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
|
/*
* tkimg.c --
*
* Generic interface to XML parsers.
*
* Copyright (c) 2002 Andreas Kupries <andreas_kupries@users.sourceforge.net>
*
* Zveno Pty Ltd makes this software and associated documentation
* available free of charge for any purpose. You may make copies
* of the software but you must include all of this notice on any copy.
*
* Zveno Pty Ltd does not warrant that this software is error free
* or fit for any purpose. Zveno Pty Ltd disclaims any liability for
* all claims, expenses, losses, damages and costs any user may incur
* as a result of using, copying or modifying the software.
*
* $Id: tkimgIO.c 274 2010-06-28 13:23:34Z nijtmans $
*
*/
#include "tkimg.h"
/*
* Prototypes for procedures defined later in this file:
*/
/* Variables needed for optional read buffer. See tkimg_ReadBuffer. */
#define BUFLEN 4096
static int useReadBuf = 0;
static int bufStart = -1;
static int bufEnd = -1;
static char readBuf[BUFLEN];
/*
*--------------------------------------------------------------------------
* char64 --
*
* This procedure converts a base64 ascii character into its binary
* equivalent. This code is a slightly modified version of the
* char64 proc in N. Borenstein's metamail decoder.
*
* Results:
* The binary value, or an error code.
*
* Side effects:
* None.
*--------------------------------------------------------------------------
*/
static int char64(
int c
) {
switch(c) {
case 'A': return 0; case 'B': return 1; case 'C': return 2;
case 'D': return 3; case 'E': return 4; case 'F': return 5;
case 'G': return 6; case 'H': return 7; case 'I': return 8;
case 'J': return 9; case 'K': return 10; case 'L': return 11;
case 'M': return 12; case 'N': return 13; case 'O': return 14;
case 'P': return 15; case 'Q': return 16; case 'R': return 17;
case 'S': return 18; case 'T': return 19; case 'U': return 20;
case 'V': return 21; case 'W': return 22; case 'X': return 23;
case 'Y': return 24; case 'Z': return 25; case 'a': return 26;
case 'b': return 27; case 'c': return 28; case 'd': return 29;
case 'e': return 30; case 'f': return 31; case 'g': return 32;
case 'h': return 33; case 'i': return 34; case 'j': return 35;
case 'k': return 36; case 'l': return 37; case 'm': return 38;
case 'n': return 39; case 'o': return 40; case 'p': return 41;
case 'q': return 42; case 'r': return 43; case 's': return 44;
case 't': return 45; case 'u': return 46; case 'v': return 47;
case 'w': return 48; case 'x': return 49; case 'y': return 50;
case 'z': return 51; case '0': return 52; case '1': return 53;
case '2': return 54; case '3': return 55; case '4': return 56;
case '5': return 57; case '6': return 58; case '7': return 59;
case '8': return 60; case '9': return 61; case '+': return 62;
case '/': return 63;
case ' ': case '\t': case '\n': case '\r': case '\f': return IMG_SPACE;
case '=': return IMG_PAD;
case '\0': return IMG_DONE;
default: return IMG_BAD;
}
}
/*
*--------------------------------------------------------------
*
* tkimg_ReadBuffer --
* Initialize optional read buffer.
*
* The optional read buffer may be used for compressed image file
* formats (ex. RLE), where the file has to be read byte by byte.
* This option is only available when reading from an image file,
* i.e. "image create -file ..."
*
* CAUTION:
* - Use this option only, when you do NOT use file seeks.
* - Use tkimg_ReadBuffer (1) to initialize the read buffer before usage.
* Use tkimg_ReadBuffer (0) to switch off the read buffer after usage.
*
* Results:
* None
*
* Side effects:
* Changes the static variables needed for the read buffer.
*
*--------------------------------------------------------------
*/
void tkimg_ReadBuffer(
int onOff
) {
useReadBuf = onOff;
if (onOff) {
memset(readBuf, 0, BUFLEN);
bufStart = -1;
bufEnd = -1;
}
}
/*
*--------------------------------------------------------------------------
* tkimg_Read --
*
* This procedure returns a buffer from the stream input. This stream
* could be anything from a base-64 encoded string to a Channel.
*
* Results:
* The number of characters successfully read from the input
*
* Side effects:
* The tkimg_MFile state could change.
*--------------------------------------------------------------------------
*/
int tkimg_Read(
tkimg_MFile *handle /* mmdecode "file" handle */,
char *dst /* where to put the result */,
int count /* number of bytes */
) {
register int i, c;
int bytesRead, bytesToRead;
char *dstPtr;
switch (handle->state) {
case IMG_STRING:
if (count > handle->length) {
count = handle->length;
}
if (count) {
memcpy(dst, handle->data, count);
handle->length -= count;
handle->data += count;
}
return count;
case IMG_CHAN:
if (!useReadBuf) {
return Tcl_Read((Tcl_Channel) handle->data, dst, count);
}
dstPtr = dst;
bytesToRead = count;
bytesRead = 0;
while (bytesToRead > 0) {
#ifdef DEBUG_LOCAL
printf ("bytesToRead=%d bytesRead=%d (bufStart=%d bufEnd=%d)\n",
bytesToRead, bytesRead, bufStart, bufEnd);
#endif
if (bufStart < 0) {
bufEnd = Tcl_Read((Tcl_Channel)handle->data, readBuf, BUFLEN)-1;
#ifdef DEBUG_LOCAL
printf ("Reading new %d bytes into buffer "
"(bufStart=%d bufEnd=%d)\n",
BUFLEN, bufStart, bufEnd);
#endif
bufStart = 0;
if (bufEnd < 0)
return bufEnd;
}
if (bufStart + bytesToRead <= bufEnd +1) {
#ifdef DEBUG_LOCAL
printf("All in buffer: memcpy %d bytes\n", bytesToRead);
#endif
/* All bytes already in the buffer. Just copy them to dst. */
memcpy(dstPtr, readBuf + bufStart, bytesToRead);
bufStart += bytesToRead;
if (bufStart > BUFLEN)
bufStart = -1;
return bytesRead + bytesToRead;
} else {
#ifdef DEBUG_LOCAL
printf("Copy rest of buffer: memcpy %d bytes\n",
bufEnd+1-bufStart);
#endif
memcpy (dstPtr, readBuf + bufStart, bufEnd+1 - bufStart);
bytesRead += (bufEnd +1 - bufStart);
bytesToRead -= (bufEnd+1 - bufStart);
bufStart = -1;
dstPtr += bytesRead;
}
}
}
for(i = 0; i < count && (c = tkimg_Getc(handle)) != IMG_DONE; i++) {
*dst++ = c;
}
return i;
}
/*
*--------------------------------------------------------------------------
*
* tkimg_Getc --
*
* This procedure returns the next input byte from a stream. This stream
* could be anything from a base-64 encoded string to a Channel.
*
* Results:
* The next byte (or IMG_DONE) is returned.
*
* Side effects:
* The tkimg_MFile state could change.
*
*--------------------------------------------------------------------------
*/
int tkimg_Getc(
tkimg_MFile *handle /* Input stream handle */
) {
int c;
int result = 0; /* Initialization needed only to prevent
* gcc compiler warning */
if (handle->state == IMG_DONE) {
return IMG_DONE;
}
if (handle->state == IMG_STRING) {
if (!handle->length--) {
handle->state = IMG_DONE;
return IMG_DONE;
}
return *handle->data++;
}
do {
if (!handle->length--) {
handle->state = IMG_DONE;
return IMG_DONE;
}
c = char64(*handle->data++);
} while (c == IMG_SPACE);
if (c > IMG_SPECIAL) {
handle->state = IMG_DONE;
return IMG_DONE;
}
switch (handle->state++) {
case 0:
handle->c = c<<2;
result = tkimg_Getc(handle);
break;
case 1:
result = handle->c | (c>>4);
handle->c = (c&0xF)<<4;
break;
case 2:
result = handle->c | (c>>2);
handle->c = (c&0x3)<<6;
break;
case 3:
result = handle->c | c;
handle->state = 0;
break;
}
return result;
}
/*
*-----------------------------------------------------------------------
* tkimg_Write --
*
* This procedure is invoked to put imaged data into a stream
* using tkimg_Putc.
*
* Results:
* The return value is the number of characters "written"
*
* Side effects:
* The base64 handle will change state.
*
*-----------------------------------------------------------------------
*/
int tkimg_Write(
tkimg_MFile *handle /* mmencode "file" handle */,
const char *src /* where to get the data */,
int count /* number of bytes */
) {
register int i;
int curcount, bufcount;
if (handle->state == IMG_CHAN) {
return Tcl_Write((Tcl_Channel) handle->data, (char *) src, count);
}
curcount = handle->data - Tcl_DStringValue(handle->buffer);
bufcount = curcount + count + count/3 + count/52 + 1024;
/* make sure that the DString contains enough space */
if (bufcount >= (handle->buffer->spaceAvl)) {
Tcl_DStringSetLength(handle->buffer, bufcount + 4096);
handle->data = Tcl_DStringValue(handle->buffer) + curcount;
}
/* write the data */
for (i=0; (i<count) && (tkimg_Putc(*src++, handle) != IMG_DONE); i++) {
/* empty loop body */
}
return i;
}
/*
*-----------------------------------------------------------------------
*
* tkimg_Putc --
*
* This procedure encodes and writes the next byte to a base64
* encoded string.
*
* Results:
* The written byte is returned.
*
* Side effects:
* the base64 handle will change state.
*
*-----------------------------------------------------------------------
*/
static char const base64_table[64] = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3',
'4', '5', '6', '7', '8', '9', '+', '/'
};
int tkimg_Putc(
register int c /* character to be written */,
register tkimg_MFile *handle /* handle containing decoder data and state */
) {
/* In fact, here should be checked first if the dynamic
* string contains enough space for the next character.
* This would be very expensive to do for each character.
* Therefore we just allocate 1024 bytes immediately in
* the beginning and also take a 1024 bytes margin inside
* every tkimg_Write. At least this check is done then only
* every 256 bytes, which is much faster. Because the GIF
* header is less than 1024 bytes and pixel data is
* written in 256 byte portions, this should be safe.
*/
if (c == IMG_DONE) {
switch(handle->state) {
case 0:
break;
case 1:
*handle->data++ = base64_table[(handle->c<<4)&63];
*handle->data++ = '='; *handle->data++ = '='; break;
case 2:
*handle->data++ = base64_table[(handle->c<<2)&63];
*handle->data++ = '='; break;
default:
handle->state = IMG_DONE;
return IMG_DONE;
}
Tcl_DStringSetLength(handle->buffer,
(handle->data) - Tcl_DStringValue(handle->buffer));
handle->state = IMG_DONE;
return IMG_DONE;
}
if (handle->state == IMG_CHAN) {
char ch = (char) c;
return (Tcl_Write((Tcl_Channel) handle->data, &ch, 1)>0) ? c : IMG_DONE;
}
c &= 0xff;
switch (handle->state++) {
case 0:
*handle->data++ = base64_table[(c>>2)&63]; break;
case 1:
c |= handle->c << 8;
*handle->data++ = base64_table[(c>>4)&63]; break;
case 2:
handle->state = 0;
c |= handle->c << 8;
*handle->data++ = base64_table[(c>>6)&63];
*handle->data++ = base64_table[c&63]; break;
}
handle->c = c;
if (handle->length++ > 52) {
handle->length = 0;
*handle->data++ = '\n';
}
return c & 0xff;
};
/*
*-------------------------------------------------------------------------
* tkimg_WriteInit --
* This procedure initializes a base64 decoder handle for writing
*
* Results:
* none
*
* Side effects:
* the base64 handle is initialized
*
*-------------------------------------------------------------------------
*/
void tkimg_WriteInit(
Tcl_DString *buffer,
tkimg_MFile *handle /* mmencode "file" handle */
) {
Tcl_DStringSetLength(buffer, buffer->spaceAvl);
handle->buffer = buffer;
handle->data = Tcl_DStringValue(buffer);
handle->state = 0;
handle->length = 0;
}
/*
*-------------------------------------------------------------------------
* tkimg_ReadInit --
* This procedure initializes a base64 decoder handle for reading.
*
* Results:
* none
*
* Side effects:
* the base64 handle is initialized
*
*-------------------------------------------------------------------------
*/
int tkimg_ReadInit(
Tcl_Obj *data /* string containing initial mmencoded data */,
int c,
tkimg_MFile *handle /* mmdecode "file" handle */
) {
handle->data = (char *) tkimg_GetByteArrayFromObj(data, &handle->length);
if (*handle->data == c) {
handle->state = IMG_STRING;
return 1;
}
c = base64_table[(c>>2)&63];
while ((handle->length) && (char64(*handle->data) == IMG_SPACE)) {
handle->data++;
handle->length--;
}
if (c != *handle->data) {
handle->state = IMG_DONE;
return 0;
}
handle->state = 0;
return 1;
}
/*
*----------------------------------------------------------------------
*
* tkimg_OpenFileChannel --
*
* Open a file channel in binary mode. If permissions is 0, the
* file will be opened in read mode, otherwise in write mode.
*
* Results:
* The same as Tcl_OpenFileChannel, only the file will
* always be opened in binary mode without encoding.
*
* Side effects:
* If function fails, an error message will be left in the
* interpreter.
*
*----------------------------------------------------------------------
*/
Tcl_Channel tkimg_OpenFileChannel(
Tcl_Interp *interp,
const char *fileName,
int permissions
) {
Tcl_Channel chan = Tcl_OpenFileChannel(interp, (CONST84 char *) fileName,
permissions?"w":"r", permissions);
if (!chan) {
return NULL;
}
if (Tcl_SetChannelOption(interp, chan, "-buffersize", "131072") != TCL_OK) {
Tcl_Close(interp, chan);
return NULL;
}
if (Tcl_SetChannelOption(interp, chan, "-translation", "binary") != TCL_OK) {
Tcl_Close(interp, chan);
return NULL;
}
return chan;
}
|