meilisearch/milli/src/update/index_documents/transform.rs
2022-02-16 15:28:48 +01:00

593 lines
24 KiB
Rust

use std::borrow::Cow;
use std::collections::btree_map::Entry;
use std::collections::HashMap;
use std::fs::File;
use std::io::{Read, Seek, SeekFrom};
use std::time::Instant;
use itertools::Itertools;
use log::info;
use roaring::RoaringBitmap;
use serde_json::{Map, Value};
use super::helpers::{
create_sorter, create_writer, keep_latest_obkv, merge_obkvs, merge_two_obkvs, MergeFn,
};
use super::{IndexDocumentsMethod, IndexerConfig};
use crate::documents::{DocumentBatchReader, DocumentsBatchIndex};
use crate::error::{Error, InternalError, UserError};
use crate::index::db_name;
use crate::update::{AvailableDocumentsIds, UpdateIndexingStep};
use crate::{ExternalDocumentsIds, FieldDistribution, FieldId, FieldsIdsMap, Index, Result, BEU32};
const DEFAULT_PRIMARY_KEY_NAME: &str = "id";
pub struct TransformOutput {
pub primary_key: String,
pub fields_ids_map: FieldsIdsMap,
pub field_distribution: FieldDistribution,
pub external_documents_ids: ExternalDocumentsIds<'static>,
pub new_documents_ids: RoaringBitmap,
pub replaced_documents_ids: RoaringBitmap,
pub documents_count: usize,
pub documents_file: File,
}
/// Extract the external ids, deduplicate and compute the new internal documents ids
/// and fields ids, writing all the documents under their internal ids into a final file.
///
/// Outputs the new `FieldsIdsMap`, the new `UsersIdsDocumentsIds` map, the new documents ids,
/// the replaced documents ids, the number of documents in this update and the file
/// containing all those documents.
pub struct Transform<'a, 'i> {
pub index: &'i Index,
indexer_settings: &'a IndexerConfig,
pub autogenerate_docids: bool,
pub index_documents_method: IndexDocumentsMethod,
sorter: grenad::Sorter<MergeFn>,
documents_count: usize,
}
/// Create a mapping between the field ids found in the document batch and the one that were
/// already present in the index.
///
/// If new fields are present in the addition, they are added to the index field ids map.
fn create_fields_mapping(
index_field_map: &mut FieldsIdsMap,
batch_field_map: &DocumentsBatchIndex,
) -> Result<HashMap<FieldId, FieldId>> {
batch_field_map
.iter()
// we sort by id here to ensure a deterministic mapping of the fields, that preserves
// the original ordering.
.sorted_by_key(|(&id, _)| id)
.map(|(field, name)| match index_field_map.id(&name) {
Some(id) => Ok((*field, id)),
None => index_field_map
.insert(&name)
.ok_or(Error::UserError(UserError::AttributeLimitReached))
.map(|id| (*field, id)),
})
.collect()
}
fn find_primary_key(index: &DocumentsBatchIndex) -> Option<&str> {
index
.iter()
.sorted_by_key(|(k, _)| *k)
.map(|(_, v)| v)
.find(|v| v.to_lowercase().contains(DEFAULT_PRIMARY_KEY_NAME))
.map(String::as_str)
}
impl<'a, 'i> Transform<'a, 'i> {
pub fn new(
index: &'i Index,
indexer_settings: &'a IndexerConfig,
index_documents_method: IndexDocumentsMethod,
autogenerate_docids: bool,
) -> Self {
// We must choose the appropriate merge function for when two or more documents
// with the same user id must be merged or fully replaced in the same batch.
let merge_function = match index_documents_method {
IndexDocumentsMethod::ReplaceDocuments => keep_latest_obkv,
IndexDocumentsMethod::UpdateDocuments => merge_obkvs,
};
// We initialize the sorter with the user indexing settings.
let sorter = create_sorter(
merge_function,
indexer_settings.chunk_compression_type,
indexer_settings.chunk_compression_level,
indexer_settings.max_nb_chunks,
indexer_settings.max_memory,
);
Transform {
index,
indexer_settings,
autogenerate_docids,
sorter,
documents_count: 0,
index_documents_method,
}
}
pub fn read_documents<R, F>(
&mut self,
mut reader: DocumentBatchReader<R>,
wtxn: &mut heed::RwTxn,
progress_callback: F,
) -> Result<usize>
where
R: Read + Seek,
F: Fn(UpdateIndexingStep) + Sync,
{
let fields_index = reader.index();
let mut fields_ids_map = self.index.fields_ids_map(wtxn)?;
let mapping = create_fields_mapping(&mut fields_ids_map, fields_index)?;
let alternative_name = self
.index
.primary_key(wtxn)?
.or_else(|| find_primary_key(fields_index))
.map(String::from);
let (primary_key_id, primary_key_name) = compute_primary_key_pair(
self.index.primary_key(wtxn)?,
&mut fields_ids_map,
alternative_name,
self.autogenerate_docids,
)?;
let mut obkv_buffer = Vec::new();
let mut documents_count = 0;
let mut external_id_buffer = Vec::new();
let mut field_buffer: Vec<(u16, &[u8])> = Vec::new();
while let Some((addition_index, document)) = reader.next_document_with_index()? {
let mut field_buffer_cache = drop_and_reuse(field_buffer);
if self.indexer_settings.log_every_n.map_or(false, |len| documents_count % len == 0) {
progress_callback(UpdateIndexingStep::RemapDocumentAddition {
documents_seen: documents_count,
});
}
for (k, v) in document.iter() {
let mapped_id = *mapping.get(&k).unwrap();
field_buffer_cache.push((mapped_id, v));
}
// We need to make sure that every document has a primary key. After we have remapped
// all the fields in the document, we try to find the primary key value. If we can find
// it, transform it into a string and validate it, and then update it in the
// document. If none is found, and we were told to generate missing document ids, then
// we create the missing field, and update the new document.
let mut uuid_buffer = [0; uuid::adapter::Hyphenated::LENGTH];
let external_id =
match field_buffer_cache.iter_mut().find(|(id, _)| *id == primary_key_id) {
Some((_, bytes)) => {
let value = match serde_json::from_slice(bytes).unwrap() {
Value::String(string) => match validate_document_id(&string) {
Some(s) if s.len() == string.len() => string,
Some(s) => s.to_string(),
None => {
return Err(UserError::InvalidDocumentId {
document_id: Value::String(string),
}
.into())
}
},
Value::Number(number) => number.to_string(),
content => {
return Err(UserError::InvalidDocumentId {
document_id: content.clone(),
}
.into())
}
};
serde_json::to_writer(&mut external_id_buffer, &value).unwrap();
Cow::Owned(value)
}
None => {
if !self.autogenerate_docids {
let mut json = Map::new();
for (key, value) in document.iter() {
let key = addition_index.name(key).cloned();
let value = serde_json::from_slice::<Value>(&value).ok();
if let Some((k, v)) = key.zip(value) {
json.insert(k, v);
}
}
return Err(UserError::MissingDocumentId {
primary_key: primary_key_name,
document: json,
}
.into());
}
let uuid =
uuid::Uuid::new_v4().to_hyphenated().encode_lower(&mut uuid_buffer);
serde_json::to_writer(&mut external_id_buffer, &uuid).unwrap();
field_buffer_cache.push((primary_key_id, &external_id_buffer));
Cow::Borrowed(&*uuid)
}
};
// Insertion in a obkv need to be done with keys ordered. For now they are ordered
// according to the document addition key order, so we sort it according to the
// fieldids map keys order.
field_buffer_cache.sort_unstable_by(|(f1, _), (f2, _)| f1.cmp(&f2));
// The last step is to build the new obkv document, and insert it in the sorter.
let mut writer = obkv::KvWriter::new(&mut obkv_buffer);
for (k, v) in field_buffer_cache.iter() {
writer.insert(*k, v)?;
}
// We use the extracted/generated user id as the key for this document.
self.sorter.insert(&external_id.as_ref().as_bytes(), &obkv_buffer)?;
documents_count += 1;
progress_callback(UpdateIndexingStep::RemapDocumentAddition {
documents_seen: documents_count,
});
obkv_buffer.clear();
field_buffer = drop_and_reuse(field_buffer_cache);
external_id_buffer.clear();
}
progress_callback(UpdateIndexingStep::RemapDocumentAddition {
documents_seen: documents_count,
});
self.index.put_fields_ids_map(wtxn, &fields_ids_map)?;
self.index.put_primary_key(wtxn, &primary_key_name)?;
self.documents_count += documents_count;
// Now that we have a valid sorter that contains the user id and the obkv we
// give it to the last transforming function which returns the TransformOutput.
Ok(documents_count)
}
/// Generate the `TransformOutput` based on the given sorter that can be generated from any
/// format like CSV, JSON or JSON stream. This sorter must contain a key that is the document
/// id for the user side and the value must be an obkv where keys are valid fields ids.
pub(crate) fn output_from_sorter<F>(
self,
wtxn: &mut heed::RwTxn,
progress_callback: F,
) -> Result<TransformOutput>
where
F: Fn(UpdateIndexingStep) + Sync,
{
let primary_key = self
.index
.primary_key(&wtxn)?
.ok_or(Error::UserError(UserError::MissingPrimaryKey))?
.to_string();
let fields_ids_map = self.index.fields_ids_map(wtxn)?;
let approximate_number_of_documents = self.documents_count;
let mut external_documents_ids = self.index.external_documents_ids(wtxn).unwrap();
let documents_ids = self.index.documents_ids(wtxn)?;
let mut field_distribution = self.index.field_distribution(wtxn)?;
let mut available_documents_ids = AvailableDocumentsIds::from_documents_ids(&documents_ids);
// consume sorter, in order to free the internal allocation, before creating a new one.
let mut iter = self.sorter.into_stream_merger_iter()?;
// Once we have sort and deduplicated the documents we write them into a final file.
let mut final_sorter = create_sorter(
|_id, obkvs| {
if obkvs.len() == 1 {
Ok(obkvs[0].clone())
} else {
Err(InternalError::IndexingMergingKeys { process: "documents" }.into())
}
},
self.indexer_settings.chunk_compression_type,
self.indexer_settings.chunk_compression_level,
self.indexer_settings.max_nb_chunks,
self.indexer_settings.max_memory,
);
let mut new_external_documents_ids_builder = fst::MapBuilder::memory();
let mut replaced_documents_ids = RoaringBitmap::new();
let mut new_documents_ids = RoaringBitmap::new();
let mut obkv_buffer = Vec::new();
// While we write into final file we get or generate the internal documents ids.
let mut documents_count = 0;
while let Some((external_id, update_obkv)) = iter.next()? {
if self.indexer_settings.log_every_n.map_or(false, |len| documents_count % len == 0) {
progress_callback(UpdateIndexingStep::ComputeIdsAndMergeDocuments {
documents_seen: documents_count,
total_documents: approximate_number_of_documents,
});
}
let (docid, obkv) = match external_documents_ids.get(external_id) {
Some(docid) => {
// If we find the user id in the current external documents ids map
// we use it and insert it in the list of replaced documents.
replaced_documents_ids.insert(docid);
let key = BEU32::new(docid);
let base_obkv = self.index.documents.get(wtxn, &key)?.ok_or(
InternalError::DatabaseMissingEntry {
db_name: db_name::DOCUMENTS,
key: None,
},
)?;
// we remove all the fields that were already counted
for (field_id, _) in base_obkv.iter() {
let field_name = fields_ids_map.name(field_id).unwrap();
if let Entry::Occupied(mut entry) =
field_distribution.entry(field_name.to_string())
{
match entry.get().checked_sub(1) {
Some(0) | None => entry.remove(),
Some(count) => entry.insert(count),
};
}
}
// Depending on the update indexing method we will merge
// the document update with the current document or not.
match self.index_documents_method {
IndexDocumentsMethod::ReplaceDocuments => (docid, update_obkv),
IndexDocumentsMethod::UpdateDocuments => {
let update_obkv = obkv::KvReader::new(update_obkv);
merge_two_obkvs(base_obkv, update_obkv, &mut obkv_buffer);
(docid, obkv_buffer.as_slice())
}
}
}
None => {
// If this user id is new we add it to the external documents ids map
// for new ids and into the list of new documents.
let new_docid =
available_documents_ids.next().ok_or(UserError::DocumentLimitReached)?;
new_external_documents_ids_builder.insert(external_id, new_docid as u64)?;
new_documents_ids.insert(new_docid);
(new_docid, update_obkv)
}
};
// We insert the document under the documents ids map into the final file.
final_sorter.insert(docid.to_be_bytes(), obkv)?;
documents_count += 1;
let reader = obkv::KvReader::new(obkv);
for (field_id, _) in reader.iter() {
let field_name = fields_ids_map.name(field_id).unwrap();
*field_distribution.entry(field_name.to_string()).or_default() += 1;
}
}
progress_callback(UpdateIndexingStep::ComputeIdsAndMergeDocuments {
documents_seen: documents_count,
total_documents: documents_count,
});
// We create a final writer to write the new documents in order from the sorter.
let mut writer = create_writer(
self.indexer_settings.chunk_compression_type,
self.indexer_settings.chunk_compression_level,
tempfile::tempfile()?,
);
// Once we have written all the documents into the final sorter, we write the documents
// into this writer, extract the file and reset the seek to be able to read it again.
final_sorter.write_into_stream_writer(&mut writer)?;
let mut documents_file = writer.into_inner()?;
documents_file.seek(SeekFrom::Start(0))?;
let before_docids_merging = Instant::now();
// We merge the new external ids with existing external documents ids.
let new_external_documents_ids = new_external_documents_ids_builder.into_map();
external_documents_ids.insert_ids(&new_external_documents_ids)?;
info!("Documents external merging took {:.02?}", before_docids_merging.elapsed());
Ok(TransformOutput {
primary_key,
fields_ids_map,
field_distribution,
external_documents_ids: external_documents_ids.into_static(),
new_documents_ids,
replaced_documents_ids,
documents_count,
documents_file,
})
}
/// Returns a `TransformOutput` with a file that contains the documents of the index
/// with the attributes reordered accordingly to the `FieldsIdsMap` given as argument.
// TODO this can be done in parallel by using the rayon `ThreadPool`.
pub fn remap_index_documents(
self,
wtxn: &mut heed::RwTxn,
old_fields_ids_map: FieldsIdsMap,
new_fields_ids_map: FieldsIdsMap,
) -> Result<TransformOutput> {
// There already has been a document addition, the primary key should be set by now.
let primary_key =
self.index.primary_key(wtxn)?.ok_or(UserError::MissingPrimaryKey)?.to_string();
let field_distribution = self.index.field_distribution(wtxn)?;
let external_documents_ids = self.index.external_documents_ids(wtxn)?;
let documents_ids = self.index.documents_ids(wtxn)?;
let documents_count = documents_ids.len() as usize;
// We create a final writer to write the new documents in order from the sorter.
let mut writer = create_writer(
self.indexer_settings.chunk_compression_type,
self.indexer_settings.chunk_compression_level,
tempfile::tempfile()?,
);
let mut obkv_buffer = Vec::new();
for result in self.index.documents.iter(wtxn)? {
let (docid, obkv) = result?;
let docid = docid.get();
obkv_buffer.clear();
let mut obkv_writer = obkv::KvWriter::<_, FieldId>::new(&mut obkv_buffer);
// We iterate over the new `FieldsIdsMap` ids in order and construct the new obkv.
for (id, name) in new_fields_ids_map.iter() {
if let Some(val) = old_fields_ids_map.id(name).and_then(|id| obkv.get(id)) {
obkv_writer.insert(id, val)?;
}
}
let buffer = obkv_writer.into_inner()?;
writer.insert(docid.to_be_bytes(), buffer)?;
}
// Once we have written all the documents, we extract
// the file and reset the seek to be able to read it again.
let mut documents_file = writer.into_inner()?;
documents_file.seek(SeekFrom::Start(0))?;
Ok(TransformOutput {
primary_key,
fields_ids_map: new_fields_ids_map,
field_distribution,
external_documents_ids: external_documents_ids.into_static(),
new_documents_ids: documents_ids,
replaced_documents_ids: RoaringBitmap::default(),
documents_count,
documents_file,
})
}
}
/// Given an optional primary key and an optional alternative name, returns the (field_id, attr_name)
/// for the primary key according to the following rules:
/// - if primary_key is `Some`, returns the id and the name, else
/// - if alternative_name is Some, adds alternative to the fields_ids_map, and returns the pair, else
/// - if autogenerate_docids is true, insert the default id value in the field ids map ("id") and
/// returns the pair, else
/// - returns an error.
fn compute_primary_key_pair(
primary_key: Option<&str>,
fields_ids_map: &mut FieldsIdsMap,
alternative_name: Option<String>,
autogenerate_docids: bool,
) -> Result<(FieldId, String)> {
match primary_key {
Some(primary_key) => {
let id = fields_ids_map.insert(primary_key).ok_or(UserError::AttributeLimitReached)?;
Ok((id, primary_key.to_string()))
}
None => {
let name = match alternative_name {
Some(key) => key,
None => {
if !autogenerate_docids {
// If there is no primary key in the current document batch, we must
// return an error and not automatically generate any document id.
return Err(UserError::MissingPrimaryKey.into());
}
DEFAULT_PRIMARY_KEY_NAME.to_string()
}
};
let id = fields_ids_map.insert(&name).ok_or(UserError::AttributeLimitReached)?;
Ok((id, name))
}
}
}
fn validate_document_id(document_id: &str) -> Option<&str> {
let document_id = document_id.trim();
Some(document_id).filter(|id| {
!id.is_empty()
&& id.chars().all(|c| matches!(c, 'a'..='z' | 'A'..='Z' | '0'..='9' | '-' | '_'))
})
}
/// Drops all the value of type `U` in vec, and reuses the allocation to create a `Vec<T>`.
///
/// The size and alignment of T and U must match.
fn drop_and_reuse<U, T>(mut vec: Vec<U>) -> Vec<T> {
debug_assert_eq!(std::mem::align_of::<U>(), std::mem::align_of::<T>());
debug_assert_eq!(std::mem::size_of::<U>(), std::mem::size_of::<T>());
vec.clear();
debug_assert!(vec.is_empty());
vec.into_iter().map(|_| unreachable!()).collect()
}
#[cfg(test)]
mod test {
use super::*;
mod compute_primary_key {
use super::{compute_primary_key_pair, FieldsIdsMap};
#[test]
fn should_return_primary_key_if_is_some() {
let mut fields_map = FieldsIdsMap::new();
fields_map.insert("toto").unwrap();
let result = compute_primary_key_pair(
Some("toto"),
&mut fields_map,
Some("tata".to_string()),
false,
);
assert_eq!(result.unwrap(), (0, "toto".to_string()));
assert_eq!(fields_map.len(), 1);
}
#[test]
fn should_return_alternative_if_primary_is_none() {
let mut fields_map = FieldsIdsMap::new();
let result =
compute_primary_key_pair(None, &mut fields_map, Some("tata".to_string()), false);
assert_eq!(result.unwrap(), (0, "tata".to_string()));
assert_eq!(fields_map.len(), 1);
}
#[test]
fn should_return_default_if_both_are_none() {
let mut fields_map = FieldsIdsMap::new();
let result = compute_primary_key_pair(None, &mut fields_map, None, true);
assert_eq!(result.unwrap(), (0, "id".to_string()));
assert_eq!(fields_map.len(), 1);
}
#[test]
fn should_return_err_if_both_are_none_and_recompute_is_false() {
let mut fields_map = FieldsIdsMap::new();
let result = compute_primary_key_pair(None, &mut fields_map, None, false);
assert!(result.is_err());
assert_eq!(fields_map.len(), 0);
}
}
mod primary_key_inference {
use bimap::BiHashMap;
use crate::documents::DocumentsBatchIndex;
use crate::update::index_documents::transform::find_primary_key;
#[test]
fn primary_key_infered_on_first_field() {
// We run the test multiple times to change the order in which the fields are iterated upon.
for _ in 1..50 {
let mut map = BiHashMap::new();
map.insert(1, "fakeId".to_string());
map.insert(2, "fakeId".to_string());
map.insert(3, "fakeId".to_string());
map.insert(4, "fakeId".to_string());
map.insert(0, "realId".to_string());
assert_eq!(find_primary_key(&DocumentsBatchIndex(map)), Some("realId"));
}
}
}
}