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Update QueryGraph to use new lazy query terms + build from paths

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This commit is contained in:
Loïc Lecrenier 2023-03-30 11:05:51 +02:00
parent 9507ff5e31
commit 223e82a10d
1 changed files with 241 additions and 142 deletions
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383
milli/src/search/new/query_graph.rs
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@ -1,10 +1,14 @@
use std::collections::HashSet;
use super::interner::{FixedSizeInterner, Interned};
use super::query_term::{self, number_of_typos_allowed, LocatedQueryTerm};
use super::query_term::{
self, number_of_typos_allowed, LocatedQueryTerm, LocatedQueryTermSubset, NTypoTermSubset,
QueryTermSubset,
};
use super::small_bitmap::SmallBitmap;
use super::SearchContext;
use crate::search::new::interner::DedupInterner;
use crate::Result;
use std::cmp::Ordering;
use std::collections::BTreeMap;
/// A node of the [`QueryGraph`].
///
@ -21,9 +25,9 @@ pub struct QueryNode {
pub predecessors: SmallBitmap<QueryNode>,
pub successors: SmallBitmap<QueryNode>,
}
#[derive(Clone)]
#[derive(Clone, PartialEq, Eq, Hash)]
pub enum QueryNodeData {
Term(LocatedQueryTerm),
Term(LocatedQueryTermSubset),
Deleted,
Start,
End,
@ -83,51 +87,15 @@ pub struct QueryGraph {
pub nodes: FixedSizeInterner<QueryNode>,
}
// impl Default for QueryGraph {
// /// Create a new QueryGraph with two disconnected nodes: the root and end nodes.
// fn default() -> Self {
// let nodes = vec![
// QueryNode {
// data: QueryNodeData::Start,
// predecessors: SmallBitmap::new(QUERY_GRAPH_NODE_LENGTH_LIMIT),
// successors: SmallBitmap::new(QUERY_GRAPH_NODE_LENGTH_LIMIT),
// },
// QueryNode {
// data: QueryNodeData::End,
// predecessors: SmallBitmap::new(QUERY_GRAPH_NODE_LENGTH_LIMIT),
// successors: SmallBitmap::new(QUERY_GRAPH_NODE_LENGTH_LIMIT),
// },
// ];
// Self { root_node: 0, end_node: 1, nodes }
// }
// }
impl QueryGraph {
/// Connect all the given predecessor nodes to the given successor node
fn connect_to_node(
&mut self,
from_nodes: &[Interned<QueryNode>],
to_node: Interned<QueryNode>,
) {
for &from_node in from_nodes {
self.nodes.get_mut(from_node).successors.insert(to_node);
self.nodes.get_mut(to_node).predecessors.insert(from_node);
}
}
}
impl QueryGraph {
/// Build the query graph from the parsed user search query.
///
/// The ngrams are made at this point.
pub fn from_query(ctx: &mut SearchContext, terms: Vec<LocatedQueryTerm>) -> Result<QueryGraph> {
pub fn from_query(
ctx: &mut SearchContext,
// NOTE: the terms here must be consecutive
terms: &[LocatedQueryTerm],
) -> Result<QueryGraph> {
let nbr_typos = number_of_typos_allowed(ctx)?;
let mut empty_nodes = vec![];
let mut predecessors: Vec<HashSet<u16>> = vec![HashSet::new(), HashSet::new()];
let mut successors: Vec<HashSet<u16>> = vec![HashSet::new(), HashSet::new()];
let mut nodes_data: Vec<QueryNodeData> = vec![QueryNodeData::Start, QueryNodeData::End];
let root_node = 0;
let end_node = 1;
@ -136,21 +104,23 @@ impl QueryGraph {
let (mut prev2, mut prev1, mut prev0): (Vec<u16>, Vec<u16>, Vec<u16>) =
(vec![], vec![], vec![root_node]);
for term_idx in 0..terms.len() {
let term0 = &terms[term_idx];
let original_terms_len = terms.len();
for term_idx in 0..original_terms_len {
let mut new_nodes = vec![];
let new_node_idx = add_node(
&mut nodes_data,
QueryNodeData::Term(term0.clone()),
&prev0,
&mut successors,
&mut predecessors,
QueryNodeData::Term(LocatedQueryTermSubset {
term_subset: QueryTermSubset {
original: Interned::from_raw(term_idx as u16),
zero_typo_subset: NTypoTermSubset::All,
one_typo_subset: NTypoTermSubset::All,
two_typo_subset: NTypoTermSubset::All,
},
positions: terms[term_idx].positions.clone(),
term_ids: term_idx as u8..=term_idx as u8,
}),
);
new_nodes.push(new_node_idx);
if term0.is_empty(&ctx.term_interner) {
empty_nodes.push(new_node_idx);
}
if !prev1.is_empty() {
if let Some(ngram) =
@ -158,10 +128,16 @@ impl QueryGraph {
{
let ngram_idx = add_node(
&mut nodes_data,
QueryNodeData::Term(ngram),
&prev1,
&mut successors,
&mut predecessors,
QueryNodeData::Term(LocatedQueryTermSubset {
term_subset: QueryTermSubset {
original: ngram.value,
zero_typo_subset: NTypoTermSubset::All,
one_typo_subset: NTypoTermSubset::All,
two_typo_subset: NTypoTermSubset::All,
},
positions: ngram.positions,
term_ids: term_idx as u8 - 1..=term_idx as u8,
}),
);
new_nodes.push(ngram_idx);
}
@ -172,10 +148,16 @@ impl QueryGraph {
{
let ngram_idx = add_node(
&mut nodes_data,
QueryNodeData::Term(ngram),
&prev2,
&mut successors,
&mut predecessors,
QueryNodeData::Term(LocatedQueryTermSubset {
term_subset: QueryTermSubset {
original: ngram.value,
zero_typo_subset: NTypoTermSubset::All,
one_typo_subset: NTypoTermSubset::All,
two_typo_subset: NTypoTermSubset::All,
},
positions: ngram.positions,
term_ids: term_idx as u8 - 2..=term_idx as u8,
}),
);
new_nodes.push(ngram_idx);
}
@ -193,35 +175,17 @@ impl QueryGraph {
successors: SmallBitmap::new(nodes_data.len() as u16),
},
);
for (node_idx, ((node_data, predecessors), successors)) in nodes_data
.into_iter()
.zip(predecessors.into_iter())
.zip(successors.into_iter())
.enumerate()
{
for (node_idx, node_data) in nodes_data.into_iter().enumerate() {
let node = nodes.get_mut(Interned::from_raw(node_idx as u16));
node.data = node_data;
for x in predecessors {
node.predecessors.insert(Interned::from_raw(x));
}
for x in successors {
node.successors.insert(Interned::from_raw(x));
}
}
let mut graph = QueryGraph { root_node, end_node, nodes };
graph.connect_to_node(
prev0.into_iter().map(Interned::from_raw).collect::<Vec<_>>().as_slice(),
end_node,
);
let empty_nodes = empty_nodes.into_iter().map(Interned::from_raw).collect::<Vec<_>>();
graph.remove_nodes_keep_edges(&empty_nodes);
graph.rebuild_edges();
Ok(graph)
}
/// Remove the given nodes and all their edges from the query graph.
/// TODO: need to check where this is used, and if this is correct.
pub fn remove_nodes(&mut self, nodes: &[Interned<QueryNode>]) {
for &node_id in nodes {
let node = &self.nodes.get(node_id);
@ -240,85 +204,220 @@ impl QueryGraph {
node.predecessors.clear();
node.successors.clear();
}
self.rebuild_edges();
}
/// Remove the given nodes, connecting all their predecessors to all their successors.
pub fn remove_nodes_keep_edges(&mut self, nodes: &[Interned<QueryNode>]) {
for &node_id in nodes {
let node = self.nodes.get(node_id);
let old_node_pred = node.predecessors.clone();
let old_node_succ = node.successors.clone();
for pred in old_node_pred.iter() {
let pred_successors = &mut self.nodes.get_mut(pred).successors;
pred_successors.remove(node_id);
pred_successors.union(&old_node_succ);
}
for succ in old_node_succ.iter() {
let succ_predecessors = &mut self.nodes.get_mut(succ).predecessors;
succ_predecessors.remove(node_id);
succ_predecessors.union(&old_node_pred);
}
let node = self.nodes.get_mut(node_id);
node.data = QueryNodeData::Deleted;
node.predecessors.clear();
fn rebuild_edges(&mut self) {
for (_, node) in self.nodes.iter_mut() {
node.successors.clear();
node.predecessors.clear();
}
for node_id in self.nodes.indexes() {
let node = self.nodes.get(node_id);
let end_position = match &node.data {
QueryNodeData::Term(term) => *term.positions.end(),
QueryNodeData::Start => -1,
QueryNodeData::Deleted => continue,
QueryNodeData::End => continue,
};
let successors = {
let mut successors = SmallBitmap::for_interned_values_in(&self.nodes);
let mut min = i8::MAX;
for (node_id, node) in self.nodes.iter() {
let start_position = match &node.data {
QueryNodeData::Term(term) => *term.positions.start(),
QueryNodeData::End => i8::MAX,
QueryNodeData::Start => continue,
QueryNodeData::Deleted => continue,
};
if start_position <= end_position {
continue;
}
match start_position.cmp(&min) {
Ordering::Less => {
min = start_position;
successors.clear();
successors.insert(node_id);
}
Ordering::Equal => {
successors.insert(node_id);
}
Ordering::Greater => continue,
}
}
successors
};
let node = self.nodes.get_mut(node_id);
node.successors = successors.clone();
for successor in successors.iter() {
let successor = self.nodes.get_mut(successor);
successor.predecessors.insert(node_id);
}
}
}
/// Remove all the nodes that correspond to a word starting at the given position, and connect
/// the predecessors of these nodes to their successors.
/// Return `true` if any node was removed.
/// Remove all the nodes that correspond to a word starting at the given position and rebuild
/// the edges of the graph appropriately.
pub fn remove_words_starting_at_position(&mut self, position: i8) -> bool {
let mut nodes_to_remove_keeping_edges = vec![];
let mut nodes_to_remove = vec![];
for (node_idx, node) in self.nodes.iter() {
let QueryNodeData::Term(LocatedQueryTerm { value: _, positions }) = &node.data else { continue };
let QueryNodeData::Term(LocatedQueryTermSubset { term_subset: _, positions, term_ids: _ }) = &node.data else { continue };
if positions.start() == &position {
nodes_to_remove_keeping_edges.push(node_idx);
nodes_to_remove.push(node_idx);
}
}
self.remove_nodes_keep_edges(&nodes_to_remove_keeping_edges);
self.remove_nodes(&nodes_to_remove);
self.simplify();
!nodes_to_remove_keeping_edges.is_empty()
!nodes_to_remove.is_empty()
}
/// Simplify the query graph by removing all nodes that are disconnected from
/// the start or end nodes.
pub fn simplify(&mut self) {
loop {
let mut nodes_to_remove = vec![];
for (node_idx, node) in self.nodes.iter() {
if (!matches!(node.data, QueryNodeData::End | QueryNodeData::Deleted)
&& node.successors.is_empty())
|| (!matches!(node.data, QueryNodeData::Start | QueryNodeData::Deleted)
&& node.predecessors.is_empty())
{
nodes_to_remove.push(node_idx);
pub fn removal_order_for_terms_matching_strategy_last(&self) -> Vec<SmallBitmap<QueryNode>> {
let (first_term_idx, last_term_idx) = {
let mut first_term_idx = u8::MAX;
let mut last_term_idx = 0u8;
for (_, node) in self.nodes.iter() {
match &node.data {
QueryNodeData::Term(t) => {
if *t.term_ids.end() > last_term_idx {
last_term_idx = *t.term_ids.end();
}
if *t.term_ids.start() < first_term_idx {
first_term_idx = *t.term_ids.start();
}
}
QueryNodeData::Deleted | QueryNodeData::Start | QueryNodeData::End => continue,
}
}
if nodes_to_remove.is_empty() {
break;
} else {
self.remove_nodes(&nodes_to_remove);
}
(first_term_idx, last_term_idx)
};
if first_term_idx >= last_term_idx {
return vec![];
}
let cost_of_term_idx = |term_idx: u8| {
if term_idx == first_term_idx {
None
} else {
let rank = 1 + last_term_idx - term_idx;
Some(rank as u16)
}
};
let mut nodes_to_remove = BTreeMap::<u16, SmallBitmap<QueryNode>>::new();
for (node_id, node) in self.nodes.iter() {
let QueryNodeData::Term(t) = &node.data else { continue };
let mut cost = 0;
for id in t.term_ids.clone() {
if let Some(t_cost) = cost_of_term_idx(id) {
cost += t_cost;
} else {
continue;
}
}
nodes_to_remove
.entry(cost)
.or_insert_with(|| SmallBitmap::for_interned_values_in(&self.nodes))
.insert(node_id);
}
nodes_to_remove.into_values().collect()
}
}
fn add_node(
nodes_data: &mut Vec<QueryNodeData>,
node_data: QueryNodeData,
from_nodes: &Vec<u16>,
successors: &mut Vec<HashSet<u16>>,
predecessors: &mut Vec<HashSet<u16>>,
) -> u16 {
successors.push(HashSet::new());
predecessors.push(HashSet::new());
fn add_node(nodes_data: &mut Vec<QueryNodeData>, node_data: QueryNodeData) -> u16 {
let new_node_idx = nodes_data.len() as u16;
nodes_data.push(node_data);
for &from_node in from_nodes {
successors[from_node as usize].insert(new_node_idx);
predecessors[new_node_idx as usize].insert(from_node);
}
new_node_idx
}
impl QueryGraph {
/*
Build a query graph from a list of paths
The paths are composed of source and dest terms.
If the source term is `None`, then the last dest term is used
as the predecessor of the dest term. If the source is Some(_),
then an edge is built between the last dest term and the source,
and between the source and new dest term.
Note that the resulting graph will not correspond to a perfect
representation of the set of paths.
For example, consider the following paths:
```txt
PATH 1 : a -> b1 -> c1 -> d -> e1
PATH 2 : a -> b2 -> c2 -> d -> e2
```
Then the resulting graph will be:
```txt
┌────┐ ┌────┐ ┌────┐
┌──│ b1 │──│ c1 │─┐ ┌──│ e1 │
┌────┐ │ └────┘ └────┘ │ ┌────┐ │ └────┘
│ a │─┤ ├─│ d │─┤
└────┘ │ ┌────┐ ┌────┐ │ └────┘ │ ┌────┐
└──│ b2 │──│ c2 │─┘ └──│ e2 │
└────┘ └────┘ └────┘
```
which is different from the fully correct representation:
```txt
┌────┐ ┌────┐ ┌────┐ ┌────┐
┌──│ b1 │──│ c1 │───│ d │───│ e1 │
┌────┐ │ └────┘ └────┘ └────┘ └────┘
│ a │─┤
└────┘ │ ┌────┐ ┌────┐ ┌────┐ ┌────┐
└──│ b2 │──│ c2 │───│ d │───│ e2 │
└────┘ └────┘ └────┘ └────┘
```
But we accept the first representation as it reduces the size
of the graph and shouldn't cause much problems.
*/
pub fn build_from_paths(
paths: Vec<Vec<(Option<LocatedQueryTermSubset>, LocatedQueryTermSubset)>>,
) -> Self {
let mut node_data = DedupInterner::default();
let root_node = node_data.insert(QueryNodeData::Start);
let end_node = node_data.insert(QueryNodeData::End);
let mut paths_with_ids = vec![];
for path in paths {
let mut path_with_ids = vec![];
for node in path {
let (start_term, end_term) = node;
let src_node_id = start_term.map(|x| node_data.insert(QueryNodeData::Term(x)));
let dest_node_id = node_data.insert(QueryNodeData::Term(end_term));
path_with_ids.push((src_node_id, dest_node_id));
}
paths_with_ids.push(path_with_ids);
}
let nodes_data = node_data.freeze();
let nodes_data_len = nodes_data.len();
let mut nodes = nodes_data.map_move(|n| QueryNode {
data: n,
predecessors: SmallBitmap::new(nodes_data_len),
successors: SmallBitmap::new(nodes_data_len),
});
let root_node = Interned::from_raw(root_node.into_raw());
let end_node = Interned::from_raw(end_node.into_raw());
for path in paths_with_ids {
let mut prev_node = root_node;
for node in path {
let (start_term, dest_term) = node;
let end_term = Interned::from_raw(dest_term.into_raw());
let src = if let Some(start_term) = start_term {
let start_term = Interned::from_raw(start_term.into_raw());
nodes.get_mut(prev_node).successors.insert(start_term);
nodes.get_mut(start_term).predecessors.insert(prev_node);
start_term
} else {
prev_node
};
nodes.get_mut(src).successors.insert(end_term);
nodes.get_mut(end_term).predecessors.insert(src);
prev_node = end_term;
}
nodes.get_mut(prev_node).successors.insert(end_node);
nodes.get_mut(end_node).predecessors.insert(prev_node);
}
QueryGraph { root_node, end_node, nodes }
}
}