3571: Introduce two filters to select documents with `null` and empty fields r=irevoire a=Kerollmops

# Pull Request

## Related issue
This PR implements the `X IS NULL`, `X IS NOT NULL`, `X IS EMPTY`, `X IS NOT EMPTY` filters that [this comment](https://github.com/meilisearch/product/discussions/539#discussioncomment-5115884) is describing in a very detailed manner.

## What does this PR do?

### `IS NULL` and `IS NOT NULL`

This PR will be exposed as a prototype for now. Below is the copy/pasted version of a spec that defines this filter.

- `IS NULL` matches fields that `EXISTS` AND `= IS NULL`
- `IS NOT NULL` matches fields that `NOT EXISTS` OR `!= IS NULL`

1. `{"name": "A", "price": null}`
2. `{"name": "A", "price": 10}`
3. `{"name": "A"}`

`price IS NULL` would match 1
`price IS NOT NULL` or `NOT price IS NULL` would match 2,3
`price EXISTS` would match 1, 2
`price NOT EXISTS` or `NOT price EXISTS` would match 3

common query : `(price EXISTS) AND (price IS NOT NULL)` would match 2

### `IS EMPTY` and `IS NOT EMPTY`

- `IS EMPTY` matches Array `[]`, Object `{}`, or String `""` fields that `EXISTS` and are empty
- `IS NOT EMPTY` matches fields that `NOT EXISTS` OR are not empty.

1. `{"name": "A", "tags": null}`
2. `{"name": "A", "tags": [null]}`
3. `{"name": "A", "tags": []}`
4. `{"name": "A", "tags": ["hello","world"]}`
5. `{"name": "A", "tags": [""]}`
6. `{"name": "A"}`
7. `{"name": "A", "tags": {}}`
8. `{"name": "A", "tags": {"t1":"v1"}}`
9. `{"name": "A", "tags": {"t1":""}}`
10. `{"name": "A", "tags": ""}`

`tags IS EMPTY` would match 3,7,10
`tags IS NOT EMPTY` or `NOT tags IS EMPTY` would match 1,2,4,5,6,8,9
`tags IS NULL` would match 1
`tags IS NOT NULL` or `NOT tags IS NULL` would match 2,3,4,5,6,7,8,9,10
`tags EXISTS` would match 1,2,3,4,5,7,8,9,10
`tags NOT EXISTS` or `NOT tags EXISTS` would match 6

common query : `(tags EXISTS) AND (tags IS NOT NULL) AND (tags IS NOT EMPTY)` would match 2,4,5,8,9

## What should the reviewer do?

- Check that I tested the filters
- Check that I deleted the ids of the documents when deleting documents


Co-authored-by: Clément Renault <clement@meilisearch.com>
Co-authored-by: Kerollmops <clement@meilisearch.com>
This commit is contained in:
bors[bot] 2023-04-27 13:14:00 +00:00 committed by GitHub
commit 414b3fae89
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GPG key ID: 4AEE18F83AFDEB23
18 changed files with 730 additions and 118 deletions

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@ -7,7 +7,7 @@ use std::mem::size_of;
use heed::zerocopy::AsBytes;
use heed::BytesEncode;
use roaring::RoaringBitmap;
use serde_json::Value;
use serde_json::{from_slice, Value};
use super::helpers::{create_sorter, keep_first, sorter_into_reader, GrenadParameters};
use crate::error::InternalError;
@ -15,6 +15,15 @@ use crate::facet::value_encoding::f64_into_bytes;
use crate::update::index_documents::{create_writer, writer_into_reader};
use crate::{CboRoaringBitmapCodec, DocumentId, FieldId, Result, BEU32, MAX_FACET_VALUE_LENGTH};
/// The extracted facet values stored in grenad files by type.
pub struct ExtractedFacetValues {
pub docid_fid_facet_numbers_chunk: grenad::Reader<File>,
pub docid_fid_facet_strings_chunk: grenad::Reader<File>,
pub fid_facet_is_null_docids_chunk: grenad::Reader<File>,
pub fid_facet_is_empty_docids_chunk: grenad::Reader<File>,
pub fid_facet_exists_docids_chunk: grenad::Reader<File>,
}
/// Extracts the facet values of each faceted field of each document.
///
/// Returns the generated grenad reader containing the docid the fid and the orginal value as key
@ -24,7 +33,7 @@ pub fn extract_fid_docid_facet_values<R: io::Read + io::Seek>(
obkv_documents: grenad::Reader<R>,
indexer: GrenadParameters,
faceted_fields: &HashSet<FieldId>,
) -> Result<(grenad::Reader<File>, grenad::Reader<File>, grenad::Reader<File>)> {
) -> Result<ExtractedFacetValues> {
let max_memory = indexer.max_memory_by_thread();
let mut fid_docid_facet_numbers_sorter = create_sorter(
@ -46,6 +55,8 @@ pub fn extract_fid_docid_facet_values<R: io::Read + io::Seek>(
);
let mut facet_exists_docids = BTreeMap::<FieldId, RoaringBitmap>::new();
let mut facet_is_null_docids = BTreeMap::<FieldId, RoaringBitmap>::new();
let mut facet_is_empty_docids = BTreeMap::<FieldId, RoaringBitmap>::new();
let mut key_buffer = Vec::new();
let mut cursor = obkv_documents.into_cursor()?;
@ -69,33 +80,44 @@ pub fn extract_fid_docid_facet_values<R: io::Read + io::Seek>(
// For the other extraction tasks, prefix the key with the field_id and the document_id
key_buffer.extend_from_slice(docid_bytes);
let value =
serde_json::from_slice(field_bytes).map_err(InternalError::SerdeJson)?;
let value = from_slice(field_bytes).map_err(InternalError::SerdeJson)?;
let (numbers, strings) = extract_facet_values(&value);
// insert facet numbers in sorter
for number in numbers {
key_buffer.truncate(size_of::<FieldId>() + size_of::<DocumentId>());
if let Some(value_bytes) = f64_into_bytes(number) {
key_buffer.extend_from_slice(&value_bytes);
key_buffer.extend_from_slice(&number.to_be_bytes());
fid_docid_facet_numbers_sorter.insert(&key_buffer, ().as_bytes())?;
match extract_facet_values(&value) {
FilterableValues::Null => {
facet_is_null_docids.entry(field_id).or_default().insert(document);
}
}
FilterableValues::Empty => {
facet_is_empty_docids.entry(field_id).or_default().insert(document);
}
FilterableValues::Values { numbers, strings } => {
// insert facet numbers in sorter
for number in numbers {
key_buffer.truncate(size_of::<FieldId>() + size_of::<DocumentId>());
if let Some(value_bytes) = f64_into_bytes(number) {
key_buffer.extend_from_slice(&value_bytes);
key_buffer.extend_from_slice(&number.to_be_bytes());
// insert normalized and original facet string in sorter
for (normalized, original) in strings.into_iter().filter(|(n, _)| !n.is_empty()) {
let normalised_truncated_value: String = normalized
.char_indices()
.take_while(|(idx, _)| idx + 4 < MAX_FACET_VALUE_LENGTH)
.map(|(_, c)| c)
.collect();
fid_docid_facet_numbers_sorter
.insert(&key_buffer, ().as_bytes())?;
}
}
key_buffer.truncate(size_of::<FieldId>() + size_of::<DocumentId>());
key_buffer.extend_from_slice(normalised_truncated_value.as_bytes());
fid_docid_facet_strings_sorter.insert(&key_buffer, original.as_bytes())?;
// insert normalized and original facet string in sorter
for (normalized, original) in
strings.into_iter().filter(|(n, _)| !n.is_empty())
{
let normalized_truncated_value: String = normalized
.char_indices()
.take_while(|(idx, _)| idx + 4 < MAX_FACET_VALUE_LENGTH)
.map(|(_, c)| c)
.collect();
key_buffer.truncate(size_of::<FieldId>() + size_of::<DocumentId>());
key_buffer.extend_from_slice(normalized_truncated_value.as_bytes());
fid_docid_facet_strings_sorter
.insert(&key_buffer, original.as_bytes())?;
}
}
}
}
}
@ -112,14 +134,48 @@ pub fn extract_fid_docid_facet_values<R: io::Read + io::Seek>(
}
let facet_exists_docids_reader = writer_into_reader(facet_exists_docids_writer)?;
Ok((
sorter_into_reader(fid_docid_facet_numbers_sorter, indexer)?,
sorter_into_reader(fid_docid_facet_strings_sorter, indexer)?,
facet_exists_docids_reader,
))
let mut facet_is_null_docids_writer = create_writer(
indexer.chunk_compression_type,
indexer.chunk_compression_level,
tempfile::tempfile()?,
);
for (fid, bitmap) in facet_is_null_docids.into_iter() {
let bitmap_bytes = CboRoaringBitmapCodec::bytes_encode(&bitmap).unwrap();
facet_is_null_docids_writer.insert(fid.to_be_bytes(), &bitmap_bytes)?;
}
let facet_is_null_docids_reader = writer_into_reader(facet_is_null_docids_writer)?;
let mut facet_is_empty_docids_writer = create_writer(
indexer.chunk_compression_type,
indexer.chunk_compression_level,
tempfile::tempfile()?,
);
for (fid, bitmap) in facet_is_empty_docids.into_iter() {
let bitmap_bytes = CboRoaringBitmapCodec::bytes_encode(&bitmap).unwrap();
facet_is_empty_docids_writer.insert(fid.to_be_bytes(), &bitmap_bytes)?;
}
let facet_is_empty_docids_reader = writer_into_reader(facet_is_empty_docids_writer)?;
Ok(ExtractedFacetValues {
docid_fid_facet_numbers_chunk: sorter_into_reader(fid_docid_facet_numbers_sorter, indexer)?,
docid_fid_facet_strings_chunk: sorter_into_reader(fid_docid_facet_strings_sorter, indexer)?,
fid_facet_is_null_docids_chunk: facet_is_null_docids_reader,
fid_facet_is_empty_docids_chunk: facet_is_empty_docids_reader,
fid_facet_exists_docids_chunk: facet_exists_docids_reader,
})
}
fn extract_facet_values(value: &Value) -> (Vec<f64>, Vec<(String, String)>) {
/// Represent what a document field contains.
enum FilterableValues {
/// Corresponds to the JSON `null` value.
Null,
/// Corresponds to either, an empty string `""`, an empty array `[]`, or an empty object `{}`.
Empty,
/// Represents all the numbers and strings values found in this document field.
Values { numbers: Vec<f64>, strings: Vec<(String, String)> },
}
fn extract_facet_values(value: &Value) -> FilterableValues {
fn inner_extract_facet_values(
value: &Value,
can_recurse: bool,
@ -149,9 +205,16 @@ fn extract_facet_values(value: &Value) -> (Vec<f64>, Vec<(String, String)>) {
}
}
let mut facet_number_values = Vec::new();
let mut facet_string_values = Vec::new();
inner_extract_facet_values(value, true, &mut facet_number_values, &mut facet_string_values);
(facet_number_values, facet_string_values)
match value {
Value::Null => FilterableValues::Null,
Value::String(s) if s.is_empty() => FilterableValues::Empty,
Value::Array(a) if a.is_empty() => FilterableValues::Empty,
Value::Object(o) if o.is_empty() => FilterableValues::Empty,
otherwise => {
let mut numbers = Vec::new();
let mut strings = Vec::new();
inner_extract_facet_values(otherwise, true, &mut numbers, &mut strings);
FilterableValues::Values { numbers, strings }
}
}
}