1 files changed, 307 insertions, 0 deletions
diff --git a/vendor/github.com/blevesearch/zap/v11/docvalues.go b/vendor/github.com/blevesearch/zap/v11/docvalues.go
new file mode 100644
index 0000000000..2566dc6d8c
--- /dev/null
+++ b/vendor/github.com/blevesearch/zap/v11/docvalues.go
@@ -0,0 +1,307 @@
+//  Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"math"
+	"reflect"
+	"sort"
+
+	"github.com/blevesearch/bleve/index"
+	"github.com/blevesearch/bleve/index/scorch/segment"
+	"github.com/blevesearch/bleve/size"
+	"github.com/golang/snappy"
+)
+
+var reflectStaticSizedocValueReader int
+
+func init() {
+	var dvi docValueReader
+	reflectStaticSizedocValueReader = int(reflect.TypeOf(dvi).Size())
+}
+
+type docNumTermsVisitor func(docNum uint64, terms []byte) error
+
+type docVisitState struct {
+	dvrs    map[uint16]*docValueReader
+	segment *SegmentBase
+}
+
+type docValueReader struct {
+	field          string
+	curChunkNum    uint64
+	chunkOffsets   []uint64
+	dvDataLoc      uint64
+	curChunkHeader []MetaData
+	curChunkData   []byte // compressed data cache
+	uncompressed   []byte // temp buf for snappy decompression
+}
+
+func (di *docValueReader) size() int {
+	return reflectStaticSizedocValueReader + size.SizeOfPtr +
+		len(di.field) +
+		len(di.chunkOffsets)*size.SizeOfUint64 +
+		len(di.curChunkHeader)*reflectStaticSizeMetaData +
+		len(di.curChunkData)
+}
+
+func (di *docValueReader) cloneInto(rv *docValueReader) *docValueReader {
+	if rv == nil {
+		rv = &docValueReader{}
+	}
+
+	rv.field = di.field
+	rv.curChunkNum = math.MaxUint64
+	rv.chunkOffsets = di.chunkOffsets // immutable, so it's sharable
+	rv.dvDataLoc = di.dvDataLoc
+	rv.curChunkHeader = rv.curChunkHeader[:0]
+	rv.curChunkData = nil
+	rv.uncompressed = rv.uncompressed[:0]
+
+	return rv
+}
+
+func (di *docValueReader) curChunkNumber() uint64 {
+	return di.curChunkNum
+}
+
+func (s *SegmentBase) loadFieldDocValueReader(field string,
+	fieldDvLocStart, fieldDvLocEnd uint64) (*docValueReader, error) {
+	// get the docValue offset for the given fields
+	if fieldDvLocStart == fieldNotUninverted {
+		// no docValues found, nothing to do
+		return nil, nil
+	}
+
+	// read the number of chunks, and chunk offsets position
+	var numChunks, chunkOffsetsPosition uint64
+
+	if fieldDvLocEnd-fieldDvLocStart > 16 {
+		numChunks = binary.BigEndian.Uint64(s.mem[fieldDvLocEnd-8 : fieldDvLocEnd])
+		// read the length of chunk offsets
+		chunkOffsetsLen := binary.BigEndian.Uint64(s.mem[fieldDvLocEnd-16 : fieldDvLocEnd-8])
+		// acquire position of chunk offsets
+		chunkOffsetsPosition = (fieldDvLocEnd - 16) - chunkOffsetsLen
+	} else {
+		return nil, fmt.Errorf("loadFieldDocValueReader: fieldDvLoc too small: %d-%d", fieldDvLocEnd, fieldDvLocStart)
+	}
+
+	fdvIter := &docValueReader{
+		curChunkNum:  math.MaxUint64,
+		field:        field,
+		chunkOffsets: make([]uint64, int(numChunks)),
+	}
+
+	// read the chunk offsets
+	var offset uint64
+	for i := 0; i < int(numChunks); i++ {
+		loc, read := binary.Uvarint(s.mem[chunkOffsetsPosition+offset : chunkOffsetsPosition+offset+binary.MaxVarintLen64])
+		if read <= 0 {
+			return nil, fmt.Errorf("corrupted chunk offset during segment load")
+		}
+		fdvIter.chunkOffsets[i] = loc
+		offset += uint64(read)
+	}
+
+	// set the data offset
+	fdvIter.dvDataLoc = fieldDvLocStart
+
+	return fdvIter, nil
+}
+
+func (di *docValueReader) loadDvChunk(chunkNumber uint64, s *SegmentBase) error {
+	// advance to the chunk where the docValues
+	// reside for the given docNum
+	destChunkDataLoc, curChunkEnd := di.dvDataLoc, di.dvDataLoc
+	start, end := readChunkBoundary(int(chunkNumber), di.chunkOffsets)
+	if start >= end {
+		di.curChunkHeader = di.curChunkHeader[:0]
+		di.curChunkData = nil
+		di.curChunkNum = chunkNumber
+		di.uncompressed = di.uncompressed[:0]
+		return nil
+	}
+
+	destChunkDataLoc += start
+	curChunkEnd += end
+
+	// read the number of docs reside in the chunk
+	numDocs, read := binary.Uvarint(s.mem[destChunkDataLoc : destChunkDataLoc+binary.MaxVarintLen64])
+	if read <= 0 {
+		return fmt.Errorf("failed to read the chunk")
+	}
+	chunkMetaLoc := destChunkDataLoc + uint64(read)
+
+	offset := uint64(0)
+	if cap(di.curChunkHeader) < int(numDocs) {
+		di.curChunkHeader = make([]MetaData, int(numDocs))
+	} else {
+		di.curChunkHeader = di.curChunkHeader[:int(numDocs)]
+	}
+	for i := 0; i < int(numDocs); i++ {
+		di.curChunkHeader[i].DocNum, read = binary.Uvarint(s.mem[chunkMetaLoc+offset : chunkMetaLoc+offset+binary.MaxVarintLen64])
+		offset += uint64(read)
+		di.curChunkHeader[i].DocDvOffset, read = binary.Uvarint(s.mem[chunkMetaLoc+offset : chunkMetaLoc+offset+binary.MaxVarintLen64])
+		offset += uint64(read)
+	}
+
+	compressedDataLoc := chunkMetaLoc + offset
+	dataLength := curChunkEnd - compressedDataLoc
+	di.curChunkData = s.mem[compressedDataLoc : compressedDataLoc+dataLength]
+	di.curChunkNum = chunkNumber
+	di.uncompressed = di.uncompressed[:0]
+	return nil
+}
+
+func (di *docValueReader) iterateAllDocValues(s *SegmentBase, visitor docNumTermsVisitor) error {
+	for i := 0; i < len(di.chunkOffsets); i++ {
+		err := di.loadDvChunk(uint64(i), s)
+		if err != nil {
+			return err
+		}
+		if di.curChunkData == nil || len(di.curChunkHeader) == 0 {
+			continue
+		}
+
+		// uncompress the already loaded data
+		uncompressed, err := snappy.Decode(di.uncompressed[:cap(di.uncompressed)], di.curChunkData)
+		if err != nil {
+			return err
+		}
+		di.uncompressed = uncompressed
+
+		start := uint64(0)
+		for _, entry := range di.curChunkHeader {
+			err = visitor(entry.DocNum, uncompressed[start:entry.DocDvOffset])
+			if err != nil {
+				return err
+			}
+
+			start = entry.DocDvOffset
+		}
+	}
+
+	return nil
+}
+
+func (di *docValueReader) visitDocValues(docNum uint64,
+	visitor index.DocumentFieldTermVisitor) error {
+	// binary search the term locations for the docNum
+	start, end := di.getDocValueLocs(docNum)
+	if start == math.MaxUint64 || end == math.MaxUint64 || start == end {
+		return nil
+	}
+
+	var uncompressed []byte
+	var err error
+	// use the uncompressed copy if available
+	if len(di.uncompressed) > 0 {
+		uncompressed = di.uncompressed
+	} else {
+		// uncompress the already loaded data
+		uncompressed, err = snappy.Decode(di.uncompressed[:cap(di.uncompressed)], di.curChunkData)
+		if err != nil {
+			return err
+		}
+		di.uncompressed = uncompressed
+	}
+
+	// pick the terms for the given docNum
+	uncompressed = uncompressed[start:end]
+	for {
+		i := bytes.Index(uncompressed, termSeparatorSplitSlice)
+		if i < 0 {
+			break
+		}
+
+		visitor(di.field, uncompressed[0:i])
+		uncompressed = uncompressed[i+1:]
+	}
+
+	return nil
+}
+
+func (di *docValueReader) getDocValueLocs(docNum uint64) (uint64, uint64) {
+	i := sort.Search(len(di.curChunkHeader), func(i int) bool {
+		return di.curChunkHeader[i].DocNum >= docNum
+	})
+	if i < len(di.curChunkHeader) && di.curChunkHeader[i].DocNum == docNum {
+		return ReadDocValueBoundary(i, di.curChunkHeader)
+	}
+	return math.MaxUint64, math.MaxUint64
+}
+
+// VisitDocumentFieldTerms is an implementation of the
+// DocumentFieldTermVisitable interface
+func (s *SegmentBase) VisitDocumentFieldTerms(localDocNum uint64, fields []string,
+	visitor index.DocumentFieldTermVisitor, dvsIn segment.DocVisitState) (
+	segment.DocVisitState, error) {
+	dvs, ok := dvsIn.(*docVisitState)
+	if !ok || dvs == nil {
+		dvs = &docVisitState{}
+	} else {
+		if dvs.segment != s {
+			dvs.segment = s
+			dvs.dvrs = nil
+		}
+	}
+
+	var fieldIDPlus1 uint16
+	if dvs.dvrs == nil {
+		dvs.dvrs = make(map[uint16]*docValueReader, len(fields))
+		for _, field := range fields {
+			if fieldIDPlus1, ok = s.fieldsMap[field]; !ok {
+				continue
+			}
+			fieldID := fieldIDPlus1 - 1
+			if dvIter, exists := s.fieldDvReaders[fieldID]; exists &&
+				dvIter != nil {
+				dvs.dvrs[fieldID] = dvIter.cloneInto(dvs.dvrs[fieldID])
+			}
+		}
+	}
+
+	// find the chunkNumber where the docValues are stored
+	docInChunk := localDocNum / uint64(s.chunkFactor)
+	var dvr *docValueReader
+	for _, field := range fields {
+		if fieldIDPlus1, ok = s.fieldsMap[field]; !ok {
+			continue
+		}
+		fieldID := fieldIDPlus1 - 1
+		if dvr, ok = dvs.dvrs[fieldID]; ok && dvr != nil {
+			// check if the chunk is already loaded
+			if docInChunk != dvr.curChunkNumber() {
+				err := dvr.loadDvChunk(docInChunk, s)
+				if err != nil {
+					return dvs, err
+				}
+			}
+
+			_ = dvr.visitDocValues(localDocNum, visitor)
+		}
+	}
+	return dvs, nil
+}
+
+// VisitableDocValueFields returns the list of fields with
+// persisted doc value terms ready to be visitable using the
+// VisitDocumentFieldTerms method.
+func (s *SegmentBase) VisitableDocValueFields() ([]string, error) {
+	return s.fieldDvNames, nil
+}