>(self, _value: &T) -> Result<Self::Ok, Self::Error>
+    where T: ser::Serialize,
+    {
+        Err(SerializerError::UnserializableType { type_name: "Option" })
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "()" })
+    }
+
+    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "unit struct" })
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str
+    ) -> Result<Self::Ok, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { type_name: "unit variant" })
+    }
+
+    fn serialize_newtype_struct<T: ?Sized>(
+        self,
+        _name: &'static str,
+        value: &T
+    ) -> Result<Self::Ok, Self::Error>
+    where T: ser::Serialize,
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized>(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _value: &T
+    ) -> Result<Self::Ok, Self::Error>
+    where T: ser::Serialize,
+    {
+        Err(SerializerError::UnserializableType { type_name: "newtype variant" })
+    }
+
+    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "sequence" })
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
+        Err(SerializerError::UnserializableType { type_name: "tuple" })
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeTupleStruct, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { type_name: "tuple struct" })
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeTupleVariant, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { type_name: "tuple variant" })
+    }
+
+    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
+        Ok(MapSerializer {
+            schema: self.schema,
+            document_id: self.document_id,
+            document_store: self.document_store,
+            indexer: self.indexer,
+            ranked_map: self.ranked_map,
+            current_key_name: None,
+        })
+    }
+
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStruct, Self::Error>
+    {
+        Ok(StructSerializer {
+            schema: self.schema,
+            document_id: self.document_id,
+            document_store: self.document_store,
+            indexer: self.indexer,
+            ranked_map: self.ranked_map,
+        })
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStructVariant, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { type_name: "struct variant" })
+    }
+}
+
+pub struct MapSerializer<'a> {
+    schema: &'a Schema,
+    document_id: DocumentId,
+    document_store: &'a mut RamDocumentStore,
+    indexer: &'a mut RawIndexer,
+    ranked_map: &'a mut RankedMap,
+    current_key_name: Option<String>,
+}
+
+impl<'a> ser::SerializeMap for MapSerializer<'a> {
+    type Ok = ();
+    type Error = SerializerError;
+
+    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
+    where T: ser::Serialize,
+    {
+        let key = key.serialize(ConvertToString)?;
+        self.current_key_name = Some(key);
+        Ok(())
+    }
+
+    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    where T: ser::Serialize,
+    {
+        let key = self.current_key_name.take().unwrap();
+        self.serialize_entry(&key, value)
+    }
+
+    fn serialize_entry<K: ?Sized, V: ?Sized>(
+        &mut self,
+        key: &K,
+        value: &V,
+    ) -> Result<(), Self::Error>
+    where K: ser::Serialize, V: ser::Serialize,
+    {
+        let key = key.serialize(ConvertToString)?;
+
+        serialize_value(
+            self.schema,
+            self.document_id,
+            self.document_store,
+            self.indexer,
+            self.ranked_map,
+            &key,
+            value,
+        )
+    }
+
+    fn end(self) -> Result<Self::Ok, Self::Error> {
+        Ok(())
+    }
+}
+
+pub struct StructSerializer<'a> {
+    schema: &'a Schema,
+    document_id: DocumentId,
+    document_store: &'a mut RamDocumentStore,
+    indexer: &'a mut RawIndexer,
+    ranked_map: &'a mut RankedMap,
+}
+
+impl<'a> ser::SerializeStruct for StructSerializer<'a> {
+    type Ok = ();
+    type Error = SerializerError;
+
+    fn serialize_field<T: ?Sized>(
+        &mut self,
+        key: &'static str,
+        value: &T,
+    ) -> Result<(), Self::Error>
+    where T: ser::Serialize,
+    {
+        serialize_value(
+            self.schema,
+            self.document_id,
+            self.document_store,
+            self.indexer,
+            self.ranked_map,
+            key,
+            value,
+        )
+    }
+
+    fn end(self) -> Result<Self::Ok, Self::Error> {
+        Ok(())
+    }
+}
+
+fn serialize_value<T: ?Sized>(
+    schema: &Schema,
+    document_id: DocumentId,
+    document_store: &mut RamDocumentStore,
+    indexer: &mut RawIndexer,
+    ranked_map: &mut RankedMap,
+    key: &str,
+    value: &T,
+) -> Result<(), SerializerError>
+where T: ser::Serialize,
+{
+    if let Some(attribute) = schema.attribute(key) {
+        let props = schema.props(attribute);
+
+        let serialized = rmp_serde::to_vec_named(value)?;
+        document_store.set_document_field(document_id, attribute, serialized);
+
+        if props.is_indexed() {
+            let indexer = Indexer { attribute, indexer, document_id };
+            value.serialize(indexer)?;
+        }
+
+        if props.is_ranked() {
+            let number = value.serialize(ConvertToNumber)?;
+            ranked_map.insert(document_id, attribute, number);
+        }
+    }
+
+    Ok(())
+}

meilidb-core/src/store.rs

@@ -1,34 +0,0 @@
-use std::error::Error;
-use fst::Set;
-use sdset::SetBuf;
-use crate::DocIndex;
-
-pub trait Store {
-    type Error: Error;
-
-    fn words(&self) -> Result<&Set, Self::Error>;
-    fn word_indexes(&self, word: &[u8]) -> Result<Option<SetBuf<DocIndex>>, Self::Error>;
-
-    fn synonyms(&self) -> Result<&Set, Self::Error>;
-    fn alternatives_to(&self, word: &[u8]) -> Result<Option<Set>, Self::Error>;
-}
-
-impl<T> Store for &'_ T where T: Store {
-    type Error = T::Error;
-
-    fn words(&self) -> Result<&Set, Self::Error> {
-        (*self).words()
-    }
-
-    fn word_indexes(&self, word: &[u8]) -> Result<Option<SetBuf<DocIndex>>, Self::Error> {
-        (*self).word_indexes(word)
-    }
-
-    fn synonyms(&self) -> Result<&Set, Self::Error> {
-        (*self).synonyms()
-    }
-
-    fn alternatives_to(&self, word: &[u8]) -> Result<Option<Set>, Self::Error> {
-        (*self).alternatives_to(word)
-    }
-}

meilidb-core/src/store/docs_words.rs

@@ -0,0 +1,55 @@
+use std::sync::Arc;
+use rkv::{Value, StoreError};
+use crate::{DocumentId, MResult};
+
+#[derive(Copy, Clone)]
+pub struct DocsWords {
+    pub(crate) docs_words: rkv::SingleStore,
+}
+
+impl DocsWords {
+    pub fn put_doc_words(
+        &self,
+        writer: &mut rkv::Writer,
+        document_id: DocumentId,
+        words: &fst::Set,
+    ) -> Result<(), rkv::StoreError>
+    {
+        let document_id_bytes = document_id.0.to_be_bytes();
+        let bytes = words.as_fst().as_bytes();
+        self.docs_words.put(writer, document_id_bytes, &Value::Blob(bytes))
+    }
+
+    pub fn del_doc_words(
+        &self,
+        writer: &mut rkv::Writer,
+        document_id: DocumentId,
+    ) -> Result<bool, rkv::StoreError>
+    {
+        let document_id_bytes = document_id.0.to_be_bytes();
+        match self.docs_words.delete(writer, document_id_bytes) {
+            Ok(()) => Ok(true),
+            Err(StoreError::LmdbError(lmdb::Error::NotFound)) => Ok(false),
+            Err(e) => Err(e),
+        }
+    }
+
+    pub fn doc_words<T: rkv::Readable>(
+        &self,
+        reader: &T,
+        document_id: DocumentId,
+    ) -> MResult<Option<fst::Set>>
+    {
+        let document_id_bytes = document_id.0.to_be_bytes();
+        match self.docs_words.get(reader, document_id_bytes)? {
+            Some(Value::Blob(bytes)) => {
+                let len = bytes.len();
+                let bytes = Arc::from(bytes);
+                let fst = fst::raw::Fst::from_shared_bytes(bytes, 0, len)?;
+                Ok(Some(fst::Set::from(fst)))
+            },
+            Some(value) => panic!("invalid type {:?}", value),
+            None => Ok(None),
+        }
+    }
+}

meilidb-core/src/store/documents_fields.rs

@@ -0,0 +1,127 @@
+use std::convert::TryFrom;
+use meilidb_schema::SchemaAttr;
+use crate::DocumentId;
+
+#[derive(Copy, Clone)]
+pub struct DocumentsFields {
+    pub(crate) documents_fields: rkv::SingleStore,
+}
+
+fn document_attribute_into_key(document_id: DocumentId, attribute: SchemaAttr) -> [u8; 10] {
+    let document_id_bytes = document_id.0.to_be_bytes();
+    let attr_bytes = attribute.0.to_be_bytes();
+
+    let mut key = [0u8; 10];
+    key[0..8].copy_from_slice(&document_id_bytes);
+    key[8..10].copy_from_slice(&attr_bytes);
+
+    key
+}
+
+fn document_attribute_from_key(key: [u8; 10]) -> (DocumentId, SchemaAttr) {
+    let document_id = {
+        let array = TryFrom::try_from(&key[0..8]).unwrap();
+        DocumentId(u64::from_be_bytes(array))
+    };
+
+    let schema_attr = {
+        let array = TryFrom::try_from(&key[8..8+2]).unwrap();
+        SchemaAttr(u16::from_be_bytes(array))
+    };
+
+    (document_id, schema_attr)
+}
+
+impl DocumentsFields {
+    pub fn put_document_field(
+        &self,
+        writer: &mut rkv::Writer,
+        document_id: DocumentId,
+        attribute: SchemaAttr,
+        value: &[u8],
+    ) -> Result<(), rkv::StoreError>
+    {
+        let key = document_attribute_into_key(document_id, attribute);
+        self.documents_fields.put(writer, key, &rkv::Value::Blob(value))
+    }
+
+    pub fn del_all_document_fields(
+        &self,
+        writer: &mut rkv::Writer,
+        document_id: DocumentId,
+    ) -> Result<usize, rkv::StoreError>
+    {
+        let document_id_bytes = document_id.0.to_be_bytes();
+        let mut keys_to_delete = Vec::new();
+
+        // WARN we can not delete the keys using the iterator
+        //      so we store them and delete them just after
+        let iter = self.documents_fields.iter_from(writer, document_id_bytes)?;
+        for result in iter {
+            let (key, _) = result?;
+            let array = TryFrom::try_from(key).unwrap();
+            let (current_document_id, _) = document_attribute_from_key(array);
+            if current_document_id != document_id { break }
+
+            keys_to_delete.push(key.to_owned());
+        }
+
+        let count = keys_to_delete.len();
+        for key in keys_to_delete {
+            self.documents_fields.delete(writer, key)?;
+        }
+
+        Ok(count)
+    }
+
+    pub fn document_attribute<'a>(
+        &self,
+        reader: &'a impl rkv::Readable,
+        document_id: DocumentId,
+        attribute: SchemaAttr,
+    ) -> Result<Option<&'a [u8]>, rkv::StoreError>
+    {
+        let key = document_attribute_into_key(document_id, attribute);
+
+        match self.documents_fields.get(reader, key)? {
+            Some(rkv::Value::Blob(bytes)) => Ok(Some(bytes)),
+            Some(value) => panic!("invalid type {:?}", value),
+            None => Ok(None),
+        }
+    }
+
+    pub fn document_fields<'r, T: rkv::Readable>(
+        &self,
+        reader: &'r T,
+        document_id: DocumentId,
+    ) -> Result<DocumentFieldsIter<'r>, rkv::StoreError>
+    {
+        let document_id_bytes = document_id.0.to_be_bytes();
+        let iter = self.documents_fields.iter_from(reader, document_id_bytes)?;
+        Ok(DocumentFieldsIter { document_id, iter })
+    }
+}
+
+pub struct DocumentFieldsIter<'r> {
+    document_id: DocumentId,
+    iter: rkv::store::single::Iter<'r>,
+}
+
+impl<'r> Iterator for DocumentFieldsIter<'r> {
+    type Item = Result<(SchemaAttr, &'r [u8]), rkv::StoreError>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        match self.iter.next() {
+            Some(Ok((key, Some(rkv::Value::Blob(bytes))))) => {
+                let array = TryFrom::try_from(key).unwrap();
+                let (current_document_id, attr) = document_attribute_from_key(array);
+                if current_document_id != self.document_id { return None; }
+
+                Some(Ok((attr, bytes)))
+            },
+            Some(Ok((key, data))) => panic!("{:?}, {:?}", key, data),
+            Some(Err(e)) => Some(Err(e)),
+            None => None,
+        }
+    }
+}

meilidb-core/src/store/main.rs

@@ -0,0 +1,154 @@
+use std::sync::Arc;
+use std::convert::TryInto;
+
+use meilidb_schema::Schema;
+use rkv::Value;
+use crate::{RankedMap, MResult};
+
+const NUMBER_OF_DOCUMENTS_KEY: &str = "number-of-documents";
+const RANKED_MAP_KEY:          &str = "ranked-map";
+const SCHEMA_KEY:              &str = "schema";
+const SYNONYMS_KEY:            &str = "synonyms";
+const WORDS_KEY:               &str = "words";
+
+#[derive(Copy, Clone)]
+pub struct Main {
+    pub(crate) main: rkv::SingleStore,
+}
+
+impl Main {
+    pub fn put_words_fst(
+        &self,
+        writer: &mut rkv::Writer,
+        fst: &fst::Set,
+    ) -> Result<(), rkv::StoreError>
+    {
+        let blob = rkv::Value::Blob(fst.as_fst().as_bytes());
+        self.main.put(writer, WORDS_KEY, &blob)
+    }
+
+    pub fn words_fst(
+        &self,
+        reader: &impl rkv::Readable,
+    ) -> MResult<Option<fst::Set>>
+    {
+        match self.main.get(reader, WORDS_KEY)? {
+            Some(Value::Blob(bytes)) => {
+                let len = bytes.len();
+                let bytes = Arc::from(bytes);
+                let fst = fst::raw::Fst::from_shared_bytes(bytes, 0, len)?;
+                Ok(Some(fst::Set::from(fst)))
+            },
+            Some(value) => panic!("invalid type {:?}", value),
+            None => Ok(None),
+        }
+    }
+
+    pub fn put_schema(
+        &self,
+        writer: &mut rkv::Writer,
+        schema: &Schema,
+    ) -> MResult<()>
+    {
+        let bytes = bincode::serialize(schema)?;
+        let blob = Value::Blob(&bytes[..]);
+        self.main.put(writer, SCHEMA_KEY, &blob)?;
+        Ok(())
+    }
+
+    pub fn schema(
+        &self,
+        reader: &impl rkv::Readable,
+    ) -> MResult<Option<Schema>>
+    {
+        match self.main.get(reader, SCHEMA_KEY)? {
+            Some(Value::Blob(bytes)) => {
+                let schema = bincode::deserialize_from(bytes.as_ref())?;
+                Ok(Some(schema))
+            },
+            Some(value) => panic!("invalid type {:?}", value),
+            None => Ok(None),
+        }
+    }
+
+    pub fn put_ranked_map(
+        &self,
+        writer: &mut rkv::Writer,
+        ranked_map: &RankedMap,
+    ) -> MResult<()>
+    {
+        let mut bytes = Vec::new();
+        ranked_map.write_to_bin(&mut bytes)?;
+        let blob = Value::Blob(&bytes[..]);
+        self.main.put(writer, RANKED_MAP_KEY, &blob)?;
+        Ok(())
+    }
+
+    pub fn ranked_map(
+        &self,
+        reader: &impl rkv::Readable,
+    ) -> MResult<Option<RankedMap>>
+    {
+        match self.main.get(reader, RANKED_MAP_KEY)? {
+            Some(Value::Blob(bytes)) => {
+                let ranked_map = RankedMap::read_from_bin(bytes)?;
+                Ok(Some(ranked_map))
+            },
+            Some(value) => panic!("invalid type {:?}", value),
+            None => Ok(None),
+        }
+    }
+
+    pub fn put_synonyms_fst(
+        &self,
+        writer: &mut rkv::Writer,
+        fst: &fst::Set,
+    ) -> MResult<()>
+    {
+        let blob = rkv::Value::Blob(fst.as_fst().as_bytes());
+        Ok(self.main.put(writer, SYNONYMS_KEY, &blob)?)
+    }
+
+    pub fn synonyms_fst(
+        &self,
+        reader: &impl rkv::Readable,
+    ) -> MResult<Option<fst::Set>>
+    {
+        match self.main.get(reader, SYNONYMS_KEY)? {
+            Some(Value::Blob(bytes)) => {
+                let len = bytes.len();
+                let bytes = Arc::from(bytes);
+                let fst = fst::raw::Fst::from_shared_bytes(bytes, 0, len)?;
+                Ok(Some(fst::Set::from(fst)))
+            },
+            Some(value) => panic!("invalid type {:?}", value),
+            None => Ok(None),
+        }
+    }
+
+    pub fn put_number_of_documents<F: Fn(u64) -> u64>(
+        &self,
+        writer: &mut rkv::Writer,
+        f: F,
+    ) -> Result<u64, rkv::StoreError>
+    {
+        let new = self.number_of_documents(writer).map(f)?;
+        self.main.put(writer, NUMBER_OF_DOCUMENTS_KEY, &Value::Blob(&new.to_be_bytes()))?;
+        Ok(new)
+    }
+
+    pub fn number_of_documents(
+        &self,
+        reader: &impl rkv::Readable,
+    ) -> Result<u64, rkv::StoreError>
+    {
+        match self.main.get(reader, NUMBER_OF_DOCUMENTS_KEY)? {
+            Some(Value::Blob(bytes)) => {
+                let array = bytes.try_into().unwrap();
+                Ok(u64::from_be_bytes(array))
+            },
+            Some(value) => panic!("invalid type {:?}", value),
+            None => Ok(0),
+        }
+    }
+}

meilidb-core/src/store/mod.rs

@@ -0,0 +1,224 @@
+mod docs_words;
+mod documents_fields;
+mod main;
+mod postings_lists;
+mod synonyms;
+mod updates;
+mod updates_results;
+
+pub use self::docs_words::DocsWords;
+pub use self::documents_fields::{DocumentsFields, DocumentFieldsIter};
+pub use self::main::Main;
+pub use self::postings_lists::PostingsLists;
+pub use self::synonyms::Synonyms;
+pub use self::updates::Updates;
+pub use self::updates_results::UpdatesResults;
+
+use std::collections::HashSet;
+use meilidb_schema::{Schema, SchemaAttr};
+use serde::de;
+use crate::{update, query_builder::QueryBuilder, DocumentId, MResult, Error};
+use crate::serde::Deserializer;
+
+fn aligned_to(bytes: &[u8], align: usize) -> bool {
+    (bytes as *const _ as *const () as usize) % align == 0
+}
+
+fn main_name(name: &str) -> String {
+    format!("store-{}", name)
+}
+
+fn postings_lists_name(name: &str) -> String {
+    format!("store-{}-postings-lists", name)
+}
+
+fn documents_fields_name(name: &str) -> String {
+    format!("store-{}-documents-fields", name)
+}
+
+fn synonyms_name(name: &str) -> String {
+    format!("store-{}-synonyms", name)
+}
+
+fn docs_words_name(name: &str) -> String {
+    format!("store-{}-docs-words", name)
+}
+
+fn updates_name(name: &str) -> String {
+    format!("store-{}-updates", name)
+}
+
+fn updates_results_name(name: &str) -> String {
+    format!("store-{}-updates-results", name)
+}
+
+#[derive(Clone)]
+pub struct Index {
+    pub main: Main,
+    pub postings_lists: PostingsLists,
+    pub documents_fields: DocumentsFields,
+    pub synonyms: Synonyms,
+    pub docs_words: DocsWords,
+
+    pub updates: Updates,
+    pub updates_results: UpdatesResults,
+    updates_notifier: crossbeam_channel::Sender<()>,
+}
+
+impl Index {
+    pub fn document<T: de::DeserializeOwned, R: rkv::Readable>(
+        &self,
+        reader: &R,
+        attributes: Option<&HashSet<&str>>,
+        document_id: DocumentId,
+    ) -> MResult<Option<T>>
+    {
+        let schema = self.main.schema(reader)?;
+        let schema = schema.ok_or(Error::SchemaMissing)?;
+
+        let attributes = match attributes {
+            Some(attributes) => attributes.into_iter().map(|name| schema.attribute(name)).collect(),
+            None => None,
+        };
+
+        let mut deserializer = Deserializer {
+            document_id,
+            reader,
+            documents_fields: self.documents_fields,
+            schema: &schema,
+            attributes: attributes.as_ref(),
+        };
+
+        // TODO: currently we return an error if all document fields are missing,
+        //       returning None would have been better
+        Ok(T::deserialize(&mut deserializer).map(Some)?)
+    }
+
+    pub fn document_attribute<T: de::DeserializeOwned, R: rkv::Readable>(
+        &self,
+        reader: &R,
+        document_id: DocumentId,
+        attribute: SchemaAttr,
+    ) -> MResult<Option<T>>
+    {
+        let bytes = self.documents_fields.document_attribute(reader, document_id, attribute)?;
+        match bytes {
+            Some(bytes) => Ok(Some(rmp_serde::from_read_ref(bytes)?)),
+            None => Ok(None),
+        }
+    }
+
+    pub fn schema_update(&self, mut writer: rkv::Writer, schema: Schema) -> MResult<()> {
+        update::push_schema_update(&mut writer, self.updates, self.updates_results, schema)?;
+        writer.commit()?;
+        let _ = self.updates_notifier.send(());
+        Ok(())
+    }
+
+    pub fn documents_addition<D>(&self) -> update::DocumentsAddition<D> {
+        update::DocumentsAddition::new(
+            self.updates,
+            self.updates_results,
+            self.updates_notifier.clone(),
+        )
+    }
+
+    pub fn documents_deletion<D>(&self) -> update::DocumentsDeletion {
+        update::DocumentsDeletion::new(
+            self.updates,
+            self.updates_results,
+            self.updates_notifier.clone(),
+        )
+    }
+
+    pub fn synonyms_addition(&self) -> update::SynonymsAddition {
+        update::SynonymsAddition::new(
+            self.updates,
+            self.updates_results,
+            self.updates_notifier.clone(),
+        )
+    }
+
+    pub fn synonyms_deletion(&self) -> update::SynonymsDeletion {
+        update::SynonymsDeletion::new(
+            self.updates,
+            self.updates_results,
+            self.updates_notifier.clone(),
+        )
+    }
+
+    pub fn update_status<T: rkv::Readable>(
+        &self,
+        reader: &T,
+        update_id: u64,
+    ) -> MResult<update::UpdateStatus>
+    {
+        update::update_status(
+            reader,
+            self.updates,
+            self.updates_results,
+            update_id,
+        )
+    }
+
+    pub fn query_builder(&self) -> QueryBuilder {
+        QueryBuilder::new(self.main, self.postings_lists, self.synonyms)
+    }
+}
+
+pub fn create(
+    env: &rkv::Rkv,
+    name: &str,
+    updates_notifier: crossbeam_channel::Sender<()>,
+) -> Result<Index, rkv::StoreError>
+{
+    open_options(env, name, rkv::StoreOptions::create(), updates_notifier)
+}
+
+pub fn open(
+    env: &rkv::Rkv,
+    name: &str,
+    updates_notifier: crossbeam_channel::Sender<()>,
+) -> Result<Index, rkv::StoreError>
+{
+    let mut options = rkv::StoreOptions::default();
+    options.create = false;
+    open_options(env, name, options, updates_notifier)
+}
+
+fn open_options(
+    env: &rkv::Rkv,
+    name: &str,
+    options: rkv::StoreOptions,
+    updates_notifier: crossbeam_channel::Sender<()>,
+) -> Result<Index, rkv::StoreError>
+{
+    // create all the store names
+    let main_name = main_name(name);
+    let postings_lists_name = postings_lists_name(name);
+    let documents_fields_name = documents_fields_name(name);
+    let synonyms_name = synonyms_name(name);
+    let docs_words_name = docs_words_name(name);
+    let updates_name = updates_name(name);
+    let updates_results_name = updates_results_name(name);
+
+    // open all the stores
+    let main = env.open_single(main_name.as_str(), options)?;
+    let postings_lists = env.open_single(postings_lists_name.as_str(), options)?;
+    let documents_fields = env.open_single(documents_fields_name.as_str(), options)?;
+    let synonyms = env.open_single(synonyms_name.as_str(), options)?;
+    let docs_words = env.open_single(docs_words_name.as_str(), options)?;
+    let updates = env.open_single(updates_name.as_str(), options)?;
+    let updates_results = env.open_single(updates_results_name.as_str(), options)?;
+
+    Ok(Index {
+        main: Main { main },
+        postings_lists: PostingsLists { postings_lists },
+        documents_fields: DocumentsFields { documents_fields },
+        synonyms: Synonyms { synonyms },
+        docs_words: DocsWords { docs_words },
+        updates: Updates { updates },
+        updates_results: UpdatesResults { updates_results },
+        updates_notifier,
+    })
+}

meilidb-core/src/store/postings_lists.rs

@@ -0,0 +1,81 @@
+use std::borrow::Cow;
+use std::{mem, ptr};
+
+use zerocopy::{AsBytes, LayoutVerified};
+use rkv::StoreError;
+
+use crate::DocIndex;
+use crate::store::aligned_to;
+
+#[derive(Copy, Clone)]
+pub struct PostingsLists {
+    pub(crate) postings_lists: rkv::SingleStore,
+}
+
+impl PostingsLists {
+    pub fn put_postings_list(
+        &self,
+        writer: &mut rkv::Writer,
+        word: &[u8],
+        words_indexes: &[DocIndex],
+    ) -> Result<(), rkv::StoreError>
+    {
+        let blob = rkv::Value::Blob(words_indexes.as_bytes());
+        self.postings_lists.put(writer, word, &blob)
+    }
+
+    pub fn del_postings_list(
+        &self,
+        writer: &mut rkv::Writer,
+        word: &[u8],
+    ) -> Result<bool, rkv::StoreError>
+    {
+        match self.postings_lists.delete(writer, word) {
+            Ok(()) => Ok(true),
+            Err(StoreError::LmdbError(lmdb::Error::NotFound)) => Ok(false),
+            Err(e) => Err(e),
+        }
+    }
+
+    pub fn postings_list<'a>(
+        &self,
+        reader: &'a impl rkv::Readable,
+        word: &[u8],
+    ) -> Result<Option<Cow<'a, sdset::Set<DocIndex>>>, rkv::StoreError>
+    {
+        let bytes = match self.postings_lists.get(reader, word)? {
+            Some(rkv::Value::Blob(bytes)) => bytes,
+            Some(value) => panic!("invalid type {:?}", value),
+            None => return Ok(None),
+        };
+
+        match LayoutVerified::new_slice(bytes) {
+            Some(layout) => {
+                let set = sdset::Set::new(layout.into_slice()).unwrap();
+                Ok(Some(Cow::Borrowed(set)))
+            },
+            None => {
+                let len = bytes.len();
+                let elem_size = mem::size_of::<DocIndex>();
+
+                // ensure that it is the alignment that is wrong
+                // and the length is valid
+                if len % elem_size == 0 && !aligned_to(bytes, mem::align_of::<DocIndex>()) {
+                    let elems = len / elem_size;
+                    let mut vec = Vec::<DocIndex>::with_capacity(elems);
+
+                    unsafe {
+                        let dst = vec.as_mut_ptr() as *mut u8;
+                        ptr::copy_nonoverlapping(bytes.as_ptr(), dst, len);
+                        vec.set_len(elems);
+                    }
+
+                    let setbuf = sdset::SetBuf::new(vec).unwrap();
+                    return Ok(Some(Cow::Owned(setbuf)))
+                }
+
+                Ok(None)
+            },
+        }
+    }
+}

meilidb-core/src/store/synonyms.rs

@@ -0,0 +1,52 @@
+use std::sync::Arc;
+use rkv::StoreError;
+use crate::error::MResult;
+
+#[derive(Copy, Clone)]
+pub struct Synonyms {
+    pub(crate) synonyms: rkv::SingleStore,
+}
+
+impl Synonyms {
+    pub fn put_synonyms(
+        &self,
+        writer: &mut rkv::Writer,
+        word: &[u8],
+        synonyms: &fst::Set,
+    ) -> Result<(), rkv::StoreError>
+    {
+        let blob = rkv::Value::Blob(synonyms.as_fst().as_bytes());
+        self.synonyms.put(writer, word, &blob)
+    }
+
+    pub fn del_synonyms(
+        &self,
+        writer: &mut rkv::Writer,
+        word: &[u8],
+    ) -> Result<bool, rkv::StoreError>
+    {
+        match self.synonyms.delete(writer, word) {
+            Ok(()) => Ok(true),
+            Err(StoreError::LmdbError(lmdb::Error::NotFound)) => Ok(false),
+            Err(e) => Err(e),
+        }
+    }
+
+    pub fn synonyms(
+        &self,
+        reader: &impl rkv::Readable,
+        word: &[u8],
+    ) -> MResult<Option<fst::Set>>
+    {
+        match self.synonyms.get(reader, word)? {
+            Some(rkv::Value::Blob(bytes)) => {
+                let len = bytes.len();
+                let bytes = Arc::from(bytes);
+                let fst = fst::raw::Fst::from_shared_bytes(bytes, 0, len)?;
+                Ok(Some(fst::Set::from(fst)))
+            },
+            Some(value) => panic!("invalid type {:?}", value),
+            None => Ok(None),
+        }
+    }
+}

meilidb-core/src/store/updates.rs

@@ -0,0 +1,101 @@
+use std::convert::TryInto;
+use rkv::Value;
+use crate::{update::Update, MResult};
+
+#[derive(Copy, Clone)]
+pub struct Updates {
+    pub(crate) updates: rkv::SingleStore,
+}
+
+impl Updates {
+    // TODO we should use the MDB_LAST op but
+    //      it is not exposed by the rkv library
+    pub fn last_update_id<'a>(
+        &self,
+        reader: &'a impl rkv::Readable,
+    ) -> Result<Option<(u64, Option<Value<'a>>)>, rkv::StoreError>
+    {
+        let mut last = None;
+        let iter = self.updates.iter_start(reader)?;
+        for result in iter {
+            let (key, data) = result?;
+            last = Some((key, data));
+        }
+
+        let (last_key, last_data) = match last {
+            Some(entry) => entry,
+            None => return Ok(None),
+        };
+
+        let array = last_key.try_into().unwrap();
+        let number = u64::from_be_bytes(array);
+
+        Ok(Some((number, last_data)))
+    }
+
+    fn first_update_id<'a>(
+        &self,
+        reader: &'a impl rkv::Readable,
+    ) -> Result<Option<(u64, Option<Value<'a>>)>, rkv::StoreError>
+    {
+        let mut iter = self.updates.iter_start(reader)?;
+        let (first_key, first_data) = match iter.next() {
+            Some(result) => result?,
+            None => return Ok(None),
+        };
+
+        let array = first_key.try_into().unwrap();
+        let number = u64::from_be_bytes(array);
+
+        Ok(Some((number, first_data)))
+    }
+
+    pub fn contains(
+        &self,
+        reader: &impl rkv::Readable,
+        update_id: u64,
+    ) -> Result<bool, rkv::StoreError>
+    {
+        let update_id_bytes = update_id.to_be_bytes();
+        self.updates.get(reader, update_id_bytes).map(|v| v.is_some())
+    }
+
+    pub fn put_update(
+        &self,
+        writer: &mut rkv::Writer,
+        update_id: u64,
+        update: &Update,
+    ) -> MResult<()>
+    {
+        let update_id_bytes = update_id.to_be_bytes();
+        let update = rmp_serde::to_vec_named(&update)?;
+        let blob = Value::Blob(&update);
+        self.updates.put(writer, update_id_bytes, &blob)?;
+        Ok(())
+    }
+
+    pub fn pop_front(
+        &self,
+        writer: &mut rkv::Writer,
+    ) -> MResult<Option<(u64, Update)>>
+    {
+        let (first_id, first_data) = match self.first_update_id(writer)? {
+            Some(entry) => entry,
+            None => return Ok(None),
+        };
+
+        match first_data {
+            Some(Value::Blob(bytes)) => {
+                let update = rmp_serde::from_read_ref(&bytes)?;
+
+                // remove it from the database now
+                let first_id_bytes = first_id.to_be_bytes();
+                self.updates.delete(writer, first_id_bytes)?;
+
+                Ok(Some((first_id, update)))
+            },
+            Some(value) => panic!("invalid type {:?}", value),
+            None => Ok(None),
+        }
+    }
+}

meilidb-core/src/store/updates_results.rs

@@ -0,0 +1,67 @@
+use std::convert::TryInto;
+use rkv::Value;
+use crate::{update::UpdateResult, MResult};
+
+#[derive(Copy, Clone)]
+pub struct UpdatesResults {
+    pub(crate) updates_results: rkv::SingleStore,
+}
+
+impl UpdatesResults {
+    // TODO we should use the MDB_LAST op but
+    //      it is not exposed by the rkv library
+    pub fn last_update_id<'a>(
+        &self,
+        reader: &'a impl rkv::Readable,
+    ) -> Result<Option<(u64, Option<Value<'a>>)>, rkv::StoreError>
+    {
+        let mut last = None;
+        let iter = self.updates_results.iter_start(reader)?;
+        for result in iter {
+            let (key, data) = result?;
+            last = Some((key, data));
+        }
+
+        let (last_key, last_data) = match last {
+            Some(entry) => entry,
+            None => return Ok(None),
+        };
+
+        let array = last_key.try_into().unwrap();
+        let number = u64::from_be_bytes(array);
+
+        Ok(Some((number, last_data)))
+    }
+
+    pub fn put_update_result(
+        &self,
+        writer: &mut rkv::Writer,
+        update_id: u64,
+        update_result: &UpdateResult,
+    ) -> MResult<()>
+    {
+        let update_id_bytes = update_id.to_be_bytes();
+        let update_result = bincode::serialize(&update_result)?;
+        let blob = Value::Blob(&update_result);
+        self.updates_results.put(writer, update_id_bytes, &blob)?;
+        Ok(())
+    }
+
+    pub fn update_result(
+        &self,
+        reader: &impl rkv::Readable,
+        update_id: u64,
+    ) -> MResult<Option<UpdateResult>>
+    {
+        let update_id_bytes = update_id.to_be_bytes();
+
+        match self.updates_results.get(reader, update_id_bytes)? {
+            Some(Value::Blob(bytes)) => {
+                let update_result = bincode::deserialize(&bytes)?;
+                Ok(Some(update_result))
+            },
+            Some(value) => panic!("invalid type {:?}", value),
+            None => Ok(None),
+        }
+    }
+}

meilidb-core/src/update/documents_addition.rs

@@ -0,0 +1,189 @@
+use std::collections::HashSet;
+
+use fst::{SetBuilder, set::OpBuilder};
+use sdset::{SetOperation, duo::Union};
+use serde::Serialize;
+
+use crate::raw_indexer::RawIndexer;
+use crate::serde::{extract_document_id, Serializer, RamDocumentStore};
+use crate::store;
+use crate::update::{Update, next_update_id, apply_documents_deletion};
+use crate::{MResult, Error, RankedMap};
+
+pub struct DocumentsAddition<D> {
+    updates_store: store::Updates,
+    updates_results_store: store::UpdatesResults,
+    updates_notifier: crossbeam_channel::Sender<()>,
+    documents: Vec<D>,
+}
+
+impl<D> DocumentsAddition<D> {
+    pub fn new(
+        updates_store: store::Updates,
+        updates_results_store: store::UpdatesResults,
+        updates_notifier: crossbeam_channel::Sender<()>,
+    ) -> DocumentsAddition<D>
+    {
+        DocumentsAddition {
+            updates_store,
+            updates_results_store,
+            updates_notifier,
+            documents: Vec::new(),
+        }
+    }
+
+    pub fn update_document(&mut self, document: D) {
+        self.documents.push(document);
+    }
+
+    pub fn finalize(self, mut writer: rkv::Writer) -> MResult<u64>
+    where D: serde::Serialize
+    {
+        let update_id = push_documents_addition(
+            &mut writer,
+            self.updates_store,
+            self.updates_results_store,
+            self.documents,
+        )?;
+        writer.commit()?;
+        let _ = self.updates_notifier.send(());
+
+        Ok(update_id)
+    }
+}
+
+impl<D> Extend<D> for DocumentsAddition<D> {
+    fn extend<T: IntoIterator<Item=D>>(&mut self, iter: T) {
+        self.documents.extend(iter)
+    }
+}
+
+pub fn push_documents_addition<D: serde::Serialize>(
+    writer: &mut rkv::Writer,
+    updates_store: store::Updates,
+    updates_results_store: store::UpdatesResults,
+    addition: Vec<D>,
+) -> MResult<u64>
+{
+    let mut values = Vec::with_capacity(addition.len());
+    for add in addition {
+        let vec = rmp_serde::to_vec_named(&add)?;
+        let add = rmp_serde::from_read(&vec[..])?;
+        values.push(add);
+    }
+
+    let last_update_id = next_update_id(writer, updates_store, updates_results_store)?;
+
+    let update = Update::DocumentsAddition(values);
+    updates_store.put_update(writer, last_update_id, &update)?;
+
+    Ok(last_update_id)
+}
+
+pub fn apply_documents_addition(
+    writer: &mut rkv::Writer,
+    main_store: store::Main,
+    documents_fields_store: store::DocumentsFields,
+    postings_lists_store: store::PostingsLists,
+    docs_words_store: store::DocsWords,
+    mut ranked_map: RankedMap,
+    addition: Vec<rmpv::Value>,
+) -> MResult<()>
+{
+    let mut document_ids = HashSet::new();
+    let mut document_store = RamDocumentStore::new();
+    let mut indexer = RawIndexer::new();
+
+    let schema = match main_store.schema(writer)? {
+        Some(schema) => schema,
+        None => return Err(Error::SchemaMissing),
+    };
+
+    let identifier = schema.identifier_name();
+
+    for document in addition {
+        let document_id = match extract_document_id(identifier, &document)? {
+            Some(id) => id,
+            None => return Err(Error::MissingDocumentId),
+        };
+
+        // 1. store the document id for future deletion
+        document_ids.insert(document_id);
+
+        // 2. index the document fields in ram stores
+        let serializer = Serializer {
+            schema: &schema,
+            document_store: &mut document_store,
+            indexer: &mut indexer,
+            ranked_map: &mut ranked_map,
+            document_id,
+        };
+
+        document.serialize(serializer)?;
+    }
+
+    // 1. remove the previous documents match indexes
+    let documents_to_insert = document_ids.iter().cloned().collect();
+    apply_documents_deletion(
+        writer,
+        main_store,
+        documents_fields_store,
+        postings_lists_store,
+        docs_words_store,
+        ranked_map.clone(),
+        documents_to_insert,
+    )?;
+
+    // 2. insert new document attributes in the database
+    for ((id, attr), value) in document_store.into_inner() {
+        documents_fields_store.put_document_field(writer, id, attr, &value)?;
+    }
+
+    let indexed = indexer.build();
+    let mut delta_words_builder = SetBuilder::memory();
+
+    for (word, delta_set) in indexed.words_doc_indexes {
+        delta_words_builder.insert(&word).unwrap();
+
+        let set = match postings_lists_store.postings_list(writer, &word)? {
+            Some(set) => Union::new(&set, &delta_set).into_set_buf(),
+            None => delta_set,
+        };
+
+        postings_lists_store.put_postings_list(writer, &word, &set)?;
+    }
+
+    for (id, words) in indexed.docs_words {
+        docs_words_store.put_doc_words(writer, id, &words)?;
+    }
+
+    let delta_words = delta_words_builder
+        .into_inner()
+        .and_then(fst::Set::from_bytes)
+        .unwrap();
+
+    let words = match main_store.words_fst(writer)? {
+        Some(words) => {
+            let op = OpBuilder::new()
+                .add(words.stream())
+                .add(delta_words.stream())
+                .r#union();
+
+            let mut words_builder = SetBuilder::memory();
+            words_builder.extend_stream(op).unwrap();
+            words_builder
+                .into_inner()
+                .and_then(fst::Set::from_bytes)
+                .unwrap()
+        },
+        None => delta_words,
+    };
+
+    main_store.put_words_fst(writer, &words)?;
+    main_store.put_ranked_map(writer, &ranked_map)?;
+
+    let inserted_documents_len = document_ids.len() as u64;
+    main_store.put_number_of_documents(writer, |old| old + inserted_documents_len)?;
+
+    Ok(())
+}

meilidb-core/src/update/documents_deletion.rs

@@ -0,0 +1,180 @@
+use std::collections::{HashMap, HashSet, BTreeSet};
+
+use fst::{SetBuilder, Streamer};
+use meilidb_schema::Schema;
+use sdset::{SetBuf, SetOperation, duo::DifferenceByKey};
+
+use crate::{DocumentId, RankedMap, MResult, Error};
+use crate::serde::extract_document_id;
+use crate::update::{Update, next_update_id};
+use crate::store;
+
+pub struct DocumentsDeletion {
+    updates_store: store::Updates,
+    updates_results_store: store::UpdatesResults,
+    updates_notifier: crossbeam_channel::Sender<()>,
+    documents: Vec<DocumentId>,
+}
+
+impl DocumentsDeletion {
+    pub fn new(
+        updates_store: store::Updates,
+        updates_results_store: store::UpdatesResults,
+        updates_notifier: crossbeam_channel::Sender<()>,
+    ) -> DocumentsDeletion
+    {
+        DocumentsDeletion {
+            updates_store,
+            updates_results_store,
+            updates_notifier,
+            documents: Vec::new(),
+        }
+    }
+
+    pub fn delete_document_by_id(&mut self, document_id: DocumentId) {
+        self.documents.push(document_id);
+    }
+
+    pub fn delete_document<D>(&mut self, schema: &Schema, document: D) -> MResult<()>
+    where D: serde::Serialize,
+    {
+        let identifier = schema.identifier_name();
+        let document_id = match extract_document_id(identifier, &document)? {
+            Some(id) => id,
+            None => return Err(Error::MissingDocumentId),
+        };
+
+        self.delete_document_by_id(document_id);
+
+        Ok(())
+    }
+
+    pub fn finalize(self, mut writer: rkv::Writer) -> MResult<u64> {
+        let update_id = push_documents_deletion(
+            &mut writer,
+            self.updates_store,
+            self.updates_results_store,
+            self.documents,
+        )?;
+        writer.commit()?;
+        let _ = self.updates_notifier.send(());
+
+        Ok(update_id)
+    }
+}
+
+impl Extend<DocumentId> for DocumentsDeletion {
+    fn extend<T: IntoIterator<Item=DocumentId>>(&mut self, iter: T) {
+        self.documents.extend(iter)
+    }
+}
+
+pub fn push_documents_deletion(
+    writer: &mut rkv::Writer,
+    updates_store: store::Updates,
+    updates_results_store: store::UpdatesResults,
+    deletion: Vec<DocumentId>,
+) -> MResult<u64>
+{
+    let last_update_id = next_update_id(writer, updates_store, updates_results_store)?;
+
+    let update = Update::DocumentsDeletion(deletion);
+    updates_store.put_update(writer, last_update_id, &update)?;
+
+    Ok(last_update_id)
+}
+
+pub fn apply_documents_deletion(
+    writer: &mut rkv::Writer,
+    main_store: store::Main,
+    documents_fields_store: store::DocumentsFields,
+    postings_lists_store: store::PostingsLists,
+    docs_words_store: store::DocsWords,
+    mut ranked_map: RankedMap,
+    deletion: Vec<DocumentId>,
+) -> MResult<()>
+{
+    let idset = SetBuf::from_dirty(deletion);
+
+    let schema = match main_store.schema(writer)? {
+        Some(schema) => schema,
+        None => return Err(Error::SchemaMissing),
+    };
+
+    // collect the ranked attributes according to the schema
+    let ranked_attrs: Vec<_> = schema.iter()
+        .filter_map(|(_, attr, prop)| {
+            if prop.is_ranked() { Some(attr) } else { None }
+        })
+        .collect();
+
+    let mut words_document_ids = HashMap::new();
+    for id in idset {
+        // remove all the ranked attributes from the ranked_map
+        for ranked_attr in &ranked_attrs {
+            ranked_map.remove(id, *ranked_attr);
+        }
+
+        if let Some(words) = docs_words_store.doc_words(writer, id)? {
+            let mut stream = words.stream();
+            while let Some(word) = stream.next() {
+                let word = word.to_vec();
+                words_document_ids.entry(word).or_insert_with(Vec::new).push(id);
+            }
+        }
+    }
+
+    let mut deleted_documents = HashSet::new();
+    let mut removed_words = BTreeSet::new();
+    for (word, document_ids) in words_document_ids {
+        let document_ids = SetBuf::from_dirty(document_ids);
+
+        if let Some(doc_indexes) = postings_lists_store.postings_list(writer, &word)? {
+            let op = DifferenceByKey::new(&doc_indexes, &document_ids, |d| d.document_id, |id| *id);
+            let doc_indexes = op.into_set_buf();
+
+            if !doc_indexes.is_empty() {
+                postings_lists_store.put_postings_list(writer, &word, &doc_indexes)?;
+            } else {
+                postings_lists_store.del_postings_list(writer, &word)?;
+                removed_words.insert(word);
+            }
+        }
+
+        for id in document_ids {
+            if documents_fields_store.del_all_document_fields(writer, id)? != 0 {
+                deleted_documents.insert(id);
+            }
+        }
+    }
+
+    let deleted_documents_len = deleted_documents.len() as u64;
+    for id in deleted_documents {
+        docs_words_store.del_doc_words(writer, id)?;
+    }
+
+    let removed_words = fst::Set::from_iter(removed_words).unwrap();
+    let words = match main_store.words_fst(writer)? {
+        Some(words_set) => {
+            let op = fst::set::OpBuilder::new()
+                .add(words_set.stream())
+                .add(removed_words.stream())
+                .difference();
+
+            let mut words_builder = SetBuilder::memory();
+            words_builder.extend_stream(op).unwrap();
+            words_builder
+                .into_inner()
+                .and_then(fst::Set::from_bytes)
+                .unwrap()
+        },
+        None => fst::Set::default(),
+    };
+
+    main_store.put_words_fst(writer, &words)?;
+    main_store.put_ranked_map(writer, &ranked_map)?;
+
+    main_store.put_number_of_documents(writer, |old| old - deleted_documents_len)?;
+
+    Ok(())
+}

meilidb-core/src/update/mod.rs

@@ -0,0 +1,202 @@
+mod documents_addition;
+mod documents_deletion;
+mod schema_update;
+mod synonyms_addition;
+mod synonyms_deletion;
+
+pub use self::documents_addition::{DocumentsAddition, apply_documents_addition};
+pub use self::documents_deletion::{DocumentsDeletion, apply_documents_deletion};
+pub use self::schema_update::{apply_schema_update, push_schema_update};
+pub use self::synonyms_addition::{SynonymsAddition, apply_synonyms_addition};
+pub use self::synonyms_deletion::{SynonymsDeletion, apply_synonyms_deletion};
+
+use std::time::{Duration, Instant};
+use std::collections::BTreeMap;
+use std::cmp;
+
+use log::debug;
+use serde::{Serialize, Deserialize};
+
+use crate::{store, MResult, DocumentId, RankedMap};
+use meilidb_schema::Schema;
+
+#[derive(Debug, Serialize, Deserialize)]
+pub enum Update {
+    SchemaUpdate(Schema),
+    DocumentsAddition(Vec<rmpv::Value>),
+    DocumentsDeletion(Vec<DocumentId>),
+    SynonymsAddition(BTreeMap<String, Vec<String>>),
+    SynonymsDeletion(BTreeMap<String, Option<Vec<String>>>),
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub enum UpdateType {
+    SchemaUpdate { schema: Schema },
+    DocumentsAddition { number: usize },
+    DocumentsDeletion { number: usize },
+    SynonymsAddition { number: usize },
+    SynonymsDeletion { number: usize },
+}
+
+#[derive(Clone, Serialize, Deserialize)]
+pub struct DetailedDuration {
+    pub main: Duration,
+}
+
+#[derive(Clone, Serialize, Deserialize)]
+pub struct UpdateResult {
+    pub update_id: u64,
+    pub update_type: UpdateType,
+    pub result: Result<(), String>,
+    pub detailed_duration: DetailedDuration,
+}
+
+#[derive(Clone, Serialize, Deserialize)]
+pub enum UpdateStatus {
+    Enqueued,
+    Processed(UpdateResult),
+    Unknown,
+}
+
+pub fn update_status<T: rkv::Readable>(
+    reader: &T,
+    updates_store: store::Updates,
+    updates_results_store: store::UpdatesResults,
+    update_id: u64,
+) -> MResult<UpdateStatus>
+{
+    match updates_results_store.update_result(reader, update_id)? {
+        Some(result) => Ok(UpdateStatus::Processed(result)),
+        None => {
+            if updates_store.contains(reader, update_id)? {
+                Ok(UpdateStatus::Enqueued)
+            } else {
+                Ok(UpdateStatus::Unknown)
+            }
+        }
+    }
+}
+
+pub fn next_update_id(
+    writer: &mut rkv::Writer,
+    updates_store: store::Updates,
+    updates_results_store: store::UpdatesResults,
+) -> MResult<u64>
+{
+    let last_update_id = updates_store.last_update_id(writer)?;
+    let last_update_id = last_update_id.map(|(n, _)| n);
+
+    let last_update_results_id = updates_results_store.last_update_id(writer)?;
+    let last_update_results_id = last_update_results_id.map(|(n, _)| n);
+
+    let max_update_id = cmp::max(last_update_id, last_update_results_id);
+    let new_update_id = max_update_id.map_or(0, |n| n + 1);
+
+    Ok(new_update_id)
+}
+
+pub fn update_task(writer: &mut rkv::Writer, index: store::Index) -> MResult<Option<UpdateResult>> {
+    let (update_id, update) = match index.updates.pop_front(writer)? {
+        Some(value) => value,
+        None => return Ok(None),
+    };
+
+    debug!("Processing update number {}", update_id);
+
+    let (update_type, result, duration) = match update {
+        Update::SchemaUpdate(schema) => {
+            let start = Instant::now();
+
+            let update_type = UpdateType::SchemaUpdate { schema: schema.clone() };
+            let result = apply_schema_update(writer, index.main, &schema);
+
+            (update_type, result, start.elapsed())
+        },
+        Update::DocumentsAddition(documents) => {
+            let start = Instant::now();
+
+            let ranked_map = match index.main.ranked_map(writer)? {
+                Some(ranked_map) => ranked_map,
+                None => RankedMap::default(),
+            };
+
+            let update_type = UpdateType::DocumentsAddition { number: documents.len() };
+
+            let result = apply_documents_addition(
+                writer,
+                index.main,
+                index.documents_fields,
+                index.postings_lists,
+                index.docs_words,
+                ranked_map,
+                documents,
+            );
+
+            (update_type, result, start.elapsed())
+        },
+        Update::DocumentsDeletion(documents) => {
+            let start = Instant::now();
+
+            let ranked_map = match index.main.ranked_map(writer)? {
+                Some(ranked_map) => ranked_map,
+                None => RankedMap::default(),
+            };
+
+            let update_type = UpdateType::DocumentsDeletion { number: documents.len() };
+
+            let result = apply_documents_deletion(
+                writer,
+                index.main,
+                index.documents_fields,
+                index.postings_lists,
+                index.docs_words,
+                ranked_map,
+                documents,
+            );
+
+            (update_type, result, start.elapsed())
+        },
+        Update::SynonymsAddition(synonyms) => {
+            let start = Instant::now();
+
+            let update_type = UpdateType::SynonymsAddition { number: synonyms.len() };
+
+            let result = apply_synonyms_addition(
+                writer,
+                index.main,
+                index.synonyms,
+                synonyms,
+            );
+
+            (update_type, result, start.elapsed())
+        },
+        Update::SynonymsDeletion(synonyms) => {
+            let start = Instant::now();
+
+            let update_type = UpdateType::SynonymsDeletion { number: synonyms.len() };
+
+            let result = apply_synonyms_deletion(
+                writer,
+                index.main,
+                index.synonyms,
+                synonyms,
+            );
+
+            (update_type, result, start.elapsed())
+        },
+    };
+
+    debug!("Processed update number {} {:?} {:?}", update_id, update_type, result);
+
+    let detailed_duration = DetailedDuration { main: duration };
+    let status = UpdateResult {
+        update_id,
+        update_type,
+        result: result.map_err(|e| e.to_string()),
+        detailed_duration,
+    };
+
+    index.updates_results.put_update_result(writer, update_id, &status)?;
+
+    Ok(Some(status))
+}

meilidb-core/src/update/schema_update.rs

@@ -0,0 +1,31 @@
+use meilidb_schema::Schema;
+use crate::{store, error::UnsupportedOperation, MResult};
+use crate::update::{Update, next_update_id};
+
+pub fn apply_schema_update(
+    writer: &mut rkv::Writer,
+    main_store: store::Main,
+    new_schema: &Schema,
+) -> MResult<()>
+{
+    if let Some(_) = main_store.schema(writer)? {
+        return Err(UnsupportedOperation::SchemaAlreadyExists.into())
+    }
+
+    main_store.put_schema(writer, new_schema)
+}
+
+pub fn push_schema_update(
+    writer: &mut rkv::Writer,
+    updates_store: store::Updates,
+    updates_results_store: store::UpdatesResults,
+    schema: Schema,
+) -> MResult<u64>
+{
+    let last_update_id = next_update_id(writer, updates_store, updates_results_store)?;
+
+    let update = Update::SchemaUpdate(schema);
+    updates_store.put_update(writer, last_update_id, &update)?;
+
+    Ok(last_update_id)
+}

meilidb-core/src/update/synonyms_addition.rs

@@ -0,0 +1,119 @@
+use std::collections::BTreeMap;
+
+use fst::{SetBuilder, set::OpBuilder};
+use sdset::SetBuf;
+
+use crate::automaton::normalize_str;
+use crate::update::{Update, next_update_id};
+use crate::{store, MResult};
+
+pub struct SynonymsAddition {
+    updates_store: store::Updates,
+    updates_results_store: store::UpdatesResults,
+    updates_notifier: crossbeam_channel::Sender<()>,
+    synonyms: BTreeMap<String, Vec<String>>,
+}
+
+impl SynonymsAddition {
+    pub fn new(
+        updates_store: store::Updates,
+        updates_results_store: store::UpdatesResults,
+        updates_notifier: crossbeam_channel::Sender<()>,
+    ) -> SynonymsAddition
+    {
+        SynonymsAddition {
+            updates_store,
+            updates_results_store,
+            updates_notifier,
+            synonyms: BTreeMap::new(),
+        }
+    }
+
+    pub fn add_synonym<S, T, I>(&mut self, synonym: S, alternatives: I)
+    where S: AsRef<str>,
+          T: AsRef<str>,
+          I: IntoIterator<Item=T>,
+    {
+        let synonym = normalize_str(synonym.as_ref());
+        let alternatives = alternatives.into_iter().map(|s| s.as_ref().to_lowercase());
+        self.synonyms.entry(synonym).or_insert_with(Vec::new).extend(alternatives);
+    }
+
+    pub fn finalize(self, mut writer: rkv::Writer) -> MResult<u64> {
+        let update_id = push_synonyms_addition(
+            &mut writer,
+            self.updates_store,
+            self.updates_results_store,
+            self.synonyms,
+        )?;
+        writer.commit()?;
+        let _ = self.updates_notifier.send(());
+
+        Ok(update_id)
+    }
+}
+
+pub fn push_synonyms_addition(
+    writer: &mut rkv::Writer,
+    updates_store: store::Updates,
+    updates_results_store: store::UpdatesResults,
+    addition: BTreeMap<String, Vec<String>>,
+) -> MResult<u64>
+{
+    let last_update_id = next_update_id(writer, updates_store, updates_results_store)?;
+
+    let update = Update::SynonymsAddition(addition);
+    updates_store.put_update(writer, last_update_id, &update)?;
+
+    Ok(last_update_id)
+}
+
+pub fn apply_synonyms_addition(
+    writer: &mut rkv::Writer,
+    main_store: store::Main,
+    synonyms_store: store::Synonyms,
+    addition: BTreeMap<String, Vec<String>>,
+) -> MResult<()>
+{
+    let mut synonyms_builder = SetBuilder::memory();
+
+    for (word, alternatives) in addition {
+        synonyms_builder.insert(&word).unwrap();
+
+        let alternatives = {
+            let alternatives = SetBuf::from_dirty(alternatives);
+            let mut alternatives_builder = SetBuilder::memory();
+            alternatives_builder.extend_iter(alternatives).unwrap();
+            let bytes = alternatives_builder.into_inner().unwrap();
+            fst::Set::from_bytes(bytes).unwrap()
+        };
+
+        synonyms_store.put_synonyms(writer, word.as_bytes(), &alternatives)?;
+    }
+
+    let delta_synonyms = synonyms_builder
+        .into_inner()
+        .and_then(fst::Set::from_bytes)
+        .unwrap();
+
+    let synonyms = match main_store.synonyms_fst(writer)? {
+        Some(synonyms) => {
+            let op = OpBuilder::new()
+                .add(synonyms.stream())
+                .add(delta_synonyms.stream())
+                .r#union();
+
+            let mut synonyms_builder = SetBuilder::memory();
+            synonyms_builder.extend_stream(op).unwrap();
+            synonyms_builder
+                .into_inner()
+                .and_then(fst::Set::from_bytes)
+                .unwrap()
+        },
+        None => delta_synonyms,
+    };
+
+    main_store.put_synonyms_fst(writer, &synonyms)?;
+
+    Ok(())
+}

meilidb-core/src/update/synonyms_deletion.rs

@@ -0,0 +1,162 @@
+use std::collections::BTreeMap;
+use std::iter::FromIterator;
+
+use fst::{SetBuilder, set::OpBuilder};
+use sdset::SetBuf;
+
+use crate::automaton::normalize_str;
+use crate::update::{Update, next_update_id};
+use crate::{store, MResult};
+
+pub struct SynonymsDeletion {
+    updates_store: store::Updates,
+    updates_results_store: store::UpdatesResults,
+    updates_notifier: crossbeam_channel::Sender<()>,
+    synonyms: BTreeMap<String, Option<Vec<String>>>,
+}
+
+impl SynonymsDeletion {
+    pub fn new(
+        updates_store: store::Updates,
+        updates_results_store: store::UpdatesResults,
+        updates_notifier: crossbeam_channel::Sender<()>,
+    ) -> SynonymsDeletion
+    {
+        SynonymsDeletion {
+            updates_store,
+            updates_results_store,
+            updates_notifier,
+            synonyms: BTreeMap::new(),
+        }
+    }
+
+    pub fn delete_all_alternatives_of<S: AsRef<str>>(&mut self, synonym: S) {
+        let synonym = normalize_str(synonym.as_ref());
+        self.synonyms.insert(synonym, None);
+    }
+
+    pub fn delete_specific_alternatives_of<S, T, I>(&mut self, synonym: S, alternatives: I)
+    where S: AsRef<str>,
+          T: AsRef<str>,
+          I: Iterator<Item=T>,
+    {
+        let synonym = normalize_str(synonym.as_ref());
+        let value = self.synonyms.entry(synonym).or_insert(None);
+        let alternatives = alternatives.map(|s| s.as_ref().to_lowercase());
+        match value {
+            Some(v) => v.extend(alternatives),
+            None => *value = Some(Vec::from_iter(alternatives)),
+        }
+    }
+
+    pub fn finalize(self, mut writer: rkv::Writer) -> MResult<u64> {
+        let update_id = push_synonyms_deletion(
+            &mut writer,
+            self.updates_store,
+            self.updates_results_store,
+            self.synonyms,
+        )?;
+        writer.commit()?;
+        let _ = self.updates_notifier.send(());
+
+        Ok(update_id)
+    }
+}
+
+pub fn push_synonyms_deletion(
+    writer: &mut rkv::Writer,
+    updates_store: store::Updates,
+    updates_results_store: store::UpdatesResults,
+    deletion: BTreeMap<String, Option<Vec<String>>>,
+) -> MResult<u64>
+{
+    let last_update_id = next_update_id(writer, updates_store, updates_results_store)?;
+
+    let update = Update::SynonymsDeletion(deletion);
+    updates_store.put_update(writer, last_update_id, &update)?;
+
+    Ok(last_update_id)
+}
+
+pub fn apply_synonyms_deletion(
+    writer: &mut rkv::Writer,
+    main_store: store::Main,
+    synonyms_store: store::Synonyms,
+    deletion: BTreeMap<String, Option<Vec<String>>>,
+) -> MResult<()>
+{
+    let mut delete_whole_synonym_builder = SetBuilder::memory();
+
+    for (synonym, alternatives) in deletion {
+        match alternatives {
+            Some(alternatives) => {
+                let prev_alternatives = synonyms_store.synonyms(writer, synonym.as_bytes())?;
+                let prev_alternatives = match prev_alternatives {
+                    Some(alternatives) => alternatives,
+                    None => continue,
+                };
+
+                let delta_alternatives = {
+                    let alternatives = SetBuf::from_dirty(alternatives);
+                    let mut builder = SetBuilder::memory();
+                    builder.extend_iter(alternatives).unwrap();
+                    builder.into_inner()
+                        .and_then(fst::Set::from_bytes)
+                        .unwrap()
+                };
+
+                let op = OpBuilder::new()
+                    .add(prev_alternatives.stream())
+                    .add(delta_alternatives.stream())
+                    .difference();
+
+                let (alternatives, empty_alternatives) = {
+                    let mut builder = SetBuilder::memory();
+                    let len = builder.get_ref().len();
+                    builder.extend_stream(op).unwrap();
+                    let is_empty = len == builder.get_ref().len();
+                    let bytes = builder.into_inner().unwrap();
+                    let alternatives = fst::Set::from_bytes(bytes).unwrap();
+
+                    (alternatives, is_empty)
+                };
+
+                if empty_alternatives {
+                    delete_whole_synonym_builder.insert(synonym.as_bytes())?;
+                } else {
+                    synonyms_store.put_synonyms(writer, synonym.as_bytes(), &alternatives)?;
+                }
+            },
+            None => {
+                delete_whole_synonym_builder.insert(&synonym).unwrap();
+                synonyms_store.del_synonyms(writer, synonym.as_bytes())?;
+            }
+        }
+    }
+
+    let delta_synonyms = delete_whole_synonym_builder
+        .into_inner()
+        .and_then(fst::Set::from_bytes)
+        .unwrap();
+
+    let synonyms = match main_store.synonyms_fst(writer)? {
+        Some(synonyms) => {
+            let op = OpBuilder::new()
+                .add(synonyms.stream())
+                .add(delta_synonyms.stream())
+                .difference();
+
+            let mut synonyms_builder = SetBuilder::memory();
+            synonyms_builder.extend_stream(op).unwrap();
+            synonyms_builder
+                .into_inner()
+                .and_then(fst::Set::from_bytes)
+                .unwrap()
+        },
+        None => fst::Set::default(),
+    };
+
+    main_store.put_synonyms_fst(writer, &synonyms)?;
+
+    Ok(())
+}