mirror of
https://github.com/meilisearch/meilisearch.git
synced 2024-11-23 10:37:41 +08:00
Re-implement set based algorithm for attribute criterion
This commit is contained in:
many
parent
31c18f0953
commit
75d341d928
@ -1,7 +1,7 @@
|
||||
use std::borrow::Cow;
|
||||
use std::cmp::{self, Ordering};
|
||||
use std::collections::binary_heap::PeekMut;
|
||||
use std::collections::{btree_map, BTreeMap, BinaryHeap, HashMap};
|
||||
use std::iter::Peekable;
|
||||
use std::mem::take;
|
||||
|
||||
use roaring::RoaringBitmap;
|
||||
@ -17,10 +17,6 @@ use crate::{Result, TreeLevel};
|
||||
/// We chose the LCM of all numbers between 1 and 10 as the multiplier (https://en.wikipedia.org/wiki/Least_common_multiple).
|
||||
const LCM_10_FIRST_NUMBERS: u32 = 2520;
|
||||
|
||||
/// To compute the interval size of a level,
|
||||
/// we use 4 as the exponentiation base and the level as the exponent.
|
||||
const LEVEL_EXPONENTIATION_BASE: u32 = 4;
|
||||
|
||||
/// Threshold on the number of candidates that will make
|
||||
/// the system to choose between one algorithm or another.
|
||||
const CANDIDATES_THRESHOLD: u64 = 1000;
|
||||
@ -32,7 +28,8 @@ pub struct Attribute<'t> {
|
||||
state: Option<(Operation, FlattenedQueryTree, RoaringBitmap)>,
|
||||
bucket_candidates: RoaringBitmap,
|
||||
parent: Box<dyn Criterion + 't>,
|
||||
current_buckets: Option<btree_map::IntoIter<u64, RoaringBitmap>>,
|
||||
linear_buckets: Option<btree_map::IntoIter<u64, RoaringBitmap>>,
|
||||
set_buckets: Option<BinaryHeap<Branch<'t>>>,
|
||||
}
|
||||
|
||||
impl<'t> Attribute<'t> {
|
||||
@ -42,7 +39,8 @@ impl<'t> Attribute<'t> {
|
||||
state: None,
|
||||
bucket_candidates: RoaringBitmap::new(),
|
||||
parent,
|
||||
current_buckets: None,
|
||||
linear_buckets: None,
|
||||
set_buckets: None,
|
||||
}
|
||||
}
|
||||
}
|
||||
@ -67,19 +65,19 @@ impl<'t> Criterion for Attribute<'t> {
|
||||
}
|
||||
Some((query_tree, flattened_query_tree, mut allowed_candidates)) => {
|
||||
let found_candidates = if allowed_candidates.len() < CANDIDATES_THRESHOLD {
|
||||
let current_buckets = match self.current_buckets.as_mut() {
|
||||
Some(current_buckets) => current_buckets,
|
||||
let linear_buckets = match self.linear_buckets.as_mut() {
|
||||
Some(linear_buckets) => linear_buckets,
|
||||
None => {
|
||||
let new_buckets = linear_compute_candidates(
|
||||
let new_buckets = initialize_linear_buckets(
|
||||
self.ctx,
|
||||
&flattened_query_tree,
|
||||
&allowed_candidates,
|
||||
)?;
|
||||
self.current_buckets.get_or_insert(new_buckets.into_iter())
|
||||
self.linear_buckets.get_or_insert(new_buckets.into_iter())
|
||||
}
|
||||
};
|
||||
|
||||
match current_buckets.next() {
|
||||
match linear_buckets.next() {
|
||||
Some((_score, candidates)) => candidates,
|
||||
None => {
|
||||
return Ok(Some(CriterionResult {
|
||||
@ -91,13 +89,21 @@ impl<'t> Criterion for Attribute<'t> {
|
||||
}
|
||||
}
|
||||
} else {
|
||||
match set_compute_candidates(
|
||||
self.ctx,
|
||||
&flattened_query_tree,
|
||||
&allowed_candidates,
|
||||
params.wdcache,
|
||||
)? {
|
||||
Some(candidates) => candidates,
|
||||
let mut set_buckets = match self.set_buckets.as_mut() {
|
||||
Some(set_buckets) => set_buckets,
|
||||
None => {
|
||||
let new_buckets = initialize_set_buckets(
|
||||
self.ctx,
|
||||
&flattened_query_tree,
|
||||
&allowed_candidates,
|
||||
params.wdcache,
|
||||
)?;
|
||||
self.set_buckets.get_or_insert(new_buckets)
|
||||
}
|
||||
};
|
||||
|
||||
match set_compute_candidates(&mut set_buckets, &allowed_candidates)? {
|
||||
Some((_score, candidates)) => candidates,
|
||||
None => {
|
||||
return Ok(Some(CriterionResult {
|
||||
query_tree: Some(query_tree),
|
||||
@ -148,7 +154,7 @@ impl<'t> Criterion for Attribute<'t> {
|
||||
}
|
||||
|
||||
self.state = Some((query_tree, flattened_query_tree, candidates));
|
||||
self.current_buckets = None;
|
||||
self.linear_buckets = None;
|
||||
}
|
||||
Some(CriterionResult {
|
||||
query_tree: None,
|
||||
@ -170,142 +176,52 @@ impl<'t> Criterion for Attribute<'t> {
|
||||
}
|
||||
}
|
||||
|
||||
/// WordLevelIterator is an pseudo-Iterator over intervals of word-position for one word,
|
||||
/// it will begin at the first non-empty interval and will return every interval without
|
||||
/// jumping over empty intervals.
|
||||
struct WordLevelIterator<'t, 'q> {
|
||||
inner: Box<
|
||||
dyn Iterator<Item = heed::Result<((&'t str, TreeLevel, u32, u32), RoaringBitmap)>> + 't,
|
||||
>,
|
||||
level: TreeLevel,
|
||||
interval_size: u32,
|
||||
word: Cow<'q, str>,
|
||||
in_prefix_cache: bool,
|
||||
inner_next: Option<(u32, u32, RoaringBitmap)>,
|
||||
current_interval: Option<(u32, u32)>,
|
||||
}
|
||||
|
||||
impl<'t, 'q> WordLevelIterator<'t, 'q> {
|
||||
fn new(
|
||||
ctx: &'t dyn Context<'t>,
|
||||
word: Cow<'q, str>,
|
||||
in_prefix_cache: bool,
|
||||
) -> heed::Result<Option<Self>> {
|
||||
match ctx.word_position_last_level(&word, in_prefix_cache)? {
|
||||
Some(_) => {
|
||||
// HOTFIX Meilisearch#1707: it is better to only iterate over level 0 for performances reasons.
|
||||
let level = TreeLevel::min_value();
|
||||
let interval_size = LEVEL_EXPONENTIATION_BASE.pow(Into::<u8>::into(level) as u32);
|
||||
let inner =
|
||||
ctx.word_position_iterator(&word, level, in_prefix_cache, None, None)?;
|
||||
Ok(Some(Self {
|
||||
inner,
|
||||
level,
|
||||
interval_size,
|
||||
word,
|
||||
in_prefix_cache,
|
||||
inner_next: None,
|
||||
current_interval: None,
|
||||
}))
|
||||
}
|
||||
None => Ok(None),
|
||||
}
|
||||
}
|
||||
|
||||
fn dig(
|
||||
&self,
|
||||
ctx: &'t dyn Context<'t>,
|
||||
level: &TreeLevel,
|
||||
left_interval: Option<u32>,
|
||||
) -> heed::Result<Self> {
|
||||
let level = *level.min(&self.level);
|
||||
let interval_size = LEVEL_EXPONENTIATION_BASE.pow(Into::<u8>::into(level) as u32);
|
||||
let word = self.word.clone();
|
||||
let in_prefix_cache = self.in_prefix_cache;
|
||||
let inner =
|
||||
ctx.word_position_iterator(&word, level, in_prefix_cache, left_interval, None)?;
|
||||
|
||||
Ok(Self {
|
||||
inner,
|
||||
level,
|
||||
interval_size,
|
||||
word,
|
||||
in_prefix_cache,
|
||||
inner_next: None,
|
||||
current_interval: None,
|
||||
})
|
||||
}
|
||||
|
||||
fn next(&mut self) -> heed::Result<Option<(u32, u32, RoaringBitmap)>> {
|
||||
fn is_next_interval(last_right: u32, next_left: u32) -> bool {
|
||||
last_right + 1 == next_left
|
||||
}
|
||||
|
||||
let inner_next = match self.inner_next.take() {
|
||||
Some(inner_next) => Some(inner_next),
|
||||
None => self
|
||||
.inner
|
||||
.next()
|
||||
.transpose()?
|
||||
.map(|((_, _, left, right), docids)| (left, right, docids)),
|
||||
};
|
||||
|
||||
match inner_next {
|
||||
Some((left, right, docids)) => match self.current_interval {
|
||||
Some((last_left, last_right)) if !is_next_interval(last_right, left) => {
|
||||
let blank_left = last_left + self.interval_size;
|
||||
let blank_right = last_right + self.interval_size;
|
||||
self.current_interval = Some((blank_left, blank_right));
|
||||
self.inner_next = Some((left, right, docids));
|
||||
Ok(Some((blank_left, blank_right, RoaringBitmap::new())))
|
||||
}
|
||||
_ => {
|
||||
self.current_interval = Some((left, right));
|
||||
Ok(Some((left, right, docids)))
|
||||
}
|
||||
},
|
||||
None => Ok(None),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// QueryLevelIterator is an pseudo-Iterator for a Query,
|
||||
/// It contains WordLevelIterators and is chainned with other QueryLevelIterator.
|
||||
struct QueryLevelIterator<'t, 'q> {
|
||||
parent: Option<Box<QueryLevelIterator<'t, 'q>>>,
|
||||
inner: Vec<WordLevelIterator<'t, 'q>>,
|
||||
level: TreeLevel,
|
||||
accumulator: Vec<Option<(u32, u32, RoaringBitmap)>>,
|
||||
parent_accumulator: Vec<Option<(u32, u32, RoaringBitmap)>>,
|
||||
interval_to_skip: usize,
|
||||
struct QueryLevelIterator<'t> {
|
||||
inner: Vec<
|
||||
Peekable<
|
||||
Box<
|
||||
dyn Iterator<Item = heed::Result<((&'t str, TreeLevel, u32, u32), RoaringBitmap)>>
|
||||
+ 't,
|
||||
>,
|
||||
>,
|
||||
>,
|
||||
}
|
||||
|
||||
impl<'t, 'q> QueryLevelIterator<'t, 'q> {
|
||||
impl<'t> QueryLevelIterator<'t> {
|
||||
fn new(
|
||||
ctx: &'t dyn Context<'t>,
|
||||
queries: &'q [Query],
|
||||
queries: &[Query],
|
||||
wdcache: &mut WordDerivationsCache,
|
||||
) -> Result<Option<Self>> {
|
||||
) -> Result<Self> {
|
||||
let mut inner = Vec::with_capacity(queries.len());
|
||||
for query in queries {
|
||||
let in_prefix_cache = query.prefix && ctx.in_prefix_cache(query.kind.word());
|
||||
match &query.kind {
|
||||
QueryKind::Exact { word, .. } => {
|
||||
if !query.prefix || ctx.in_prefix_cache(&word) {
|
||||
let word = Cow::Borrowed(query.kind.word());
|
||||
if let Some(word_level_iterator) =
|
||||
WordLevelIterator::new(ctx, word, query.prefix)?
|
||||
{
|
||||
inner.push(word_level_iterator);
|
||||
}
|
||||
if !query.prefix || in_prefix_cache {
|
||||
let iter = ctx.word_position_iterator(
|
||||
query.kind.word(),
|
||||
TreeLevel::min_value(),
|
||||
in_prefix_cache,
|
||||
None,
|
||||
None,
|
||||
)?;
|
||||
|
||||
inner.push(iter.peekable());
|
||||
} else {
|
||||
for (word, _) in word_derivations(&word, true, 0, ctx.words_fst(), wdcache)?
|
||||
{
|
||||
let word = Cow::Owned(word.to_owned());
|
||||
if let Some(word_level_iterator) =
|
||||
WordLevelIterator::new(ctx, word, false)?
|
||||
{
|
||||
inner.push(word_level_iterator);
|
||||
}
|
||||
let iter = ctx.word_position_iterator(
|
||||
&word,
|
||||
TreeLevel::min_value(),
|
||||
in_prefix_cache,
|
||||
None,
|
||||
None,
|
||||
)?;
|
||||
|
||||
inner.push(iter.peekable());
|
||||
}
|
||||
}
|
||||
}
|
||||
@ -313,360 +229,255 @@ impl<'t, 'q> QueryLevelIterator<'t, 'q> {
|
||||
for (word, _) in
|
||||
word_derivations(&word, query.prefix, *typo, ctx.words_fst(), wdcache)?
|
||||
{
|
||||
let word = Cow::Owned(word.to_owned());
|
||||
if let Some(word_level_iterator) = WordLevelIterator::new(ctx, word, false)?
|
||||
{
|
||||
inner.push(word_level_iterator);
|
||||
}
|
||||
let iter = ctx.word_position_iterator(
|
||||
&word,
|
||||
TreeLevel::min_value(),
|
||||
in_prefix_cache,
|
||||
None,
|
||||
None,
|
||||
)?;
|
||||
|
||||
inner.push(iter.peekable());
|
||||
}
|
||||
}
|
||||
}
|
||||
};
|
||||
}
|
||||
|
||||
let highest = inner.iter().max_by_key(|wli| wli.level).map(|wli| wli.level);
|
||||
match highest {
|
||||
Some(level) => Ok(Some(Self {
|
||||
parent: None,
|
||||
inner,
|
||||
level,
|
||||
accumulator: vec![],
|
||||
parent_accumulator: vec![],
|
||||
interval_to_skip: 0,
|
||||
})),
|
||||
None => Ok(None),
|
||||
}
|
||||
}
|
||||
|
||||
fn parent(&mut self, parent: QueryLevelIterator<'t, 'q>) -> &Self {
|
||||
self.parent = Some(Box::new(parent));
|
||||
self
|
||||
}
|
||||
|
||||
/// create a new QueryLevelIterator with a lower level than the current one.
|
||||
fn dig(&self, ctx: &'t dyn Context<'t>) -> heed::Result<Self> {
|
||||
let (level, parent) = match &self.parent {
|
||||
Some(parent) => {
|
||||
let parent = parent.dig(ctx)?;
|
||||
(parent.level.min(self.level), Some(Box::new(parent)))
|
||||
}
|
||||
None => (self.level.saturating_sub(1), None),
|
||||
};
|
||||
|
||||
let left_interval = self
|
||||
.accumulator
|
||||
.get(self.interval_to_skip)
|
||||
.map(|opt| opt.as_ref().map(|(left, _, _)| *left))
|
||||
.flatten();
|
||||
let mut inner = Vec::with_capacity(self.inner.len());
|
||||
for word_level_iterator in self.inner.iter() {
|
||||
inner.push(word_level_iterator.dig(ctx, &level, left_interval)?);
|
||||
}
|
||||
|
||||
Ok(Self {
|
||||
parent,
|
||||
inner,
|
||||
level,
|
||||
accumulator: vec![],
|
||||
parent_accumulator: vec![],
|
||||
interval_to_skip: 0,
|
||||
})
|
||||
}
|
||||
|
||||
fn inner_next(&mut self, level: TreeLevel) -> heed::Result<Option<(u32, u32, RoaringBitmap)>> {
|
||||
let mut accumulated: Option<(u32, u32, RoaringBitmap)> = None;
|
||||
let u8_level = Into::<u8>::into(level);
|
||||
let interval_size = LEVEL_EXPONENTIATION_BASE.pow(u8_level as u32);
|
||||
for wli in self.inner.iter_mut() {
|
||||
let wli_u8_level = Into::<u8>::into(wli.level);
|
||||
let accumulated_count = LEVEL_EXPONENTIATION_BASE.pow((u8_level - wli_u8_level) as u32);
|
||||
for _ in 0..accumulated_count {
|
||||
if let Some((next_left, _, next_docids)) = wli.next()? {
|
||||
accumulated = match accumulated.take() {
|
||||
Some((acc_left, acc_right, mut acc_docids)) => {
|
||||
acc_docids |= next_docids;
|
||||
Some((acc_left, acc_right, acc_docids))
|
||||
}
|
||||
None => Some((next_left, next_left + interval_size, next_docids)),
|
||||
};
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
Ok(accumulated)
|
||||
}
|
||||
|
||||
/// return the next meta-interval created from inner WordLevelIterators,
|
||||
/// and from eventual chainned QueryLevelIterator.
|
||||
fn next(
|
||||
&mut self,
|
||||
allowed_candidates: &RoaringBitmap,
|
||||
tree_level: TreeLevel,
|
||||
) -> heed::Result<Option<(u32, u32, RoaringBitmap)>> {
|
||||
let parent_result = match self.parent.as_mut() {
|
||||
Some(parent) => Some(parent.next(allowed_candidates, tree_level)?),
|
||||
None => None,
|
||||
};
|
||||
|
||||
match parent_result {
|
||||
Some(parent_next) => {
|
||||
let inner_next = self.inner_next(tree_level)?;
|
||||
self.interval_to_skip += interval_to_skip(
|
||||
&self.parent_accumulator,
|
||||
&self.accumulator,
|
||||
self.interval_to_skip,
|
||||
allowed_candidates,
|
||||
);
|
||||
self.accumulator.push(inner_next);
|
||||
self.parent_accumulator.push(parent_next);
|
||||
let mut merged_interval: Option<(u32, u32, RoaringBitmap)> = None;
|
||||
|
||||
for current in self
|
||||
.accumulator
|
||||
.iter()
|
||||
.rev()
|
||||
.zip(self.parent_accumulator.iter())
|
||||
.skip(self.interval_to_skip)
|
||||
{
|
||||
if let (Some((left_a, right_a, a)), Some((left_b, right_b, b))) = current {
|
||||
match merged_interval.as_mut() {
|
||||
Some((_, _, merged_docids)) => *merged_docids |= a & b,
|
||||
None => {
|
||||
merged_interval = Some((left_a + left_b, right_a + right_b, a & b))
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
Ok(merged_interval)
|
||||
}
|
||||
None => {
|
||||
let level = self.level;
|
||||
match self.inner_next(level)? {
|
||||
Some((left, right, mut candidates)) => {
|
||||
self.accumulator = vec![Some((left, right, RoaringBitmap::new()))];
|
||||
candidates &= allowed_candidates;
|
||||
Ok(Some((left, right, candidates)))
|
||||
}
|
||||
None => {
|
||||
self.accumulator = vec![None];
|
||||
Ok(None)
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
Ok(Self { inner })
|
||||
}
|
||||
}
|
||||
|
||||
/// Count the number of interval that can be skiped when we make the cross-intersections
|
||||
/// in order to compute the next meta-interval.
|
||||
/// A pair of intervals is skiped when both intervals doesn't contain any allowed docids.
|
||||
fn interval_to_skip(
|
||||
parent_accumulator: &[Option<(u32, u32, RoaringBitmap)>],
|
||||
current_accumulator: &[Option<(u32, u32, RoaringBitmap)>],
|
||||
already_skiped: usize,
|
||||
allowed_candidates: &RoaringBitmap,
|
||||
) -> usize {
|
||||
parent_accumulator
|
||||
.iter()
|
||||
.zip(current_accumulator.iter())
|
||||
.skip(already_skiped)
|
||||
.take_while(|(parent, current)| {
|
||||
let skip_parent = parent.as_ref().map_or(true, |(_, _, docids)| docids.is_empty());
|
||||
let skip_current = current
|
||||
.as_ref()
|
||||
.map_or(true, |(_, _, docids)| docids.is_disjoint(allowed_candidates));
|
||||
skip_parent && skip_current
|
||||
})
|
||||
.count()
|
||||
impl<'t> Iterator for QueryLevelIterator<'t> {
|
||||
type Item = heed::Result<(u32, RoaringBitmap)>;
|
||||
|
||||
fn next(&mut self) -> Option<Self::Item> {
|
||||
// sort inner words from the closest next position to the more far next position.
|
||||
let expected_pos = self
|
||||
.inner
|
||||
.iter_mut()
|
||||
.filter_map(|wli| match wli.peek() {
|
||||
Some(Ok(((_, _, pos, _), _))) => Some(*pos),
|
||||
_ => None,
|
||||
})
|
||||
.min()?;
|
||||
|
||||
let mut candidates = None;
|
||||
for wli in self.inner.iter_mut() {
|
||||
if let Some(Ok(((_, _, pos, _), _))) = wli.peek() {
|
||||
if *pos > expected_pos {
|
||||
continue;
|
||||
}
|
||||
}
|
||||
|
||||
match wli.next() {
|
||||
Some(Ok((_, docids))) => {
|
||||
candidates = match candidates.take() {
|
||||
Some(candidates) => Some(candidates | docids),
|
||||
None => Some(docids),
|
||||
}
|
||||
}
|
||||
Some(Err(e)) => return Some(Err(e)),
|
||||
None => continue,
|
||||
}
|
||||
}
|
||||
|
||||
candidates.map(|candidates| Ok((expected_pos, candidates)))
|
||||
}
|
||||
}
|
||||
|
||||
/// A Branch is represent a possible alternative of the original query and is build with the Query Tree,
|
||||
/// This branch allows us to iterate over meta-interval of position and to dig in it if it contains interesting candidates.
|
||||
struct Branch<'t, 'q> {
|
||||
query_level_iterator: QueryLevelIterator<'t, 'q>,
|
||||
last_result: (u32, u32, RoaringBitmap),
|
||||
tree_level: TreeLevel,
|
||||
struct Branch<'t> {
|
||||
query_level_iterator: Vec<(u32, RoaringBitmap, Peekable<QueryLevelIterator<'t>>)>,
|
||||
last_result: (u32, RoaringBitmap),
|
||||
branch_size: u32,
|
||||
}
|
||||
|
||||
impl<'t, 'q> Branch<'t, 'q> {
|
||||
impl<'t> Branch<'t> {
|
||||
fn new(
|
||||
ctx: &'t dyn Context<'t>,
|
||||
flatten_branch: &[Vec<Query>],
|
||||
wdcache: &mut WordDerivationsCache,
|
||||
allowed_candidates: &RoaringBitmap,
|
||||
) -> Result<Self> {
|
||||
let mut query_level_iterator = Vec::new();
|
||||
for queries in flatten_branch {
|
||||
let mut qli = QueryLevelIterator::new(ctx, queries, wdcache)?.peekable();
|
||||
let (pos, docids) = qli.next().transpose()?.unwrap_or((0, RoaringBitmap::new()));
|
||||
query_level_iterator.push((pos, docids & allowed_candidates, qli));
|
||||
}
|
||||
|
||||
let mut branch = Self {
|
||||
query_level_iterator,
|
||||
last_result: (0, RoaringBitmap::new()),
|
||||
branch_size: flatten_branch.len() as u32,
|
||||
};
|
||||
|
||||
branch.update_last_result();
|
||||
|
||||
Ok(branch)
|
||||
}
|
||||
|
||||
/// return the next meta-interval of the branch,
|
||||
/// and update inner interval in order to be ranked by the BinaryHeap.
|
||||
fn next(&mut self, allowed_candidates: &RoaringBitmap) -> heed::Result<bool> {
|
||||
let tree_level = self.query_level_iterator.level;
|
||||
match self.query_level_iterator.next(allowed_candidates, tree_level)? {
|
||||
Some(last_result) => {
|
||||
self.last_result = last_result;
|
||||
self.tree_level = tree_level;
|
||||
Ok(true)
|
||||
}
|
||||
None => Ok(false),
|
||||
// update the first query.
|
||||
let index = self.lowest_iterator_index();
|
||||
match self.query_level_iterator.get_mut(index) {
|
||||
Some((cur_pos, cur_docids, qli)) => match qli.next().transpose()? {
|
||||
Some((next_pos, next_docids)) => {
|
||||
*cur_pos = next_pos;
|
||||
*cur_docids |= next_docids & allowed_candidates;
|
||||
}
|
||||
None => return Ok(false),
|
||||
},
|
||||
None => return Ok(false),
|
||||
}
|
||||
|
||||
self.update_last_result();
|
||||
|
||||
Ok(true)
|
||||
}
|
||||
|
||||
/// make the current Branch iterate over smaller intervals.
|
||||
fn dig(&mut self, ctx: &'t dyn Context<'t>) -> heed::Result<()> {
|
||||
self.query_level_iterator = self.query_level_iterator.dig(ctx)?;
|
||||
Ok(())
|
||||
fn lowest_iterator_index(&mut self) -> usize {
|
||||
let (index, _) = self
|
||||
.query_level_iterator
|
||||
.iter_mut()
|
||||
.map(|(pos, docids, qli)| {
|
||||
if docids.is_empty() {
|
||||
0
|
||||
} else {
|
||||
qli.peek()
|
||||
.map(|result| {
|
||||
result.as_ref().map(|(next_pos, _)| *next_pos - *pos).unwrap_or(0)
|
||||
})
|
||||
.unwrap_or(u32::MAX)
|
||||
}
|
||||
})
|
||||
.enumerate()
|
||||
.min_by_key(|(_, diff)| *diff)
|
||||
.unwrap_or((0, 0));
|
||||
|
||||
index
|
||||
}
|
||||
|
||||
/// because next() method could be time consuming,
|
||||
/// update inner interval in order to be ranked by the binary_heap without computing it,
|
||||
/// the next() method should be called when the real interval is needed.
|
||||
fn lazy_next(&mut self) {
|
||||
let u8_level = Into::<u8>::into(self.tree_level);
|
||||
let interval_size = LEVEL_EXPONENTIATION_BASE.pow(u8_level as u32);
|
||||
let (left, right, _) = self.last_result;
|
||||
fn update_last_result(&mut self) {
|
||||
let mut result_pos = 0;
|
||||
let mut result_docids = None;
|
||||
|
||||
self.last_result = (left + interval_size, right + interval_size, RoaringBitmap::new());
|
||||
for (pos, docids, _qli) in self.query_level_iterator.iter() {
|
||||
result_pos += pos;
|
||||
result_docids = result_docids
|
||||
.take()
|
||||
.map_or_else(|| Some(docids.clone()), |candidates| Some(candidates & docids));
|
||||
}
|
||||
|
||||
// remove last result docids from inner iterators
|
||||
if let Some(docids) = result_docids.as_ref() {
|
||||
for (_, query_docids, _) in self.query_level_iterator.iter_mut() {
|
||||
*query_docids -= docids;
|
||||
}
|
||||
}
|
||||
|
||||
self.last_result = (result_pos, result_docids.unwrap_or_default());
|
||||
}
|
||||
|
||||
/// return the score of the current inner interval.
|
||||
fn compute_rank(&self) -> u32 {
|
||||
// we compute a rank from the left interval.
|
||||
let (left, _, _) = self.last_result;
|
||||
left.saturating_sub((0..self.branch_size).sum()) * LCM_10_FIRST_NUMBERS / self.branch_size
|
||||
// we compute a rank from the position.
|
||||
let (pos, _) = self.last_result;
|
||||
pos.saturating_sub((0..self.branch_size).sum()) * LCM_10_FIRST_NUMBERS / self.branch_size
|
||||
}
|
||||
|
||||
fn cmp(&self, other: &Self) -> Ordering {
|
||||
let self_rank = self.compute_rank();
|
||||
let other_rank = other.compute_rank();
|
||||
let left_cmp = self_rank.cmp(&other_rank);
|
||||
// on level: lower is better,
|
||||
// we want to dig faster into levels on interesting branches.
|
||||
let level_cmp = self.tree_level.cmp(&other.tree_level);
|
||||
|
||||
left_cmp.then(level_cmp).then(self.last_result.2.len().cmp(&other.last_result.2.len()))
|
||||
// lower rank is better, and because BinaryHeap give the higher ranked branch, we reverse it.
|
||||
self_rank.cmp(&other_rank).reverse()
|
||||
}
|
||||
}
|
||||
|
||||
impl<'t, 'q> Ord for Branch<'t, 'q> {
|
||||
impl<'t> Ord for Branch<'t> {
|
||||
fn cmp(&self, other: &Self) -> Ordering {
|
||||
self.cmp(other)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'t, 'q> PartialOrd for Branch<'t, 'q> {
|
||||
impl<'t> PartialOrd for Branch<'t> {
|
||||
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
|
||||
Some(self.cmp(other))
|
||||
}
|
||||
}
|
||||
|
||||
impl<'t, 'q> PartialEq for Branch<'t, 'q> {
|
||||
impl<'t> PartialEq for Branch<'t> {
|
||||
fn eq(&self, other: &Self) -> bool {
|
||||
self.cmp(other) == Ordering::Equal
|
||||
}
|
||||
}
|
||||
|
||||
impl<'t, 'q> Eq for Branch<'t, 'q> {}
|
||||
impl<'t> Eq for Branch<'t> {}
|
||||
|
||||
fn initialize_query_level_iterators<'t, 'q>(
|
||||
ctx: &'t dyn Context<'t>,
|
||||
branches: &'q FlattenedQueryTree,
|
||||
allowed_candidates: &RoaringBitmap,
|
||||
wdcache: &mut WordDerivationsCache,
|
||||
) -> Result<BinaryHeap<Branch<'t, 'q>>> {
|
||||
let mut positions = BinaryHeap::with_capacity(branches.len());
|
||||
for branch in branches {
|
||||
let mut branch_positions = Vec::with_capacity(branch.len());
|
||||
for queries in branch {
|
||||
match QueryLevelIterator::new(ctx, queries, wdcache)? {
|
||||
Some(qli) => branch_positions.push(qli),
|
||||
None => {
|
||||
// the branch seems to be invalid, so we skip it.
|
||||
branch_positions.clear();
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
// QueryLevelIterator need to be sorted by level and folded in descending order.
|
||||
branch_positions.sort_unstable_by_key(|qli| qli.level);
|
||||
let folded_query_level_iterators =
|
||||
branch_positions.into_iter().fold(None, |fold: Option<QueryLevelIterator>, mut qli| {
|
||||
match fold {
|
||||
Some(fold) => {
|
||||
qli.parent(fold);
|
||||
Some(qli)
|
||||
}
|
||||
None => Some(qli),
|
||||
}
|
||||
});
|
||||
|
||||
if let Some(mut folded_query_level_iterators) = folded_query_level_iterators {
|
||||
let tree_level = folded_query_level_iterators.level;
|
||||
let last_result = folded_query_level_iterators.next(allowed_candidates, tree_level)?;
|
||||
if let Some(last_result) = last_result {
|
||||
let branch = Branch {
|
||||
last_result,
|
||||
tree_level,
|
||||
query_level_iterator: folded_query_level_iterators,
|
||||
branch_size: branch.len() as u32,
|
||||
};
|
||||
positions.push(branch);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
Ok(positions)
|
||||
}
|
||||
|
||||
fn set_compute_candidates<'t>(
|
||||
fn initialize_set_buckets<'t>(
|
||||
ctx: &'t dyn Context<'t>,
|
||||
branches: &FlattenedQueryTree,
|
||||
allowed_candidates: &RoaringBitmap,
|
||||
wdcache: &mut WordDerivationsCache,
|
||||
) -> Result<Option<RoaringBitmap>> {
|
||||
let mut branches_heap =
|
||||
initialize_query_level_iterators(ctx, branches, allowed_candidates, wdcache)?;
|
||||
let lowest_level = TreeLevel::min_value();
|
||||
) -> Result<BinaryHeap<Branch<'t>>> {
|
||||
let mut heap = BinaryHeap::new();
|
||||
for flatten_branch in branches {
|
||||
let branch = Branch::new(ctx, flatten_branch, wdcache, allowed_candidates)?;
|
||||
heap.push(branch);
|
||||
}
|
||||
|
||||
Ok(heap)
|
||||
}
|
||||
|
||||
fn set_compute_candidates(
|
||||
branches_heap: &mut BinaryHeap<Branch>,
|
||||
allowed_candidates: &RoaringBitmap,
|
||||
) -> Result<Option<(u32, RoaringBitmap)>> {
|
||||
let mut final_candidates: Option<(u32, RoaringBitmap)> = None;
|
||||
let mut allowed_candidates = allowed_candidates.clone();
|
||||
|
||||
while let Some(mut branch) = branches_heap.peek_mut() {
|
||||
let is_lowest_level = branch.tree_level == lowest_level;
|
||||
let branch_rank = branch.compute_rank();
|
||||
// if current is worst than best we break to return
|
||||
// candidates that correspond to the best rank
|
||||
let branch_rank = branch.compute_rank();
|
||||
if let Some((best_rank, _)) = final_candidates {
|
||||
if branch_rank > best_rank {
|
||||
break;
|
||||
}
|
||||
}
|
||||
let _left = branch.last_result.0;
|
||||
let candidates = take(&mut branch.last_result.2);
|
||||
|
||||
let candidates = take(&mut branch.last_result.1);
|
||||
if candidates.is_empty() {
|
||||
// we don't have candidates, get next interval.
|
||||
if !branch.next(&allowed_candidates)? {
|
||||
PeekMut::pop(branch);
|
||||
}
|
||||
} else if is_lowest_level {
|
||||
// we have candidates, but we can't dig deeper.
|
||||
} else {
|
||||
allowed_candidates -= &candidates;
|
||||
final_candidates = match final_candidates.take() {
|
||||
// we add current candidates to best candidates
|
||||
Some((best_rank, mut best_candidates)) => {
|
||||
best_candidates |= candidates;
|
||||
branch.lazy_next();
|
||||
branch.next(&allowed_candidates)?;
|
||||
Some((best_rank, best_candidates))
|
||||
}
|
||||
// we take current candidates as best candidates
|
||||
None => {
|
||||
branch.lazy_next();
|
||||
branch.next(&allowed_candidates)?;
|
||||
Some((branch_rank, candidates))
|
||||
}
|
||||
};
|
||||
} else {
|
||||
// we have candidates, lets dig deeper in levels.
|
||||
branch.dig(ctx)?;
|
||||
if !branch.next(&allowed_candidates)? {
|
||||
PeekMut::pop(branch);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
Ok(final_candidates.map(|(_rank, candidates)| candidates))
|
||||
Ok(final_candidates)
|
||||
}
|
||||
|
||||
fn linear_compute_candidates(
|
||||
fn initialize_linear_buckets(
|
||||
ctx: &dyn Context,
|
||||
branches: &FlattenedQueryTree,
|
||||
allowed_candidates: &RoaringBitmap,
|
||||
|
||||
Loading…
Reference in New Issue
Block a user