forked from blevesearch/bleve
/
snapshot_segment.go
279 lines (233 loc) · 6.22 KB
/
snapshot_segment.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
// 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 scorch
import (
"bytes"
"sync"
"sync/atomic"
"github.com/RoaringBitmap/roaring"
"github.com/blevesearch/bleve/index"
"github.com/blevesearch/bleve/index/scorch/segment"
"github.com/blevesearch/bleve/size"
)
var TermSeparator byte = 0xff
var TermSeparatorSplitSlice = []byte{TermSeparator}
type SegmentSnapshot struct {
id uint64
segment segment.Segment
deleted *roaring.Bitmap
creator string
cachedDocs *cachedDocs
}
func (s *SegmentSnapshot) Segment() segment.Segment {
return s.segment
}
func (s *SegmentSnapshot) Deleted() *roaring.Bitmap {
return s.deleted
}
func (s *SegmentSnapshot) Id() uint64 {
return s.id
}
func (s *SegmentSnapshot) FullSize() int64 {
return int64(s.segment.Count())
}
func (s SegmentSnapshot) LiveSize() int64 {
return int64(s.Count())
}
func (s *SegmentSnapshot) Close() error {
return s.segment.Close()
}
func (s *SegmentSnapshot) VisitDocument(num uint64, visitor segment.DocumentFieldValueVisitor) error {
return s.segment.VisitDocument(num, visitor)
}
func (s *SegmentSnapshot) DocID(num uint64) ([]byte, error) {
return s.segment.DocID(num)
}
func (s *SegmentSnapshot) Count() uint64 {
rv := s.segment.Count()
if s.deleted != nil {
rv -= s.deleted.GetCardinality()
}
return rv
}
func (s *SegmentSnapshot) DocNumbers(docIDs []string) (*roaring.Bitmap, error) {
rv, err := s.segment.DocNumbers(docIDs)
if err != nil {
return nil, err
}
if s.deleted != nil {
rv.AndNot(s.deleted)
}
return rv, nil
}
// DocNumbersLive returns a bitmap containing doc numbers for all live docs
func (s *SegmentSnapshot) DocNumbersLive() *roaring.Bitmap {
rv := roaring.NewBitmap()
rv.AddRange(0, s.segment.Count())
if s.deleted != nil {
rv.AndNot(s.deleted)
}
return rv
}
func (s *SegmentSnapshot) Fields() []string {
return s.segment.Fields()
}
func (s *SegmentSnapshot) Size() (rv int) {
rv = s.segment.Size()
if s.deleted != nil {
rv += int(s.deleted.GetSizeInBytes())
}
rv += s.cachedDocs.Size()
return
}
type cachedFieldDocs struct {
m sync.Mutex
readyCh chan struct{} // closed when the cachedFieldDocs.docs is ready to be used.
err error // Non-nil if there was an error when preparing this cachedFieldDocs.
docs map[uint64][]byte // Keyed by localDocNum, value is a list of terms delimited by 0xFF.
size uint64
}
func (cfd *cachedFieldDocs) Size() int {
var rv int
cfd.m.Lock()
for _, entry := range cfd.docs {
rv += 8 /* size of uint64 */ + len(entry)
}
cfd.m.Unlock()
return rv
}
func (cfd *cachedFieldDocs) prepareField(field string, ss *SegmentSnapshot) {
cfd.m.Lock()
defer func() {
close(cfd.readyCh)
cfd.m.Unlock()
}()
cfd.size += uint64(size.SizeOfUint64) /* size field */
dict, err := ss.segment.Dictionary(field)
if err != nil {
cfd.err = err
return
}
var postings segment.PostingsList
var postingsItr segment.PostingsIterator
dictItr := dict.Iterator()
next, err := dictItr.Next()
for err == nil && next != nil {
var err1 error
postings, err1 = dict.PostingsList([]byte(next.Term), nil, postings)
if err1 != nil {
cfd.err = err1
return
}
cfd.size += uint64(size.SizeOfUint64) /* map key */
postingsItr = postings.Iterator(false, false, false, postingsItr)
nextPosting, err2 := postingsItr.Next()
for err2 == nil && nextPosting != nil {
docNum := nextPosting.Number()
cfd.docs[docNum] = append(cfd.docs[docNum], []byte(next.Term)...)
cfd.docs[docNum] = append(cfd.docs[docNum], TermSeparator)
cfd.size += uint64(len(next.Term) + 1) // map value
nextPosting, err2 = postingsItr.Next()
}
if err2 != nil {
cfd.err = err2
return
}
next, err = dictItr.Next()
}
if err != nil {
cfd.err = err
return
}
}
type cachedDocs struct {
size uint64
m sync.Mutex // As the cache is asynchronously prepared, need a lock
cache map[string]*cachedFieldDocs // Keyed by field
}
func (c *cachedDocs) prepareFields(wantedFields []string, ss *SegmentSnapshot) error {
c.m.Lock()
if c.cache == nil {
c.cache = make(map[string]*cachedFieldDocs, len(ss.Fields()))
}
for _, field := range wantedFields {
_, exists := c.cache[field]
if !exists {
c.cache[field] = &cachedFieldDocs{
readyCh: make(chan struct{}),
docs: make(map[uint64][]byte),
}
go c.cache[field].prepareField(field, ss)
}
}
for _, field := range wantedFields {
cachedFieldDocs := c.cache[field]
c.m.Unlock()
<-cachedFieldDocs.readyCh
if cachedFieldDocs.err != nil {
return cachedFieldDocs.err
}
c.m.Lock()
}
c.updateSizeLOCKED()
c.m.Unlock()
return nil
}
// hasFields returns true if the cache has all the given fields
func (c *cachedDocs) hasFields(fields []string) bool {
c.m.Lock()
for _, field := range fields {
if _, exists := c.cache[field]; !exists {
c.m.Unlock()
return false // found a field not in cache
}
}
c.m.Unlock()
return true
}
func (c *cachedDocs) Size() int {
return int(atomic.LoadUint64(&c.size))
}
func (c *cachedDocs) updateSizeLOCKED() {
sizeInBytes := 0
for k, v := range c.cache { // cachedFieldDocs
sizeInBytes += len(k)
if v != nil {
sizeInBytes += v.Size()
}
}
atomic.StoreUint64(&c.size, uint64(sizeInBytes))
}
func (c *cachedDocs) visitDoc(localDocNum uint64,
fields []string, visitor index.DocumentFieldTermVisitor) {
c.m.Lock()
for _, field := range fields {
if cachedFieldDocs, exists := c.cache[field]; exists {
c.m.Unlock()
<-cachedFieldDocs.readyCh
c.m.Lock()
if tlist, exists := cachedFieldDocs.docs[localDocNum]; exists {
for {
i := bytes.Index(tlist, TermSeparatorSplitSlice)
if i < 0 {
break
}
visitor(field, tlist[0:i])
tlist = tlist[i+1:]
}
}
}
}
c.m.Unlock()
}