forked from johnnadratowski/golang-neo4j-bolt-driver
-
Notifications
You must be signed in to change notification settings - Fork 1
/
decoder.go
529 lines (458 loc) · 15 KB
/
decoder.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
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
package encoding
import (
"bytes"
"encoding/binary"
"io"
"github.com/ONSdigital/golang-neo4j-bolt-driver/errors"
"github.com/ONSdigital/golang-neo4j-bolt-driver/structures/graph"
"github.com/ONSdigital/golang-neo4j-bolt-driver/structures/messages"
)
// Decoder decodes a message from the bolt protocol stream
// Attempts to support all builtin golang types, when it can be confidently
// mapped to a data type from: http://alpha.neohq.net/docs/server-manual/bolt-serialization.html#bolt-packstream-structures
// (version v3.1.0-M02 at the time of writing this.
//
// Maps and Slices are a special case, where only
// map[string]interface{} and []interface{} are supported.
// The interface for maps and slices may be more permissive in the future.
type Decoder struct {
r io.Reader
buf *bytes.Buffer
}
// NewDecoder Creates a new Decoder object
func NewDecoder(r io.Reader) Decoder {
return Decoder{
r: r,
buf: &bytes.Buffer{},
}
}
// Unmarshal is used to marshal an object to the bolt interface encoded bytes
func Unmarshal(b []byte) (interface{}, error) {
return NewDecoder(bytes.NewBuffer(b)).Decode()
}
// Read out the object bytes to decode
func (d Decoder) read() (*bytes.Buffer, error) {
output := &bytes.Buffer{}
for {
lengthBytes := make([]byte, 2)
if numRead, err := io.ReadFull(d.r, lengthBytes); numRead != 2 {
return nil, errors.Wrap(err, "Couldn't read expected bytes for message length. Read: %d Expected: 2.", numRead)
}
// Chunk header contains length of current message
messageLen := binary.BigEndian.Uint16(lengthBytes)
if messageLen == 0 {
// If the length is 0, the chunk is done.
return output, nil
}
data, err := d.readData(messageLen)
if err != nil {
return output, errors.Wrap(err, "An error occurred reading message data")
}
numWritten, err := output.Write(data)
if numWritten < len(data) {
return output, errors.New("Didn't write full data on output. Expected: %d Wrote: %d", len(data), numWritten)
} else if err != nil {
return output, errors.Wrap(err, "Error writing data to output")
}
}
}
func (d Decoder) readData(messageLen uint16) ([]byte, error) {
output := make([]byte, messageLen)
var totalRead uint16
for totalRead < messageLen {
data := make([]byte, messageLen-totalRead)
numRead, err := d.r.Read(data)
if err != nil {
return nil, errors.Wrap(err, "An error occurred reading from stream")
} else if numRead == 0 {
return nil, errors.Wrap(err, "Couldn't read expected bytes for message. Read: %d Expected: %d.", totalRead, messageLen)
}
for idx, b := range data {
output[uint16(idx)+totalRead] = b
}
totalRead += uint16(numRead)
}
return output, nil
}
// Decode decodes the stream to an object
func (d Decoder) Decode() (interface{}, error) {
data, err := d.read()
if err != nil {
return nil, err
}
return d.decode(data)
}
func (d Decoder) decode(buffer *bytes.Buffer) (interface{}, error) {
marker, err := buffer.ReadByte()
if err != nil {
return nil, errors.Wrap(err, "Error reading marker")
}
// Here we have to get the marker as an int to check and see
// if it's a TINYINT
var markerInt int8
err = binary.Read(bytes.NewBuffer([]byte{marker}), binary.BigEndian, &markerInt)
if err != nil {
return nil, errors.Wrap(err, "Error reading marker as int8 from bolt message")
}
switch {
// NIL
case marker == NilMarker:
return nil, nil
// BOOL
case marker == TrueMarker:
return true, nil
case marker == FalseMarker:
return false, nil
// INT
case markerInt >= -16 && markerInt <= 127:
return int64(int8(marker)), nil
case marker == Int8Marker:
var out int8
err := binary.Read(buffer, binary.BigEndian, &out)
return int64(out), err
case marker == Int16Marker:
var out int16
err := binary.Read(buffer, binary.BigEndian, &out)
return int64(out), err
case marker == Int32Marker:
var out int32
err := binary.Read(buffer, binary.BigEndian, &out)
return int64(out), err
case marker == Int64Marker:
var out int64
err := binary.Read(buffer, binary.BigEndian, &out)
return int64(out), err
// FLOAT
case marker == FloatMarker:
var out float64
err := binary.Read(buffer, binary.BigEndian, &out)
return out, err
// STRING
case marker >= TinyStringMarker && marker <= TinyStringMarker+0x0F:
size := int(marker) - int(TinyStringMarker)
if size == 0 {
return "", nil
}
return string(buffer.Next(size)), nil
case marker == String8Marker:
var size int8
if err := binary.Read(buffer, binary.BigEndian, &size); err != nil {
return nil, errors.Wrap(err, "An error occurred reading string size")
}
return string(buffer.Next(int(size))), nil
case marker == String16Marker:
var size int16
if err := binary.Read(buffer, binary.BigEndian, &size); err != nil {
return nil, errors.Wrap(err, "An error occurred reading string size")
}
return string(buffer.Next(int(size))), nil
case marker == String32Marker:
var size int32
if err := binary.Read(buffer, binary.BigEndian, &size); err != nil {
return nil, errors.Wrap(err, "An error occurred reading string size")
}
return string(buffer.Next(int(size))), nil
// SLICE
case marker >= TinySliceMarker && marker <= TinySliceMarker+0x0F:
size := int(marker) - int(TinySliceMarker)
return d.decodeSlice(buffer, size)
case marker == Slice8Marker:
var size int8
if err := binary.Read(buffer, binary.BigEndian, &size); err != nil {
return nil, errors.Wrap(err, "An error occurred reading slice size")
}
return d.decodeSlice(buffer, int(size))
case marker == Slice16Marker:
var size int16
if err := binary.Read(buffer, binary.BigEndian, &size); err != nil {
return nil, errors.Wrap(err, "An error occurred reading slice size")
}
return d.decodeSlice(buffer, int(size))
case marker == Slice32Marker:
var size int32
if err := binary.Read(buffer, binary.BigEndian, &size); err != nil {
return nil, errors.Wrap(err, "An error occurred reading slice size")
}
return d.decodeSlice(buffer, int(size))
// MAP
case marker >= TinyMapMarker && marker <= TinyMapMarker+0x0F:
size := int(marker) - int(TinyMapMarker)
return d.decodeMap(buffer, size)
case marker == Map8Marker:
var size int8
if err := binary.Read(buffer, binary.BigEndian, &size); err != nil {
return nil, errors.Wrap(err, "An error occurred reading map size")
}
return d.decodeMap(buffer, int(size))
case marker == Map16Marker:
var size int16
if err := binary.Read(buffer, binary.BigEndian, &size); err != nil {
return nil, errors.Wrap(err, "An error occurred reading map size")
}
return d.decodeMap(buffer, int(size))
case marker == Map32Marker:
var size int32
if err := binary.Read(buffer, binary.BigEndian, &size); err != nil {
return nil, errors.Wrap(err, "An error occurred reading map size")
}
return d.decodeMap(buffer, int(size))
// STRUCTURES
case marker >= TinyStructMarker && marker <= TinyStructMarker+0x0F:
size := int(marker) - int(TinyStructMarker)
return d.decodeStruct(buffer, size)
case marker == Struct8Marker:
var size int8
if err := binary.Read(buffer, binary.BigEndian, &size); err != nil {
return nil, errors.Wrap(err, "An error occurred reading struct size")
}
return d.decodeStruct(buffer, int(size))
case marker == Struct16Marker:
var size int16
if err := binary.Read(buffer, binary.BigEndian, &size); err != nil {
return nil, errors.Wrap(err, "An error occurred reading struct size")
}
return d.decodeStruct(buffer, int(size))
default:
return nil, errors.New("Unrecognized marker byte!: %x", marker)
}
}
func (d Decoder) decodeSlice(buffer *bytes.Buffer, size int) ([]interface{}, error) {
slice := make([]interface{}, size)
for i := 0; i < size; i++ {
item, err := d.decode(buffer)
if err != nil {
return nil, err
}
slice[i] = item
}
return slice, nil
}
func (d Decoder) decodeMap(buffer *bytes.Buffer, size int) (map[string]interface{}, error) {
mapp := make(map[string]interface{}, size)
for i := 0; i < size; i++ {
keyInt, err := d.decode(buffer)
if err != nil {
return nil, err
}
val, err := d.decode(buffer)
if err != nil {
return nil, err
}
key, ok := keyInt.(string)
if !ok {
return nil, errors.New("Unexpected key type: %T with value %+v", keyInt, keyInt)
}
mapp[key] = val
}
return mapp, nil
}
func (d Decoder) decodeStruct(buffer *bytes.Buffer, size int) (interface{}, error) {
signature, err := buffer.ReadByte()
if err != nil {
return nil, errors.Wrap(err, "An error occurred reading struct signature byte")
}
switch signature {
case graph.NodeSignature:
return d.decodeNode(buffer)
case graph.RelationshipSignature:
return d.decodeRelationship(buffer)
case graph.PathSignature:
return d.decodePath(buffer)
case graph.UnboundRelationshipSignature:
return d.decodeUnboundRelationship(buffer)
case messages.RecordMessageSignature:
return d.decodeRecordMessage(buffer)
case messages.FailureMessageSignature:
return d.decodeFailureMessage(buffer)
case messages.IgnoredMessageSignature:
return d.decodeIgnoredMessage(buffer)
case messages.SuccessMessageSignature:
return d.decodeSuccessMessage(buffer)
case messages.AckFailureMessageSignature:
return d.decodeAckFailureMessage(buffer)
case messages.DiscardAllMessageSignature:
return d.decodeDiscardAllMessage(buffer)
case messages.PullAllMessageSignature:
return d.decodePullAllMessage(buffer)
case messages.ResetMessageSignature:
return d.decodeResetMessage(buffer)
default:
return nil, errors.New("Unrecognized type decoding struct with signature %x", signature)
}
}
func (d Decoder) decodeNode(buffer *bytes.Buffer) (graph.Node, error) {
node := graph.Node{}
nodeIdentityInt, err := d.decode(buffer)
if err != nil {
return node, err
}
node.NodeIdentity = nodeIdentityInt.(int64)
labelInt, err := d.decode(buffer)
if err != nil {
return node, err
}
labelIntSlice, ok := labelInt.([]interface{})
if !ok {
return node, errors.New("Expected: Labels []string, but got %T %+v", labelInt, labelInt)
}
node.Labels, err = sliceInterfaceToString(labelIntSlice)
if err != nil {
return node, err
}
propertiesInt, err := d.decode(buffer)
if err != nil {
return node, err
}
node.Properties, ok = propertiesInt.(map[string]interface{})
if !ok {
return node, errors.New("Expected: Properties map[string]interface{}, but got %T %+v", propertiesInt, propertiesInt)
}
return node, nil
}
func (d Decoder) decodeRelationship(buffer *bytes.Buffer) (graph.Relationship, error) {
rel := graph.Relationship{}
relIdentityInt, err := d.decode(buffer)
if err != nil {
return rel, err
}
rel.RelIdentity = relIdentityInt.(int64)
startNodeIdentityInt, err := d.decode(buffer)
if err != nil {
return rel, err
}
rel.StartNodeIdentity = startNodeIdentityInt.(int64)
endNodeIdentityInt, err := d.decode(buffer)
if err != nil {
return rel, err
}
rel.EndNodeIdentity = endNodeIdentityInt.(int64)
var ok bool
typeInt, err := d.decode(buffer)
if err != nil {
return rel, err
}
rel.Type, ok = typeInt.(string)
if !ok {
return rel, errors.New("Expected: Type string, but got %T %+v", typeInt, typeInt)
}
propertiesInt, err := d.decode(buffer)
if err != nil {
return rel, err
}
rel.Properties, ok = propertiesInt.(map[string]interface{})
if !ok {
return rel, errors.New("Expected: Properties map[string]interface{}, but got %T %+v", propertiesInt, propertiesInt)
}
return rel, nil
}
func (d Decoder) decodePath(buffer *bytes.Buffer) (graph.Path, error) {
path := graph.Path{}
nodesInt, err := d.decode(buffer)
if err != nil {
return path, err
}
nodesIntSlice, ok := nodesInt.([]interface{})
if !ok {
return path, errors.New("Expected: Nodes []Node, but got %T %+v", nodesInt, nodesInt)
}
path.Nodes, err = sliceInterfaceToNode(nodesIntSlice)
if err != nil {
return path, err
}
relsInt, err := d.decode(buffer)
if err != nil {
return path, err
}
relsIntSlice, ok := relsInt.([]interface{})
if !ok {
return path, errors.New("Expected: Relationships []Relationship, but got %T %+v", relsInt, relsInt)
}
path.Relationships, err = sliceInterfaceToUnboundRelationship(relsIntSlice)
if err != nil {
return path, err
}
seqInt, err := d.decode(buffer)
if err != nil {
return path, err
}
seqIntSlice, ok := seqInt.([]interface{})
if !ok {
return path, errors.New("Expected: Sequence []int, but got %T %+v", seqInt, seqInt)
}
path.Sequence, err = sliceInterfaceToInt(seqIntSlice)
return path, err
}
func (d Decoder) decodeUnboundRelationship(buffer *bytes.Buffer) (graph.UnboundRelationship, error) {
rel := graph.UnboundRelationship{}
relIdentityInt, err := d.decode(buffer)
if err != nil {
return rel, err
}
rel.RelIdentity = relIdentityInt.(int64)
var ok bool
typeInt, err := d.decode(buffer)
if err != nil {
return rel, err
}
rel.Type, ok = typeInt.(string)
if !ok {
return rel, errors.New("Expected: Type string, but got %T %+v", typeInt, typeInt)
}
propertiesInt, err := d.decode(buffer)
if err != nil {
return rel, err
}
rel.Properties, ok = propertiesInt.(map[string]interface{})
if !ok {
return rel, errors.New("Expected: Properties map[string]interface{}, but got %T %+v", propertiesInt, propertiesInt)
}
return rel, nil
}
func (d Decoder) decodeRecordMessage(buffer *bytes.Buffer) (messages.RecordMessage, error) {
fieldsInt, err := d.decode(buffer)
if err != nil {
return messages.RecordMessage{}, err
}
fields, ok := fieldsInt.([]interface{})
if !ok {
return messages.RecordMessage{}, errors.New("Expected: Fields []interface{}, but got %T %+v", fieldsInt, fieldsInt)
}
return messages.NewRecordMessage(fields), nil
}
func (d Decoder) decodeFailureMessage(buffer *bytes.Buffer) (messages.FailureMessage, error) {
metadataInt, err := d.decode(buffer)
if err != nil {
return messages.FailureMessage{}, err
}
metadata, ok := metadataInt.(map[string]interface{})
if !ok {
return messages.FailureMessage{}, errors.New("Expected: Metadata map[string]interface{}, but got %T %+v", metadataInt, metadataInt)
}
return messages.NewFailureMessage(metadata), nil
}
func (d Decoder) decodeIgnoredMessage(buffer *bytes.Buffer) (messages.IgnoredMessage, error) {
return messages.NewIgnoredMessage(), nil
}
func (d Decoder) decodeSuccessMessage(buffer *bytes.Buffer) (messages.SuccessMessage, error) {
metadataInt, err := d.decode(buffer)
if err != nil {
return messages.SuccessMessage{}, err
}
metadata, ok := metadataInt.(map[string]interface{})
if !ok {
return messages.SuccessMessage{}, errors.New("Expected: Metadata map[string]interface{}, but got %T %+v", metadataInt, metadataInt)
}
return messages.NewSuccessMessage(metadata), nil
}
func (d Decoder) decodeAckFailureMessage(buffer *bytes.Buffer) (messages.AckFailureMessage, error) {
return messages.NewAckFailureMessage(), nil
}
func (d Decoder) decodeDiscardAllMessage(buffer *bytes.Buffer) (messages.DiscardAllMessage, error) {
return messages.NewDiscardAllMessage(), nil
}
func (d Decoder) decodePullAllMessage(buffer *bytes.Buffer) (messages.PullAllMessage, error) {
return messages.NewPullAllMessage(), nil
}
func (d Decoder) decodeResetMessage(buffer *bytes.Buffer) (messages.ResetMessage, error) {
return messages.NewResetMessage(), nil
}