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
|
# -*- encoding: utf-8 -*-
"""
Functions for decoding data of various types including field tables and arrays
"""
import datetime
import decimal as _decimal
import typing
from pamqp import common
def by_type(value: bytes,
data_type: str,
offset: int = 0) -> typing.Tuple[int, common.FieldValue]:
"""Decodes values using the specified type
:param value: The binary value to decode
:param data_type: The data type name of the value
:param offset: The starting position of the data in the byte stream
:rtype: :class:`tuple` (:class:`int`, :const:`pamqp.common.FieldValue`)
:raises ValueError: when the data type is unknown
"""
if data_type == 'bit':
return bit(value, offset)
decoder = METHODS.get(data_type)
if decoder is None:
raise ValueError('Unknown type: {}'.format(data_type))
return decoder(value)
def bit(value: bytes, position: int) -> typing.Tuple[int, bool]:
"""Decode a bit value, returning bytes consumed and the value.
:param value: The binary value to decode
:param position: The position in the byte of the bit value
:rtype: :class:`tuple` (:class:`int`, :class:`bool`)
:raises ValueError: when the binary data can not be unpacked
"""
bit_buffer = common.Struct.byte.unpack_from(value)[0]
try:
return 0, (bit_buffer & (1 << position)) != 0
except TypeError:
raise ValueError('Could not unpack bit value')
def boolean(value: bytes) -> typing.Tuple[int, bool]:
"""Decode a boolean value, returning bytes consumed and the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`bool`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
return 1, bool(common.Struct.byte.unpack_from(value[0:1])[0])
except TypeError:
raise ValueError('Could not unpack boolean value')
def byte_array(value: bytes) -> typing.Tuple[int, bytearray]:
"""Decode a byte_array value, returning bytes consumed and the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`bytearray`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
length = common.Struct.integer.unpack(value[0:4])[0]
return length + 4, bytearray(value[4:length + 4])
except TypeError:
raise ValueError('Could not unpack byte array value')
def decimal(value: bytes) -> typing.Tuple[int, _decimal.Decimal]:
"""Decode a decimal value, returning bytes consumed and the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`decimal.Decimal`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
decimals = common.Struct.byte.unpack(value[0:1])[0]
raw = common.Struct.integer.unpack(value[1:5])[0]
return 5, _decimal.Decimal(raw) * (_decimal.Decimal(10)**-decimals)
except TypeError:
raise ValueError('Could not unpack decimal value')
def double(value: bytes) -> typing.Tuple[int, float]:
"""Decode a double value, returning bytes consumed and the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`float`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
return 8, common.Struct.double.unpack_from(value)[0]
except TypeError:
raise ValueError('Could not unpack double value')
def floating_point(value: bytes) -> typing.Tuple[int, float]:
"""Decode a floating point value, returning bytes consumed and the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`float`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
return 4, common.Struct.float.unpack_from(value)[0]
except TypeError:
raise ValueError('Could not unpack floating point value')
def long_int(value: bytes) -> typing.Tuple[int, int]:
"""Decode a long integer value, returning bytes consumed and the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`int`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
return 4, common.Struct.long.unpack(value[0:4])[0]
except TypeError:
raise ValueError('Could not unpack long integer value')
def long_uint(value: bytes) -> typing.Tuple[int, int]:
"""Decode an unsigned long integer value, returning bytes consumed and
the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`int`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
return 4, common.Struct.ulong.unpack(value[0:4])[0]
except TypeError:
raise ValueError('Could not unpack unsigned long integer value')
def long_long_int(value: bytes) -> typing.Tuple[int, int]:
"""Decode a long-long integer value, returning bytes consumed and the
value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`int`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
return 8, common.Struct.long_long_int.unpack(value[0:8])[0]
except TypeError:
raise ValueError('Could not unpack long-long integer value')
def long_str(value: bytes) -> typing.Tuple[int, typing.Union[str, bytes]]:
"""Decode a string value, returning bytes consumed and the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`str`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
length = common.Struct.integer.unpack(value[0:4])[0]
return length + 4, value[4:length + 4].decode('utf-8')
except TypeError:
raise ValueError('Could not unpack long string value')
except UnicodeDecodeError:
return length + 4, value[4:length + 4]
def octet(value: bytes) -> typing.Tuple[int, int]:
"""Decode an octet value, returning bytes consumed and the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`int`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
return 1, common.Struct.byte.unpack(value[0:1])[0]
except TypeError:
raise ValueError('Could not unpack octet value')
def short_int(value: bytes) -> typing.Tuple[int, int]:
"""Decode a short integer value, returning bytes consumed and the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`int`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
return 2, common.Struct.short.unpack_from(value[0:2])[0]
except TypeError:
raise ValueError('Could not unpack short integer value')
def short_uint(value: bytes) -> typing.Tuple[int, int]:
"""Decode an unsigned short integer value, returning bytes consumed and
the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`int`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
return 2, common.Struct.ushort.unpack_from(value[0:2])[0]
except TypeError:
raise ValueError('Could not unpack unsigned short integer value')
def short_short_int(value: bytes) -> typing.Tuple[int, int]:
"""Decode a short-short integer value, returning bytes consumed and the
value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`int`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
return 1, common.Struct.short_short_int.unpack_from(value[0:1])[0]
except TypeError:
raise ValueError('Could not unpack short-short integer value')
def short_short_uint(value: bytes) -> typing.Tuple[int, int]:
"""Decode a unsigned short-short integer value, returning bytes consumed
and the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`int`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
return 1, common.Struct.short_short_uint.unpack_from(value[0:1])[0]
except TypeError:
raise ValueError('Could not unpack unsigned short-short integer value')
def short_str(value: bytes) -> typing.Tuple[int, str]:
"""Decode a string value, returning bytes consumed and the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`str`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
length = common.Struct.byte.unpack(value[0:1])[0]
return length + 1, value[1:length + 1].decode('utf-8')
except TypeError:
raise ValueError('Could not unpack short string value')
def timestamp(value: bytes) -> typing.Tuple[int, datetime.datetime]:
"""Decode a timestamp value, returning bytes consumed and the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :class:`datetime.datetime`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
temp = common.Struct.timestamp.unpack(value[0:8])
ts_value = temp[0]
# Anything above the year 2106 is likely milliseconds
if ts_value > 0xFFFFFFFF:
ts_value /= 1000.0
return 8, datetime.datetime.fromtimestamp(ts_value,
tz=datetime.timezone.utc)
except TypeError:
raise ValueError('Could not unpack timestamp value')
def embedded_value(value: bytes) -> typing.Tuple[int, common.FieldValue]:
"""Dynamically decode a value based upon the starting byte
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :const:`pamqp.common.FieldValue`)
:raises ValueError: when the binary data can not be unpacked
"""
if not value:
return 0, None
try:
bytes_consumed, temp = TABLE_MAPPING[value[0:1]](value[1:])
except KeyError:
raise ValueError('Unknown type: {!r}'.format(value[:1]))
return bytes_consumed + 1, temp
def field_array(value: bytes) -> typing.Tuple[int, common.FieldArray]:
"""Decode a field array value, returning bytes consumed and the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :const:`pamqp.common.FieldArray`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
length = common.Struct.integer.unpack(value[0:4])[0]
offset = 4
data = []
field_array_end = offset + length
while offset < field_array_end:
consumed, result = embedded_value(value[offset:])
offset += consumed
data.append(result)
return offset, data
except TypeError:
raise ValueError('Could not unpack data')
def field_table(value: bytes) -> typing.Tuple[int, common.FieldTable]:
"""Decode a field array value, returning bytes consumed and the value.
:param value: The binary value to decode
:rtype: :class:`tuple` (:class:`int`, :const:`pamqp.common.FieldTable`)
:raises ValueError: when the binary data can not be unpacked
"""
try:
length = common.Struct.integer.unpack(value[0:4])[0]
offset = 4
data = {}
field_table_end = offset + length
while offset < field_table_end:
key_length = common.Struct.byte.unpack_from(value, offset)[0]
offset += 1
key = value[offset:offset + key_length].decode('utf-8')
offset += key_length
consumed, result = embedded_value(value[offset:])
offset += consumed
data[key] = result
return field_table_end, data
except TypeError:
raise ValueError('Could not unpack data')
def void(_: bytes) -> typing.Tuple[int, None]:
"""Return a void, no data to decode
:param _: The empty bytes object to ignore
:rtype: :class:`tuple` (:class:`int`, :const:`None`)
"""
return 0, None
METHODS = {
'array': field_array,
'bit': bit,
'boolean': boolean,
'byte_array': byte_array,
'decimal': decimal,
'double': double,
'float': floating_point,
'long': long_uint,
'longlong': long_long_int,
'longstr': long_str,
'octet': octet,
'short': short_uint,
'shortstr': short_str,
'table': field_table,
'timestamp': timestamp,
'void': void,
} # Define a data type mapping to methods for by_type()
# See https://www.rabbitmq.com/amqp-0-9-1-errata.html
TABLE_MAPPING = {
b't': boolean,
b'b': short_short_int,
b'B': short_short_uint,
b's': short_int,
b'u': short_uint,
b'I': long_int,
b'i': long_uint,
b'l': long_long_int,
b'L': long_long_int,
b'f': floating_point,
b'd': double,
b'D': decimal,
b'S': long_str,
b'A': field_array,
b'T': timestamp,
b'F': field_table,
b'V': void,
b'\x00': void, # While not documented, have seen this in the wild
b'x': byte_array,
} # Define a mapping for use in `field_array()` and `field_table()`
|
