Merge pull request #56 from Kerollmops/new-index-struct

New Index structure

examples/create-database.rs

@@ -5,7 +5,7 @@ use serde_derive::{Serialize, Deserialize};
 use structopt::StructOpt;
 
 use meilidb::database::schema::{Schema, SchemaBuilder, STORED, INDEXED};
-use meilidb::database::PositiveUpdateBuilder;
+use meilidb::database::UpdateBuilder;
 use meilidb::tokenizer::DefaultBuilder;
 use meilidb::database::Database;
 
@@ -44,7 +44,7 @@ fn index(schema: Schema, database_path: &Path, csv_data_path: &Path) -> Result<D
 
     let tokenizer_builder = DefaultBuilder::new();
     let update_path = tempfile::NamedTempFile::new()?;
-    let mut update = PositiveUpdateBuilder::new(update_path.path(), schema, tokenizer_builder);
+    let mut update = UpdateBuilder::new(update_path.path().to_path_buf(), schema);
 
     let mut rdr = csv::Reader::from_path(csv_data_path)?;
     let mut raw_record = csv::StringRecord::new();
@@ -59,12 +59,10 @@ fn index(schema: Schema, database_path: &Path, csv_data_path: &Path) -> Result<D
             }
         };
 
-        update.update(&document).unwrap();
+        update.update_document(&document, &tokenizer_builder)?;
     }
 
-    let mut update = update.build()?;
+    let update = update.build()?;
-
-    update.set_move(true);
     database.ingest_update_file(update)?;
 
     Ok(database)

src/data/doc_ids.rs

@@ -1,59 +1,54 @@
+use std::io::{self, Cursor, BufRead};
 use std::slice::from_raw_parts;
-use std::error::Error;
+use std::mem::size_of;
-use std::path::Path;
-use std::sync::Arc;
-use std::{io, mem};
 
+use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
 use sdset::Set;
-use fst::raw::MmapReadOnly;
-use serde::ser::{Serialize, Serializer};
 
 use crate::DocumentId;
-use crate::data::Data;
+use crate::data::SharedData;
+use super::into_u8_slice;
 
 #[derive(Default, Clone)]
-pub struct DocIds {
+pub struct DocIds(SharedData);
-    data: Data,
-}
 
 impl DocIds {
-    pub unsafe fn from_path<P: AsRef<Path>>(path: P) -> io::Result<Self> {
+    pub fn new(ids: &Set<DocumentId>) -> DocIds {
-        let mmap = MmapReadOnly::open_path(path)?;
+        let bytes = unsafe { into_u8_slice(ids.as_slice()) };
-        let data = Data::Mmap(mmap);
+        let data = SharedData::from_bytes(bytes.to_vec());
-        Ok(DocIds { data })
+        DocIds(data)
     }
 
-    pub fn from_bytes(vec: Vec<u8>) -> Result<Self, Box<Error>> {
+    pub fn from_cursor(cursor: &mut Cursor<SharedData>) -> io::Result<DocIds> {
-        // FIXME check if modulo DocumentId
+        let len = cursor.read_u64::<LittleEndian>()? as usize;
-        let len = vec.len();
+        let offset = cursor.position() as usize;
-        let data = Data::Shared {
+        let doc_ids = cursor.get_ref().range(offset, len);
-            bytes: Arc::new(vec),
+        cursor.consume(len);
-            offset: 0,
+
-            len: len
+        Ok(DocIds(doc_ids))
-        };
-        Ok(DocIds { data })
     }
 
-    pub fn from_document_ids(vec: Vec<DocumentId>) -> Self {
+    pub fn write_to_bytes(&self, bytes: &mut Vec<u8>) {
-        DocIds::from_bytes(unsafe { mem::transmute(vec) }).unwrap()
+        let len = self.0.len() as u64;
+        bytes.write_u64::<LittleEndian>(len).unwrap();
+        bytes.extend_from_slice(&self.0);
     }
 
-    pub fn contains(&self, doc: DocumentId) -> bool {
+    pub fn is_empty(&self) -> bool {
-        // FIXME prefer using the sdset::exponential_search function
+        self.0.is_empty()
-        self.doc_ids().binary_search(&doc).is_ok()
     }
 
-    pub fn doc_ids(&self) -> &Set<DocumentId> {
+    pub fn as_bytes(&self) -> &[u8] {
-        let slice = &self.data;
+        &self.0
+    }
+}
+
+impl AsRef<Set<DocumentId>> for DocIds {
+    fn as_ref(&self) -> &Set<DocumentId> {
+        let slice = &self.0;
         let ptr = slice.as_ptr() as *const DocumentId;
-        let len = slice.len() / mem::size_of::<DocumentId>();
+        let len = slice.len() / size_of::<DocumentId>();
         let slice = unsafe { from_raw_parts(ptr, len) };
         Set::new_unchecked(slice)
     }
 }
-
-impl Serialize for DocIds {
-    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
-        self.data.as_ref().serialize(serializer)
-    }
-}

src/data/doc_indexes.rs

@@ -1,16 +1,15 @@
+use std::io::{self, Write, Cursor, BufRead};
 use std::slice::from_raw_parts;
-use std::io::{self, Write};
 use std::mem::size_of;
 use std::ops::Index;
-use std::path::Path;
 use std::sync::Arc;
 
 use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
-use fst::raw::MmapReadOnly;
 use sdset::Set;
 
 use crate::DocIndex;
-use crate::data::Data;
+use crate::data::SharedData;
+use super::into_u8_slice;
 
 #[derive(Debug)]
 #[repr(C)]
@@ -21,52 +20,45 @@ struct Range {
 
 #[derive(Clone, Default)]
 pub struct DocIndexes {
-    ranges: Data,
+    ranges: SharedData,
-    indexes: Data,
+    indexes: SharedData,
 }
 
 impl DocIndexes {
-    pub unsafe fn from_path<P: AsRef<Path>>(path: P) -> io::Result<Self> {
+    pub fn from_bytes(bytes: Vec<u8>) -> io::Result<DocIndexes> {
-        let mmap = MmapReadOnly::open_path(path)?;
+        let bytes = Arc::new(bytes);
-        DocIndexes::from_data(Data::Mmap(mmap))
+        let len = bytes.len();
+        let data = SharedData::new(bytes, 0, len);
+        let mut  cursor = Cursor::new(data);
+        DocIndexes::from_cursor(&mut cursor)
     }
 
-    pub fn from_bytes(vec: Vec<u8>) -> io::Result<Self> {
+    pub fn from_cursor(cursor: &mut Cursor<SharedData>) -> io::Result<DocIndexes> {
-        let len = vec.len();
+        let len = cursor.read_u64::<LittleEndian>()? as usize;
-        DocIndexes::from_shared_bytes(Arc::new(vec), 0, len)
+        let offset = cursor.position() as usize;
-    }
+        let ranges = cursor.get_ref().range(offset, len);
+        cursor.consume(len);
 
-    pub fn from_shared_bytes(bytes: Arc<Vec<u8>>, offset: usize, len: usize) -> io::Result<Self> {
+        let len = cursor.read_u64::<LittleEndian>()? as usize;
-        let data = Data::Shared { bytes, offset, len };
+        let offset = cursor.position() as usize;
-        DocIndexes::from_data(data)
+        let indexes = cursor.get_ref().range(offset, len);
-    }
+        cursor.consume(len);
-
-    fn from_data(data: Data) -> io::Result<Self> {
-        let ranges_len_offset = data.len() - size_of::<u64>();
-        let ranges_len = (&data[ranges_len_offset..]).read_u64::<LittleEndian>()?;
-        let ranges_len = ranges_len as usize;
-
-        let ranges_offset = ranges_len_offset - ranges_len;
-        let ranges = data.range(ranges_offset, ranges_len);
-
-        let indexes = data.range(0, ranges_offset);
 
         Ok(DocIndexes { ranges, indexes })
     }
 
-    pub fn to_vec(&self) -> Vec<u8> {
+    pub fn write_to_bytes(&self, bytes: &mut Vec<u8>) {
-        let capacity = self.indexes.len() + self.ranges.len() + size_of::<u64>();
+        let ranges_len = self.ranges.len() as u64;
-        let mut bytes = Vec::with_capacity(capacity);
+        let _ = bytes.write_u64::<LittleEndian>(ranges_len);
-
-        bytes.extend_from_slice(&self.indexes);
         bytes.extend_from_slice(&self.ranges);
-        bytes.write_u64::<LittleEndian>(self.ranges.len() as u64).unwrap();
 
-        bytes
+        let indexes_len = self.indexes.len() as u64;
+        let _ = bytes.write_u64::<LittleEndian>(indexes_len);
+        bytes.extend_from_slice(&self.indexes);
     }
 
     pub fn get(&self, index: usize) -> Option<&Set<DocIndex>> {
-        self.ranges().get(index as usize).map(|Range { start, end }| {
+        self.ranges().get(index).map(|Range { start, end }| {
             let start = *start as usize;
             let end = *end as usize;
             let slice = &self.indexes()[start..end];
@@ -102,12 +94,17 @@ impl Index<usize> for DocIndexes {
 
 pub struct DocIndexesBuilder<W> {
     ranges: Vec<Range>,
+    indexes: Vec<DocIndex>,
     wtr: W,
 }
 
 impl DocIndexesBuilder<Vec<u8>> {
     pub fn memory() -> Self {
-        DocIndexesBuilder::new(Vec::new())
+        DocIndexesBuilder {
+            ranges: Vec::new(),
+            indexes: Vec::new(),
+            wtr: Vec::new(),
+        }
     }
 }
 
@@ -115,19 +112,18 @@ impl<W: Write> DocIndexesBuilder<W> {
     pub fn new(wtr: W) -> Self {
         DocIndexesBuilder {
             ranges: Vec::new(),
+            indexes: Vec::new(),
             wtr: wtr,
         }
     }
 
-    pub fn insert(&mut self, indexes: &Set<DocIndex>) -> io::Result<()> {
+    pub fn insert(&mut self, indexes: &Set<DocIndex>) {
         let len = indexes.len() as u64;
         let start = self.ranges.last().map(|r| r.end).unwrap_or(0);
         let range = Range { start, end: start + len };
         self.ranges.push(range);
 
-        // write the values
+        self.indexes.extend_from_slice(indexes);
-        let indexes = unsafe { into_u8_slice(indexes) };
-        self.wtr.write_all(indexes)
     }
 
     pub fn finish(self) -> io::Result<()> {
@@ -135,24 +131,20 @@ impl<W: Write> DocIndexesBuilder<W> {
     }
 
     pub fn into_inner(mut self) -> io::Result<W> {
-        // write the ranges
+        let ranges = unsafe { into_u8_slice(&self.ranges) };
-        let ranges = unsafe { into_u8_slice(self.ranges.as_slice()) };
-        self.wtr.write_all(ranges)?;
-
-        // write the length of the ranges
         let len = ranges.len() as u64;
         self.wtr.write_u64::<LittleEndian>(len)?;
+        self.wtr.write_all(ranges)?;
+
+        let indexes = unsafe { into_u8_slice(&self.indexes) };
+        let len = indexes.len() as u64;
+        self.wtr.write_u64::<LittleEndian>(len)?;
+        self.wtr.write_all(indexes)?;
 
         Ok(self.wtr)
     }
 }
 
-unsafe fn into_u8_slice<T>(slice: &[T]) -> &[u8] {
-    let ptr = slice.as_ptr() as *const u8;
-    let len = slice.len() * size_of::<T>();
-    from_raw_parts(ptr, len)
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -182,9 +174,9 @@ mod tests {
 
         let mut builder = DocIndexesBuilder::memory();
 
-        builder.insert(Set::new(&[a])?)?;
+        builder.insert(Set::new(&[a])?);
-        builder.insert(Set::new(&[a, b, c])?)?;
+        builder.insert(Set::new(&[a, b, c])?);
-        builder.insert(Set::new(&[a, c])?)?;
+        builder.insert(Set::new(&[a, c])?);
 
         let bytes = builder.into_inner()?;
         let docs = DocIndexes::from_bytes(bytes)?;
@@ -217,13 +209,15 @@ mod tests {
 
         let mut builder = DocIndexesBuilder::memory();
 
-        builder.insert(Set::new(&[a])?)?;
+        builder.insert(Set::new(&[a])?);
-        builder.insert(Set::new(&[a, b, c])?)?;
+        builder.insert(Set::new(&[a, b, c])?);
-        builder.insert(Set::new(&[a, c])?)?;
+        builder.insert(Set::new(&[a, c])?);
 
         let builder_bytes = builder.into_inner()?;
         let docs = DocIndexes::from_bytes(builder_bytes.clone())?;
-        let bytes = docs.to_vec();
+
+        let mut bytes = Vec::new();
+        docs.write_to_bytes(&mut bytes);
 
         assert_eq!(builder_bytes, bytes);
 

src/data/mod.rs

@@ -1,51 +1,43 @@
 mod doc_ids;
 mod doc_indexes;
 
+use std::slice::from_raw_parts;
+use std::mem::size_of;
 use std::ops::Deref;
 use std::sync::Arc;
 
-use fst::raw::MmapReadOnly;
-
 pub use self::doc_ids::DocIds;
 pub use self::doc_indexes::{DocIndexes, DocIndexesBuilder};
 
-#[derive(Clone)]
+#[derive(Default, Clone)]
-enum Data {
+pub struct SharedData {
-    Shared {
+    pub bytes: Arc<Vec<u8>>,
-        bytes: Arc<Vec<u8>>,
+    pub offset: usize,
-        offset: usize,
+    pub len: usize,
-        len: usize,
-    },
-    Mmap(MmapReadOnly),
 }
 
-impl Data {
+impl SharedData {
-    pub fn range(&self, off: usize, l: usize) -> Data {
+    pub fn from_bytes(vec: Vec<u8>) -> SharedData {
-        match self {
+        let len = vec.len();
-            Data::Shared { bytes, offset, len } => {
+        let bytes = Arc::new(vec);
-                assert!(off + l <= *len);
+        SharedData::new(bytes, 0, len)
-                Data::Shared {
-                    bytes: bytes.clone(),
-                    offset: offset + off,
-                    len: l,
     }
-            },
+
-            Data::Mmap(mmap) => Data::Mmap(mmap.range(off, l)),
+    pub fn new(bytes: Arc<Vec<u8>>, offset: usize, len: usize) -> SharedData {
+        SharedData { bytes, offset, len }
+    }
+
+    pub fn range(&self, offset: usize, len: usize) -> SharedData {
+        assert!(offset + len <= self.len);
+        SharedData {
+            bytes: self.bytes.clone(),
+            offset: self.offset + offset,
+            len: len,
         }
     }
 }
 
-impl Default for Data {
+impl Deref for SharedData {
-    fn default() -> Data {
-        Data::Shared {
-            bytes: Arc::default(),
-            offset: 0,
-            len: 0,
-        }
-    }
-}
-
-impl Deref for Data {
     type Target = [u8];
 
     fn deref(&self) -> &Self::Target {
@@ -53,13 +45,14 @@ impl Deref for Data {
     }
 }
 
-impl AsRef<[u8]> for Data {
+impl AsRef<[u8]> for SharedData {
     fn as_ref(&self) -> &[u8] {
-        match self {
+        &self.bytes[self.offset..self.offset + self.len]
-            Data::Shared { bytes, offset, len } => {
-                &bytes[*offset..offset + len]
-            },
-            Data::Mmap(m) => m.as_slice(),
-        }
     }
 }
+
+unsafe fn into_u8_slice<T: Sized>(slice: &[T]) -> &[u8] {
+    let ptr = slice.as_ptr() as *const u8;
+    let len = slice.len() * size_of::<T>();
+    from_raw_parts(ptr, len)
+}

src/database/blob/mod.rs

@@ -1,110 +0,0 @@
-mod ops;
-pub mod positive;
-pub mod negative;
-
-pub use self::positive::{PositiveBlob, PositiveBlobBuilder};
-pub use self::negative::NegativeBlob;
-pub use self::ops::OpBuilder;
-
-use std::fmt;
-
-use serde_derive::{Serialize, Deserialize};
-use serde::ser::{Serialize, Serializer, SerializeTuple};
-use serde::de::{self, Deserialize, Deserializer, SeqAccess, Visitor};
-
-#[derive(Debug)]
-pub enum Blob {
-    Positive(PositiveBlob),
-    Negative(NegativeBlob),
-}
-
-impl Blob {
-    pub fn is_negative(&self) -> bool {
-        self.sign() == Sign::Negative
-    }
-
-    pub fn is_positive(&self) -> bool {
-        self.sign() == Sign::Positive
-    }
-
-    pub fn sign(&self) -> Sign {
-        match self {
-            Blob::Positive(_) => Sign::Positive,
-            Blob::Negative(_) => Sign::Negative,
-        }
-    }
-}
-
-impl Serialize for Blob {
-    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
-        match self {
-            Blob::Positive(blob) => {
-                let mut tuple = serializer.serialize_tuple(2)?;
-                tuple.serialize_element(&Sign::Positive)?;
-                tuple.serialize_element(&blob)?;
-                tuple.end()
-            },
-            Blob::Negative(blob) => {
-                let mut tuple = serializer.serialize_tuple(2)?;
-                tuple.serialize_element(&Sign::Negative)?;
-                tuple.serialize_element(&blob)?;
-                tuple.end()
-            },
-        }
-    }
-}
-
-impl<'de> Deserialize<'de> for Blob {
-    fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Blob, D::Error> {
-        struct TupleVisitor;
-
-        impl<'de> Visitor<'de> for TupleVisitor {
-            type Value = Blob;
-
-            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-                formatter.write_str("a Blob struct")
-            }
-
-            #[inline]
-            fn visit_seq<A: SeqAccess<'de>>(self, mut seq: A) -> Result<Self::Value, A::Error> {
-                let sign = match seq.next_element()? {
-                    Some(value) => value,
-                    None => return Err(de::Error::invalid_length(0, &self)),
-                };
-                match sign {
-                    Sign::Positive => {
-                        let blob = match seq.next_element()? {
-                            Some(value) => value,
-                            None => return Err(de::Error::invalid_length(1, &self)),
-                        };
-                        Ok(Blob::Positive(blob))
-                    },
-                    Sign::Negative => {
-                        let blob = match seq.next_element()? {
-                            Some(value) => value,
-                            None => return Err(de::Error::invalid_length(1, &self)),
-                        };
-                        Ok(Blob::Negative(blob))
-                    },
-                }
-            }
-        }
-
-        deserializer.deserialize_tuple(2, TupleVisitor)
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
-pub enum Sign {
-    Positive,
-    Negative,
-}
-
-impl Sign {
-    pub fn invert(self) -> Sign {
-        match self {
-            Sign::Positive => Sign::Negative,
-            Sign::Negative => Sign::Positive,
-        }
-    }
-}

src/database/blob/negative/blob.rs

@@ -1,67 +0,0 @@
-use std::error::Error;
-use std::path::Path;
-use std::fmt;
-
-use sdset::Set;
-use serde::de::{self, Deserialize, Deserializer};
-use serde::ser::{Serialize, Serializer};
-use crate::data::DocIds;
-use crate::DocumentId;
-
-#[derive(Default)]
-pub struct NegativeBlob {
-    doc_ids: DocIds,
-}
-
-impl NegativeBlob {
-    pub unsafe fn from_path<P>(doc_ids: P) -> Result<Self, Box<Error>>
-    where P: AsRef<Path>,
-    {
-        let doc_ids = DocIds::from_path(doc_ids)?;
-        Ok(NegativeBlob { doc_ids })
-    }
-
-    pub fn from_bytes(doc_ids: Vec<u8>) -> Result<Self, Box<Error>> {
-        let doc_ids = DocIds::from_bytes(doc_ids)?;
-        Ok(NegativeBlob { doc_ids })
-    }
-
-    pub fn from_raw(doc_ids: DocIds) -> Self {
-        NegativeBlob { doc_ids }
-    }
-
-    pub fn as_ids(&self) -> &DocIds {
-        &self.doc_ids
-    }
-
-    pub fn into_doc_ids(self) -> DocIds {
-        self.doc_ids
-    }
-}
-
-impl AsRef<Set<DocumentId>> for NegativeBlob {
-    fn as_ref(&self) -> &Set<DocumentId> {
-        self.as_ids().doc_ids()
-    }
-}
-
-impl fmt::Debug for NegativeBlob {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "NegativeBlob(")?;
-        f.debug_list().entries(self.as_ref().as_slice()).finish()?;
-        write!(f, ")")
-    }
-}
-
-impl Serialize for NegativeBlob {
-    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
-        self.doc_ids.serialize(serializer)
-    }
-}
-
-impl<'de> Deserialize<'de> for NegativeBlob {
-    fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<NegativeBlob, D::Error> {
-        let bytes = Vec::deserialize(deserializer)?;
-        NegativeBlob::from_bytes(bytes).map_err(de::Error::custom)
-    }
-}

src/database/blob/negative/mod.rs

@@ -1,5 +0,0 @@
-mod blob;
-mod ops;
-
-pub use self::blob::NegativeBlob;
-pub use self::ops::OpBuilder;

src/database/blob/negative/ops.rs

@@ -1,73 +0,0 @@
-use sdset::multi::OpBuilder as SdOpBuilder;
-use sdset::Set;
-
-use crate::database::blob::NegativeBlob;
-use crate::data::DocIds;
-use crate::DocumentId;
-
-pub struct OpBuilder<'a> {
-    inner: SdOpBuilder<'a, DocumentId>,
-}
-
-/// Do a set operation on multiple negative blobs.
-impl<'a> OpBuilder<'a> {
-    pub fn new() -> Self {
-        Self { inner: SdOpBuilder::new() }
-    }
-
-    pub fn with_capacity(cap: usize) -> Self {
-        Self { inner: SdOpBuilder::with_capacity(cap) }
-    }
-
-    pub fn add(mut self, blob: &'a NegativeBlob) -> Self {
-        self.push(blob);
-        self
-    }
-
-    pub fn push(&mut self, blob: &'a NegativeBlob) {
-        let set = Set::new_unchecked(blob.as_ref());
-        self.inner.push(set);
-    }
-
-    pub fn union(self) -> Union<'a> {
-        Union::new(self.inner.union())
-    }
-
-    pub fn intersection(self) -> Intersection<'a> {
-        Intersection::new(self.inner.intersection())
-    }
-
-    pub fn difference(self) -> Difference<'a> {
-        Difference::new(self.inner.difference())
-    }
-
-    pub fn symmetric_difference(self) -> SymmetricDifference<'a> {
-        SymmetricDifference::new(self.inner.symmetric_difference())
-    }
-}
-
-macro_rules! logical_operation {
-    (struct $name:ident, $operation:ident) => {
-
-pub struct $name<'a> {
-    op: sdset::multi::$name<'a, DocumentId>,
-}
-
-impl<'a> $name<'a> {
-    fn new(op: sdset::multi::$name<'a, DocumentId>) -> Self {
-        $name { op }
-    }
-
-    pub fn into_negative_blob(self) -> NegativeBlob {
-        let document_ids = sdset::SetOperation::into_set_buf(self.op);
-        let doc_ids = DocIds::from_document_ids(document_ids.into_vec());
-        NegativeBlob::from_raw(doc_ids)
-    }
-}
-
-}}
-
-logical_operation!(struct Union, union);
-logical_operation!(struct Intersection, intersection);
-logical_operation!(struct Difference, difference);
-logical_operation!(struct SymmetricDifference, symmetric_difference);

src/database/blob/ops.rs

@@ -1,109 +0,0 @@
-use std::error::Error;
-
-use fst::{IntoStreamer, Streamer};
-use sdset::duo::DifferenceByKey;
-use sdset::{Set, SetOperation};
-use group_by::GroupBy;
-
-use crate::database::blob::{Blob, Sign, PositiveBlob, PositiveBlobBuilder, NegativeBlob};
-use crate::database::blob::{positive, negative};
-
-fn blob_same_sign(a: &Blob, b: &Blob) -> bool {
-    a.sign() == b.sign()
-}
-
-fn unwrap_positive(blob: &Blob) -> &PositiveBlob {
-    match blob {
-        Blob::Positive(blob) => blob,
-        Blob::Negative(_) => panic!("called `unwrap_positive()` on a `Negative` value"),
-    }
-}
-
-fn unwrap_negative(blob: &Blob) -> &NegativeBlob {
-    match blob {
-        Blob::Negative(blob) => blob,
-        Blob::Positive(_) => panic!("called `unwrap_negative()` on a `Positive` value"),
-    }
-}
-
-pub struct OpBuilder {
-    blobs: Vec<Blob>,
-}
-
-impl OpBuilder {
-    pub fn new() -> OpBuilder {
-        OpBuilder { blobs: Vec::new() }
-    }
-
-    pub fn with_capacity(cap: usize) -> OpBuilder {
-        OpBuilder { blobs: Vec::with_capacity(cap) }
-    }
-
-    pub fn push(&mut self, blob: Blob) {
-        if self.blobs.is_empty() && blob.is_negative() { return }
-        self.blobs.push(blob);
-    }
-
-    pub fn merge(self) -> Result<PositiveBlob, Box<Error>> {
-        let groups = GroupBy::new(&self.blobs, blob_same_sign);
-        let mut aggregated = Vec::new();
-
-        for blobs in groups {
-            match blobs[0].sign() {
-                Sign::Positive => {
-                    let mut op_builder = positive::OpBuilder::with_capacity(blobs.len());
-                    for blob in blobs {
-                        op_builder.push(unwrap_positive(blob));
-                    }
-
-                    let mut stream = op_builder.union().into_stream();
-                    let mut builder = PositiveBlobBuilder::memory();
-                    while let Some((input, doc_indexes)) = stream.next() {
-                        // FIXME empty doc_indexes must be handled by OpBuilder
-                        if !doc_indexes.is_empty() {
-                            builder.insert(input, doc_indexes).unwrap();
-                        }
-                    }
-                    let (map, doc_indexes) = builder.into_inner().unwrap();
-                    let blob = PositiveBlob::from_bytes(map, doc_indexes).unwrap();
-                    aggregated.push(Blob::Positive(blob));
-                },
-                Sign::Negative => {
-                    let mut op_builder = negative::OpBuilder::with_capacity(blobs.len());
-                    for blob in blobs {
-                        op_builder.push(unwrap_negative(blob));
-                    }
-                    let blob = op_builder.union().into_negative_blob();
-                    aggregated.push(Blob::Negative(blob));
-                },
-            }
-        }
-
-        let mut buffer = Vec::new();
-        aggregated.chunks(2).try_fold(PositiveBlob::default(), |base, slice| {
-            let negative = NegativeBlob::default();
-            let (positive, negative) = match slice {
-                [a, b] => (unwrap_positive(a), unwrap_negative(b)),
-                [a] => (unwrap_positive(a), &negative),
-                _ => unreachable!(),
-            };
-
-            let mut builder = PositiveBlobBuilder::memory();
-
-            let op_builder = positive::OpBuilder::new().add(&base).add(&positive);
-            let mut stream = op_builder.union().into_stream();
-            while let Some((input, doc_indexes)) = stream.next() {
-                let op = DifferenceByKey::new(doc_indexes, negative.as_ref(), |x| x.document_id, |x| *x);
-
-                buffer.clear();
-                op.extend_vec(&mut buffer);
-                if !buffer.is_empty() {
-                    builder.insert(input, Set::new_unchecked(&buffer))?;
-                }
-            }
-
-            let (map, doc_indexes) = builder.into_inner()?;
-            PositiveBlob::from_bytes(map, doc_indexes)
-        })
-    }
-}

src/database/blob/positive/blob.rs

@@ -1,282 +0,0 @@
-use std::fmt;
-use std::io::Write;
-use std::path::Path;
-use std::error::Error;
-
-use fst::{map, Map, Streamer, IntoStreamer};
-use sdset::Set;
-
-use crate::DocIndex;
-use crate::data::{DocIndexes, DocIndexesBuilder};
-use serde::ser::{Serialize, Serializer, SerializeTuple};
-use serde::de::{self, Deserialize, Deserializer, SeqAccess, Visitor};
-
-#[derive(Default)]
-pub struct PositiveBlob {
-    map: Map,
-    indexes: DocIndexes,
-}
-
-impl PositiveBlob {
-    pub unsafe fn from_paths<P, Q>(map: P, indexes: Q) -> Result<Self, Box<Error>>
-    where P: AsRef<Path>,
-          Q: AsRef<Path>,
-    {
-        let map = Map::from_path(map)?;
-        let indexes = DocIndexes::from_path(indexes)?;
-        Ok(PositiveBlob { map, indexes })
-    }
-
-    pub fn from_bytes(map: Vec<u8>, indexes: Vec<u8>) -> Result<Self, Box<Error>> {
-        let map = Map::from_bytes(map)?;
-        let indexes = DocIndexes::from_bytes(indexes)?;
-        Ok(PositiveBlob { map, indexes })
-    }
-
-    pub fn from_raw(map: Map, indexes: DocIndexes) -> Self {
-        PositiveBlob { map, indexes }
-    }
-
-    pub fn get<K: AsRef<[u8]>>(&self, key: K) -> Option<&[DocIndex]> {
-        self.map.get(key).map(|index| &self.indexes[index as usize])
-    }
-
-    pub fn as_map(&self) -> &Map {
-        &self.map
-    }
-
-    pub fn as_indexes(&self) -> &DocIndexes {
-        &self.indexes
-    }
-
-    pub fn explode(self) -> (Map, DocIndexes) {
-        (self.map, self.indexes)
-    }
-}
-
-impl fmt::Debug for PositiveBlob {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "PositiveBlob([")?;
-        let mut stream = self.into_stream();
-        let mut first = true;
-        while let Some((k, v)) = stream.next() {
-            if !first {
-                write!(f, ", ")?;
-            }
-            first = false;
-            write!(f, "({}, {:?})", String::from_utf8_lossy(k), v)?;
-        }
-        write!(f, "])")
-    }
-}
-
-impl<'m, 'a> IntoStreamer<'a> for &'m PositiveBlob {
-    type Item = (&'a [u8], &'a [DocIndex]);
-    /// The type of the stream to be constructed.
-    type Into = PositiveBlobStream<'m>;
-
-    /// Construct a stream from `Self`.
-    fn into_stream(self) -> Self::Into {
-        PositiveBlobStream {
-            map_stream: self.map.into_stream(),
-            doc_indexes: &self.indexes,
-        }
-    }
-}
-
-pub struct PositiveBlobStream<'m> {
-    map_stream: map::Stream<'m>,
-    doc_indexes: &'m DocIndexes,
-}
-
-impl<'m, 'a> Streamer<'a> for PositiveBlobStream<'m> {
-    type Item = (&'a [u8], &'a [DocIndex]);
-
-    fn next(&'a mut self) -> Option<Self::Item> {
-        match self.map_stream.next() {
-            Some((input, index)) => {
-                let doc_indexes = &self.doc_indexes[index as usize];
-                Some((input, doc_indexes))
-            },
-            None => None,
-        }
-    }
-}
-
-impl Serialize for PositiveBlob {
-    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
-        let mut tuple = serializer.serialize_tuple(2)?;
-        tuple.serialize_element(&self.map.as_fst().to_vec())?;
-        tuple.serialize_element(&self.indexes.to_vec())?;
-        tuple.end()
-    }
-}
-
-impl<'de> Deserialize<'de> for PositiveBlob {
-    fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<PositiveBlob, D::Error> {
-        struct TupleVisitor;
-
-        impl<'de> Visitor<'de> for TupleVisitor {
-            type Value = PositiveBlob;
-
-            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-                formatter.write_str("a PositiveBlob struct")
-            }
-
-            #[inline]
-            fn visit_seq<A: SeqAccess<'de>>(self, mut seq: A) -> Result<Self::Value, A::Error> {
-                let map = match seq.next_element()? {
-                    Some(bytes) => match Map::from_bytes(bytes) {
-                        Ok(value) => value,
-                        Err(err) => return Err(de::Error::custom(err)),
-                    },
-                    None => return Err(de::Error::invalid_length(0, &self)),
-                };
-
-                let indexes = match seq.next_element()? {
-                    Some(bytes) => match DocIndexes::from_bytes(bytes) {
-                        Ok(value) => value,
-                        Err(err) => return Err(de::Error::custom(err)),
-                    },
-                    None => return Err(de::Error::invalid_length(1, &self)),
-                };
-
-                Ok(PositiveBlob { map, indexes })
-            }
-        }
-
-        deserializer.deserialize_tuple(2, TupleVisitor)
-    }
-}
-
-pub struct PositiveBlobBuilder<W, X> {
-    map: fst::MapBuilder<W>,
-    indexes: DocIndexesBuilder<X>,
-    value: u64,
-}
-
-impl PositiveBlobBuilder<Vec<u8>, Vec<u8>> {
-    pub fn memory() -> Self {
-        PositiveBlobBuilder {
-            map: fst::MapBuilder::memory(),
-            indexes: DocIndexesBuilder::memory(),
-            value: 0,
-        }
-    }
-}
-
-impl<W: Write, X: Write> PositiveBlobBuilder<W, X> {
-    pub fn new(map: W, indexes: X) -> Result<Self, Box<Error>> {
-        Ok(PositiveBlobBuilder {
-            map: fst::MapBuilder::new(map)?,
-            indexes: DocIndexesBuilder::new(indexes),
-            value: 0,
-        })
-    }
-
-    /// If a key is inserted that is less than or equal to any previous key added,
-    /// then an error is returned. Similarly, if there was a problem writing
-    /// to the underlying writer, an error is returned.
-    // FIXME what if one write doesn't work but the other do ?
-    pub fn insert<K>(&mut self, key: K, doc_indexes: &Set<DocIndex>) -> Result<(), Box<Error>>
-    where K: AsRef<[u8]>,
-    {
-        self.map.insert(key, self.value)?;
-        self.indexes.insert(doc_indexes)?;
-        self.value += 1;
-        Ok(())
-    }
-
-    pub fn finish(self) -> Result<(), Box<Error>> {
-        self.into_inner().map(drop)
-    }
-
-    pub fn into_inner(self) -> Result<(W, X), Box<Error>> {
-        let map = self.map.into_inner()?;
-        let indexes = self.indexes.into_inner()?;
-        Ok((map, indexes))
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    use std::error::Error;
-    use crate::{Attribute, WordArea};
-
-    use crate::DocumentId;
-
-    #[test]
-    fn serialize_deserialize() -> Result<(), Box<Error>> {
-        let a = DocIndex {
-            document_id: DocumentId(0),
-            attribute: Attribute::new_faillible(3, 11),
-            word_area: WordArea::new_faillible(30, 4)
-        };
-        let b = DocIndex {
-            document_id: DocumentId(1),
-            attribute: Attribute::new_faillible(4, 21),
-            word_area: WordArea::new_faillible(35, 6)
-        };
-        let c = DocIndex {
-            document_id: DocumentId(2),
-            attribute: Attribute::new_faillible(8, 2),
-            word_area: WordArea::new_faillible(89, 6)
-        };
-
-        let mut builder = PositiveBlobBuilder::memory();
-
-        builder.insert("aaa", Set::new(&[a])?)?;
-        builder.insert("aab", Set::new(&[a, b, c])?)?;
-        builder.insert("aac", Set::new(&[a, c])?)?;
-
-        let (map_bytes, indexes_bytes) = builder.into_inner()?;
-        let positive_blob = PositiveBlob::from_bytes(map_bytes, indexes_bytes)?;
-
-        assert_eq!(positive_blob.get("aaa"), Some(&[a][..]));
-        assert_eq!(positive_blob.get("aab"), Some(&[a, b, c][..]));
-        assert_eq!(positive_blob.get("aac"), Some(&[a, c][..]));
-        assert_eq!(positive_blob.get("aad"), None);
-
-        Ok(())
-    }
-
-    #[test]
-    fn serde_serialize_deserialize() -> Result<(), Box<Error>> {
-        let a = DocIndex {
-            document_id: DocumentId(0),
-            attribute: Attribute::new_faillible(3, 11),
-            word_area: WordArea::new_faillible(30, 4)
-        };
-        let b = DocIndex {
-            document_id: DocumentId(1),
-            attribute: Attribute::new_faillible(4, 21),
-            word_area: WordArea::new_faillible(35, 6)
-        };
-        let c = DocIndex {
-            document_id: DocumentId(2),
-            attribute: Attribute::new_faillible(8, 2),
-            word_area: WordArea::new_faillible(89, 6)
-        };
-
-        let mut builder = PositiveBlobBuilder::memory();
-
-        builder.insert("aaa", Set::new(&[a])?)?;
-        builder.insert("aab", Set::new(&[a, b, c])?)?;
-        builder.insert("aac", Set::new(&[a, c])?)?;
-
-        let (map_bytes, indexes_bytes) = builder.into_inner()?;
-        let positive_blob = PositiveBlob::from_bytes(map_bytes, indexes_bytes)?;
-
-        let bytes = bincode::serialize(&positive_blob)?;
-        let positive_blob: PositiveBlob = bincode::deserialize(&bytes)?;
-
-        assert_eq!(positive_blob.get("aaa"), Some(&[a][..]));
-        assert_eq!(positive_blob.get("aab"), Some(&[a, b, c][..]));
-        assert_eq!(positive_blob.get("aac"), Some(&[a, c][..]));
-        assert_eq!(positive_blob.get("aad"), None);
-
-        Ok(())
-    }
-}

src/database/blob/positive/mod.rs

@@ -1,5 +0,0 @@
-mod blob;
-mod ops;
-
-pub use self::blob::{PositiveBlob, PositiveBlobBuilder};
-pub use self::ops::OpBuilder;

src/database/blob/positive/ops.rs

@@ -1,128 +0,0 @@
-use sdset::multi::OpBuilder as SdOpBuilder;
-use sdset::{SetOperation, Set};
-
-use crate::database::blob::PositiveBlob;
-use crate::data::DocIndexes;
-use crate::DocIndex;
-
-pub struct OpBuilder<'m> {
-    // the operation on the maps is always an union.
-    map_op: fst::map::OpBuilder<'m>,
-    indexes: Vec<&'m DocIndexes>,
-}
-
-/// Do a set operation on multiple positive blobs.
-impl<'m> OpBuilder<'m> {
-    pub fn new() -> Self {
-        Self {
-            map_op: fst::map::OpBuilder::new(),
-            indexes: Vec::new(),
-        }
-    }
-
-    pub fn with_capacity(cap: usize) -> Self {
-        Self {
-            map_op: fst::map::OpBuilder::new(), // TODO patch fst to add with_capacity
-            indexes: Vec::with_capacity(cap),
-        }
-    }
-
-    pub fn add(mut self, blob: &'m PositiveBlob) -> Self {
-        self.push(blob);
-        self
-    }
-
-    pub fn push(&mut self, blob: &'m PositiveBlob) {
-        self.map_op.push(blob.as_map());
-        self.indexes.push(blob.as_indexes());
-    }
-
-    pub fn union(self) -> Union<'m> {
-        Union::new(self.map_op.union(), self.indexes)
-    }
-
-    pub fn intersection(self) -> Intersection<'m> {
-        Intersection::new(self.map_op.union(), self.indexes)
-    }
-
-    pub fn difference(self) -> Difference<'m> {
-        Difference::new(self.map_op.union(), self.indexes)
-    }
-
-    pub fn symmetric_difference(self) -> SymmetricDifference<'m> {
-        SymmetricDifference::new(self.map_op.union(), self.indexes)
-    }
-}
-
-macro_rules! logical_operation {
-    (struct $name:ident, $operation:ident) => {
-
-pub struct $name<'m> {
-    stream: fst::map::Union<'m>,
-    indexes: Vec<&'m DocIndexes>,
-    outs: Vec<DocIndex>,
-}
-
-impl<'m> $name<'m> {
-    fn new(stream: fst::map::Union<'m>, indexes: Vec<&'m DocIndexes>) -> Self {
-        $name {
-            stream: stream,
-            indexes: indexes,
-            outs: Vec::new(),
-        }
-    }
-}
-
-impl<'m, 'a> fst::Streamer<'a> for $name<'m> {
-    type Item = (&'a [u8], &'a Set<DocIndex>);
-
-    fn next(&'a mut self) -> Option<Self::Item> {
-        // loop {
-        //     let (input, ivalues) = match self.stream.next() {
-        //         Some(value) => value,
-        //         None => return None,
-        //     };
-
-        //     self.outs.clear();
-
-        //     let mut builder = SdOpBuilder::with_capacity(ivalues.len());
-        //     for ivalue in ivalues {
-        //         let indexes = self.indexes[ivalue.index];
-        //         let indexes = indexes.get(ivalue.value).expect("BUG: could not find document indexes");
-        //         let set = Set::new_unchecked(indexes);
-        //         builder.push(set);
-        //     }
-
-        //     builder.$operation().extend_vec(&mut self.outs);
-
-        //     if self.outs.is_empty() { continue }
-        //     return Some((input, &self.outs))
-        // }
-
-        // FIXME make the above code compile
-        match self.stream.next() {
-            Some((input, ivalues)) => {
-                self.outs.clear();
-
-                let mut builder = SdOpBuilder::with_capacity(ivalues.len());
-                for ivalue in ivalues {
-                    let doc_indexes = &self.indexes[ivalue.index][ivalue.value as usize];
-                    let set = Set::new_unchecked(doc_indexes);
-                    builder.push(set);
-                }
-
-                builder.$operation().extend_vec(&mut self.outs);
-
-                if self.outs.is_empty() { return None }
-                return Some((input, Set::new_unchecked(&self.outs)))
-            },
-            None => None
-        }
-    }
-}
-}}
-
-logical_operation!(struct Union, union);
-logical_operation!(struct Intersection, intersection);
-logical_operation!(struct Difference, difference);
-logical_operation!(struct SymmetricDifference, symmetric_difference);

src/database/database.rs

@@ -7,9 +7,9 @@ use rocksdb::rocksdb::{Writable, Snapshot};
 use rocksdb::{DB, DBVector, MergeOperands};
 use crossbeam::atomic::ArcCell;
 
+use crate::database::index::Index;
 use crate::database::{DatabaseView, Update, Schema};
 use crate::database::{DATA_INDEX, DATA_SCHEMA};
-use crate::database::blob::{self, Blob};
 
 pub struct Database {
     // DB is under a Mutex to sync update ingestions and separate DB update locking
@@ -85,12 +85,9 @@ impl Database {
                 Err(e) => return Err(e.to_string().into()),
             };
 
-            let move_update = update.can_be_moved();
+            let path = update.path().to_string_lossy();
-            let path = update.into_path_buf();
+            let options = IngestExternalFileOptions::new();
-            let path = path.to_string_lossy();
+            // options.move_files(move_update);
-
-            let mut options = IngestExternalFileOptions::new();
-            options.move_files(move_update);
 
             let cf_handle = db.cf_handle("default").expect("\"default\" column family not found");
             db.ingest_external_file_optimized(&cf_handle, &options, &[&path])?;
@@ -124,30 +121,29 @@ impl Database {
     }
 }
 
-fn merge_indexes(key: &[u8], existing_value: Option<&[u8]>, operands: &mut MergeOperands) -> Vec<u8> {
+fn merge_indexes(key: &[u8], existing: Option<&[u8]>, operands: &mut MergeOperands) -> Vec<u8> {
-    if key != DATA_INDEX {
+    assert_eq!(key, DATA_INDEX, "The merge operator only supports \"data-index\" merging");
-        panic!("The merge operator only supports \"data-index\" merging")
-    }
 
-    let capacity = {
+    let mut index: Option<Index> = None;
-        let remaining = operands.size_hint().0;
+
-        let already_exist = usize::from(existing_value.is_some());
+    for bytes in existing.into_iter().chain(operands) {
-        remaining + already_exist
+        let bytes_len = bytes.len();
+        let bytes = Arc::new(bytes.to_vec());
+        let operand = Index::from_shared_bytes(bytes, 0, bytes_len);
+        let operand = operand.expect("BUG: could not deserialize index");
+
+        let merged = match index {
+            Some(ref index) => index.merge(&operand).expect("BUG: could not merge index"),
+            None            => operand,
         };
 
-    let mut op = blob::OpBuilder::with_capacity(capacity);
+        index.replace(merged);
-    if let Some(existing_value) = existing_value {
-        let blob = bincode::deserialize(existing_value).expect("BUG: could not deserialize data-index");
-        op.push(Blob::Positive(blob));
     }
 
-    for bytes in operands {
+    let index = index.unwrap_or_default();
-        let blob = bincode::deserialize(bytes).expect("BUG: could not deserialize blob");
+    let mut bytes = Vec::new();
-        op.push(blob);
+    index.write_to_bytes(&mut bytes);
-    }
+    bytes
-
-    let blob = op.merge().expect("BUG: could not merge blobs");
-    bincode::serialize(&blob).expect("BUG: could not serialize merged blob")
 }
 
 #[cfg(test)]
@@ -158,12 +154,12 @@ mod tests {
     use serde_derive::{Serialize, Deserialize};
     use tempfile::tempdir;
 
-    use crate::tokenizer::DefaultBuilder;
-    use crate::database::update::PositiveUpdateBuilder;
     use crate::database::schema::{SchemaBuilder, STORED, INDEXED};
+    use crate::database::update::UpdateBuilder;
+    use crate::tokenizer::DefaultBuilder;
 
     #[test]
-    fn ingest_update_file() -> Result<(), Box<Error>> {
+    fn ingest_one_update_file() -> Result<(), Box<Error>> {
         let dir = tempdir()?;
 
         let rocksdb_path = dir.path().join("rocksdb.rdb");
@@ -186,7 +182,6 @@ mod tests {
         };
 
         let database = Database::create(&rocksdb_path, schema.clone())?;
-        let tokenizer_builder = DefaultBuilder::new();
 
         let update_path = dir.path().join("update.sst");
 
@@ -205,16 +200,16 @@ mod tests {
 
         let docid0;
         let docid1;
-        let mut update = {
+        let update = {
-            let mut builder = PositiveUpdateBuilder::new(update_path, schema, tokenizer_builder);
+            let tokenizer_builder = DefaultBuilder::new();
+            let mut builder = UpdateBuilder::new(update_path, schema);
 
-            docid0 = builder.update(&doc0).unwrap();
+            docid0 = builder.update_document(&doc0, &tokenizer_builder)?;
-            docid1 = builder.update(&doc1).unwrap();
+            docid1 = builder.update_document(&doc1, &tokenizer_builder)?;
 
             builder.build()?
         };
 
-        update.set_move(true);
         database.ingest_update_file(update)?;
         let view = database.view();
 
@@ -226,4 +221,100 @@ mod tests {
 
         Ok(dir.close()?)
     }
+
+    #[test]
+    fn ingest_two_update_files() -> Result<(), Box<Error>> {
+        let dir = tempdir()?;
+
+        let rocksdb_path = dir.path().join("rocksdb.rdb");
+
+        #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
+        struct SimpleDoc {
+            id: u64,
+            title: String,
+            description: String,
+            timestamp: u64,
+        }
+
+        let schema = {
+            let mut builder = SchemaBuilder::with_identifier("id");
+            builder.new_attribute("id", STORED);
+            builder.new_attribute("title", STORED | INDEXED);
+            builder.new_attribute("description", STORED | INDEXED);
+            builder.new_attribute("timestamp", STORED);
+            builder.build()
+        };
+
+        let database = Database::create(&rocksdb_path, schema.clone())?;
+
+        let doc0 = SimpleDoc {
+            id: 0,
+            title: String::from("I am a title"),
+            description: String::from("I am a description"),
+            timestamp: 1234567,
+        };
+        let doc1 = SimpleDoc {
+            id: 1,
+            title: String::from("I am the second title"),
+            description: String::from("I am the second description"),
+            timestamp: 7654321,
+        };
+        let doc2 = SimpleDoc {
+            id: 2,
+            title: String::from("I am the third title"),
+            description: String::from("I am the third description"),
+            timestamp: 7654321,
+        };
+        let doc3 = SimpleDoc {
+            id: 3,
+            title: String::from("I am the fourth title"),
+            description: String::from("I am the fourth description"),
+            timestamp: 7654321,
+        };
+
+        let docid0;
+        let docid1;
+        let update1 = {
+            let tokenizer_builder = DefaultBuilder::new();
+            let update_path = dir.path().join("update-000.sst");
+            let mut builder = UpdateBuilder::new(update_path, schema.clone());
+
+            docid0 = builder.update_document(&doc0, &tokenizer_builder)?;
+            docid1 = builder.update_document(&doc1, &tokenizer_builder)?;
+
+            builder.build()?
+        };
+
+        let docid2;
+        let docid3;
+        let update2 = {
+            let tokenizer_builder = DefaultBuilder::new();
+            let update_path = dir.path().join("update-001.sst");
+            let mut builder = UpdateBuilder::new(update_path, schema);
+
+            docid2 = builder.update_document(&doc2, &tokenizer_builder)?;
+            docid3 = builder.update_document(&doc3, &tokenizer_builder)?;
+
+            builder.build()?
+        };
+
+        database.ingest_update_file(update1)?;
+        database.ingest_update_file(update2)?;
+
+        let view = database.view();
+
+        let de_doc0: SimpleDoc = view.document_by_id(docid0)?;
+        let de_doc1: SimpleDoc = view.document_by_id(docid1)?;
+
+        assert_eq!(doc0, de_doc0);
+        assert_eq!(doc1, de_doc1);
+
+        let de_doc2: SimpleDoc = view.document_by_id(docid2)?;
+        let de_doc3: SimpleDoc = view.document_by_id(docid3)?;
+
+        assert_eq!(doc2, de_doc2);
+        assert_eq!(doc3, de_doc3);
+
+        Ok(dir.close()?)
+    }
 }

src/database/database_view.rs

@@ -9,9 +9,9 @@ use serde::de::DeserializeOwned;
 
 use crate::database::{DocumentKey, DocumentKeyAttr};
 use crate::database::{retrieve_data_schema, retrieve_data_index};
-use crate::database::blob::positive::PositiveBlob;
 use crate::database::deserializer::Deserializer;
 use crate::database::schema::Schema;
+use crate::database::index::Index;
 use crate::rank::{QueryBuilder, FilterFunc};
 use crate::DocumentId;
 
@@ -19,7 +19,7 @@ pub struct DatabaseView<D>
 where D: Deref<Target=DB>
 {
     snapshot: Snapshot<D>,
-    blob: PositiveBlob,
+    index: Index,
     schema: Schema,
 }
 
@@ -28,16 +28,16 @@ where D: Deref<Target=DB>
 {
     pub fn new(snapshot: Snapshot<D>) -> Result<DatabaseView<D>, Box<Error>> {
         let schema = retrieve_data_schema(&snapshot)?;
-        let blob = retrieve_data_index(&snapshot)?;
+        let index = retrieve_data_index(&snapshot)?;
-        Ok(DatabaseView { snapshot, blob, schema })
+        Ok(DatabaseView { snapshot, index, schema })
     }
 
     pub fn schema(&self) -> &Schema {
         &self.schema
     }
 
-    pub fn blob(&self) -> &PositiveBlob {
+    pub fn index(&self) -> &Index {
-        &self.blob
+        &self.index
     }
 
     pub fn into_snapshot(self) -> Snapshot<D> {

src/database/index/mod.rs

@@ -0,0 +1,82 @@
+mod negative;
+mod positive;
+
+pub(crate) use self::negative::Negative;
+pub(crate) use self::positive::{Positive, PositiveBuilder};
+
+use std::error::Error;
+use std::io::Cursor;
+use std::sync::Arc;
+
+use fst::{IntoStreamer, Streamer};
+use sdset::duo::DifferenceByKey;
+use sdset::{Set, SetOperation};
+use fst::Map;
+
+use crate::data::{SharedData, DocIndexes};
+
+#[derive(Default)]
+pub struct Index {
+    pub(crate) negative: Negative,
+    pub(crate) positive: Positive,
+}
+
+impl Index {
+    pub fn from_bytes(bytes: Vec<u8>) -> Result<Index, Box<Error>> {
+        let len = bytes.len();
+        Index::from_shared_bytes(Arc::new(bytes), 0, len)
+    }
+
+    pub fn from_shared_bytes(
+        bytes: Arc<Vec<u8>>,
+        offset: usize,
+        len: usize,
+    ) -> Result<Index, Box<Error>>
+    {
+        let data = SharedData::new(bytes, offset, len);
+        let mut cursor = Cursor::new(data);
+
+        let negative = Negative::from_cursor(&mut cursor)?;
+        let positive = Positive::from_cursor(&mut cursor)?;
+        Ok(Index { negative, positive })
+    }
+
+    pub fn write_to_bytes(&self, bytes: &mut Vec<u8>) {
+        self.negative.write_to_bytes(bytes);
+        self.positive.write_to_bytes(bytes);
+    }
+
+    pub fn merge(&self, other: &Index) -> Result<Index, Box<Error>> {
+        if other.negative.is_empty() {
+            let negative = Negative::default();
+            let positive = self.positive.union(&other.positive)?;
+            return Ok(Index { negative, positive })
+        }
+
+        let mut buffer = Vec::new();
+        let mut builder = PositiveBuilder::memory();
+        let mut stream = self.positive.into_stream();
+        while let Some((key, indexes)) = stream.next() {
+            let op = DifferenceByKey::new(indexes, &other.negative, |x| x.document_id, |x| *x);
+
+            buffer.clear();
+            op.extend_vec(&mut buffer);
+
+            if !buffer.is_empty() {
+                let indexes = Set::new_unchecked(&buffer);
+                builder.insert(key, indexes)?;
+            }
+        }
+
+        let positive = {
+            let (map, indexes) = builder.into_inner()?;
+            let map = Map::from_bytes(map)?;
+            let indexes = DocIndexes::from_bytes(indexes)?;
+            Positive::new(map, indexes)
+        };
+
+        let negative = Negative::default();
+        let positive = positive.union(&other.positive)?;
+        Ok(Index { negative, positive })
+    }
+}

src/database/index/negative.rs

@@ -0,0 +1,43 @@
+use std::error::Error;
+use std::io::Cursor;
+use std::ops::Deref;
+
+use sdset::Set;
+use byteorder::{LittleEndian, WriteBytesExt};
+
+use crate::data::SharedData;
+use crate::data::DocIds;
+use crate::DocumentId;
+
+#[derive(Default)]
+pub struct Negative(DocIds);
+
+impl Negative {
+    pub fn new(doc_ids: DocIds) -> Negative {
+        Negative(doc_ids)
+    }
+
+    pub fn from_cursor(cursor: &mut Cursor<SharedData>) -> Result<Negative, Box<Error>> {
+        let doc_ids = DocIds::from_cursor(cursor)?;
+        Ok(Negative(doc_ids))
+    }
+
+    pub fn write_to_bytes(&self, bytes: &mut Vec<u8>) {
+        let slice = self.0.as_bytes();
+        let len = slice.len() as u64;
+        let _ = bytes.write_u64::<LittleEndian>(len);
+        bytes.extend_from_slice(slice);
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+}
+
+impl Deref for Negative {
+    type Target = Set<DocumentId>;
+
+    fn deref(&self) -> &Self::Target {
+        self.0.as_ref()
+    }
+}

src/database/index/positive.rs

@@ -0,0 +1,166 @@
+use std::io::{Write, BufRead, Cursor};
+use std::error::Error;
+
+use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
+use fst::{map, Map, Streamer, IntoStreamer};
+use sdset::{Set, SetOperation};
+use sdset::duo::Union;
+use fst::raw::Fst;
+
+use crate::data::{DocIndexes, DocIndexesBuilder};
+use crate::data::SharedData;
+use crate::DocIndex;
+
+#[derive(Default)]
+pub struct Positive {
+    map: Map,
+    indexes: DocIndexes,
+}
+
+impl Positive {
+    pub fn new(map: Map, indexes: DocIndexes) -> Positive {
+        Positive { map, indexes }
+    }
+
+    pub fn from_cursor(cursor: &mut Cursor<SharedData>) -> Result<Positive, Box<Error>> {
+        let len = cursor.read_u64::<LittleEndian>()? as usize;
+        let offset = cursor.position() as usize;
+        let data = cursor.get_ref().range(offset, len);
+
+        let fst = Fst::from_shared_bytes(data.bytes, data.offset, data.len)?;
+        let map = Map::from(fst);
+        cursor.consume(len);
+
+        let indexes = DocIndexes::from_cursor(cursor)?;
+
+        Ok(Positive { map, indexes})
+    }
+
+    pub fn write_to_bytes(&self, bytes: &mut Vec<u8>) {
+        let slice = self.map.as_fst().as_bytes();
+        let len = slice.len() as u64;
+        let _ = bytes.write_u64::<LittleEndian>(len);
+        bytes.extend_from_slice(slice);
+
+        self.indexes.write_to_bytes(bytes);
+    }
+
+    pub fn map(&self) -> &Map {
+        &self.map
+    }
+
+    pub fn indexes(&self) -> &DocIndexes {
+        &self.indexes
+    }
+
+    pub fn union(&self, other: &Positive) -> Result<Positive, Box<Error>> {
+        let mut builder = PositiveBuilder::memory();
+        let mut stream = map::OpBuilder::new().add(&self.map).add(&other.map).union();
+
+        let mut buffer = Vec::new();
+        while let Some((key, ivalues)) = stream.next() {
+            buffer.clear();
+            match ivalues {
+                [a, b] => {
+                    let indexes = if a.index == 0 { &self.indexes } else { &other.indexes };
+                    let indexes = indexes.get(a.value as usize).ok_or(format!("index not found"))?;
+                    let a = Set::new_unchecked(indexes);
+
+                    let indexes = if b.index == 0 { &self.indexes } else { &other.indexes };
+                    let indexes = indexes.get(b.value as usize).ok_or(format!("index not found"))?;
+                    let b = Set::new_unchecked(indexes);
+
+                    let op = Union::new(a, b);
+                    op.extend_vec(&mut buffer);
+                },
+                [a] => {
+                    let indexes = if a.index == 0 { &self.indexes } else { &other.indexes };
+                    let indexes = indexes.get(a.value as usize).ok_or(format!("index not found"))?;
+                    buffer.extend_from_slice(indexes)
+                },
+                _ => continue,
+            }
+
+            if !buffer.is_empty() {
+                let indexes = Set::new_unchecked(&buffer);
+                builder.insert(key, indexes)?;
+            }
+        }
+
+        let (map, indexes) = builder.into_inner()?;
+        let map = Map::from_bytes(map)?;
+        let indexes = DocIndexes::from_bytes(indexes)?;
+        Ok(Positive { map, indexes })
+    }
+}
+
+impl<'m, 'a> IntoStreamer<'a> for &'m Positive {
+    type Item = (&'a [u8], &'a Set<DocIndex>);
+    /// The type of the stream to be constructed.
+    type Into = Stream<'m>;
+
+    /// Construct a stream from `Self`.
+    fn into_stream(self) -> Self::Into {
+        Stream {
+            map_stream: self.map.into_stream(),
+            indexes: &self.indexes,
+        }
+    }
+}
+
+pub struct Stream<'m> {
+    map_stream: map::Stream<'m>,
+    indexes: &'m DocIndexes,
+}
+
+impl<'m, 'a> Streamer<'a> for Stream<'m> {
+    type Item = (&'a [u8], &'a Set<DocIndex>);
+
+    fn next(&'a mut self) -> Option<Self::Item> {
+        match self.map_stream.next() {
+            Some((input, index)) => {
+                let indexes = &self.indexes[index as usize];
+                let indexes = Set::new_unchecked(indexes);
+                Some((input, indexes))
+            },
+            None => None,
+        }
+    }
+}
+
+pub struct PositiveBuilder<W, X> {
+    map: fst::MapBuilder<W>,
+    indexes: DocIndexesBuilder<X>,
+    value: u64,
+}
+
+impl PositiveBuilder<Vec<u8>, Vec<u8>> {
+    pub fn memory() -> Self {
+        PositiveBuilder {
+            map: fst::MapBuilder::memory(),
+            indexes: DocIndexesBuilder::memory(),
+            value: 0,
+        }
+    }
+}
+
+impl<W: Write, X: Write> PositiveBuilder<W, X> {
+    /// If a key is inserted that is less than or equal to any previous key added,
+    /// then an error is returned. Similarly, if there was a problem writing
+    /// to the underlying writer, an error is returned.
+    // FIXME what if one write doesn't work but the other do ?
+    pub fn insert<K>(&mut self, key: K, indexes: &Set<DocIndex>) -> Result<(), Box<Error>>
+    where K: AsRef<[u8]>,
+    {
+        self.map.insert(key, self.value)?;
+        self.indexes.insert(indexes);
+        self.value += 1;
+        Ok(())
+    }
+
+    pub fn into_inner(self) -> Result<(W, X), Box<Error>> {
+        let map = self.map.into_inner()?;
+        let indexes = self.indexes.into_inner()?;
+        Ok((map, indexes))
+    }
+}

src/database/mod.rs

@@ -1,47 +1,29 @@
-use std::collections::hash_map::DefaultHasher;
-use std::hash::{Hash, Hasher};
 use std::error::Error;
 use std::ops::Deref;
+use std::sync::Arc;
 
 use rocksdb::rocksdb::{DB, Snapshot};
 
-pub use self::update::{
-    Update, PositiveUpdateBuilder, NewState,
-    SerializerError, NegativeUpdateBuilder
-};
 pub use self::document_key::{DocumentKey, DocumentKeyAttr};
 pub use self::database_view::{DatabaseView, DocumentIter};
+pub use self::update::{Update, UpdateBuilder};
+pub use self::serde::SerializerError;
 pub use self::database::Database;
 pub use self::schema::Schema;
-use self::blob::positive::PositiveBlob;
+pub use self::index::Index;
 
 const DATA_INDEX:  &[u8] = b"data-index";
 const DATA_SCHEMA: &[u8] = b"data-schema";
 
-macro_rules! forward_to_unserializable_type {
-    ($($ty:ident => $se_method:ident,)*) => {
-        $(
-            fn $se_method(self, _v: $ty) -> Result<Self::Ok, Self::Error> {
-                Err(SerializerError::UnserializableType { name: "$ty" })
-            }
-        )*
-    }
-}
-
-pub mod blob;
 pub mod schema;
+pub(crate) mod index;
 mod update;
+mod serde;
 mod database;
 mod document_key;
 mod database_view;
 mod deserializer;
 
-fn calculate_hash<T: Hash>(t: &T) -> u64 {
-    let mut s = DefaultHasher::new();
-    t.hash(&mut s);
-    s.finish()
-}
-
 fn retrieve_data_schema<D>(snapshot: &Snapshot<D>) -> Result<Schema, Box<Error>>
 where D: Deref<Target=DB>
 {
@@ -51,11 +33,15 @@ where D: Deref<Target=DB>
     }
 }
 
-fn retrieve_data_index<D>(snapshot: &Snapshot<D>) -> Result<PositiveBlob, Box<Error>>
+fn retrieve_data_index<D>(snapshot: &Snapshot<D>) -> Result<Index, Box<Error>>
 where D: Deref<Target=DB>
 {
     match snapshot.get(DATA_INDEX)? {
-        Some(vector) => Ok(bincode::deserialize(&*vector)?),
+        Some(vector) => {
-        None => Ok(PositiveBlob::default()),
+            let bytes_len = vector.as_ref().len();
+            let bytes = Arc::new(vector.as_ref().to_vec());
+            Ok(Index::from_shared_bytes(bytes, 0, bytes_len)?)
+        },
+        None => Ok(Index::default()),
     }
 }

src/database/schema.rs

@@ -1,6 +1,4 @@
-use crate::database::update::SerializerError;
 use std::collections::{HashMap, BTreeMap};
-use crate::database::calculate_hash;
 use std::io::{Read, Write};
 use std::error::Error;
 use std::{fmt, u16};
@@ -8,9 +6,11 @@ use std::ops::BitOr;
 use std::sync::Arc;
 
 use serde_derive::{Serialize, Deserialize};
-use serde::ser::{self, Serialize};
 use linked_hash_map::LinkedHashMap;
+use serde::Serialize;
 
+use crate::database::serde::find_id::FindDocumentIdSerializer;
+use crate::database::serde::SerializerError;
 use crate::DocumentId;
 
 pub const STORED: SchemaProps = SchemaProps { stored: true, indexed: false };
@@ -141,13 +141,12 @@ impl Schema {
         attributes
     }
 
-    pub fn document_id<T>(&self, document: &T) -> Result<DocumentId, SerializerError>
+    pub fn document_id<T>(&self, document: T) -> Result<DocumentId, SerializerError>
     where T: Serialize,
     {
-        let find_document_id = FindDocumentIdSerializer {
+        let id_attribute_name = &self.inner.identifier;
-            id_attribute_name: self.identifier_name(),
+        let serializer = FindDocumentIdSerializer { id_attribute_name };
-        };
+        document.serialize(serializer)
-        document.serialize(find_document_id)
     }
 
     pub fn props(&self, attr: SchemaAttr) -> SchemaProps {
@@ -188,192 +187,6 @@ impl fmt::Display for SchemaAttr {
     }
 }
 
-struct FindDocumentIdSerializer<'a> {
-    id_attribute_name: &'a str,
-}
-
-impl<'a> ser::Serializer for FindDocumentIdSerializer<'a> {
-    type Ok = 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 = ser::Impossible<Self::Ok, Self::Error>;
-    type SerializeStruct = FindDocumentIdStructSerializer<'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 { name: "str" })
-    }
-
-    fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "&[u8]" })
-    }
-
-    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "Option" })
-    }
-
-    fn serialize_some<T: ?Sized>(self, _value: &T) -> Result<Self::Ok, Self::Error>
-    where T: Serialize,
-    {
-        Err(SerializerError::UnserializableType { name: "Option" })
-    }
-
-    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "()" })
-    }
-
-    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
-        Err(SerializerError::UnserializableType { 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 { 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 { name: "newtype variant" })
-    }
-
-    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "sequence" })
-    }
-
-    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "tuple" })
-    }
-
-    fn serialize_tuple_struct(
-        self,
-        _name: &'static str,
-        _len: usize
-    ) -> Result<Self::SerializeTupleStruct, Self::Error>
-    {
-        Err(SerializerError::UnserializableType { 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 { 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,
-        //     new_states: self.new_states,
-        // })
-        Err(SerializerError::UnserializableType { name: "map" })
-    }
-
-    fn serialize_struct(
-        self,
-        _name: &'static str,
-        _len: usize
-    ) -> Result<Self::SerializeStruct, Self::Error>
-    {
-        Ok(FindDocumentIdStructSerializer {
-            id_attribute_name: self.id_attribute_name,
-            document_id: None,
-        })
-    }
-
-    fn serialize_struct_variant(
-        self,
-        _name: &'static str,
-        _variant_index: u32,
-        _variant: &'static str,
-        _len: usize
-    ) -> Result<Self::SerializeStructVariant, Self::Error>
-    {
-        Err(SerializerError::UnserializableType { name: "struct variant" })
-    }
-}
-
-struct FindDocumentIdStructSerializer<'a> {
-    id_attribute_name: &'a str,
-    document_id: Option<DocumentId>,
-}
-
-impl<'a> ser::SerializeStruct for FindDocumentIdStructSerializer<'a> {
-    type Ok = DocumentId;
-    type Error = SerializerError;
-
-    fn serialize_field<T: ?Sized>(
-        &mut self,
-        key: &'static str,
-        value: &T
-    ) -> Result<(), Self::Error>
-    where T: Serialize,
-    {
-        if self.id_attribute_name == key {
-            // TODO can it be possible to have multiple ids?
-            let id = bincode::serialize(value).unwrap();
-            let hash = calculate_hash(&id);
-            self.document_id = Some(DocumentId(hash));
-        }
-
-        Ok(())
-    }
-
-    fn end(self) -> Result<Self::Ok, Self::Error> {
-        match self.document_id {
-            Some(document_id) => Ok(document_id),
-            None => Err(SerializerError::DocumentIdNotFound)
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

src/database/serde/find_id.rs

@@ -0,0 +1,243 @@
+use serde::Serialize;
+use serde::ser;
+
+use crate::database::serde::key_to_string::KeyToStringSerializer;
+use crate::database::serde::{SerializerError, calculate_hash};
+use crate::DocumentId;
+
+pub struct FindDocumentIdSerializer<'a> {
+    pub id_attribute_name: &'a str,
+}
+
+impl<'a> ser::Serializer for FindDocumentIdSerializer<'a> {
+    type Ok = 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 = FindDocumentIdMapSerializer<'a>;
+    type SerializeStruct = FindDocumentIdStructSerializer<'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 { name: "str" })
+    }
+
+    fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "&[u8]" })
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "Option" })
+    }
+
+    fn serialize_some<T: ?Sized>(self, _value: &T) -> Result<Self::Ok, Self::Error>
+    where T: Serialize,
+    {
+        Err(SerializerError::UnserializableType { name: "Option" })
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "()" })
+    }
+
+    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { 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 { 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 { name: "newtype variant" })
+    }
+
+    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "sequence" })
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "tuple" })
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeTupleStruct, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { 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 { name: "tuple variant" })
+    }
+
+    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
+        Ok(FindDocumentIdMapSerializer {
+            id_attribute_name: self.id_attribute_name,
+            document_id: None,
+            current_key_name: None,
+        })
+    }
+
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStruct, Self::Error>
+    {
+        Ok(FindDocumentIdStructSerializer {
+            id_attribute_name: self.id_attribute_name,
+            document_id: None,
+        })
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStructVariant, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { name: "struct variant" })
+    }
+}
+
+pub struct FindDocumentIdMapSerializer<'a> {
+    id_attribute_name: &'a str,
+    document_id: Option<DocumentId>,
+    current_key_name: Option<String>,
+}
+
+impl<'a> ser::SerializeMap for FindDocumentIdMapSerializer<'a> {
+    type Ok = DocumentId;
+    type Error = SerializerError;
+
+    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
+    where T: Serialize,
+    {
+        let key = key.serialize(KeyToStringSerializer)?;
+        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(KeyToStringSerializer)?;
+
+        if self.id_attribute_name == key {
+            // TODO is it possible to have multiple ids?
+            let id = bincode::serialize(value).unwrap();
+            let hash = calculate_hash(&id);
+            self.document_id = Some(DocumentId(hash));
+        }
+
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok, Self::Error> {
+        match self.document_id {
+            Some(document_id) => Ok(document_id),
+            None => Err(SerializerError::DocumentIdNotFound)
+        }
+    }
+}
+
+pub struct FindDocumentIdStructSerializer<'a> {
+    id_attribute_name: &'a str,
+    document_id: Option<DocumentId>,
+}
+
+impl<'a> ser::SerializeStruct for FindDocumentIdStructSerializer<'a> {
+    type Ok = DocumentId;
+    type Error = SerializerError;
+
+    fn serialize_field<T: ?Sized>(
+        &mut self,
+        key: &'static str,
+        value: &T
+    ) -> Result<(), Self::Error>
+    where T: Serialize,
+    {
+        if self.id_attribute_name == key {
+            // TODO can it be possible to have multiple ids?
+            let id = bincode::serialize(value).unwrap();
+            let hash = calculate_hash(&id);
+            self.document_id = Some(DocumentId(hash));
+        }
+
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok, Self::Error> {
+        match self.document_id {
+            Some(document_id) => Ok(document_id),
+            None => Err(SerializerError::DocumentIdNotFound)
+        }
+    }
+}

src/database/serde/indexer_serializer.rs

@@ -0,0 +1,188 @@
+use crate::database::update::RawUpdateBuilder;
+use crate::database::schema::SchemaAttr;
+use crate::database::serde::SerializerError;
+use crate::tokenizer::TokenizerBuilder;
+use crate::tokenizer::Token;
+use crate::{DocumentId, DocIndex, Attribute, WordArea};
+
+use serde::Serialize;
+use serde::ser;
+
+pub struct IndexerSerializer<'a, B> {
+    pub tokenizer_builder: &'a B,
+    pub builder: &'a mut RawUpdateBuilder,
+    pub document_id: DocumentId,
+    pub attribute: SchemaAttr,
+}
+
+impl<'a, B> ser::Serializer for IndexerSerializer<'a, B>
+where B: TokenizerBuilder
+{
+    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 = ser::Impossible<Self::Ok, Self::Error>;
+    type SerializeStruct = ser::Impossible<Self::Ok, Self::Error>;
+    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> {
+        for Token { word, word_index, char_index } in self.tokenizer_builder.build(v) {
+            // FIXME must u32::try_from instead
+            let attribute = match Attribute::new(self.attribute.0, word_index as u32) {
+                Ok(attribute) => attribute,
+                Err(_) => return Ok(()),
+            };
+
+            // FIXME must u16/u32::try_from instead
+            let word_area = match WordArea::new(char_index as u32, word.len() as u16) {
+                Ok(word_area) => word_area,
+                Err(_) => return Ok(()),
+            };
+
+            let doc_index = DocIndex {
+                document_id: self.document_id,
+                attribute,
+                word_area
+            };
+
+            // insert the exact representation
+            let word_lower = word.to_lowercase();
+
+            // and the unidecoded lowercased version
+            let word_unidecoded = unidecode::unidecode(word).to_lowercase();
+            if word_lower != word_unidecoded {
+                self.builder.insert_doc_index(word_unidecoded.into_bytes(), doc_index);
+            }
+
+            self.builder.insert_doc_index(word_lower.into_bytes(), doc_index);
+        }
+        Ok(())
+    }
+
+    fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "&[u8]" })
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "Option" })
+    }
+
+    fn serialize_some<T: ?Sized>(self, _value: &T) -> Result<Self::Ok, Self::Error>
+    where T: Serialize,
+    {
+        Err(SerializerError::UnserializableType { name: "Option" })
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "()" })
+    }
+
+    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { 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 { 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 { name: "newtype variant" })
+    }
+
+    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "seq" })
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "tuple" })
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeTupleStruct, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { 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 { name: "tuple variant" })
+    }
+
+    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "map" })
+    }
+
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStruct, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { 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 { name: "struct variant" })
+    }
+}

src/database/serde/key_to_string.rs

@@ -0,0 +1,146 @@
+use serde::Serialize;
+use serde::ser;
+
+use crate::database::serde::SerializerError;
+
+pub struct KeyToStringSerializer;
+
+impl ser::Serializer for KeyToStringSerializer {
+    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>;
+
+    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> {
+        Ok(value.to_string())
+    }
+
+    fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "&[u8]" })
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "Option" })
+    }
+
+    fn serialize_some<T: ?Sized>(self, _value: &T) -> Result<Self::Ok, Self::Error>
+    where T: Serialize,
+    {
+        Err(SerializerError::UnserializableType { name: "Option" })
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "()" })
+    }
+
+    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { 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 { 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 { name: "newtype variant" })
+    }
+
+    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "sequence" })
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "tuple" })
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeTupleStruct, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { 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 { name: "tuple variant" })
+    }
+
+    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "map" })
+    }
+
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStruct, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { 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 { name: "struct variant" })
+    }
+}

src/database/serde/mod.rs

@@ -0,0 +1,57 @@
+use std::collections::hash_map::DefaultHasher;
+use std::hash::{Hash, Hasher};
+use std::error::Error;
+use std::fmt;
+
+use serde::ser;
+
+macro_rules! forward_to_unserializable_type {
+    ($($ty:ident => $se_method:ident,)*) => {
+        $(
+            fn $se_method(self, _v: $ty) -> Result<Self::Ok, Self::Error> {
+                Err(SerializerError::UnserializableType { name: "$ty" })
+            }
+        )*
+    }
+}
+
+pub mod find_id;
+pub mod key_to_string;
+pub mod serializer;
+pub mod indexer_serializer;
+
+pub fn calculate_hash<T: Hash>(t: &T) -> u64 {
+    let mut s = DefaultHasher::new();
+    t.hash(&mut s);
+    s.finish()
+}
+
+#[derive(Debug)]
+pub enum SerializerError {
+    DocumentIdNotFound,
+    UnserializableType { 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::UnserializableType { name } => {
+                write!(f, "Only struct and map types are considered valid documents and
+                           can be serialized, not {} types directly.", name)
+            },
+            SerializerError::Custom(s) => f.write_str(&s),
+        }
+    }
+}
+
+impl Error for SerializerError {}

src/database/serde/serializer.rs

@@ -0,0 +1,281 @@
+use serde::Serialize;
+use serde::ser;
+
+use crate::database::serde::indexer_serializer::IndexerSerializer;
+use crate::database::serde::key_to_string::KeyToStringSerializer;
+use crate::database::document_key::DocumentKeyAttr;
+use crate::database::update::RawUpdateBuilder;
+use crate::database::serde::SerializerError;
+use crate::tokenizer::TokenizerBuilder;
+use crate::database::schema::Schema;
+use crate::DocumentId;
+
+pub struct Serializer<'a, B> {
+    pub schema: &'a Schema,
+    pub document_id: DocumentId,
+    pub tokenizer_builder: &'a B,
+    pub builder: &'a mut RawUpdateBuilder,
+}
+
+impl<'a, B> ser::Serializer for Serializer<'a, B>
+where B: TokenizerBuilder
+{
+    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, B>;
+    type SerializeStruct = StructSerializer<'a, B>;
+    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 { name: "str" })
+    }
+
+    fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "&[u8]" })
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "Option" })
+    }
+
+    fn serialize_some<T: ?Sized>(self, _value: &T) -> Result<Self::Ok, Self::Error>
+    where T: Serialize,
+    {
+        Err(SerializerError::UnserializableType { name: "Option" })
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "()" })
+    }
+
+    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
+        Err(SerializerError::UnserializableType { 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 { 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 { name: "newtype variant" })
+    }
+
+    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "sequence" })
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
+        Err(SerializerError::UnserializableType { name: "tuple" })
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeTupleStruct, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { 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 { name: "tuple variant" })
+    }
+
+    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
+        Ok(MapSerializer {
+            schema: self.schema,
+            tokenizer_builder: self.tokenizer_builder,
+            document_id: self.document_id,
+            current_key_name: None,
+            builder: self.builder,
+        })
+    }
+
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStruct, Self::Error>
+    {
+        Ok(StructSerializer {
+            schema: self.schema,
+            tokenizer_builder: self.tokenizer_builder,
+            document_id: self.document_id,
+            builder: self.builder,
+        })
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize
+    ) -> Result<Self::SerializeStructVariant, Self::Error>
+    {
+        Err(SerializerError::UnserializableType { name: "struct variant" })
+    }
+}
+
+pub struct MapSerializer<'a, B> {
+    pub schema: &'a Schema,
+    pub tokenizer_builder: &'a B,
+    pub document_id: DocumentId,
+    pub current_key_name: Option<String>,
+    pub builder: &'a mut RawUpdateBuilder,
+}
+
+impl<'a, B> ser::SerializeMap for MapSerializer<'a, B>
+where B: TokenizerBuilder
+{
+    type Ok = ();
+    type Error = SerializerError;
+
+    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
+    where T: Serialize,
+    {
+        let key = key.serialize(KeyToStringSerializer)?;
+        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(KeyToStringSerializer)?;
+
+        if let Some(attr) = self.schema.attribute(key) {
+            let props = self.schema.props(attr);
+            if props.is_stored() {
+                let value = bincode::serialize(value).unwrap();
+                let key = DocumentKeyAttr::new(self.document_id, attr);
+                self.builder.insert_attribute_value(key, value);
+            }
+            if props.is_indexed() {
+                let serializer = IndexerSerializer {
+                    builder: self.builder,
+                    tokenizer_builder: self.tokenizer_builder,
+                    document_id: self.document_id,
+                    attribute: attr,
+                };
+                value.serialize(serializer)?;
+            }
+        }
+
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok, Self::Error> {
+        Ok(())
+    }
+}
+
+pub struct StructSerializer<'a, B> {
+    pub schema: &'a Schema,
+    pub document_id: DocumentId,
+    pub tokenizer_builder: &'a B,
+    pub builder: &'a mut RawUpdateBuilder,
+}
+
+impl<'a, B> ser::SerializeStruct for StructSerializer<'a, B>
+where B: TokenizerBuilder
+{
+    type Ok = ();
+    type Error = SerializerError;
+
+    fn serialize_field<T: ?Sized>(
+        &mut self,
+        key: &'static str,
+        value: &T
+    ) -> Result<(), Self::Error>
+    where T: Serialize,
+    {
+        if let Some(attr) = self.schema.attribute(key) {
+            let props = self.schema.props(attr);
+            if props.is_stored() {
+                let value = bincode::serialize(value).unwrap();
+                let key = DocumentKeyAttr::new(self.document_id, attr);
+                self.builder.insert_attribute_value(key, value);
+            }
+            if props.is_indexed() {
+                let serializer = IndexerSerializer {
+                    builder: self.builder,
+                    tokenizer_builder: self.tokenizer_builder,
+                    document_id: self.document_id,
+                    attribute: attr,
+                };
+                value.serialize(serializer)?;
+            }
+        }
+
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok, Self::Error> {
+        Ok(())
+    }
+}

src/database/update/builder.rs

@@ -0,0 +1,60 @@
+use std::path::PathBuf;
+use std::error::Error;
+
+use serde::Serialize;
+
+use crate::database::serde::serializer::Serializer;
+use crate::database::serde::SerializerError;
+use crate::tokenizer::TokenizerBuilder;
+use crate::database::Schema;
+
+use crate::DocumentId;
+use super::{Update, RawUpdateBuilder};
+
+pub struct UpdateBuilder {
+    schema: Schema,
+    raw_builder: RawUpdateBuilder,
+}
+
+impl UpdateBuilder {
+    pub fn new(path: PathBuf, schema: Schema) -> UpdateBuilder {
+        UpdateBuilder {
+            schema: schema,
+            raw_builder: RawUpdateBuilder::new(path),
+        }
+    }
+
+    pub fn update_document<T, B>(
+        &mut self,
+        document: T,
+        tokenizer_builder: &B,
+    ) -> Result<DocumentId, SerializerError>
+    where T: Serialize,
+          B: TokenizerBuilder,
+    {
+        let document_id = self.schema.document_id(&document)?;
+
+        let serializer = Serializer {
+            schema: &self.schema,
+            document_id: document_id,
+            tokenizer_builder: tokenizer_builder,
+            builder: &mut self.raw_builder,
+        };
+
+        document.serialize(serializer)?;
+
+        Ok(document_id)
+    }
+
+    pub fn remove_document<T>(&mut self, document: T) -> Result<DocumentId, SerializerError>
+    where T: Serialize,
+    {
+        let document_id = self.schema.document_id(&document)?;
+        self.raw_builder.remove_document(document_id);
+        Ok(document_id)
+    }
+
+    pub fn build(self) -> Result<Update, Box<Error>> {
+        self.raw_builder.build()
+    }
+}

src/database/update/mod.rs

@@ -1,35 +1,17 @@
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
-use std::error::Error;
 
-mod negative;
+mod builder;
-mod positive;
+mod raw_builder;
 
-pub use self::positive::{PositiveUpdateBuilder, NewState, SerializerError};
+pub use self::builder::UpdateBuilder;
-pub use self::negative::NegativeUpdateBuilder;
+pub use self::raw_builder::RawUpdateBuilder;
 
 pub struct Update {
-    path: PathBuf,
+    sst_file: PathBuf,
-    can_be_moved: bool,
 }
 
 impl Update {
-    pub fn open<P: Into<PathBuf>>(path: P) -> Result<Update, Box<Error>> {
+    pub fn path(&self) -> &Path {
-        Ok(Update { path: path.into(), can_be_moved: false })
+        &self.sst_file
-    }
-
-    pub fn open_and_move<P: Into<PathBuf>>(path: P) -> Result<Update, Box<Error>> {
-        Ok(Update { path: path.into(), can_be_moved: true })
-    }
-
-    pub fn set_move(&mut self, can_be_moved: bool) {
-        self.can_be_moved = can_be_moved
-    }
-
-    pub fn can_be_moved(&self) -> bool {
-        self.can_be_moved
-    }
-
-    pub fn into_path_buf(self) -> PathBuf {
-        self.path
     }
 }

src/database/update/negative/mod.rs

@@ -1,4 +0,0 @@
-mod update;
-mod unordered_builder;
-
-pub use self::update::NegativeUpdateBuilder;

src/database/update/negative/unordered_builder.rs

@@ -1,37 +0,0 @@
-use std::collections::BTreeSet;
-use std::io;
-
-use byteorder::{NativeEndian, WriteBytesExt};
-
-use crate::DocumentId;
-
-pub struct UnorderedNegativeBlobBuilder<W> {
-    doc_ids: BTreeSet<DocumentId>, // TODO: prefer a linked-list
-    wrt: W,
-}
-
-impl UnorderedNegativeBlobBuilder<Vec<u8>> {
-    pub fn memory() -> Self {
-        UnorderedNegativeBlobBuilder::new(Vec::new())
-    }
-}
-
-impl<W: io::Write> UnorderedNegativeBlobBuilder<W> {
-    pub fn new(wrt: W) -> Self {
-        Self {
-            doc_ids: BTreeSet::new(),
-            wrt: wrt,
-        }
-    }
-
-    pub fn insert(&mut self, doc: DocumentId) -> bool {
-        self.doc_ids.insert(doc)
-    }
-
-    pub fn into_inner(mut self) -> io::Result<W> {
-        for id in self.doc_ids {
-            self.wrt.write_u64::<NativeEndian>(id.0)?;
-        }
-        Ok(self.wrt)
-    }
-}

src/database/update/negative/update.rs

@@ -1,60 +0,0 @@
-use std::path::PathBuf;
-use std::error::Error;
-
-use ::rocksdb::rocksdb_options;
-
-use crate::database::update::negative::unordered_builder::UnorderedNegativeBlobBuilder;
-use crate::database::blob::{Blob, NegativeBlob};
-use crate::database::update::Update;
-use crate::database::DocumentKey;
-use crate::database::DATA_INDEX;
-use crate::DocumentId;
-
-pub struct NegativeUpdateBuilder {
-    path: PathBuf,
-    doc_ids: UnorderedNegativeBlobBuilder<Vec<u8>>,
-}
-
-impl NegativeUpdateBuilder {
-    pub fn new<P: Into<PathBuf>>(path: P) -> NegativeUpdateBuilder {
-        NegativeUpdateBuilder {
-            path: path.into(),
-            doc_ids: UnorderedNegativeBlobBuilder::memory(),
-        }
-    }
-
-    pub fn remove(&mut self, id: DocumentId) -> bool {
-        self.doc_ids.insert(id)
-    }
-
-    pub fn build(self) -> Result<Update, Box<Error>> {
-        let env_options = rocksdb_options::EnvOptions::new();
-        let column_family_options = rocksdb_options::ColumnFamilyOptions::new();
-        let mut file_writer = rocksdb::SstFileWriter::new(env_options, column_family_options);
-        file_writer.open(&self.path.to_string_lossy())?;
-
-        let bytes = self.doc_ids.into_inner()?;
-        let negative_blob = NegativeBlob::from_bytes(bytes)?;
-        let blob = Blob::Negative(negative_blob);
-
-        // write the data-index aka negative blob
-        let bytes = bincode::serialize(&blob)?;
-        file_writer.merge(DATA_INDEX, &bytes)?;
-
-        // FIXME remove this ugly thing !
-        // let Blob::Negative(negative_blob) = blob;
-        let negative_blob = match blob {
-            Blob::Negative(blob) => blob,
-            Blob::Positive(_) => unreachable!(),
-        };
-
-        for &document_id in negative_blob.as_ref().as_slice() {
-            let start = DocumentKey::new(document_id);
-            let end = start.with_attribute_max();
-            file_writer.delete_range(start.as_ref(), end.as_ref())?;
-        }
-
-        file_writer.finish()?;
-        Update::open(self.path)
-    }
-}

src/database/update/positive/mod.rs

@@ -1,4 +0,0 @@
-mod update;
-mod unordered_builder;
-
-pub use self::update::{PositiveUpdateBuilder, NewState, SerializerError};

src/database/update/positive/unordered_builder.rs

@@ -1,49 +0,0 @@
-#![allow(unused)]
-
-use std::collections::BTreeMap;
-use std::error::Error;
-use std::io::Write;
-
-use sdset::Set;
-
-use crate::database::blob::positive::PositiveBlobBuilder;
-use crate::DocIndex;
-
-pub struct UnorderedPositiveBlobBuilder<W, X> {
-    builder: PositiveBlobBuilder<W, X>,
-    map: BTreeMap<Vec<u8>, Vec<DocIndex>>,
-}
-
-impl UnorderedPositiveBlobBuilder<Vec<u8>, Vec<u8>> {
-    pub fn memory() -> Self {
-        Self {
-            builder: PositiveBlobBuilder::memory(),
-            map: BTreeMap::new(),
-        }
-    }
-}
-
-impl<W: Write, X: Write> UnorderedPositiveBlobBuilder<W, X> {
-    pub fn new(map_wtr: W, doc_wtr: X) -> Result<Self, Box<Error>> {
-        Ok(UnorderedPositiveBlobBuilder {
-            builder: PositiveBlobBuilder::new(map_wtr, doc_wtr)?,
-            map: BTreeMap::new(),
-        })
-    }
-
-    pub fn insert<K: Into<Vec<u8>>>(&mut self, input: K, doc_index: DocIndex) {
-        self.map.entry(input.into()).or_insert_with(Vec::new).push(doc_index);
-    }
-
-    pub fn finish(self) -> Result<(), Box<Error>> {
-        self.into_inner().map(drop)
-    }
-
-    pub fn into_inner(mut self) -> Result<(W, X), Box<Error>> {
-        for (key, mut doc_indexes) in self.map {
-            doc_indexes.sort_unstable();
-            self.builder.insert(&key, Set::new_unchecked(&doc_indexes))?;
-        }
-        self.builder.into_inner()
-    }
-}

src/database/update/positive/update.rs

@@ -1,504 +0,0 @@
-use std::collections::BTreeMap;
-use std::path::PathBuf;
-use std::error::Error;
-use std::fmt;
-
-use ::rocksdb::rocksdb_options;
-use serde::ser::{self, Serialize};
-
-use crate::database::update::positive::unordered_builder::UnorderedPositiveBlobBuilder;
-use crate::database::blob::positive::PositiveBlob;
-use crate::database::schema::{Schema, SchemaAttr};
-use crate::tokenizer::{TokenizerBuilder, Token};
-use crate::database::DocumentKeyAttr;
-use crate::database::update::Update;
-use crate::database::DATA_INDEX;
-use crate::database::blob::Blob;
-use crate::{DocumentId, DocIndex, Attribute, WordArea};
-
-pub enum NewState {
-    Updated { value: Vec<u8> },
-    Removed,
-}
-
-pub struct PositiveUpdateBuilder<B> {
-    path: PathBuf,
-    schema: Schema,
-    tokenizer_builder: B,
-    builder: UnorderedPositiveBlobBuilder<Vec<u8>, Vec<u8>>,
-    new_states: BTreeMap<DocumentKeyAttr, NewState>,
-}
-
-impl<B> PositiveUpdateBuilder<B> {
-    pub fn new<P: Into<PathBuf>>(path: P, schema: Schema, tokenizer_builder: B) -> PositiveUpdateBuilder<B> {
-        PositiveUpdateBuilder {
-            path: path.into(),
-            schema: schema,
-            tokenizer_builder: tokenizer_builder,
-            builder: UnorderedPositiveBlobBuilder::memory(),
-            new_states: BTreeMap::new(),
-        }
-    }
-
-    pub fn update<T: Serialize>(&mut self, document: &T) -> Result<DocumentId, SerializerError>
-    where B: TokenizerBuilder
-    {
-        let document_id = self.schema.document_id(document)?;
-
-        let serializer = Serializer {
-            schema: &self.schema,
-            tokenizer_builder: &self.tokenizer_builder,
-            document_id: document_id,
-            builder: &mut self.builder,
-            new_states: &mut self.new_states
-        };
-        document.serialize(serializer)?;
-
-        Ok(document_id)
-    }
-
-    // TODO value must be a field that can be indexed
-    pub fn update_field(&mut self, id: DocumentId, attr: SchemaAttr, value: String) {
-        let value = bincode::serialize(&value).unwrap();
-        self.new_states.insert(DocumentKeyAttr::new(id, attr), NewState::Updated { value });
-    }
-
-    pub fn remove_field(&mut self, id: DocumentId, attr: SchemaAttr) {
-        self.new_states.insert(DocumentKeyAttr::new(id, attr), NewState::Removed);
-    }
-}
-
-#[derive(Debug)]
-pub enum SerializerError {
-    DocumentIdNotFound,
-    UnserializableType { 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::UnserializableType { name } => {
-                write!(f, "Only struct and map types are considered valid documents and
-                           can be serialized, not {} types directly.", name)
-            },
-            SerializerError::Custom(s) => f.write_str(&s),
-        }
-    }
-}
-
-impl Error for SerializerError {}
-
-struct Serializer<'a, B> {
-    schema: &'a Schema,
-    tokenizer_builder: &'a B,
-    document_id: DocumentId,
-    builder: &'a mut UnorderedPositiveBlobBuilder<Vec<u8>, Vec<u8>>,
-    new_states: &'a mut BTreeMap<DocumentKeyAttr, NewState>,
-}
-
-impl<'a, B> ser::Serializer for Serializer<'a, B>
-where B: TokenizerBuilder
-{
-    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 = ser::Impossible<Self::Ok, Self::Error>;
-    type SerializeStruct = StructSerializer<'a, B>;
-    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 { name: "str" })
-    }
-
-    fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "&[u8]" })
-    }
-
-    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "Option" })
-    }
-
-    fn serialize_some<T: ?Sized>(self, _value: &T) -> Result<Self::Ok, Self::Error>
-    where T: Serialize,
-    {
-        Err(SerializerError::UnserializableType { name: "Option" })
-    }
-
-    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "()" })
-    }
-
-    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
-        Err(SerializerError::UnserializableType { 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 { 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 { name: "newtype variant" })
-    }
-
-    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "sequence" })
-    }
-
-    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "tuple" })
-    }
-
-    fn serialize_tuple_struct(
-        self,
-        _name: &'static str,
-        _len: usize
-    ) -> Result<Self::SerializeTupleStruct, Self::Error>
-    {
-        Err(SerializerError::UnserializableType { 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 { 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,
-        //     new_states: self.new_states,
-        // })
-        Err(SerializerError::UnserializableType { name: "map" })
-    }
-
-    fn serialize_struct(
-        self,
-        _name: &'static str,
-        _len: usize
-    ) -> Result<Self::SerializeStruct, Self::Error>
-    {
-        Ok(StructSerializer {
-            schema: self.schema,
-            tokenizer_builder: self.tokenizer_builder,
-            document_id: self.document_id,
-            builder: self.builder,
-            new_states: self.new_states,
-        })
-    }
-
-    fn serialize_struct_variant(
-        self,
-        _name: &'static str,
-        _variant_index: u32,
-        _variant: &'static str,
-        _len: usize
-    ) -> Result<Self::SerializeStructVariant, Self::Error>
-    {
-        Err(SerializerError::UnserializableType { name: "struct variant" })
-    }
-}
-
-struct StructSerializer<'a, B> {
-    schema: &'a Schema,
-    tokenizer_builder: &'a B,
-    document_id: DocumentId,
-    builder: &'a mut UnorderedPositiveBlobBuilder<Vec<u8>, Vec<u8>>,
-    new_states: &'a mut BTreeMap<DocumentKeyAttr, NewState>,
-}
-
-impl<'a, B> ser::SerializeStruct for StructSerializer<'a, B>
-where B: TokenizerBuilder
-{
-    type Ok = ();
-    type Error = SerializerError;
-
-    fn serialize_field<T: ?Sized>(
-        &mut self,
-        key: &'static str,
-        value: &T
-    ) -> Result<(), Self::Error>
-    where T: Serialize,
-    {
-        if let Some(attr) = self.schema.attribute(key) {
-            let props = self.schema.props(attr);
-            if props.is_stored() {
-                let value = bincode::serialize(value).unwrap();
-                let key = DocumentKeyAttr::new(self.document_id, attr);
-                self.new_states.insert(key, NewState::Updated { value });
-            }
-            if props.is_indexed() {
-                let serializer = IndexerSerializer {
-                    builder: self.builder,
-                    tokenizer_builder: self.tokenizer_builder,
-                    document_id: self.document_id,
-                    attribute: attr,
-                };
-                value.serialize(serializer)?;
-            }
-        }
-
-        Ok(())
-    }
-
-    fn end(self) -> Result<Self::Ok, Self::Error> {
-        Ok(())
-    }
-}
-
-struct IndexerSerializer<'a, B> {
-    tokenizer_builder: &'a B,
-    builder: &'a mut UnorderedPositiveBlobBuilder<Vec<u8>, Vec<u8>>,
-    document_id: DocumentId,
-    attribute: SchemaAttr,
-}
-
-impl<'a, B> ser::Serializer for IndexerSerializer<'a, B>
-where B: TokenizerBuilder
-{
-    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 = ser::Impossible<Self::Ok, Self::Error>;
-    type SerializeStruct = ser::Impossible<Self::Ok, Self::Error>;
-    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> {
-        for Token { word, word_index, char_index } in self.tokenizer_builder.build(v) {
-            let doc_index = DocIndex {
-                document_id: self.document_id,
-                attribute: Attribute::new_faillible(self.attribute.0, word_index as u32),
-                word_area: WordArea::new_faillible(char_index as u32, word.len() as u16),
-            };
-
-            // insert the exact representation
-            let word_lower = word.to_lowercase();
-
-            // and the unidecoded lowercased version
-            let word_unidecoded = unidecode::unidecode(word).to_lowercase();
-            if word_lower != word_unidecoded {
-                self.builder.insert(word_unidecoded, doc_index);
-            }
-
-            self.builder.insert(word_lower, doc_index);
-        }
-        Ok(())
-    }
-
-    fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "&[u8]" })
-    }
-
-    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "Option" })
-    }
-
-    fn serialize_some<T: ?Sized>(self, _value: &T) -> Result<Self::Ok, Self::Error>
-    where T: Serialize,
-    {
-        Err(SerializerError::UnserializableType { name: "Option" })
-    }
-
-    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "()" })
-    }
-
-    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
-        Err(SerializerError::UnserializableType { 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 { 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 { name: "newtype variant" })
-    }
-
-    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "seq" })
-    }
-
-    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "tuple" })
-    }
-
-    fn serialize_tuple_struct(
-        self,
-        _name: &'static str,
-        _len: usize
-    ) -> Result<Self::SerializeTupleStruct, Self::Error>
-    {
-        Err(SerializerError::UnserializableType { 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 { name: "tuple variant" })
-    }
-
-    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
-        Err(SerializerError::UnserializableType { name: "map" })
-    }
-
-    fn serialize_struct(
-        self,
-        _name: &'static str,
-        _len: usize
-    ) -> Result<Self::SerializeStruct, Self::Error>
-    {
-        Err(SerializerError::UnserializableType { 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 { name: "struct variant" })
-    }
-}
-
-impl<B> PositiveUpdateBuilder<B> {
-    pub fn build(self) -> Result<Update, Box<Error>> {
-        let env_options = rocksdb_options::EnvOptions::new();
-        let column_family_options = rocksdb_options::ColumnFamilyOptions::new();
-        let mut file_writer = rocksdb::SstFileWriter::new(env_options, column_family_options);
-        file_writer.open(&self.path.to_string_lossy())?;
-
-        let (blob_fst_map, blob_doc_idx) = self.builder.into_inner()?;
-        let positive_blob = PositiveBlob::from_bytes(blob_fst_map, blob_doc_idx)?;
-        let blob = Blob::Positive(positive_blob);
-
-        // write the data-index aka positive blob
-        let bytes = bincode::serialize(&blob)?;
-        file_writer.merge(DATA_INDEX, &bytes)?;
-
-        // write all the documents fields updates
-        for (key, state) in self.new_states {
-            match state {
-                NewState::Updated { value } => {
-                    file_writer.put(key.as_ref(), &value)?
-                },
-                NewState::Removed => file_writer.delete(key.as_ref())?,
-            }
-        }
-
-        file_writer.finish()?;
-        Update::open(self.path)
-    }
-}

src/database/update/raw_builder.rs

@@ -0,0 +1,93 @@
+use std::collections::{BTreeMap, BTreeSet};
+use std::path::PathBuf;
+use std::error::Error;
+
+use rocksdb::rocksdb_options;
+use fst::map::Map;
+use sdset::Set;
+
+use crate::database::index::{Index, Positive, PositiveBuilder, Negative};
+use crate::database::{DATA_INDEX, DocumentKeyAttr};
+use crate::data::{DocIds, DocIndexes};
+use crate::{DocumentId, DocIndex};
+use super::Update;
+
+type Token = Vec<u8>; // TODO could be replaced by a SmallVec
+type Value = Vec<u8>;
+
+pub struct RawUpdateBuilder {
+    sst_file: PathBuf,
+    removed_documents: BTreeSet<DocumentId>,
+    words_indexes: BTreeMap<Token, Vec<DocIndex>>,
+    keys_values: BTreeMap<DocumentKeyAttr, Value>,
+}
+
+impl RawUpdateBuilder {
+    pub fn new(path: PathBuf) -> RawUpdateBuilder {
+        RawUpdateBuilder {
+            sst_file: path,
+            removed_documents: BTreeSet::new(),
+            words_indexes: BTreeMap::new(),
+            keys_values: BTreeMap::new(),
+        }
+    }
+
+    pub fn insert_doc_index(&mut self, token: Vec<u8>, doc_index: DocIndex) {
+        self.words_indexes.entry(token).or_insert_with(Vec::new).push(doc_index)
+    }
+
+    pub fn insert_attribute_value(&mut self, key_attr: DocumentKeyAttr, value: Vec<u8>) -> Option<Vec<u8>> {
+        self.keys_values.insert(key_attr, value)
+    }
+
+    pub fn remove_document(&mut self, id: DocumentId) {
+        self.removed_documents.insert(id);
+    }
+
+    pub fn build(self) -> Result<Update, Box<Error>> {
+        let tree = {
+            let negative = {
+                let documents_ids: Vec<_> = self.removed_documents.into_iter().collect();
+                let documents_ids = Set::new_unchecked(&documents_ids);
+                let doc_ids = DocIds::new(documents_ids);
+                Negative::new(doc_ids)
+            };
+
+            let positive = {
+                let mut builder = PositiveBuilder::memory();
+
+                for (key, mut indexes) in self.words_indexes {
+                    indexes.sort_unstable();
+                    let indexes = Set::new_unchecked(&indexes);
+                    builder.insert(key, indexes)?;
+                }
+
+                let (map, indexes) = builder.into_inner()?;
+                let map = Map::from_bytes(map)?;
+                let indexes = DocIndexes::from_bytes(indexes)?;
+                Positive::new(map, indexes)
+            };
+
+            Index { negative, positive }
+        };
+
+        let env_options = rocksdb_options::EnvOptions::new();
+        let column_family_options = rocksdb_options::ColumnFamilyOptions::new();
+        let mut file_writer = rocksdb::SstFileWriter::new(env_options, column_family_options);
+        file_writer.open(&self.sst_file.to_string_lossy())?;
+
+        // write the data-index
+        let mut bytes = Vec::new();
+        tree.write_to_bytes(&mut bytes);
+        file_writer.merge(DATA_INDEX, &bytes)?;
+
+        // write all the documents attributes updates
+        for (key, value) in self.keys_values {
+            file_writer.put(key.as_ref(), &value)?;
+        }
+
+        file_writer.finish()?;
+
+        Ok(Update { sst_file: self.sst_file })
+    }
+}

src/rank/query_builder.rs

@@ -86,7 +86,7 @@ where D: Deref<Target=DB>,
         let mut stream = {
             let mut op_builder = fst::map::OpBuilder::new();
             for automaton in &automatons {
-                let stream = self.view.blob().as_map().search(automaton);
+                let stream = self.view.index().positive.map().search(automaton);
                 op_builder.push(stream);
             }
             op_builder.union()
@@ -100,7 +100,7 @@ where D: Deref<Target=DB>,
                 let distance = automaton.eval(input).to_u8();
                 let is_exact = distance == 0 && input.len() == automaton.query_len();
 
-                let doc_indexes = self.view.blob().as_indexes();
+                let doc_indexes = &self.view.index().positive.indexes();
                 let doc_indexes = &doc_indexes[iv.value as usize];
 
                 for doc_index in doc_indexes {