/
merger.rs
2063 lines (1923 loc) · 81.7 KB
/
merger.rs
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use super::doc_id_mapping::DocIdMapping;
use crate::error::DataCorruption;
use crate::fastfield::CompositeFastFieldSerializer;
use crate::fastfield::DeleteBitSet;
use crate::fastfield::DynamicFastFieldReader;
use crate::fastfield::FastFieldReader;
use crate::fastfield::FastFieldSerializer;
use crate::fastfield::MultiValuedFastFieldReader;
use crate::fieldnorm::FieldNormsSerializer;
use crate::fieldnorm::FieldNormsWriter;
use crate::fieldnorm::{FieldNormReader, FieldNormReaders};
use crate::indexer::SegmentSerializer;
use crate::postings::Postings;
use crate::postings::{InvertedIndexSerializer, SegmentPostings};
use crate::schema::Cardinality;
use crate::schema::FieldType;
use crate::schema::{Field, Schema};
use crate::store::StoreWriter;
use crate::termdict::TermMerger;
use crate::termdict::TermOrdinal;
use crate::{common::HasLen, fastfield::MultiValueLength};
use crate::{common::MAX_DOC_LIMIT, IndexSettings};
use crate::{core::Segment, indexer::doc_id_mapping::expect_field_id_for_sort_field};
use crate::{core::SegmentReader, Order};
use crate::{core::SerializableSegment, IndexSortByField};
use crate::{
docset::{DocSet, TERMINATED},
SegmentOrdinal,
};
use crate::{DocId, InvertedIndexReader, SegmentComponent};
use itertools::Itertools;
use std::cmp;
use std::collections::HashMap;
use std::sync::Arc;
use tantivy_bitpacker::minmax;
fn compute_total_num_tokens(readers: &[SegmentReader], field: Field) -> crate::Result<u64> {
let mut total_tokens = 0u64;
let mut count: [usize; 256] = [0; 256];
for reader in readers {
if reader.has_deletes() {
// if there are deletes, then we use an approximation
// using the fieldnorm
let fieldnorms_reader = reader.get_fieldnorms_reader(field)?;
for doc in reader.doc_ids_alive() {
let fieldnorm_id = fieldnorms_reader.fieldnorm_id(doc);
count[fieldnorm_id as usize] += 1;
}
} else {
total_tokens += reader.inverted_index(field)?.total_num_tokens();
}
}
Ok(total_tokens
+ count
.iter()
.cloned()
.enumerate()
.map(|(fieldnorm_ord, count)| {
count as u64 * u64::from(FieldNormReader::id_to_fieldnorm(fieldnorm_ord as u8))
})
.sum::<u64>())
}
/// `ReaderWithOrdinal` is used to be able to easier associate
/// data with a `SegmentReader`. The ordinal is supposed to be
/// used as an index access.
///
/// The ordinal identifies the position within `Merger` readers.
#[derive(Clone, Copy)]
pub(crate) struct SegmentReaderWithOrdinal<'a> {
pub reader: &'a SegmentReader,
pub ordinal: SegmentOrdinal,
}
impl<'a> From<(usize, &'a SegmentReader)> for SegmentReaderWithOrdinal<'a> {
fn from(data: (usize, &'a SegmentReader)) -> Self {
SegmentReaderWithOrdinal {
reader: data.1,
ordinal: data.0 as u32,
}
}
}
pub struct IndexMerger {
index_settings: IndexSettings,
schema: Schema,
readers: Vec<SegmentReader>,
max_doc: u32,
}
fn compute_min_max_val(
u64_reader: &impl FastFieldReader<u64>,
max_doc: DocId,
delete_bitset_opt: Option<&DeleteBitSet>,
) -> Option<(u64, u64)> {
if max_doc == 0 {
None
} else {
match delete_bitset_opt {
Some(delete_bitset) => {
// some deleted documents,
// we need to recompute the max / min
minmax(
(0..max_doc)
.filter(|doc_id| delete_bitset.is_alive(*doc_id))
.map(|doc_id| u64_reader.get(doc_id)),
)
}
None => {
// no deleted documents,
// we can use the previous min_val, max_val.
Some((u64_reader.min_value(), u64_reader.max_value()))
}
}
}
}
struct TermOrdinalMapping {
per_segment_new_term_ordinals: Vec<Vec<TermOrdinal>>,
}
impl TermOrdinalMapping {
fn new(max_term_ords: Vec<TermOrdinal>) -> TermOrdinalMapping {
TermOrdinalMapping {
per_segment_new_term_ordinals: max_term_ords
.into_iter()
.map(|max_term_ord| vec![TermOrdinal::default(); max_term_ord as usize])
.collect(),
}
}
fn register_from_to(&mut self, segment_ord: usize, from_ord: TermOrdinal, to_ord: TermOrdinal) {
self.per_segment_new_term_ordinals[segment_ord][from_ord as usize] = to_ord;
}
fn get_segment(&self, segment_ord: usize) -> &[TermOrdinal] {
&(self.per_segment_new_term_ordinals[segment_ord])[..]
}
fn max_term_ord(&self) -> TermOrdinal {
self.per_segment_new_term_ordinals
.iter()
.flat_map(|term_ordinals| term_ordinals.iter().cloned().max())
.max()
.unwrap_or_else(TermOrdinal::default)
}
}
struct DeltaComputer {
buffer: Vec<u32>,
}
impl DeltaComputer {
fn new() -> DeltaComputer {
DeltaComputer {
buffer: vec![0u32; 512],
}
}
fn compute_delta(&mut self, positions: &[u32]) -> &[u32] {
if positions.len() > self.buffer.len() {
self.buffer.resize(positions.len(), 0u32);
}
let mut last_pos = 0u32;
for (cur_pos, dest) in positions.iter().cloned().zip(self.buffer.iter_mut()) {
*dest = cur_pos - last_pos;
last_pos = cur_pos;
}
&self.buffer[..positions.len()]
}
}
impl IndexMerger {
pub fn open(
schema: Schema,
index_settings: IndexSettings,
segments: &[Segment],
) -> crate::Result<IndexMerger> {
let mut readers = vec![];
let mut max_doc: u32 = 0u32;
for segment in segments {
if segment.meta().num_docs() > 0 {
let reader = SegmentReader::open(segment)?;
max_doc += reader.num_docs();
readers.push(reader);
}
}
if let Some(sort_by_field) = index_settings.sort_by_field.as_ref() {
readers = Self::sort_readers_by_min_sort_field(readers, sort_by_field)?;
}
// sort segments by their natural sort setting
if max_doc >= MAX_DOC_LIMIT {
let err_msg = format!(
"The segment resulting from this merge would have {} docs,\
which exceeds the limit {}.",
max_doc, MAX_DOC_LIMIT
);
return Err(crate::TantivyError::InvalidArgument(err_msg));
}
Ok(IndexMerger {
index_settings,
schema,
readers,
max_doc,
})
}
fn sort_readers_by_min_sort_field(
readers: Vec<SegmentReader>,
sort_by_field: &IndexSortByField,
) -> crate::Result<Vec<SegmentReader>> {
// presort the readers by their min_values, so that when they are disjunct, we can use
// the regular merge logic (implicitly sorted)
let mut readers_with_min_sort_values = readers
.into_iter()
.map(|reader| {
let accessor = Self::get_sort_field_accessor(&reader, &sort_by_field)?;
Ok((reader, accessor.min_value()))
})
.collect::<crate::Result<Vec<_>>>()?;
if sort_by_field.order.is_asc() {
readers_with_min_sort_values.sort_by_key(|(_, min_val)| *min_val);
} else {
readers_with_min_sort_values.sort_by_key(|(_, min_val)| std::cmp::Reverse(*min_val));
}
Ok(readers_with_min_sort_values
.into_iter()
.map(|(reader, _)| reader)
.collect())
}
fn write_fieldnorms(
&self,
mut fieldnorms_serializer: FieldNormsSerializer,
doc_id_mapping: &Option<Vec<(DocId, SegmentReaderWithOrdinal)>>,
) -> crate::Result<()> {
let fields = FieldNormsWriter::fields_with_fieldnorm(&self.schema);
let mut fieldnorms_data = Vec::with_capacity(self.max_doc as usize);
for field in fields {
fieldnorms_data.clear();
if let Some(doc_id_mapping) = doc_id_mapping {
let fieldnorms_readers: Vec<FieldNormReader> = self
.readers
.iter()
.map(|reader| reader.get_fieldnorms_reader(field))
.collect::<Result<_, _>>()?;
for (doc_id, reader_with_ordinal) in doc_id_mapping {
let fieldnorms_reader =
&fieldnorms_readers[reader_with_ordinal.ordinal as usize];
let fieldnorm_id = fieldnorms_reader.fieldnorm_id(*doc_id);
fieldnorms_data.push(fieldnorm_id);
}
} else {
for reader in &self.readers {
let fieldnorms_reader = reader.get_fieldnorms_reader(field)?;
for doc_id in reader.doc_ids_alive() {
let fieldnorm_id = fieldnorms_reader.fieldnorm_id(doc_id);
fieldnorms_data.push(fieldnorm_id);
}
}
}
fieldnorms_serializer.serialize_field(field, &fieldnorms_data[..])?;
}
fieldnorms_serializer.close()?;
Ok(())
}
fn write_fast_fields(
&self,
fast_field_serializer: &mut CompositeFastFieldSerializer,
mut term_ord_mappings: HashMap<Field, TermOrdinalMapping>,
doc_id_mapping: &Option<Vec<(DocId, SegmentReaderWithOrdinal)>>,
) -> crate::Result<()> {
for (field, field_entry) in self.schema.fields() {
let field_type = field_entry.field_type();
match field_type {
FieldType::HierarchicalFacet(_) => {
let term_ordinal_mapping = term_ord_mappings
.remove(&field)
.expect("Logic Error in Tantivy (Please report). HierarchicalFact field should have required a\
`term_ordinal_mapping`.");
self.write_hierarchical_facet_field(
field,
&term_ordinal_mapping,
fast_field_serializer,
doc_id_mapping,
)?;
}
FieldType::U64(ref options)
| FieldType::I64(ref options)
| FieldType::F64(ref options)
| FieldType::Date(ref options) => match options.get_fastfield_cardinality() {
Some(Cardinality::SingleValue) => {
self.write_single_fast_field(field, fast_field_serializer, doc_id_mapping)?;
}
Some(Cardinality::MultiValues) => {
self.write_multi_fast_field(field, fast_field_serializer, doc_id_mapping)?;
}
None => {}
},
FieldType::Str(_) => {
// We don't handle str fast field for the moment
// They can be implemented using what is done
// for facets in the future.
}
FieldType::Bytes(byte_options) => {
if byte_options.is_fast() {
self.write_bytes_fast_field(field, fast_field_serializer, doc_id_mapping)?;
}
}
}
}
Ok(())
}
// used both to merge field norms, `u64/i64` single fast fields.
fn write_single_fast_field(
&self,
field: Field,
fast_field_serializer: &mut CompositeFastFieldSerializer,
doc_id_mapping: &Option<Vec<(DocId, SegmentReaderWithOrdinal)>>,
) -> crate::Result<()> {
let (min_value, max_value) = self.readers.iter().map(|reader|{
let u64_reader: DynamicFastFieldReader<u64> = reader
.fast_fields()
.typed_fast_field_reader(field)
.expect("Failed to find a reader for single fast field. This is a tantivy bug and it should never happen.");
compute_min_max_val(&u64_reader, reader.max_doc(), reader.delete_bitset())
})
.filter_map(|x| x)
.reduce(|a, b| {
(a.0.min(b.0), a.1.max(b.1))
}).expect("Unexpected error, empty readers in IndexMerger");
let fast_field_readers = self
.readers
.iter()
.map(|reader| {
let u64_reader: DynamicFastFieldReader<u64> = reader
.fast_fields()
.typed_fast_field_reader(field)
.expect("Failed to find a reader for single fast field. This is a tantivy bug and it should never happen.");
u64_reader
})
.collect::<Vec<_>>();
if let Some(doc_id_mapping) = doc_id_mapping {
let sorted_doc_ids = doc_id_mapping.iter().map(|(doc_id, reader_with_ordinal)| {
(
doc_id,
&fast_field_readers[reader_with_ordinal.ordinal as usize],
)
});
// add values in order of the new doc_ids
let mut fast_single_field_serializer =
fast_field_serializer.new_u64_fast_field(field, min_value, max_value)?;
for (doc_id, field_reader) in sorted_doc_ids {
let val = field_reader.get(*doc_id);
fast_single_field_serializer.add_val(val)?;
}
fast_single_field_serializer.close_field()?;
Ok(())
} else {
let u64_readers = self.readers.iter()
.filter(|reader|reader.max_doc() != reader.delete_bitset().map(|bit_set|bit_set.len() as u32).unwrap_or(0))
.map(|reader|{
let u64_reader: DynamicFastFieldReader<u64> = reader
.fast_fields()
.typed_fast_field_reader(field)
.expect("Failed to find a reader for single fast field. This is a tantivy bug and it should never happen.");
(reader.max_doc(), u64_reader, reader.delete_bitset())
}).collect::<Vec<_>>();
let mut fast_single_field_serializer =
fast_field_serializer.new_u64_fast_field(field, min_value, max_value)?;
for (max_doc, u64_reader, delete_bitset_opt) in u64_readers {
for doc_id in 0u32..max_doc {
let is_deleted = delete_bitset_opt
.map(|delete_bitset| delete_bitset.is_deleted(doc_id))
.unwrap_or(false);
if !is_deleted {
let val = u64_reader.get(doc_id);
fast_single_field_serializer.add_val(val)?;
}
}
}
fast_single_field_serializer.close_field()?;
Ok(())
}
}
/// Checks if the readers are disjunct for their sort property and in the correct order to be
/// able to just stack them.
pub(crate) fn is_disjunct_and_sorted_on_sort_property(
&self,
sort_by_field: &IndexSortByField,
) -> crate::Result<bool> {
let reader_and_field_accessors = self.get_reader_with_sort_field_accessor(sort_by_field)?;
let everything_is_in_order = reader_and_field_accessors
.into_iter()
.map(|reader| reader.1)
.tuple_windows()
.all(|(field_accessor1, field_accessor2)| {
if sort_by_field.order.is_asc() {
field_accessor1.max_value() <= field_accessor2.min_value()
} else {
field_accessor1.min_value() >= field_accessor2.max_value()
}
});
Ok(everything_is_in_order)
}
pub(crate) fn get_sort_field_accessor(
reader: &SegmentReader,
sort_by_field: &IndexSortByField,
) -> crate::Result<impl FastFieldReader<u64>> {
let field_id = expect_field_id_for_sort_field(&reader.schema(), &sort_by_field)?; // for now expect fastfield, but not strictly required
let value_accessor = reader.fast_fields().u64_lenient(field_id)?;
Ok(value_accessor)
}
/// Collecting value_accessors into a vec to bind the lifetime.
pub(crate) fn get_reader_with_sort_field_accessor<'a, 'b>(
&'a self,
sort_by_field: &'b IndexSortByField,
) -> crate::Result<
Vec<(
SegmentReaderWithOrdinal<'a>,
impl FastFieldReader<u64> + Clone,
)>,
> {
let reader_and_field_accessors = self
.readers
.iter()
.enumerate()
.map(Into::into)
.map(|reader_with_ordinal: SegmentReaderWithOrdinal| {
let value_accessor =
Self::get_sort_field_accessor(reader_with_ordinal.reader, sort_by_field)?;
Ok((reader_with_ordinal, value_accessor))
})
.collect::<crate::Result<Vec<_>>>()?;
Ok(reader_and_field_accessors)
}
/// Generates the doc_id mapping where position in the vec=new
/// doc_id.
/// ReaderWithOrdinal will include the ordinal position of the
/// reader in self.readers.
pub(crate) fn generate_doc_id_mapping(
&self,
sort_by_field: &IndexSortByField,
) -> crate::Result<Vec<(DocId, SegmentReaderWithOrdinal)>> {
let reader_and_field_accessors = self.get_reader_with_sort_field_accessor(sort_by_field)?;
// Loading the field accessor on demand causes a 15x regression
// create iterators over segment/sort_accessor/doc_id tuple
let doc_id_reader_pair =
reader_and_field_accessors
.iter()
.map(|reader_and_field_accessor| {
reader_and_field_accessor
.0
.reader
.doc_ids_alive()
.map(move |doc_id| {
(
doc_id,
reader_and_field_accessor.0,
&reader_and_field_accessor.1,
)
})
});
// create iterator tuple of (old doc_id, reader) in order of the new doc_ids
let sorted_doc_ids: Vec<(DocId, SegmentReaderWithOrdinal)> = doc_id_reader_pair
.into_iter()
.kmerge_by(|a, b| {
let val1 = a.2.get(a.0);
let val2 = b.2.get(b.0);
if sort_by_field.order == Order::Asc {
val1 < val2
} else {
val1 > val2
}
})
.map(|(doc_id, reader_with_id, _)| (doc_id, reader_with_id))
.collect::<Vec<_>>();
Ok(sorted_doc_ids)
}
// Creating the index file to point into the data, generic over `BytesFastFieldReader` and
// `MultiValuedFastFieldReader`
//
// Important: reader_and_field_accessor needs
// to have the same order as self.readers since ReaderWithOrdinal
// is used to index the reader_and_field_accessors vec.
fn write_1_n_fast_field_idx_generic(
field: Field,
fast_field_serializer: &mut CompositeFastFieldSerializer,
doc_id_mapping: &Option<Vec<(DocId, SegmentReaderWithOrdinal)>>,
reader_and_field_accessors: &[(&SegmentReader, impl MultiValueLength)],
) -> crate::Result<()> {
let mut total_num_vals = 0u64;
// In the first pass, we compute the total number of vals.
//
// This is required by the bitpacker, as it needs to know
// what should be the bit length use for bitpacking.
for (reader, u64s_reader) in reader_and_field_accessors.iter() {
if let Some(delete_bitset) = reader.delete_bitset() {
for doc in 0u32..reader.max_doc() {
if delete_bitset.is_alive(doc) {
let num_vals = u64s_reader.get_len(doc) as u64;
total_num_vals += num_vals;
}
}
} else {
total_num_vals += u64s_reader.get_total_len();
}
}
// We can now create our `idx` serializer, and in a second pass,
// can effectively push the different indexes.
if let Some(doc_id_mapping) = doc_id_mapping {
let mut serialize_idx =
fast_field_serializer.new_u64_fast_field_with_idx(field, 0, total_num_vals, 0)?;
let mut offset = 0;
for (doc_id, reader) in doc_id_mapping {
let reader = &reader_and_field_accessors[reader.ordinal as usize].1;
serialize_idx.add_val(offset)?;
offset += reader.get_len(*doc_id) as u64;
}
serialize_idx.add_val(offset as u64)?;
serialize_idx.close_field()?;
} else {
let mut serialize_idx =
fast_field_serializer.new_u64_fast_field_with_idx(field, 0, total_num_vals, 0)?;
let mut idx = 0;
for (segment_reader, u64s_reader) in reader_and_field_accessors.iter() {
for doc in segment_reader.doc_ids_alive() {
serialize_idx.add_val(idx)?;
idx += u64s_reader.get_len(doc) as u64;
}
}
serialize_idx.add_val(idx)?;
serialize_idx.close_field()?;
}
Ok(())
}
fn write_multi_value_fast_field_idx(
&self,
field: Field,
fast_field_serializer: &mut CompositeFastFieldSerializer,
doc_id_mapping: &Option<Vec<(DocId, SegmentReaderWithOrdinal)>>,
) -> crate::Result<()> {
let reader_and_field_accessors = self.readers.iter().map(|reader|{
let u64s_reader: MultiValuedFastFieldReader<u64> = reader.fast_fields()
.typed_fast_field_multi_reader(field)
.expect("Failed to find index for multivalued field. This is a bug in tantivy, please report.");
(reader, u64s_reader)
}).collect::<Vec<_>>();
Self::write_1_n_fast_field_idx_generic(
field,
fast_field_serializer,
doc_id_mapping,
&reader_and_field_accessors,
)
}
fn write_hierarchical_facet_field(
&self,
field: Field,
term_ordinal_mappings: &TermOrdinalMapping,
fast_field_serializer: &mut CompositeFastFieldSerializer,
doc_id_mapping: &Option<Vec<(DocId, SegmentReaderWithOrdinal)>>,
) -> crate::Result<()> {
// Multifastfield consists in 2 fastfields.
// The first serves as an index into the second one and is stricly increasing.
// The second contains the actual values.
// First we merge the idx fast field.
self.write_multi_value_fast_field_idx(field, fast_field_serializer, doc_id_mapping)?;
let fast_field_reader = self
.readers
.iter()
.map(|reader| {
let ff_reader: MultiValuedFastFieldReader<u64> = reader
.fast_fields()
.u64s(field)
.expect("Could not find multivalued u64 fast value reader.");
ff_reader
})
.collect::<Vec<_>>();
// We can now write the actual fast field values.
// In the case of hierarchical facets, they are actually term ordinals.
let max_term_ord = term_ordinal_mappings.max_term_ord();
{
let mut serialize_vals =
fast_field_serializer.new_u64_fast_field_with_idx(field, 0u64, max_term_ord, 1)?;
let mut vals = Vec::with_capacity(100);
if let Some(doc_id_mapping) = doc_id_mapping {
for (old_doc_id, reader_with_ordinal) in doc_id_mapping {
let term_ordinal_mapping: &[TermOrdinal] =
term_ordinal_mappings.get_segment(reader_with_ordinal.ordinal as usize);
let ff_reader = &fast_field_reader[reader_with_ordinal.ordinal as usize];
ff_reader.get_vals(*old_doc_id, &mut vals);
for &prev_term_ord in &vals {
let new_term_ord = term_ordinal_mapping[prev_term_ord as usize];
serialize_vals.add_val(new_term_ord)?;
}
}
} else {
for (segment_ord, segment_reader) in self.readers.iter().enumerate() {
let term_ordinal_mapping: &[TermOrdinal] =
term_ordinal_mappings.get_segment(segment_ord);
let ff_reader = &fast_field_reader[segment_ord as usize];
// TODO optimize if no deletes
for doc in segment_reader.doc_ids_alive() {
ff_reader.get_vals(doc, &mut vals);
for &prev_term_ord in &vals {
let new_term_ord = term_ordinal_mapping[prev_term_ord as usize];
serialize_vals.add_val(new_term_ord)?;
}
}
}
}
serialize_vals.close_field()?;
}
Ok(())
}
fn write_multi_fast_field(
&self,
field: Field,
fast_field_serializer: &mut CompositeFastFieldSerializer,
doc_id_mapping: &Option<Vec<(DocId, SegmentReaderWithOrdinal)>>,
) -> crate::Result<()> {
// Multifastfield consists in 2 fastfields.
// The first serves as an index into the second one and is stricly increasing.
// The second contains the actual values.
// First we merge the idx fast field.
self.write_multi_value_fast_field_idx(field, fast_field_serializer, doc_id_mapping)?;
let mut min_value = u64::max_value();
let mut max_value = u64::min_value();
let mut vals = Vec::with_capacity(100);
let mut ff_readers = Vec::new();
// Our values are bitpacked and we need to know what should be
// our bitwidth and our minimum value before serializing any values.
//
// Computing those is non-trivial if some documents are deleted.
// We go through a complete first pass to compute the minimum and the
// maximum value and initialize our Serializer.
for reader in &self.readers {
let ff_reader: MultiValuedFastFieldReader<u64> = reader
.fast_fields()
.typed_fast_field_multi_reader(field)
.expect(
"Failed to find multivalued fast field reader. This is a bug in \
tantivy. Please report.",
);
for doc in reader.doc_ids_alive() {
ff_reader.get_vals(doc, &mut vals);
for &val in &vals {
min_value = cmp::min(val, min_value);
max_value = cmp::max(val, max_value);
}
}
ff_readers.push(ff_reader);
// TODO optimize when no deletes
}
if min_value > max_value {
min_value = 0;
max_value = 0;
}
let fast_field_reader = self
.readers
.iter()
.map(|reader| {
let ff_reader : MultiValuedFastFieldReader<u64> = reader.fast_fields()
.typed_fast_field_multi_reader(field)
.expect("Failed to find index for multivalued field. This is a bug in tantivy, please report.");
ff_reader
})
.collect::<Vec<_>>();
// We can now initialize our serializer, and push it the different values
let mut serialize_vals =
fast_field_serializer.new_u64_fast_field_with_idx(field, min_value, max_value, 1)?;
if let Some(doc_id_mapping) = doc_id_mapping {
for (doc_id, reader_with_ordinal) in doc_id_mapping {
let ff_reader = &fast_field_reader[reader_with_ordinal.ordinal as usize];
ff_reader.get_vals(*doc_id, &mut vals);
for &val in &vals {
serialize_vals.add_val(val)?;
}
}
} else {
for (reader, ff_reader) in self.readers.iter().zip(ff_readers) {
// TODO optimize if no deletes
for doc in reader.doc_ids_alive() {
ff_reader.get_vals(doc, &mut vals);
for &val in &vals {
serialize_vals.add_val(val)?;
}
}
}
}
serialize_vals.close_field()?;
Ok(())
}
fn write_bytes_fast_field(
&self,
field: Field,
fast_field_serializer: &mut CompositeFastFieldSerializer,
doc_id_mapping: &Option<Vec<(DocId, SegmentReaderWithOrdinal)>>,
) -> crate::Result<()> {
let reader_and_field_accessors = self
.readers
.iter()
.map(|reader| {
let bytes_reader = reader.fast_fields().bytes(field)
.expect("Failed to find index for bytes field. This is a bug in tantivy, please report.");
(reader, bytes_reader)
})
.collect::<Vec<_>>();
Self::write_1_n_fast_field_idx_generic(
field,
fast_field_serializer,
doc_id_mapping,
&reader_and_field_accessors,
)?;
let mut serialize_vals = fast_field_serializer.new_bytes_fast_field_with_idx(field, 1);
if let Some(doc_id_mapping) = doc_id_mapping {
for (doc_id, reader_with_ordinal) in doc_id_mapping {
let bytes_reader =
&reader_and_field_accessors[reader_with_ordinal.ordinal as usize].1;
let val = bytes_reader.get_bytes(*doc_id);
serialize_vals.write_all(val)?;
}
} else {
for segment_reader in &self.readers {
let bytes_reader = segment_reader.fast_fields().bytes(field)
.expect("Failed to find bytes field in fast field reader. This is a bug in tantivy. Please report.");
// TODO: optimize if no deletes
for doc in segment_reader.doc_ids_alive() {
let val = bytes_reader.get_bytes(doc);
serialize_vals.write_all(val)?;
}
}
}
serialize_vals.flush()?;
Ok(())
}
fn write_postings_for_field(
&self,
indexed_field: Field,
field_type: &FieldType,
serializer: &mut InvertedIndexSerializer,
fieldnorm_reader: Option<FieldNormReader>,
doc_id_mapping: &Option<Vec<(DocId, SegmentReaderWithOrdinal)>>,
) -> crate::Result<Option<TermOrdinalMapping>> {
let mut positions_buffer: Vec<u32> = Vec::with_capacity(1_000);
let mut delta_computer = DeltaComputer::new();
let mut max_term_ords: Vec<TermOrdinal> = Vec::new();
let field_readers: Vec<Arc<InvertedIndexReader>> = self
.readers
.iter()
.map(|reader| reader.inverted_index(indexed_field))
.collect::<crate::Result<Vec<_>>>()?;
let mut field_term_streams = Vec::new();
for field_reader in &field_readers {
let terms = field_reader.terms();
field_term_streams.push(terms.stream()?);
max_term_ords.push(terms.num_terms() as u64);
}
let mut term_ord_mapping_opt = match field_type {
FieldType::HierarchicalFacet(_) => Some(TermOrdinalMapping::new(max_term_ords)),
_ => None,
};
let mut merged_terms = TermMerger::new(field_term_streams);
let mut max_doc = 0;
// map from segment doc ids to the resulting merged segment doc id.
let mut merged_doc_id_map: Vec<Vec<Option<DocId>>> = Vec::with_capacity(self.readers.len());
if let Some(doc_id_mapping) = doc_id_mapping {
merged_doc_id_map = self
.readers
.iter()
.map(|reader| {
let mut segment_local_map = vec![];
segment_local_map.resize(reader.max_doc() as usize, None);
segment_local_map
})
.collect();
for (new_doc_id, (old_doc_id, segment_and_ordinal)) in doc_id_mapping.iter().enumerate()
{
let segment_map = &mut merged_doc_id_map[segment_and_ordinal.ordinal as usize];
segment_map[*old_doc_id as usize] = Some(new_doc_id as DocId);
}
} else {
for reader in &self.readers {
let mut segment_local_map = Vec::with_capacity(reader.max_doc() as usize);
for doc_id in 0..reader.max_doc() {
if reader.is_deleted(doc_id) {
segment_local_map.push(None);
} else {
segment_local_map.push(Some(max_doc));
max_doc += 1u32;
}
}
merged_doc_id_map.push(segment_local_map);
}
}
// The total number of tokens will only be exact when there has been no deletes.
//
// Otherwise, we approximate by removing deleted documents proportionally.
let total_num_tokens: u64 = compute_total_num_tokens(&self.readers, indexed_field)?;
// Create the total list of doc ids
// by stacking the doc ids from the different segment.
//
// In the new segments, the doc id from the different
// segment are stacked so that :
// - Segment 0's doc ids become doc id [0, seg.max_doc]
// - Segment 1's doc ids become [seg0.max_doc, seg0.max_doc + seg.max_doc]
// - Segment 2's doc ids become [seg0.max_doc + seg1.max_doc,
// seg0.max_doc + seg1.max_doc + seg2.max_doc]
//
// This stacking applies only when the index is not sorted, in that case the
// doc_ids are kmerged by their sort property
let mut field_serializer =
serializer.new_field(indexed_field, total_num_tokens, fieldnorm_reader)?;
let field_entry = self.schema.get_field_entry(indexed_field);
// ... set segment postings option the new field.
let segment_postings_option = field_entry.field_type().get_index_record_option().expect(
"Encountered a field that is not supposed to be
indexed. Have you modified the schema?",
);
let mut segment_postings_containing_the_term: Vec<(usize, SegmentPostings)> = vec![];
let mut doc_id_and_positions = vec![];
while merged_terms.advance() {
segment_postings_containing_the_term.clear();
let term_bytes: &[u8] = merged_terms.key();
let mut total_doc_freq = 0;
// Let's compute the list of non-empty posting lists
for (segment_ord, term_info) in merged_terms.current_segment_ordinals_and_term_infos() {
let segment_reader = &self.readers[segment_ord];
let inverted_index: &InvertedIndexReader = &*field_readers[segment_ord];
let segment_postings = inverted_index
.read_postings_from_terminfo(&term_info, segment_postings_option)?;
let delete_bitset_opt = segment_reader.delete_bitset();
let doc_freq = if let Some(delete_bitset) = delete_bitset_opt {
segment_postings.doc_freq_given_deletes(delete_bitset)
} else {
segment_postings.doc_freq()
};
if doc_freq > 0u32 {
total_doc_freq += doc_freq;
segment_postings_containing_the_term.push((segment_ord, segment_postings));
}
}
// At this point, `segment_postings` contains the posting list
// of all of the segments containing the given term (and that are non-empty)
//
// These segments are non-empty and advance has already been called.
if total_doc_freq == 0u32 {
// All docs that used to contain the term have been deleted. The `term` will be
// entirely removed.
continue;
}
let to_term_ord = field_serializer.new_term(term_bytes, total_doc_freq)?;
if let Some(ref mut term_ord_mapping) = term_ord_mapping_opt {
for (segment_ord, from_term_ord) in merged_terms.matching_segments() {
term_ord_mapping.register_from_to(segment_ord, from_term_ord, to_term_ord);
}
}
// We can now serialize this postings, by pushing each document to the
// postings serializer.
for (segment_ord, mut segment_postings) in
segment_postings_containing_the_term.drain(..)
{
let old_to_new_doc_id = &merged_doc_id_map[segment_ord];
let mut doc = segment_postings.doc();
while doc != TERMINATED {
// deleted doc are skipped as they do not have a `remapped_doc_id`.
if let Some(remapped_doc_id) = old_to_new_doc_id[doc as usize] {
// we make sure to only write the term if
// there is at least one document.
let term_freq = segment_postings.term_freq();
segment_postings.positions(&mut positions_buffer);
// if doc_id_mapping exists, the docids are reordered, they are
// not just stacked. The field serializer expects monotonically increasing
// docids, so we collect and sort them first, before writing.
//
// I think this is not strictly necessary, it would be possible to
// avoid the loading into a vec via some form of kmerge, but then the merge
// logic would deviate much more from the stacking case (unsorted index)
if doc_id_mapping.is_some() {
doc_id_and_positions.push((
remapped_doc_id,
term_freq,
positions_buffer.to_vec(),
));
} else {
let delta_positions = delta_computer.compute_delta(&positions_buffer);
field_serializer.write_doc(remapped_doc_id, term_freq, delta_positions);
}
}
doc = segment_postings.advance();
}
}
if doc_id_mapping.is_some() {
doc_id_and_positions.sort_unstable_by_key(|&(doc_id, _, _)| doc_id);
for (doc_id, term_freq, positions) in &doc_id_and_positions {
field_serializer.write_doc(*doc_id, *term_freq, positions);
}
doc_id_and_positions.clear();
}
// closing the term.
field_serializer.close_term()?;
}
field_serializer.close()?;
Ok(term_ord_mapping_opt)
}
fn write_postings(
&self,
serializer: &mut InvertedIndexSerializer,
fieldnorm_readers: FieldNormReaders,
doc_id_mapping: &Option<Vec<(DocId, SegmentReaderWithOrdinal)>>,
) -> crate::Result<HashMap<Field, TermOrdinalMapping>> {
let mut term_ordinal_mappings = HashMap::new();
for (field, field_entry) in self.schema.fields() {
let fieldnorm_reader = fieldnorm_readers.get_field(field)?;
if field_entry.is_indexed() {
if let Some(term_ordinal_mapping) = self.write_postings_for_field(
field,
field_entry.field_type(),
serializer,
fieldnorm_reader,
doc_id_mapping,
)? {
term_ordinal_mappings.insert(field, term_ordinal_mapping);
}
}
}
Ok(term_ordinal_mappings)
}
fn write_storable_fields(
&self,
store_writer: &mut StoreWriter,
doc_id_mapping: &Option<Vec<(DocId, SegmentReaderWithOrdinal)>>,
) -> crate::Result<()> {
let store_readers: Vec<_> = self
.readers
.iter()
.map(|reader| reader.get_store_reader())
.collect::<Result<_, _>>()?;
let mut document_iterators: Vec<_> = store_readers
.iter()
.enumerate()
.map(|(i, store)| store.iter_raw(self.readers[i].delete_bitset()))
.collect();
if let Some(doc_id_mapping) = doc_id_mapping {