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
|
package storage
import (
"fmt"
"io"
"time"
"github.com/seaweedfs/seaweedfs/weed/util/mem"
"github.com/seaweedfs/seaweedfs/weed/glog"
"github.com/seaweedfs/seaweedfs/weed/stats"
"github.com/seaweedfs/seaweedfs/weed/storage/backend"
"github.com/seaweedfs/seaweedfs/weed/storage/needle"
"github.com/seaweedfs/seaweedfs/weed/storage/super_block"
. "github.com/seaweedfs/seaweedfs/weed/storage/types"
)
const PagedReadLimit = 1024 * 1024
// read fills in Needle content by looking up n.Id from NeedleMapper
func (v *Volume) readNeedle(n *needle.Needle, readOption *ReadOption, onReadSizeFn func(size Size)) (count int, err error) {
v.dataFileAccessLock.RLock()
defer v.dataFileAccessLock.RUnlock()
nv, ok := v.nm.Get(n.Id)
if !ok || nv.Offset.IsZero() {
return -1, ErrorNotFound
}
readSize := nv.Size
if readSize.IsDeleted() {
if readOption != nil && readOption.ReadDeleted && readSize != TombstoneFileSize {
glog.V(3).Infof("reading deleted %s", n.String())
readSize = -readSize
} else {
return -1, ErrorDeleted
}
}
if readSize == 0 {
return 0, nil
}
if onReadSizeFn != nil {
onReadSizeFn(readSize)
}
if readOption != nil && readOption.AttemptMetaOnly && readSize > PagedReadLimit {
readOption.VolumeRevision = v.SuperBlock.CompactionRevision
err = n.ReadNeedleMeta(v.DataBackend, nv.Offset.ToActualOffset(), readSize, v.Version())
if err == needle.ErrorSizeMismatch && OffsetSize == 4 {
readOption.IsOutOfRange = true
err = n.ReadNeedleMeta(v.DataBackend, nv.Offset.ToActualOffset()+int64(MaxPossibleVolumeSize), readSize, v.Version())
}
if err != nil {
return 0, err
}
if !n.IsCompressed() && !n.IsChunkedManifest() {
readOption.IsMetaOnly = true
}
}
if readOption == nil || !readOption.IsMetaOnly {
err = n.ReadData(v.DataBackend, nv.Offset.ToActualOffset(), readSize, v.Version())
v.checkReadWriteError(err)
if err != nil {
return 0, err
}
}
count = int(n.DataSize)
if !n.HasTtl() {
return
}
ttlMinutes := n.Ttl.Minutes()
if ttlMinutes == 0 {
return
}
if !n.HasLastModifiedDate() {
return
}
if time.Now().Before(time.Unix(0, int64(n.AppendAtNs)).Add(time.Duration(ttlMinutes) * time.Minute)) {
return
}
return -1, ErrorNotFound
}
// read needle at a specific offset
func (v *Volume) readNeedleMetaAt(n *needle.Needle, offset int64, size int32) (err error) {
v.dataFileAccessLock.RLock()
defer v.dataFileAccessLock.RUnlock()
// read deleted needle meta data
if size < 0 {
size = 0
}
err = n.ReadNeedleMeta(v.DataBackend, offset, Size(size), v.Version())
if err == needle.ErrorSizeMismatch && OffsetSize == 4 {
err = n.ReadNeedleMeta(v.DataBackend, offset+int64(MaxPossibleVolumeSize), Size(size), v.Version())
}
if err != nil {
return err
}
return nil
}
// read fills in Needle content by looking up n.Id from NeedleMapper
func (v *Volume) readNeedleDataInto(n *needle.Needle, readOption *ReadOption, writer io.Writer, offset int64, size int64) (err error) {
if !readOption.HasSlowRead {
v.dataFileAccessLock.RLock()
defer v.dataFileAccessLock.RUnlock()
}
if readOption.HasSlowRead {
v.dataFileAccessLock.RLock()
}
nv, ok := v.nm.Get(n.Id)
if readOption.HasSlowRead {
v.dataFileAccessLock.RUnlock()
}
if !ok || nv.Offset.IsZero() {
return ErrorNotFound
}
readSize := nv.Size
if readSize.IsDeleted() {
if readOption != nil && readOption.ReadDeleted && readSize != TombstoneFileSize {
glog.V(3).Infof("reading deleted %s", n.String())
readSize = -readSize
} else {
return ErrorDeleted
}
}
if readSize == 0 {
return nil
}
actualOffset := nv.Offset.ToActualOffset()
if readOption.IsOutOfRange {
actualOffset += int64(MaxPossibleVolumeSize)
}
buf := mem.Allocate(min(readOption.ReadBufferSize, int(size)))
defer mem.Free(buf)
// read needle data
crc := needle.CRC(0)
for x := offset; x < offset+size; x += int64(len(buf)) {
if readOption.HasSlowRead {
v.dataFileAccessLock.RLock()
}
// possibly re-read needle offset if volume is compacted
if readOption.VolumeRevision != v.SuperBlock.CompactionRevision {
// the volume is compacted
nv, ok = v.nm.Get(n.Id)
if !ok || nv.Offset.IsZero() {
if readOption.HasSlowRead {
v.dataFileAccessLock.RUnlock()
}
return ErrorNotFound
}
actualOffset = nv.Offset.ToActualOffset()
readOption.VolumeRevision = v.SuperBlock.CompactionRevision
}
count, err := n.ReadNeedleData(v.DataBackend, actualOffset, buf, x)
if readOption.HasSlowRead {
v.dataFileAccessLock.RUnlock()
}
toWrite := min(count, int(offset+size-x))
if toWrite > 0 {
crc = crc.Update(buf[0:toWrite])
// Note: CRC validation happens after the loop completes (see below)
// to avoid performance overhead in the hot read path
if _, err = writer.Write(buf[0:toWrite]); err != nil {
return fmt.Errorf("ReadNeedleData write: %w", err)
}
}
if err != nil {
if err == io.EOF {
err = nil
break
}
return fmt.Errorf("ReadNeedleData: %w", err)
}
if count <= 0 {
break
}
}
if offset == 0 && size == int64(n.DataSize) && (n.Checksum != crc && uint32(n.Checksum) != crc.Value()) {
// the crc.Value() function is to be deprecated. this double checking is for backward compatibility
// with seaweed version using crc.Value() instead of uint32(crc), which appears in commit 056c480eb
// and switch appeared in version 3.09.
stats.VolumeServerHandlerCounter.WithLabelValues(stats.ErrorCRC).Inc()
return fmt.Errorf("ReadNeedleData checksum %v expected %v for Needle: %v,%v", crc, n.Checksum, v.Id, n)
}
return nil
}
func min(x, y int) int {
if x < y {
return x
}
return y
}
// read fills in Needle content by looking up n.Id from NeedleMapper
func (v *Volume) ReadNeedleBlob(offset int64, size Size) ([]byte, error) {
v.dataFileAccessLock.RLock()
defer v.dataFileAccessLock.RUnlock()
return needle.ReadNeedleBlob(v.DataBackend, offset, size, v.Version())
}
type VolumeFileScanner interface {
VisitSuperBlock(super_block.SuperBlock) error
ReadNeedleBody() bool
VisitNeedle(n *needle.Needle, offset int64, needleHeader, needleBody []byte) error
}
func ScanVolumeFile(dirname string, collection string, id needle.VolumeId,
needleMapKind NeedleMapKind,
volumeFileScanner VolumeFileScanner) (err error) {
var v *Volume
if v, err = loadVolumeWithoutIndex(dirname, collection, id, needleMapKind, needle.GetCurrentVersion()); err != nil {
return fmt.Errorf("failed to load volume %d: %v", id, err)
}
if err = volumeFileScanner.VisitSuperBlock(v.SuperBlock); err != nil {
return fmt.Errorf("failed to process volume %d super block: %v", id, err)
}
defer v.Close()
version := v.Version()
offset := int64(v.SuperBlock.BlockSize())
return ScanVolumeFileFrom(version, v.DataBackend, offset, volumeFileScanner)
}
func ScanVolumeFileFrom(version needle.Version, datBackend backend.BackendStorageFile, offset int64, volumeFileScanner VolumeFileScanner) (err error) {
n, nh, rest, e := needle.ReadNeedleHeader(datBackend, version, offset)
if e != nil {
if e == io.EOF {
return nil
}
return fmt.Errorf("cannot read %s at offset %d: %v", datBackend.Name(), offset, e)
}
for n != nil {
var needleBody []byte
if volumeFileScanner.ReadNeedleBody() {
// println("needle", n.Id.String(), "offset", offset, "size", n.Size, "rest", rest)
if needleBody, err = n.ReadNeedleBody(datBackend, version, offset+NeedleHeaderSize, rest); err != nil {
glog.V(0).Infof("cannot read needle head [%d, %d) body [%d, %d) body length %d: %v", offset, offset+NeedleHeaderSize, offset+NeedleHeaderSize, offset+NeedleHeaderSize+rest, rest, err)
// err = fmt.Errorf("cannot read needle body: %v", err)
// return
}
}
err := volumeFileScanner.VisitNeedle(n, offset, nh, needleBody)
if err == io.EOF {
return nil
}
if err != nil {
glog.V(0).Infof("visit needle error: %v", err)
return fmt.Errorf("visit needle error: %w", err)
}
offset += NeedleHeaderSize + rest
glog.V(4).Infof("==> new entry offset %d", offset)
if n, nh, rest, err = needle.ReadNeedleHeader(datBackend, version, offset); err != nil {
if err == io.EOF {
return nil
}
return fmt.Errorf("cannot read needle header at offset %d: %v", offset, err)
}
glog.V(4).Infof("new entry needle size:%d rest:%d", n.Size, rest)
}
return nil
}
|
