MeiliSearch/milli/src/search/new/db_cache.rs
2023-06-26 14:56:19 +02:00

510 lines
19 KiB
Rust

use std::borrow::Cow;
use std::collections::hash_map::Entry;
use std::hash::Hash;
use fxhash::FxHashMap;
use heed::types::ByteSlice;
use heed::{BytesEncode, Database, RoTxn};
use roaring::RoaringBitmap;
use super::interner::Interned;
use super::Word;
use crate::heed_codec::{BytesDecodeOwned, StrBEU16Codec};
use crate::update::{merge_cbo_roaring_bitmaps, MergeFn};
use crate::{
CboRoaringBitmapCodec, CboRoaringBitmapLenCodec, Result, RoaringBitmapCodec, SearchContext,
};
/// A cache storing pointers to values in the LMDB databases.
///
/// Used for performance reasons only. By using this cache, we avoid performing a
/// database lookup and instead get a direct reference to the value using a fast
/// local HashMap lookup.
#[derive(Default)]
pub struct DatabaseCache<'ctx> {
pub word_pair_proximity_docids:
FxHashMap<(u8, Interned<String>, Interned<String>), Option<Cow<'ctx, [u8]>>>,
pub word_prefix_pair_proximity_docids:
FxHashMap<(u8, Interned<String>, Interned<String>), Option<Cow<'ctx, [u8]>>>,
pub prefix_word_pair_proximity_docids:
FxHashMap<(u8, Interned<String>, Interned<String>), Option<Cow<'ctx, [u8]>>>,
pub word_docids: FxHashMap<Interned<String>, Option<Cow<'ctx, [u8]>>>,
pub exact_word_docids: FxHashMap<Interned<String>, Option<Cow<'ctx, [u8]>>>,
pub word_prefix_docids: FxHashMap<Interned<String>, Option<Cow<'ctx, [u8]>>>,
pub exact_word_prefix_docids: FxHashMap<Interned<String>, Option<Cow<'ctx, [u8]>>>,
pub words_fst: Option<fst::Set<Cow<'ctx, [u8]>>>,
pub word_position_docids: FxHashMap<(Interned<String>, u16), Option<Cow<'ctx, [u8]>>>,
pub word_prefix_position_docids: FxHashMap<(Interned<String>, u16), Option<Cow<'ctx, [u8]>>>,
pub word_positions: FxHashMap<Interned<String>, Vec<u16>>,
pub word_prefix_positions: FxHashMap<Interned<String>, Vec<u16>>,
pub word_fid_docids: FxHashMap<(Interned<String>, u16), Option<Cow<'ctx, [u8]>>>,
pub word_prefix_fid_docids: FxHashMap<(Interned<String>, u16), Option<Cow<'ctx, [u8]>>>,
pub word_fids: FxHashMap<Interned<String>, Vec<u16>>,
pub word_prefix_fids: FxHashMap<Interned<String>, Vec<u16>>,
}
impl<'ctx> DatabaseCache<'ctx> {
fn get_value<'v, K1, KC, DC>(
txn: &'ctx RoTxn,
cache_key: K1,
db_key: &'v KC::EItem,
cache: &mut FxHashMap<K1, Option<Cow<'ctx, [u8]>>>,
db: Database<KC, ByteSlice>,
) -> Result<Option<DC::DItem>>
where
K1: Copy + Eq + Hash,
KC: BytesEncode<'v>,
DC: BytesDecodeOwned,
{
if let Entry::Vacant(entry) = cache.entry(cache_key) {
let bitmap_ptr = db.get(txn, db_key)?.map(Cow::Borrowed);
entry.insert(bitmap_ptr);
}
match cache.get(&cache_key).unwrap() {
Some(Cow::Borrowed(bytes)) => {
DC::bytes_decode_owned(bytes).ok_or(heed::Error::Decoding.into()).map(Some)
}
Some(Cow::Owned(bytes)) => {
DC::bytes_decode_owned(bytes).ok_or(heed::Error::Decoding.into()).map(Some)
}
None => Ok(None),
}
}
fn get_value_from_keys<'v, K1, KC, DC>(
txn: &'ctx RoTxn,
cache_key: K1,
db_keys: &'v [KC::EItem],
cache: &mut FxHashMap<K1, Option<Cow<'ctx, [u8]>>>,
db: Database<KC, ByteSlice>,
merger: MergeFn,
) -> Result<Option<DC::DItem>>
where
K1: Copy + Eq + Hash,
KC: BytesEncode<'v>,
DC: BytesDecodeOwned,
KC::EItem: Sized,
{
if let Entry::Vacant(entry) = cache.entry(cache_key) {
let bitmap_ptr: Option<Cow<'ctx, [u8]>> = match db_keys {
[] => None,
[key] => db.get(txn, key)?.map(Cow::Borrowed),
keys => {
let bitmaps = keys
.iter()
.filter_map(|key| db.get(txn, key).transpose())
.map(|v| v.map(Cow::Borrowed))
.collect::<std::result::Result<Vec<Cow<[u8]>>, _>>()?;
if bitmaps.is_empty() {
None
} else {
Some(merger(&[], &bitmaps[..])?)
}
}
};
entry.insert(bitmap_ptr);
}
match cache.get(&cache_key).unwrap() {
Some(Cow::Borrowed(bytes)) => {
DC::bytes_decode_owned(bytes).ok_or(heed::Error::Decoding.into()).map(Some)
}
Some(Cow::Owned(bytes)) => {
DC::bytes_decode_owned(bytes).ok_or(heed::Error::Decoding.into()).map(Some)
}
None => Ok(None),
}
}
}
impl<'ctx> SearchContext<'ctx> {
pub fn get_words_fst(&mut self) -> Result<fst::Set<Cow<'ctx, [u8]>>> {
if let Some(fst) = self.db_cache.words_fst.clone() {
Ok(fst)
} else {
let fst = self.index.words_fst(self.txn)?;
self.db_cache.words_fst = Some(fst.clone());
Ok(fst)
}
}
pub fn word_docids(&mut self, word: Word) -> Result<Option<RoaringBitmap>> {
match word {
Word::Original(word) => {
let exact = self.get_db_exact_word_docids(word)?;
let tolerant = self.get_db_word_docids(word)?;
Ok(match (exact, tolerant) {
(None, None) => None,
(None, Some(tolerant)) => Some(tolerant),
(Some(exact), None) => Some(exact),
(Some(exact), Some(tolerant)) => {
let mut both = exact;
both |= tolerant;
Some(both)
}
})
}
Word::Derived(word) => self.get_db_word_docids(word),
}
}
/// Retrieve or insert the given value in the `word_docids` database.
fn get_db_word_docids(&mut self, word: Interned<String>) -> Result<Option<RoaringBitmap>> {
match &self.restricted_fids {
Some(restricted_fids) => {
let interned = self.word_interner.get(word).as_str();
let keys: Vec<_> = restricted_fids.iter().map(|fid| (interned, *fid)).collect();
DatabaseCache::get_value_from_keys::<_, _, CboRoaringBitmapCodec>(
self.txn,
word,
&keys[..],
&mut self.db_cache.word_docids,
self.index.word_fid_docids.remap_data_type::<ByteSlice>(),
merge_cbo_roaring_bitmaps,
)
}
None => DatabaseCache::get_value::<_, _, RoaringBitmapCodec>(
self.txn,
word,
self.word_interner.get(word).as_str(),
&mut self.db_cache.word_docids,
self.index.word_docids.remap_data_type::<ByteSlice>(),
),
}
}
fn get_db_exact_word_docids(
&mut self,
word: Interned<String>,
) -> Result<Option<RoaringBitmap>> {
DatabaseCache::get_value::<_, _, RoaringBitmapCodec>(
self.txn,
word,
self.word_interner.get(word).as_str(),
&mut self.db_cache.exact_word_docids,
self.index.exact_word_docids.remap_data_type::<ByteSlice>(),
)
}
pub fn word_prefix_docids(&mut self, prefix: Word) -> Result<Option<RoaringBitmap>> {
match prefix {
Word::Original(prefix) => {
let exact = self.get_db_exact_word_prefix_docids(prefix)?;
let tolerant = self.get_db_word_prefix_docids(prefix)?;
Ok(match (exact, tolerant) {
(None, None) => None,
(None, Some(tolerant)) => Some(tolerant),
(Some(exact), None) => Some(exact),
(Some(exact), Some(tolerant)) => {
let mut both = exact;
both |= tolerant;
Some(both)
}
})
}
Word::Derived(prefix) => self.get_db_word_prefix_docids(prefix),
}
}
/// Retrieve or insert the given value in the `word_prefix_docids` database.
fn get_db_word_prefix_docids(
&mut self,
prefix: Interned<String>,
) -> Result<Option<RoaringBitmap>> {
match &self.restricted_fids {
Some(restricted_fids) => {
let interned = self.word_interner.get(prefix).as_str();
let keys: Vec<_> = restricted_fids.iter().map(|fid| (interned, *fid)).collect();
DatabaseCache::get_value_from_keys::<_, _, CboRoaringBitmapCodec>(
self.txn,
prefix,
&keys[..],
&mut self.db_cache.word_prefix_docids,
self.index.word_prefix_fid_docids.remap_data_type::<ByteSlice>(),
merge_cbo_roaring_bitmaps,
)
}
None => DatabaseCache::get_value::<_, _, RoaringBitmapCodec>(
self.txn,
prefix,
self.word_interner.get(prefix).as_str(),
&mut self.db_cache.word_prefix_docids,
self.index.word_prefix_docids.remap_data_type::<ByteSlice>(),
),
}
}
fn get_db_exact_word_prefix_docids(
&mut self,
prefix: Interned<String>,
) -> Result<Option<RoaringBitmap>> {
DatabaseCache::get_value::<_, _, RoaringBitmapCodec>(
self.txn,
prefix,
self.word_interner.get(prefix).as_str(),
&mut self.db_cache.exact_word_prefix_docids,
self.index.exact_word_prefix_docids.remap_data_type::<ByteSlice>(),
)
}
pub fn get_db_word_pair_proximity_docids(
&mut self,
word1: Interned<String>,
word2: Interned<String>,
proximity: u8,
) -> Result<Option<RoaringBitmap>> {
DatabaseCache::get_value::<_, _, CboRoaringBitmapCodec>(
self.txn,
(proximity, word1, word2),
&(
proximity,
self.word_interner.get(word1).as_str(),
self.word_interner.get(word2).as_str(),
),
&mut self.db_cache.word_pair_proximity_docids,
self.index.word_pair_proximity_docids.remap_data_type::<ByteSlice>(),
)
}
pub fn get_db_word_pair_proximity_docids_len(
&mut self,
word1: Interned<String>,
word2: Interned<String>,
proximity: u8,
) -> Result<Option<u64>> {
DatabaseCache::get_value::<_, _, CboRoaringBitmapLenCodec>(
self.txn,
(proximity, word1, word2),
&(
proximity,
self.word_interner.get(word1).as_str(),
self.word_interner.get(word2).as_str(),
),
&mut self.db_cache.word_pair_proximity_docids,
self.index.word_pair_proximity_docids.remap_data_type::<ByteSlice>(),
)
}
pub fn get_db_word_prefix_pair_proximity_docids(
&mut self,
word1: Interned<String>,
prefix2: Interned<String>,
proximity: u8,
) -> Result<Option<RoaringBitmap>> {
DatabaseCache::get_value::<_, _, CboRoaringBitmapCodec>(
self.txn,
(proximity, word1, prefix2),
&(
proximity,
self.word_interner.get(word1).as_str(),
self.word_interner.get(prefix2).as_str(),
),
&mut self.db_cache.word_prefix_pair_proximity_docids,
self.index.word_prefix_pair_proximity_docids.remap_data_type::<ByteSlice>(),
)
}
pub fn get_db_prefix_word_pair_proximity_docids(
&mut self,
left_prefix: Interned<String>,
right: Interned<String>,
proximity: u8,
) -> Result<Option<RoaringBitmap>> {
DatabaseCache::get_value::<_, _, CboRoaringBitmapCodec>(
self.txn,
(proximity, left_prefix, right),
&(
proximity,
self.word_interner.get(left_prefix).as_str(),
self.word_interner.get(right).as_str(),
),
&mut self.db_cache.prefix_word_pair_proximity_docids,
self.index.prefix_word_pair_proximity_docids.remap_data_type::<ByteSlice>(),
)
}
pub fn get_db_word_fid_docids(
&mut self,
word: Interned<String>,
fid: u16,
) -> Result<Option<RoaringBitmap>> {
// if the requested fid isn't in the restricted list, return None.
if self.restricted_fids.as_ref().map_or(false, |fids| !fids.contains(&fid)) {
return Ok(None);
}
DatabaseCache::get_value::<_, _, CboRoaringBitmapCodec>(
self.txn,
(word, fid),
&(self.word_interner.get(word).as_str(), fid),
&mut self.db_cache.word_fid_docids,
self.index.word_fid_docids.remap_data_type::<ByteSlice>(),
)
}
pub fn get_db_word_prefix_fid_docids(
&mut self,
word_prefix: Interned<String>,
fid: u16,
) -> Result<Option<RoaringBitmap>> {
// if the requested fid isn't in the restricted list, return None.
if self.restricted_fids.as_ref().map_or(false, |fids| !fids.contains(&fid)) {
return Ok(None);
}
DatabaseCache::get_value::<_, _, CboRoaringBitmapCodec>(
self.txn,
(word_prefix, fid),
&(self.word_interner.get(word_prefix).as_str(), fid),
&mut self.db_cache.word_prefix_fid_docids,
self.index.word_prefix_fid_docids.remap_data_type::<ByteSlice>(),
)
}
pub fn get_db_word_fids(&mut self, word: Interned<String>) -> Result<Vec<u16>> {
let fids = match self.db_cache.word_fids.entry(word) {
Entry::Occupied(fids) => fids.get().clone(),
Entry::Vacant(entry) => {
let mut key = self.word_interner.get(word).as_bytes().to_owned();
key.push(0);
let mut fids = vec![];
let remap_key_type = self
.index
.word_fid_docids
.remap_types::<ByteSlice, ByteSlice>()
.prefix_iter(self.txn, &key)?
.remap_key_type::<StrBEU16Codec>();
for result in remap_key_type {
let ((_, fid), value) = result?;
// filling other caches to avoid searching for them again
self.db_cache.word_fid_docids.insert((word, fid), Some(Cow::Borrowed(value)));
fids.push(fid);
}
entry.insert(fids.clone());
fids
}
};
Ok(fids)
}
pub fn get_db_word_prefix_fids(&mut self, word_prefix: Interned<String>) -> Result<Vec<u16>> {
let fids = match self.db_cache.word_prefix_fids.entry(word_prefix) {
Entry::Occupied(fids) => fids.get().clone(),
Entry::Vacant(entry) => {
let mut key = self.word_interner.get(word_prefix).as_bytes().to_owned();
key.push(0);
let mut fids = vec![];
let remap_key_type = self
.index
.word_prefix_fid_docids
.remap_types::<ByteSlice, ByteSlice>()
.prefix_iter(self.txn, &key)?
.remap_key_type::<StrBEU16Codec>();
for result in remap_key_type {
let ((_, fid), value) = result?;
// filling other caches to avoid searching for them again
self.db_cache
.word_prefix_fid_docids
.insert((word_prefix, fid), Some(Cow::Borrowed(value)));
fids.push(fid);
}
entry.insert(fids.clone());
fids
}
};
Ok(fids)
}
pub fn get_db_word_position_docids(
&mut self,
word: Interned<String>,
position: u16,
) -> Result<Option<RoaringBitmap>> {
DatabaseCache::get_value::<_, _, CboRoaringBitmapCodec>(
self.txn,
(word, position),
&(self.word_interner.get(word).as_str(), position),
&mut self.db_cache.word_position_docids,
self.index.word_position_docids.remap_data_type::<ByteSlice>(),
)
}
pub fn get_db_word_prefix_position_docids(
&mut self,
word_prefix: Interned<String>,
position: u16,
) -> Result<Option<RoaringBitmap>> {
DatabaseCache::get_value::<_, _, CboRoaringBitmapCodec>(
self.txn,
(word_prefix, position),
&(self.word_interner.get(word_prefix).as_str(), position),
&mut self.db_cache.word_prefix_position_docids,
self.index.word_prefix_position_docids.remap_data_type::<ByteSlice>(),
)
}
pub fn get_db_word_positions(&mut self, word: Interned<String>) -> Result<Vec<u16>> {
let positions = match self.db_cache.word_positions.entry(word) {
Entry::Occupied(positions) => positions.get().clone(),
Entry::Vacant(entry) => {
let mut key = self.word_interner.get(word).as_bytes().to_owned();
key.push(0);
let mut positions = vec![];
let remap_key_type = self
.index
.word_position_docids
.remap_types::<ByteSlice, ByteSlice>()
.prefix_iter(self.txn, &key)?
.remap_key_type::<StrBEU16Codec>();
for result in remap_key_type {
let ((_, position), value) = result?;
// filling other caches to avoid searching for them again
self.db_cache
.word_position_docids
.insert((word, position), Some(Cow::Borrowed(value)));
positions.push(position);
}
entry.insert(positions.clone());
positions
}
};
Ok(positions)
}
pub fn get_db_word_prefix_positions(
&mut self,
word_prefix: Interned<String>,
) -> Result<Vec<u16>> {
let positions = match self.db_cache.word_prefix_positions.entry(word_prefix) {
Entry::Occupied(positions) => positions.get().clone(),
Entry::Vacant(entry) => {
let mut key = self.word_interner.get(word_prefix).as_bytes().to_owned();
key.push(0);
let mut positions = vec![];
let remap_key_type = self
.index
.word_prefix_position_docids
.remap_types::<ByteSlice, ByteSlice>()
.prefix_iter(self.txn, &key)?
.remap_key_type::<StrBEU16Codec>();
for result in remap_key_type {
let ((_, position), value) = result?;
// filling other caches to avoid searching for them again
self.db_cache
.word_prefix_position_docids
.insert((word_prefix, position), Some(Cow::Borrowed(value)));
positions.push(position);
}
entry.insert(positions.clone());
positions
}
};
Ok(positions)
}
}