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Store documents ids under attribute ids

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Kerollmops 2020-06-05 16:32:14 +02:00
parent ce86a43779
commit f51a63e4ef
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GPG Key ID: 92ADA4E935E71FA4
3 changed files with 226 additions and 70 deletions
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112
src/bin/indexer.rs
View File

@ -1,4 +1,4 @@
use std::collections::BTreeSet;
use std::collections::{BTreeSet, BTreeMap};
use std::convert::TryFrom;
use std::fs::File;
use std::path::PathBuf;
@ -15,7 +15,10 @@ use roaring::RoaringBitmap;
use slice_group_by::StrGroupBy;
use structopt::StructOpt;
use mega_mini_indexer::{FastMap4, SmallVec32, Index, DocumentId};
use mega_mini_indexer::{FastMap4, SmallVec32, Index, DocumentId, AttributeId};
const MAX_POSITION: usize = 1000;
const MAX_ATTRIBUTES: usize = u32::max_value() as usize / MAX_POSITION;
#[cfg(target_os = "linux")]
#[global_allocator]
@ -42,8 +45,9 @@ struct Opt {
struct Indexed {
fst: fst::Set<Vec<u8>>,
postings_ids: FastMap4<SmallVec32, RoaringBitmap>,
prefix_postings_ids: FastMap4<SmallVec32, RoaringBitmap>,
postings_attrs: FastMap4<SmallVec32, RoaringBitmap>,
postings_ids: FastMap4<SmallVec32, FastMap4<AttributeId, RoaringBitmap>>,
prefix_postings_ids: FastMap4<SmallVec32, FastMap4<AttributeId, RoaringBitmap>>,
headers: Vec<u8>,
documents: Vec<(DocumentId, Vec<u8>)>,
}
@ -62,36 +66,76 @@ impl MtblKvStore {
out.add(b"\0words-fst", indexed.fst.as_fst().as_bytes())?;
// postings ids keys are all prefixed by a '1'
let mut key = vec![1];
let mut key = vec![0];
let mut buffer = Vec::new();
// We must write the postings attrs
key[0] = 1;
// We must write the postings ids in order for mtbl therefore
// we iterate over the fst to read the words in order
let mut stream = indexed.fst.stream();
while let Some(word) = stream.next() {
if let Some(attrs) = indexed.postings_attrs.remove(word) {
key.truncate(1);
key.extend_from_slice(word);
// We serialize the attrs ids into a buffer
buffer.clear();
attrs.serialize_into(&mut buffer)?;
// that we write under the generated key into MTBL
out.add(&key, &buffer).unwrap();
}
}
// We must write the postings ids
key[0] = 2;
// We must write the postings ids in order for mtbl therefore
// we iterate over the fst to read the words in order
let mut stream = indexed.fst.stream();
while let Some(word) = stream.next() {
key.truncate(1);
key.extend_from_slice(word);
if let Some(ids) = indexed.postings_ids.remove(word) {
buffer.clear();
ids.serialize_into(&mut buffer)?;
out.add(&key, &buffer).unwrap();
if let Some(attrs) = indexed.postings_ids.remove(word) {
let attrs: BTreeMap<_, _> = attrs.into_iter().collect();
// We iterate over all the attributes containing the documents ids
for (attr, ids) in attrs {
// we postfix the word by the attribute id
key.extend_from_slice(&attr.to_be_bytes());
// We serialize the document ids into a buffer
buffer.clear();
ids.serialize_into(&mut buffer)?;
// that we write under the generated key into MTBL
out.add(&key, &buffer).unwrap();
// And cleanup the attribute id afterward (u32 = 4 * u8)
key.truncate(key.len() - 4);
}
}
}
// We must write the prefix postings ids
key[0] = 2;
key[0] = 3;
let mut stream = indexed.fst.stream();
while let Some(prefix) = stream.next() {
key.truncate(1);
key.extend_from_slice(prefix);
if let Some(ids) = indexed.prefix_postings_ids.remove(prefix) {
buffer.clear();
ids.serialize_into(&mut buffer)?;
out.add(&key, &buffer).unwrap();
if let Some(attrs) = indexed.prefix_postings_ids.remove(prefix) {
let attrs: BTreeMap<_, _> = attrs.into_iter().collect();
// We iterate over all the attributes containing the documents ids
for (attr, ids) in attrs {
// we postfix the word by the attribute id
key.extend_from_slice(&attr.to_be_bytes());
// We serialize the document ids into a buffer
buffer.clear();
ids.serialize_into(&mut buffer)?;
// that we write under the generated key into MTBL
out.add(&key, &buffer).unwrap();
// And cleanup the attribute id afterward (u32 = 4 * u8)
key.truncate(key.len() - 4);
}
}
}
// postings ids keys are all prefixed by a '2'
key[0] = 3;
// postings ids keys are all prefixed by a '4'
key[0] = 4;
indexed.documents.sort_unstable();
for (id, content) in indexed.documents {
key.truncate(1);
@ -122,7 +166,8 @@ impl MtblKvStore {
assert!(values.windows(2).all(|vs| vs[0] == vs[1]));
Some(values[0].to_vec())
}
else if key.starts_with(&[1]) || key.starts_with(&[2]) {
// We either merge postings attrs, prefix postings or postings ids.
else if key.starts_with(&[1]) || key.starts_with(&[2]) || key.starts_with(&[3]) {
let mut first = RoaringBitmap::deserialize_from(values[0].as_slice()).unwrap();
for value in &values[1..] {
@ -134,7 +179,7 @@ impl MtblKvStore {
first.serialize_into(&mut vec).unwrap();
Some(vec)
}
else if key.starts_with(&[3]) {
else if key.starts_with(&[4]) {
assert!(values.windows(2).all(|vs| vs[0] == vs[1]));
Some(values[0].to_vec())
}
@ -172,10 +217,8 @@ impl MtblKvStore {
fn index_csv(mut rdr: csv::Reader<File>) -> anyhow::Result<MtblKvStore> {
eprintln!("{:?}: Indexing into an Indexed...", rayon::current_thread_index());
const MAX_POSITION: usize = 1000;
const MAX_ATTRIBUTES: usize = u32::max_value() as usize / MAX_POSITION;
let mut document = csv::StringRecord::new();
let mut postings_attrs = FastMap4::default();
let mut postings_ids = FastMap4::default();
let mut prefix_postings_ids = FastMap4::default();
let mut documents = Vec::new();
@ -190,18 +233,23 @@ fn index_csv(mut rdr: csv::Reader<File>) -> anyhow::Result<MtblKvStore> {
let document_id = ID_GENERATOR.fetch_add(1, Ordering::SeqCst);
let document_id = DocumentId::try_from(document_id).context("Generated id is too big")?;
for (_attr, content) in document.iter().enumerate().take(MAX_ATTRIBUTES) {
for (attr, content) in document.iter().enumerate().take(MAX_ATTRIBUTES) {
for (_pos, word) in simple_alphanumeric_tokens(&content).enumerate().take(MAX_POSITION) {
if !word.is_empty() && word.len() < 500 { // LMDB limits
let word = word.cow_to_lowercase();
postings_attrs.entry(SmallVec32::from(word.as_bytes()))
.or_insert_with(RoaringBitmap::new).insert(attr as u32); // attributes ids
postings_ids.entry(SmallVec32::from(word.as_bytes()))
.or_insert_with(RoaringBitmap::new)
.insert(document_id);
.or_insert_with(FastMap4::default).entry(attr as u32) // attributes
.or_insert_with(RoaringBitmap::new).insert(document_id); // document ids
if let Some(prefix) = word.as_bytes().get(0..word.len().min(5)) {
for i in 0..=prefix.len() {
prefix_postings_ids.entry(SmallVec32::from(&prefix[..i]))
.or_insert_with(RoaringBitmap::new)
.insert(document_id);
.or_insert_with(FastMap4::default).entry(attr as u32) // attributes
.or_insert_with(RoaringBitmap::new).insert(document_id); // document ids
}
}
}
@ -223,7 +271,7 @@ fn index_csv(mut rdr: csv::Reader<File>) -> anyhow::Result<MtblKvStore> {
let new_words_fst = fst::Set::from_iter(new_words.iter().map(SmallVec32::as_ref))?;
let indexed = Indexed { fst: new_words_fst, headers, postings_ids, prefix_postings_ids, documents };
let indexed = Indexed { fst: new_words_fst, headers, postings_attrs, postings_ids, prefix_postings_ids, documents };
eprintln!("{:?}: Indexed created!", rayon::current_thread_index());
MtblKvStore::from_indexed(indexed)
@ -241,15 +289,20 @@ fn writer(wtxn: &mut heed::RwTxn, index: &Index, key: &[u8], val: &[u8]) -> anyh
}
else if key.starts_with(&[1]) {
// Write the postings lists
index.postings_ids.as_polymorph()
index.postings_attrs.as_polymorph()
.put::<_, ByteSlice, ByteSlice>(wtxn, &key[1..], val)?;
}
else if key.starts_with(&[2]) {
// Write the postings lists
index.postings_ids.as_polymorph()
.put::<_, ByteSlice, ByteSlice>(wtxn, &key[1..], val)?;
}
else if key.starts_with(&[3]) {
// Write the prefix postings lists
index.prefix_postings_ids.as_polymorph()
.put::<_, ByteSlice, ByteSlice>(wtxn, &key[1..], val)?;
}
else if key.starts_with(&[3]) {
else if key.starts_with(&[4]) {
// Write the documents
index.documents.as_polymorph()
.put::<_, ByteSlice, ByteSlice>(wtxn, &key[1..], val)?;
@ -284,6 +337,7 @@ fn main() -> anyhow::Result<()> {
eprintln!("We are writing into LMDB...");
let mut wtxn = env.write_txn()?;
MtblKvStore::from_many(stores, |k, v| writer(&mut wtxn, &index, k, v))?;
// FIXME Why is this count wrong? (indicates 99 when must return 100)
let count = index.documents.len(&wtxn)?;
wtxn.commit()?;
eprintln!("Wrote {} documents into LMDB", count);

64
src/bin/stats.rs Normal file
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@ -0,0 +1,64 @@
use std::io;
use std::str::FromStr;
use anyhow::Context;
use cow_utils::CowUtils;
use roaring::RoaringBitmap;
use slice_group_by::StrGroupBy;
use mega_mini_indexer::{FastMap4, DocumentId, SmallString32};
const MAX_POSITION: usize = 1000;
const MAX_ATTRIBUTES: usize = u32::max_value() as usize / MAX_POSITION;
fn simple_alphanumeric_tokens(string: &str) -> impl Iterator<Item = &str> {
let is_alphanumeric = |s: &&str| s.chars().next().map_or(false, char::is_alphanumeric);
string.linear_group_by_key(|c| c.is_alphanumeric()).filter(is_alphanumeric)
}
fn main() -> anyhow::Result<()> {
let mut rdr = csv::Reader::from_reader(io::stdin());
let mut document = csv::StringRecord::new();
let mut postings_positions = FastMap4::default();
let headers = rdr.headers()?;
let mut writer = csv::WriterBuilder::new().has_headers(false).from_writer(Vec::new());
writer.write_byte_record(headers.as_byte_record())?;
let id_pos = headers.iter().position(|h| h == "id").context("missing 'id' header")?;
while rdr.read_record(&mut document)? {
let document_id = document.get(id_pos).unwrap();
let document_id = DocumentId::from_str(document_id).context("invalid document id")?;
for (attr, content) in document.iter().enumerate().take(MAX_ATTRIBUTES) {
if attr == id_pos { continue }
for (pos, word) in simple_alphanumeric_tokens(&content).enumerate().take(MAX_POSITION) {
if !word.is_empty() && word.len() < 500 { // LMDB limits
let word = word.cow_to_lowercase();
let position = (attr * 1000 + pos) as u32;
postings_positions.entry(SmallString32::from(word.as_ref()))
.or_insert_with(FastMap4::default).entry(position)
.or_insert_with(RoaringBitmap::new).insert(document_id);
}
}
}
}
// Write the stats to stdout
let mut wrt = csv::Writer::from_writer(io::stdout());
wrt.write_record(&["word", "position", "count"])?;
for (word, positions) in postings_positions {
let word = word.as_str();
for (pos, ids) in positions {
let pos = pos.to_string();
let count = ids.len().to_string();
wrt.write_record(&[word, &pos, &count])?;
}
}
Ok(())
}

120
src/lib.rs
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@ -11,37 +11,41 @@ use fxhash::FxHasher32;
use heed::types::*;
use heed::{PolyDatabase, Database};
use levenshtein_automata::LevenshteinAutomatonBuilder as LevBuilder;
use once_cell::sync::OnceCell;
use once_cell::sync::Lazy;
use roaring::RoaringBitmap;
use self::query_tokens::{QueryTokens, QueryToken};
static LEVDIST0: OnceCell<LevBuilder> = OnceCell::new();
static LEVDIST1: OnceCell<LevBuilder> = OnceCell::new();
static LEVDIST2: OnceCell<LevBuilder> = OnceCell::new();
// Building these factories is not free.
static LEVDIST0: Lazy<LevBuilder> = Lazy::new(|| LevBuilder::new(0, true));
static LEVDIST1: Lazy<LevBuilder> = Lazy::new(|| LevBuilder::new(1, true));
static LEVDIST2: Lazy<LevBuilder> = Lazy::new(|| LevBuilder::new(2, true));
pub type FastMap4<K, V> = HashMap<K, V, BuildHasherDefault<FxHasher32>>;
pub type SmallString32 = smallstr::SmallString<[u8; 32]>;
pub type SmallVec32 = smallvec::SmallVec<[u8; 32]>;
pub type BEU32 = heed::zerocopy::U32<heed::byteorder::BE>;
pub type DocumentId = u32;
pub type AttributeId = u32;
#[derive(Clone)]
pub struct Index {
pub main: PolyDatabase,
pub postings_ids: Database<Str, ByteSlice>,
pub prefix_postings_ids: Database<Str, ByteSlice>,
pub postings_attrs: Database<Str, ByteSlice>,
pub postings_ids: Database<ByteSlice, ByteSlice>,
pub prefix_postings_ids: Database<ByteSlice, ByteSlice>,
pub documents: Database<OwnedType<BEU32>, ByteSlice>,
}
impl Index {
pub fn new(env: &heed::Env) -> heed::Result<Index> {
let main = env.create_poly_database(None)?;
let postings_attrs = env.create_database(Some("postings-attrs"))?;
let postings_ids = env.create_database(Some("postings-ids"))?;
let prefix_postings_ids = env.create_database(Some("prefix-postings-ids"))?;
let documents = env.create_database(Some("documents"))?;
Ok(Index { main, postings_ids, prefix_postings_ids, documents })
Ok(Index { main, postings_attrs, postings_ids, prefix_postings_ids, documents })
}
pub fn headers<'t>(&self, rtxn: &'t heed::RoTxn) -> heed::Result<Option<&'t [u8]>> {
@ -54,56 +58,90 @@ impl Index {
None => return Ok(Vec::new()),
};
// Building these factories is not free.
let lev0 = LEVDIST0.get_or_init(|| LevBuilder::new(0, true));
let lev1 = LEVDIST1.get_or_init(|| LevBuilder::new(1, true));
let lev2 = LEVDIST2.get_or_init(|| LevBuilder::new(2, true));
let (lev0, lev1, lev2) = (&LEVDIST0, &LEVDIST1, &LEVDIST2);
let words: Vec<_> = QueryTokens::new(query).collect();
let ends_with_whitespace = query.chars().last().map_or(false, char::is_whitespace);
let number_of_words = words.len();
let dfas = words.into_iter().enumerate().map(|(i, word)| {
let dfas: Vec<_> = words.into_iter().enumerate().map(|(i, word)| {
let (word, quoted) = match word {
QueryToken::Free(word) => (word.cow_to_lowercase(), false),
QueryToken::Quoted(word) => (Cow::Borrowed(word), true),
};
let is_last = i + 1 == number_of_words;
let is_prefix = is_last && !ends_with_whitespace && !quoted;
let dfa = match word.len() {
0..=4 => if is_prefix { lev0.build_prefix_dfa(&word) } else if quoted { lev0.build_dfa(&word) } else { lev0.build_dfa(&word) },
5..=8 => if is_prefix { lev1.build_prefix_dfa(&word) } else if quoted { lev0.build_dfa(&word) } else { lev1.build_dfa(&word) },
_ => if is_prefix { lev2.build_prefix_dfa(&word) } else if quoted { lev0.build_dfa(&word) } else { lev2.build_dfa(&word) },
let lev = match word.len() {
0..=4 => if quoted { lev0 } else { lev0 },
5..=8 => if quoted { lev0 } else { lev1 },
_ => if quoted { lev0 } else { lev2 },
};
(word, is_prefix, dfa)
});
let mut intersect_result: Option<RoaringBitmap> = None;
for (word, is_prefix, dfa) in dfas {
let before = Instant::now();
let mut union_result = RoaringBitmap::default();
let count = if word.len() <= 4 && is_prefix {
if let Some(ids) = self.prefix_postings_ids.get(rtxn, &word[..word.len().min(5)])? {
union_result = RoaringBitmap::deserialize_from(ids)?;
}
1
let dfa = if is_prefix {
lev.build_prefix_dfa(&word)
} else {
lev.build_dfa(&word)
};
(word, is_prefix, dfa)
})
.collect();
let mut intersect_attrs: Option<RoaringBitmap> = None;
for (_word, _is_prefix, dfa) in &dfas {
let mut union_result = RoaringBitmap::default();
let mut stream = fst.search(dfa).into_stream();
while let Some(word) = stream.next() {
let word = std::str::from_utf8(word)?;
if let Some(attrs) = self.postings_attrs.get(rtxn, word)? {
let right = RoaringBitmap::deserialize_from(attrs)?;
union_result.union_with(&right);
}
}
match &mut intersect_attrs {
Some(left) => left.intersect_with(&union_result),
None => intersect_attrs = Some(union_result),
}
}
eprintln!("we should only look for documents with attrs {:?}", intersect_attrs);
let mut intersect_docids: Option<RoaringBitmap> = None;
// TODO would be faster to store and use the words
// seen in the previous attrs loop
for (word, is_prefix, dfa) in &dfas {
let mut union_result = RoaringBitmap::default();
for attr in intersect_attrs.as_ref().unwrap_or(&RoaringBitmap::default()) {
let before = Instant::now();
let mut count = 0;
let mut stream = fst.search(dfa).into_stream();
while let Some(word) = stream.next() {
count += 1;
let word = std::str::from_utf8(word)?;
if let Some(ids) = self.postings_ids.get(rtxn, word)? {
if word.len() <= 4 && *is_prefix {
let mut key = word.as_bytes()[..word.len().min(5)].to_vec();
key.extend_from_slice(&attr.to_be_bytes());
if let Some(ids) = self.prefix_postings_ids.get(rtxn, &key)? {
let right = RoaringBitmap::deserialize_from(ids)?;
union_result.union_with(&right);
count = 1;
}
} else {
let mut stream = fst.search(dfa).into_stream();
while let Some(word) = stream.next() {
count += 1;
let word = std::str::from_utf8(word)?;
let mut key = word.as_bytes().to_vec();
key.extend_from_slice(&attr.to_be_bytes());
if let Some(ids) = self.postings_ids.get(rtxn, &key)? {
let right = RoaringBitmap::deserialize_from(ids)?;
union_result.union_with(&right);
}
}
}
count
};
eprintln!("with {:?} words union for {:?} gives {:?} took {:.02?}",
count, word, union_result.len(), before.elapsed());
match &mut intersect_result {
eprintln!("with {:?} similar words (for attr {}) union for {:?} gives {:?} took {:.02?}",
count, attr, word, union_result.len(), before.elapsed());
}
match &mut intersect_docids {
Some(left) => {
let before = Instant::now();
let left_len = left.len();
@ -111,12 +149,12 @@ impl Index {
eprintln!("intersect between {:?} and {:?} gives {:?} took {:.02?}",
left_len, union_result.len(), left.len(), before.elapsed());
},
None => intersect_result = Some(union_result),
None => intersect_docids = Some(union_result),
}
}
eprintln!("{} candidates", intersect_result.as_ref().map_or(0, |r| r.len()));
eprintln!("{} candidates", intersect_docids.as_ref().map_or(0, |r| r.len()));
Ok(intersect_result.unwrap_or_default().iter().take(20).collect())
Ok(intersect_docids.unwrap_or_default().iter().take(20).collect())
}
}