ctype.js
24.7 KB
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
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
/*
* rm - Feb 2011
* ctype.js
*
* This module provides a simple abstraction towards reading and writing
* different types of binary data. It is designed to use ctio.js and provide a
* richer and more expressive API on top of it.
*
* By default we support the following as built in basic types:
* int8_t
* int16_t
* int32_t
* uint8_t
* uint16_t
* uint32_t
* uint64_t
* float
* double
* char
* char[]
*
* Each type is returned as a Number, with the exception of char and char[]
* which are returned as Node Buffers. A char is considered a uint8_t.
*
* Requests to read and write data are specified as an array of JSON objects.
* This is also the same way that one declares structs. Even if just a single
* value is requested, it must be done as a struct. The array order determines
* the order that we try and read values. Each entry has the following format
* with values marked with a * being optional.
*
* { key: { type: /type/, value*: /value/, offset*: /offset/ }
*
* If offset is defined, we lseek(offset, SEEK_SET) before reading the next
* value. Value is defined when we're writing out data, otherwise it's ignored.
*
*/
var mod_ctf = require('./ctf.js');
var mod_ctio = require('./ctio.js');
var mod_assert = require('assert');
/*
* This is the set of basic types that we support.
*
* read The function to call to read in a value from a buffer
*
* write The function to call to write a value to a buffer
*
*/
var deftypes = {
'uint8_t': { read: ctReadUint8, write: ctWriteUint8 },
'uint16_t': { read: ctReadUint16, write: ctWriteUint16 },
'uint32_t': { read: ctReadUint32, write: ctWriteUint32 },
'uint64_t': { read: ctReadUint64, write: ctWriteUint64 },
'int8_t': { read: ctReadSint8, write: ctWriteSint8 },
'int16_t': { read: ctReadSint16, write: ctWriteSint16 },
'int32_t': { read: ctReadSint32, write: ctWriteSint32 },
'int64_t': { read: ctReadSint64, write: ctWriteSint64 },
'float': { read: ctReadFloat, write: ctWriteFloat },
'double': { read: ctReadDouble, write: ctWriteDouble },
'char': { read: ctReadChar, write: ctWriteChar },
'char[]': { read: ctReadCharArray, write: ctWriteCharArray }
};
/*
* The following are wrappers around the CType IO low level API. They encode
* knowledge about the size and return something in the expected format.
*/
function ctReadUint8(endian, buffer, offset)
{
var val = mod_ctio.ruint8(buffer, endian, offset);
return ({ value: val, size: 1 });
}
function ctReadUint16(endian, buffer, offset)
{
var val = mod_ctio.ruint16(buffer, endian, offset);
return ({ value: val, size: 2 });
}
function ctReadUint32(endian, buffer, offset)
{
var val = mod_ctio.ruint32(buffer, endian, offset);
return ({ value: val, size: 4 });
}
function ctReadUint64(endian, buffer, offset)
{
var val = mod_ctio.ruint64(buffer, endian, offset);
return ({ value: val, size: 8 });
}
function ctReadSint8(endian, buffer, offset)
{
var val = mod_ctio.rsint8(buffer, endian, offset);
return ({ value: val, size: 1 });
}
function ctReadSint16(endian, buffer, offset)
{
var val = mod_ctio.rsint16(buffer, endian, offset);
return ({ value: val, size: 2 });
}
function ctReadSint32(endian, buffer, offset)
{
var val = mod_ctio.rsint32(buffer, endian, offset);
return ({ value: val, size: 4 });
}
function ctReadSint64(endian, buffer, offset)
{
var val = mod_ctio.rsint64(buffer, endian, offset);
return ({ value: val, size: 8 });
}
function ctReadFloat(endian, buffer, offset)
{
var val = mod_ctio.rfloat(buffer, endian, offset);
return ({ value: val, size: 4 });
}
function ctReadDouble(endian, buffer, offset)
{
var val = mod_ctio.rdouble(buffer, endian, offset);
return ({ value: val, size: 8 });
}
/*
* Reads a single character into a node buffer
*/
function ctReadChar(endian, buffer, offset)
{
var res = new Buffer(1);
res[0] = mod_ctio.ruint8(buffer, endian, offset);
return ({ value: res, size: 1 });
}
function ctReadCharArray(length, endian, buffer, offset)
{
var ii;
var res = new Buffer(length);
for (ii = 0; ii < length; ii++)
res[ii] = mod_ctio.ruint8(buffer, endian, offset + ii);
return ({ value: res, size: length });
}
function ctWriteUint8(value, endian, buffer, offset)
{
mod_ctio.wuint8(value, endian, buffer, offset);
return (1);
}
function ctWriteUint16(value, endian, buffer, offset)
{
mod_ctio.wuint16(value, endian, buffer, offset);
return (2);
}
function ctWriteUint32(value, endian, buffer, offset)
{
mod_ctio.wuint32(value, endian, buffer, offset);
return (4);
}
function ctWriteUint64(value, endian, buffer, offset)
{
mod_ctio.wuint64(value, endian, buffer, offset);
return (8);
}
function ctWriteSint8(value, endian, buffer, offset)
{
mod_ctio.wsint8(value, endian, buffer, offset);
return (1);
}
function ctWriteSint16(value, endian, buffer, offset)
{
mod_ctio.wsint16(value, endian, buffer, offset);
return (2);
}
function ctWriteSint32(value, endian, buffer, offset)
{
mod_ctio.wsint32(value, endian, buffer, offset);
return (4);
}
function ctWriteSint64(value, endian, buffer, offset)
{
mod_ctio.wsint64(value, endian, buffer, offset);
return (8);
}
function ctWriteFloat(value, endian, buffer, offset)
{
mod_ctio.wfloat(value, endian, buffer, offset);
return (4);
}
function ctWriteDouble(value, endian, buffer, offset)
{
mod_ctio.wdouble(value, endian, buffer, offset);
return (8);
}
/*
* Writes a single character into a node buffer
*/
function ctWriteChar(value, endian, buffer, offset)
{
if (!(value instanceof Buffer))
throw (new Error('Input must be a buffer'));
mod_ctio.ruint8(value[0], endian, buffer, offset);
return (1);
}
/*
* We're going to write 0s into the buffer if the string is shorter than the
* length of the array.
*/
function ctWriteCharArray(value, length, endian, buffer, offset)
{
var ii;
if (!(value instanceof Buffer))
throw (new Error('Input must be a buffer'));
if (value.length > length)
throw (new Error('value length greater than array length'));
for (ii = 0; ii < value.length && ii < length; ii++)
mod_ctio.wuint8(value[ii], endian, buffer, offset + ii);
for (; ii < length; ii++)
mod_ctio.wuint8(0, endian, offset + ii);
return (length);
}
/*
* Each parser has their own set of types. We want to make sure that they each
* get their own copy as they may need to modify it.
*/
function ctGetBasicTypes()
{
var ret = {};
var key;
for (key in deftypes)
ret[key] = deftypes[key];
return (ret);
}
/*
* Given a string in the form of type[length] we want to split this into an
* object that extracts that information. We want to note that we could possibly
* have nested arrays so this should only check the furthest one. It may also be
* the case that we have no [] pieces, in which case we just return the current
* type.
*/
function ctParseType(str)
{
var begInd, endInd;
var type, len;
if (typeof (str) != 'string')
throw (new Error('type must be a Javascript string'));
endInd = str.lastIndexOf(']');
if (endInd == -1) {
if (str.lastIndexOf('[') != -1)
throw (new Error('found invalid type with \'[\' but ' +
'no corresponding \']\''));
return ({ type: str });
}
begInd = str.lastIndexOf('[');
if (begInd == -1)
throw (new Error('found invalid type with \']\' but ' +
'no corresponding \'[\''));
if (begInd >= endInd)
throw (new Error('malformed type, \']\' appears before \'[\''));
type = str.substring(0, begInd);
len = str.substring(begInd + 1, endInd);
return ({ type: type, len: len });
}
/*
* Given a request validate that all of the fields for it are valid and make
* sense. This includes verifying the following notions:
* - Each type requested is present in types
* - Only allow a name for a field to be specified once
* - If an array is specified, validate that the requested field exists and
* comes before it.
* - If fields is defined, check that each entry has the occurrence of field
*/
function ctCheckReq(def, types, fields)
{
var ii, jj;
var req, keys, key;
var found = {};
if (!(def instanceof Array))
throw (new Error('definition is not an array'));
if (def.length === 0)
throw (new Error('definition must have at least one element'));
for (ii = 0; ii < def.length; ii++) {
req = def[ii];
if (!(req instanceof Object))
throw (new Error('definition must be an array of' +
'objects'));
keys = Object.keys(req);
if (keys.length != 1)
throw (new Error('definition entry must only have ' +
'one key'));
if (keys[0] in found)
throw (new Error('Specified name already ' +
'specified: ' + keys[0]));
if (!('type' in req[keys[0]]))
throw (new Error('missing required type definition'));
key = ctParseType(req[keys[0]]['type']);
/*
* We may have nested arrays, we need to check the validity of
* the types until the len field is undefined in key. However,
* each time len is defined we need to verify it is either an
* integer or corresponds to an already seen key.
*/
while (key['len'] !== undefined) {
if (isNaN(parseInt(key['len'], 10))) {
if (!(key['len'] in found))
throw (new Error('Given an array ' +
'length without a matching type'));
}
key = ctParseType(key['type']);
}
/* Now we can validate if the type is valid */
if (!(key['type'] in types))
throw (new Error('type not found or typdefed: ' +
key['type']));
/* Check for any required fields */
if (fields !== undefined) {
for (jj = 0; jj < fields.length; jj++) {
if (!(fields[jj] in req[keys[0]]))
throw (new Error('Missing required ' +
'field: ' + fields[jj]));
}
}
found[keys[0]] = true;
}
}
/*
* Create a new instance of the parser. Each parser has its own store of
* typedefs and endianness. Conf is an object with the following required
* values:
*
* endian Either 'big' or 'little' do determine the endianness we
* want to read from or write to.
*
* And the following optional values:
*
* char-type Valid options here are uint8 and int8. If uint8 is
* specified this changes the default behavior of a single
* char from being a buffer of a single character to being
* a uint8_t. If int8, it becomes an int8_t instead.
*/
function CTypeParser(conf)
{
if (!conf) throw (new Error('missing required argument'));
if (!('endian' in conf))
throw (new Error('missing required endian value'));
if (conf['endian'] != 'big' && conf['endian'] != 'little')
throw (new Error('Invalid endian type'));
if ('char-type' in conf && (conf['char-type'] != 'uint8' &&
conf['char-type'] != 'int8'))
throw (new Error('invalid option for char-type: ' +
conf['char-type']));
this.endian = conf['endian'];
this.types = ctGetBasicTypes();
/*
* There may be a more graceful way to do this, but this will have to
* serve.
*/
if ('char-type' in conf && conf['char-type'] == 'uint8')
this.types['char'] = this.types['uint8_t'];
if ('char-type' in conf && conf['char-type'] == 'int8')
this.types['char'] = this.types['int8_t'];
}
/*
* Sets the current endian value for the Parser. If the value is not valid,
* throws an Error.
*
* endian Either 'big' or 'little' do determine the endianness we
* want to read from or write to.
*
*/
CTypeParser.prototype.setEndian = function (endian)
{
if (endian != 'big' && endian != 'little')
throw (new Error('invalid endian type, must be big or ' +
'little'));
this.endian = endian;
};
/*
* Returns the current value of the endian value for the parser.
*/
CTypeParser.prototype.getEndian = function ()
{
return (this.endian);
};
/*
* A user has requested to add a type, let us honor their request. Yet, if their
* request doth spurn us, send them unto the Hells which Dante describes.
*
* name The string for the type definition we're adding
*
* value Either a string that is a type/array name or an object
* that describes a struct.
*/
CTypeParser.prototype.typedef = function (name, value)
{
var type;
if (name === undefined)
throw (new (Error('missing required typedef argument: name')));
if (value === undefined)
throw (new (Error('missing required typedef argument: value')));
if (typeof (name) != 'string')
throw (new (Error('the name of a type must be a string')));
type = ctParseType(name);
if (type['len'] !== undefined)
throw (new Error('Cannot have an array in the typedef name'));
if (name in this.types)
throw (new Error('typedef name already present: ' + name));
if (typeof (value) != 'string' && !(value instanceof Array))
throw (new Error('typedef value must either be a string or ' +
'struct'));
if (typeof (value) == 'string') {
type = ctParseType(value);
if (type['len'] !== undefined) {
if (isNaN(parseInt(type['len'], 10)))
throw (new (Error('typedef value must use ' +
'fixed size array when outside of a ' +
'struct')));
}
this.types[name] = value;
} else {
/* We have a struct, validate it */
ctCheckReq(value, this.types);
this.types[name] = value;
}
};
/*
* Include all of the typedefs, but none of the built in types. This should be
* treated as read-only.
*/
CTypeParser.prototype.lstypes = function ()
{
var key;
var ret = {};
for (key in this.types) {
if (key in deftypes)
continue;
ret[key] = this.types[key];
}
return (ret);
};
/*
* Given a type string that may have array types that aren't numbers, try and
* fill them in from the values object. The object should be of the format where
* indexing into it should return a number for that type.
*
* str The type string
*
* values An object that can be used to fulfill type information
*/
function ctResolveArray(str, values)
{
var ret = '';
var type = ctParseType(str);
while (type['len'] !== undefined) {
if (isNaN(parseInt(type['len'], 10))) {
if (typeof (values[type['len']]) != 'number')
throw (new Error('cannot sawp in non-number ' +
'for array value'));
ret = '[' + values[type['len']] + ']' + ret;
} else {
ret = '[' + type['len'] + ']' + ret;
}
type = ctParseType(type['type']);
}
ret = type['type'] + ret;
return (ret);
}
/*
* [private] Either the typedef resolves to another type string or to a struct.
* If it resolves to a struct, we just pass it off to read struct. If not, we
* can just pass it off to read entry.
*/
CTypeParser.prototype.resolveTypedef = function (type, dispatch, buffer,
offset, value)
{
var pt;
mod_assert.ok(type in this.types);
if (typeof (this.types[type]) == 'string') {
pt = ctParseType(this.types[type]);
if (dispatch == 'read')
return (this.readEntry(pt, buffer, offset));
else if (dispatch == 'write')
return (this.writeEntry(value, pt, buffer, offset));
else
throw (new Error('invalid dispatch type to ' +
'resolveTypedef'));
} else {
if (dispatch == 'read')
return (this.readStruct(this.types[type], buffer,
offset));
else if (dispatch == 'write')
return (this.writeStruct(value, this.types[type],
buffer, offset));
else
throw (new Error('invalid dispatch type to ' +
'resolveTypedef'));
}
};
/*
* [private] Try and read in the specific entry.
*/
CTypeParser.prototype.readEntry = function (type, buffer, offset)
{
var parse, len;
/*
* Because we want to special case char[]s this is unfortunately
* a bit uglier than it really should be. We want to special
* case char[]s so that we return a node buffer, thus they are a
* first class type where as all other arrays just call into a
* generic array routine which calls their data-specific routine
* the specified number of times.
*
* The valid dispatch options we have are:
* - Array and char => char[] handler
* - Generic array handler
* - Generic typedef handler
* - Basic type handler
*/
if (type['len'] !== undefined) {
len = parseInt(type['len'], 10);
if (isNaN(len))
throw (new Error('somehow got a non-numeric length'));
if (type['type'] == 'char')
parse = this.types['char[]']['read'](len,
this.endian, buffer, offset);
else
parse = this.readArray(type['type'],
len, buffer, offset);
} else {
if (type['type'] in deftypes)
parse = this.types[type['type']]['read'](this.endian,
buffer, offset);
else
parse = this.resolveTypedef(type['type'], 'read',
buffer, offset);
}
return (parse);
};
/*
* [private] Read an array of data
*/
CTypeParser.prototype.readArray = function (type, length, buffer, offset)
{
var ii, ent, pt;
var baseOffset = offset;
var ret = new Array(length);
pt = ctParseType(type);
for (ii = 0; ii < length; ii++) {
ent = this.readEntry(pt, buffer, offset);
offset += ent['size'];
ret[ii] = ent['value'];
}
return ({ value: ret, size: offset - baseOffset });
};
/*
* [private] Read a single struct in.
*/
CTypeParser.prototype.readStruct = function (def, buffer, offset)
{
var parse, ii, type, entry, key;
var baseOffset = offset;
var ret = {};
/* Walk it and handle doing what's necessary */
for (ii = 0; ii < def.length; ii++) {
key = Object.keys(def[ii])[0];
entry = def[ii][key];
/* Resolve all array values */
type = ctParseType(ctResolveArray(entry['type'], ret));
if ('offset' in entry)
offset = baseOffset + entry['offset'];
parse = this.readEntry(type, buffer, offset);
offset += parse['size'];
ret[key] = parse['value'];
}
return ({ value: ret, size: (offset-baseOffset)});
};
/*
* This is what we were born to do. We read the data from a buffer and return it
* in an object whose keys match the values from the object.
*
* def The array definition of the data to read in
*
* buffer The buffer to read data from
*
* offset The offset to start writing to
*
* Returns an object where each key corresponds to an entry in def and the value
* is the read value.
*/
CTypeParser.prototype.readData = function (def, buffer, offset)
{
/* Sanity check for arguments */
if (def === undefined)
throw (new Error('missing definition for what we should be' +
'parsing'));
if (buffer === undefined)
throw (new Error('missing buffer for what we should be ' +
'parsing'));
if (offset === undefined)
throw (new Error('missing offset for what we should be ' +
'parsing'));
/* Sanity check the object definition */
ctCheckReq(def, this.types);
return (this.readStruct(def, buffer, offset)['value']);
};
/*
* [private] Write out an array of data
*/
CTypeParser.prototype.writeArray = function (value, type, length, buffer,
offset)
{
var ii, pt;
var baseOffset = offset;
if (!(value instanceof Array))
throw (new Error('asked to write an array, but value is not ' +
'an array'));
if (value.length != length)
throw (new Error('asked to write array of length ' + length +
' but that does not match value length: ' + value.length));
pt = ctParseType(type);
for (ii = 0; ii < length; ii++)
offset += this.writeEntry(value[ii], pt, buffer, offset);
return (offset - baseOffset);
};
/*
* [private] Write the specific entry
*/
CTypeParser.prototype.writeEntry = function (value, type, buffer, offset)
{
var len, ret;
if (type['len'] !== undefined) {
len = parseInt(type['len'], 10);
if (isNaN(len))
throw (new Error('somehow got a non-numeric length'));
if (type['type'] == 'char')
ret = this.types['char[]']['write'](value, len,
this.endian, buffer, offset);
else
ret = this.writeArray(value, type['type'],
len, buffer, offset);
} else {
if (type['type'] in deftypes)
ret = this.types[type['type']]['write'](value,
this.endian, buffer, offset);
else
ret = this.resolveTypedef(type['type'], 'write',
buffer, offset, value);
}
return (ret);
};
/*
* [private] Write a single struct out.
*/
CTypeParser.prototype.writeStruct = function (value, def, buffer, offset)
{
var ii, entry, type, key;
var baseOffset = offset;
var vals = {};
for (ii = 0; ii < def.length; ii++) {
key = Object.keys(def[ii])[0];
entry = def[ii][key];
type = ctParseType(ctResolveArray(entry['type'], vals));
if ('offset' in entry)
offset = baseOffset + entry['offset'];
offset += this.writeEntry(value[ii], type, buffer, offset);
/* Now that we've written it out, we can use it for arrays */
vals[key] = value[ii];
}
return (offset);
};
/*
* Unfortunately, we're stuck with the sins of an initial poor design. Because
* of that, we are going to have to support the old way of writing data via
* writeData. There we insert the values that you want to write into the
* definition. A little baroque. Internally, we use the new model. So we need to
* just get those values out of there. But to maintain the principle of least
* surprise, we're not going to modify the input data.
*/
function getValues(def)
{
var ii, out, key;
out = [];
for (ii = 0; ii < def.length; ii++) {
key = Object.keys(def[ii])[0];
mod_assert.ok('value' in def[ii][key]);
out.push(def[ii][key]['value']);
}
return (out);
}
/*
* This is the second half of what we were born to do, write out the data
* itself. Historically this function required you to put your values in the
* definition section. This was not the smartest thing to do and a bit of an
* oversight to be honest. As such, this function now takes a values argument.
* If values is non-null and non-undefined, it will be used to determine the
* values. This means that the old method is still supported, but is no longer
* acceptable.
*
* def The array definition of the data to write out with
* values
*
* buffer The buffer to write to
*
* offset The offset in the buffer to write to
*
* values An array of values to write.
*/
CTypeParser.prototype.writeData = function (def, buffer, offset, values)
{
var hv;
if (def === undefined)
throw (new Error('missing definition for what we should be' +
'parsing'));
if (buffer === undefined)
throw (new Error('missing buffer for what we should be ' +
'parsing'));
if (offset === undefined)
throw (new Error('missing offset for what we should be ' +
'parsing'));
hv = (values != null && values != undefined);
if (hv) {
if (!Array.isArray(values))
throw (new Error('missing values for writing'));
ctCheckReq(def, this.types);
} else {
ctCheckReq(def, this.types, [ 'value' ]);
}
this.writeStruct(hv ? values : getValues(def), def, buffer, offset);
};
/*
* Functions to go to and from 64 bit numbers in a way that is compatible with
* Javascript limitations. There are two sets. One where the user is okay with
* an approximation and one where they are definitely not okay with an
* approximation.
*/
/*
* Attempts to convert an array of two integers returned from rsint64 / ruint64
* into an absolute 64 bit number. If however the value would exceed 2^52 this
* will instead throw an error. The mantissa in a double is a 52 bit number and
* rather than potentially give you a value that is an approximation this will
* error. If you would rather an approximation, please see toApprox64.
*
* val An array of two 32-bit integers
*/
function toAbs64(val)
{
if (val === undefined)
throw (new Error('missing required arg: value'));
if (!Array.isArray(val))
throw (new Error('value must be an array'));
if (val.length != 2)
throw (new Error('value must be an array of length 2'));
/* We have 20 bits worth of precision in this range */
if (val[0] >= 0x100000)
throw (new Error('value would become approximated'));
return (val[0] * Math.pow(2, 32) + val[1]);
}
/*
* Will return the 64 bit value as returned in an array from rsint64 / ruint64
* to a value as close as it can. Note that Javascript stores all numbers as a
* double and the mantissa only has 52 bits. Thus this version may approximate
* the value.
*
* val An array of two 32-bit integers
*/
function toApprox64(val)
{
if (val === undefined)
throw (new Error('missing required arg: value'));
if (!Array.isArray(val))
throw (new Error('value must be an array'));
if (val.length != 2)
throw (new Error('value must be an array of length 2'));
return (Math.pow(2, 32) * val[0] + val[1]);
}
function parseCTF(json, conf)
{
var ctype = new CTypeParser(conf);
mod_ctf.ctfParseJson(json, ctype);
return (ctype);
}
/*
* Export the few things we actually want to. Currently this is just the CType
* Parser and ctio.
*/
exports.Parser = CTypeParser;
exports.toAbs64 = toAbs64;
exports.toApprox64 = toApprox64;
exports.parseCTF = parseCTF;
exports.ruint8 = mod_ctio.ruint8;
exports.ruint16 = mod_ctio.ruint16;
exports.ruint32 = mod_ctio.ruint32;
exports.ruint64 = mod_ctio.ruint64;
exports.wuint8 = mod_ctio.wuint8;
exports.wuint16 = mod_ctio.wuint16;
exports.wuint32 = mod_ctio.wuint32;
exports.wuint64 = mod_ctio.wuint64;
exports.rsint8 = mod_ctio.rsint8;
exports.rsint16 = mod_ctio.rsint16;
exports.rsint32 = mod_ctio.rsint32;
exports.rsint64 = mod_ctio.rsint64;
exports.wsint8 = mod_ctio.wsint8;
exports.wsint16 = mod_ctio.wsint16;
exports.wsint32 = mod_ctio.wsint32;
exports.wsint64 = mod_ctio.wsint64;
exports.rfloat = mod_ctio.rfloat;
exports.rdouble = mod_ctio.rdouble;
exports.wfloat = mod_ctio.wfloat;
exports.wdouble = mod_ctio.wdouble;