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ftstream.c

Last change on this file was 2, checked in by jglee, 11 years ago
first commit
File size: 19.0 KB

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1	/***************************************************************************/
2	/* */
3	/* ftstream.c */
4	/* */
5	/* I/O stream support (body). */
6	/* */
7	/* Copyright 2000-2001, 2002, 2004, 2005, 2006, 2008 by */
8	/* David Turner, Robert Wilhelm, and Werner Lemberg. */
9	/* */
10	/* This file is part of the FreeType project, and may only be used, */
11	/* modified, and distributed under the terms of the FreeType project */
12	/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
13	/* this file you indicate that you have read the license and */
14	/* understand and accept it fully. */
15	/* */
16	/***************************************************************************/
17
18
19	#include <ft2build.h>
20	#include FT_INTERNAL_STREAM_H
21	#include FT_INTERNAL_DEBUG_H
22
23
24	/*************************************************************************/
25	/* */
26	/* The macro FT_COMPONENT is used in trace mode. It is an implicit */
27	/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */
28	/* messages during execution. */
29	/* */
30	#undef FT_COMPONENT
31	#define FT_COMPONENT trace_stream
32
33
34	FT_BASE_DEF( void )
35	FT_Stream_OpenMemory( FT_Stream stream,
36	const FT_Byte* base,
37	FT_ULong size )
38	{
39	stream->base = (FT_Byte*) base;
40	stream->size = size;
41	stream->pos = 0;
42	stream->cursor = 0;
43	stream->read = 0;
44	stream->close = 0;
45	}
46
47
48	FT_BASE_DEF( void )
49	FT_Stream_Close( FT_Stream stream )
50	{
51	if ( stream && stream->close )
52	stream->close( stream );
53	}
54
55
56	FT_BASE_DEF( FT_Error )
57	FT_Stream_Seek( FT_Stream stream,
58	FT_ULong pos )
59	{
60	FT_Error error = FT_Err_Ok;
61
62
63	stream->pos = pos;
64
65	if ( stream->read )
66	{
67	if ( stream->read( stream, pos, 0, 0 ) )
68	{
69	FT_ERROR(( "FT_Stream_Seek: invalid i/o; pos = 0x%lx, size = 0x%lx\n",
70	pos, stream->size ));
71
72	error = FT_Err_Invalid_Stream_Operation;
73	}
74	}
75	/* note that seeking to the first position after the file is valid */
76	else if ( pos > stream->size )
77	{
78	FT_ERROR(( "FT_Stream_Seek: invalid i/o; pos = 0x%lx, size = 0x%lx\n",
79	pos, stream->size ));
80
81	error = FT_Err_Invalid_Stream_Operation;
82	}
83
84	return error;
85	}
86
87
88	FT_BASE_DEF( FT_Error )
89	FT_Stream_Skip( FT_Stream stream,
90	FT_Long distance )
91	{
92	if ( distance < 0 )
93	return FT_Err_Invalid_Stream_Operation;
94
95	return FT_Stream_Seek( stream, (FT_ULong)( stream->pos + distance ) );
96	}
97
98
99	FT_BASE_DEF( FT_Long )
100	FT_Stream_Pos( FT_Stream stream )
101	{
102	return stream->pos;
103	}
104
105
106	FT_BASE_DEF( FT_Error )
107	FT_Stream_Read( FT_Stream stream,
108	FT_Byte* buffer,
109	FT_ULong count )
110	{
111	return FT_Stream_ReadAt( stream, stream->pos, buffer, count );
112	}
113
114
115	FT_BASE_DEF( FT_Error )
116	FT_Stream_ReadAt( FT_Stream stream,
117	FT_ULong pos,
118	FT_Byte* buffer,
119	FT_ULong count )
120	{
121	FT_Error error = FT_Err_Ok;
122	FT_ULong read_bytes;
123
124
125	if ( pos >= stream->size )
126	{
127	FT_ERROR(( "FT_Stream_ReadAt: invalid i/o; pos = 0x%lx, size = 0x%lx\n",
128	pos, stream->size ));
129
130	return FT_Err_Invalid_Stream_Operation;
131	}
132
133	if ( stream->read )
134	read_bytes = stream->read( stream, pos, buffer, count );
135	else
136	{
137	read_bytes = stream->size - pos;
138	if ( read_bytes > count )
139	read_bytes = count;
140
141	FT_MEM_COPY( buffer, stream->base + pos, read_bytes );
142	}
143
144	stream->pos = pos + read_bytes;
145
146	if ( read_bytes < count )
147	{
148	FT_ERROR(( "FT_Stream_ReadAt:" ));
149	FT_ERROR(( " invalid read; expected %lu bytes, got %lu\n",
150	count, read_bytes ));
151
152	error = FT_Err_Invalid_Stream_Operation;
153	}
154
155	return error;
156	}
157
158
159	FT_BASE_DEF( FT_ULong )
160	FT_Stream_TryRead( FT_Stream stream,
161	FT_Byte* buffer,
162	FT_ULong count )
163	{
164	FT_ULong read_bytes = 0;
165
166
167	if ( stream->pos >= stream->size )
168	goto Exit;
169
170	if ( stream->read )
171	read_bytes = stream->read( stream, stream->pos, buffer, count );
172	else
173	{
174	read_bytes = stream->size - stream->pos;
175	if ( read_bytes > count )
176	read_bytes = count;
177
178	FT_MEM_COPY( buffer, stream->base + stream->pos, read_bytes );
179	}
180
181	stream->pos += read_bytes;
182
183	Exit:
184	return read_bytes;
185	}
186
187
188	FT_BASE_DEF( FT_Error )
189	FT_Stream_ExtractFrame( FT_Stream stream,
190	FT_ULong count,
191	FT_Byte** pbytes )
192	{
193	FT_Error error;
194
195
196	error = FT_Stream_EnterFrame( stream, count );
197	if ( !error )
198	{
199	pbytes = (FT_Byte)stream->cursor;
200
201	/* equivalent to FT_Stream_ExitFrame(), with no memory block release */
202	stream->cursor = 0;
203	stream->limit = 0;
204	}
205
206	return error;
207	}
208
209
210	FT_BASE_DEF( void )
211	FT_Stream_ReleaseFrame( FT_Stream stream,
212	FT_Byte** pbytes )
213	{
214	if ( stream->read )
215	{
216	FT_Memory memory = stream->memory;
217
218	#ifdef FT_DEBUG_MEMORY
219	ft_mem_free( memory, *pbytes );
220	*pbytes = NULL;
221	#else
222	FT_FREE( *pbytes );
223	#endif
224	}
225	*pbytes = 0;
226	}
227
228
229	FT_BASE_DEF( FT_Error )
230	FT_Stream_EnterFrame( FT_Stream stream,
231	FT_ULong count )
232	{
233	FT_Error error = FT_Err_Ok;
234	FT_ULong read_bytes;
235
236
237	/* check for nested frame access */
238	FT_ASSERT( stream && stream->cursor == 0 );
239
240	if ( stream->read )
241	{
242	/* allocate the frame in memory */
243	FT_Memory memory = stream->memory;
244
245	#ifdef FT_DEBUG_MEMORY
246	/* assume _ft_debug_file and _ft_debug_lineno are already set */
247	stream->base = (unsigned char*)ft_mem_qalloc( memory, count, &error );
248	if ( error )
249	goto Exit;
250	#else
251	if ( FT_QALLOC( stream->base, count ) )
252	goto Exit;
253	#endif
254	/* read it */
255	read_bytes = stream->read( stream, stream->pos,
256	stream->base, count );
257	if ( read_bytes < count )
258	{
259	FT_ERROR(( "FT_Stream_EnterFrame:" ));
260	FT_ERROR(( " invalid read; expected %lu bytes, got %lu\n",
261	count, read_bytes ));
262
263	FT_FREE( stream->base );
264	error = FT_Err_Invalid_Stream_Operation;
265	}
266	stream->cursor = stream->base;
267	stream->limit = stream->cursor + count;
268	stream->pos += read_bytes;
269	}
270	else
271	{
272	/* check current and new position */
273	if ( stream->pos >= stream->size \|\|
274	stream->pos + count > stream->size )
275	{
276	FT_ERROR(( "FT_Stream_EnterFrame:" ));
277	FT_ERROR(( " invalid i/o; pos = 0x%lx, count = %lu, size = 0x%lx\n",
278	stream->pos, count, stream->size ));
279
280	error = FT_Err_Invalid_Stream_Operation;
281	goto Exit;
282	}
283
284	/* set cursor */
285	stream->cursor = stream->base + stream->pos;
286	stream->limit = stream->cursor + count;
287	stream->pos += count;
288	}
289
290	Exit:
291	return error;
292	}
293
294
295	FT_BASE_DEF( void )
296	FT_Stream_ExitFrame( FT_Stream stream )
297	{
298	/* IMPORTANT: The assertion stream->cursor != 0 was removed, given */
299	/* that it is possible to access a frame of length 0 in */
300	/* some weird fonts (usually, when accessing an array of */
301	/* 0 records, like in some strange kern tables). */
302	/* */
303	/* In this case, the loader code handles the 0-length table */
304	/* gracefully; however, stream.cursor is really set to 0 by the */
305	/* FT_Stream_EnterFrame() call, and this is not an error. */
306	/* */
307	FT_ASSERT( stream );
308
309	if ( stream->read )
310	{
311	FT_Memory memory = stream->memory;
312
313	#ifdef FT_DEBUG_MEMORY
314	ft_mem_free( memory, stream->base );
315	stream->base = NULL;
316	#else
317	FT_FREE( stream->base );
318	#endif
319	}
320	stream->cursor = 0;
321	stream->limit = 0;
322	}
323
324
325	FT_BASE_DEF( FT_Char )
326	FT_Stream_GetChar( FT_Stream stream )
327	{
328	FT_Char result;
329
330
331	FT_ASSERT( stream && stream->cursor );
332
333	result = 0;
334	if ( stream->cursor < stream->limit )
335	result = *stream->cursor++;
336
337	return result;
338	}
339
340
341	FT_BASE_DEF( FT_Short )
342	FT_Stream_GetShort( FT_Stream stream )
343	{
344	FT_Byte* p;
345	FT_Short result;
346
347
348	FT_ASSERT( stream && stream->cursor );
349
350	result = 0;
351	p = stream->cursor;
352	if ( p + 1 < stream->limit )
353	result = FT_NEXT_SHORT( p );
354	stream->cursor = p;
355
356	return result;
357	}
358
359
360	FT_BASE_DEF( FT_Short )
361	FT_Stream_GetShortLE( FT_Stream stream )
362	{
363	FT_Byte* p;
364	FT_Short result;
365
366
367	FT_ASSERT( stream && stream->cursor );
368
369	result = 0;
370	p = stream->cursor;
371	if ( p + 1 < stream->limit )
372	result = FT_NEXT_SHORT_LE( p );
373	stream->cursor = p;
374
375	return result;
376	}
377
378
379	FT_BASE_DEF( FT_Long )
380	FT_Stream_GetOffset( FT_Stream stream )
381	{
382	FT_Byte* p;
383	FT_Long result;
384
385
386	FT_ASSERT( stream && stream->cursor );
387
388	result = 0;
389	p = stream->cursor;
390	if ( p + 2 < stream->limit )
391	result = FT_NEXT_OFF3( p );
392	stream->cursor = p;
393	return result;
394	}
395
396
397	FT_BASE_DEF( FT_Long )
398	FT_Stream_GetLong( FT_Stream stream )
399	{
400	FT_Byte* p;
401	FT_Long result;
402
403
404	FT_ASSERT( stream && stream->cursor );
405
406	result = 0;
407	p = stream->cursor;
408	if ( p + 3 < stream->limit )
409	result = FT_NEXT_LONG( p );
410	stream->cursor = p;
411	return result;
412	}
413
414
415	FT_BASE_DEF( FT_Long )
416	FT_Stream_GetLongLE( FT_Stream stream )
417	{
418	FT_Byte* p;
419	FT_Long result;
420
421
422	FT_ASSERT( stream && stream->cursor );
423
424	result = 0;
425	p = stream->cursor;
426	if ( p + 3 < stream->limit )
427	result = FT_NEXT_LONG_LE( p );
428	stream->cursor = p;
429	return result;
430	}
431
432
433	FT_BASE_DEF( FT_Char )
434	FT_Stream_ReadChar( FT_Stream stream,
435	FT_Error* error )
436	{
437	FT_Byte result = 0;
438
439
440	FT_ASSERT( stream );
441
442	*error = FT_Err_Ok;
443
444	if ( stream->read )
445	{
446	if ( stream->read( stream, stream->pos, &result, 1L ) != 1L )
447	goto Fail;
448	}
449	else
450	{
451	if ( stream->pos < stream->size )
452	result = stream->base[stream->pos];
453	else
454	goto Fail;
455	}
456	stream->pos++;
457
458	return result;
459
460	Fail:
461	*error = FT_Err_Invalid_Stream_Operation;
462	FT_ERROR(( "FT_Stream_ReadChar: invalid i/o; pos = 0x%lx, size = 0x%lx\n",
463	stream->pos, stream->size ));
464
465	return 0;
466	}
467
468
469	FT_BASE_DEF( FT_Short )
470	FT_Stream_ReadShort( FT_Stream stream,
471	FT_Error* error )
472	{
473	FT_Byte reads[2];
474	FT_Byte* p = 0;
475	FT_Short result = 0;
476
477
478	FT_ASSERT( stream );
479
480	*error = FT_Err_Ok;
481
482	if ( stream->pos + 1 < stream->size )
483	{
484	if ( stream->read )
485	{
486	if ( stream->read( stream, stream->pos, reads, 2L ) != 2L )
487	goto Fail;
488
489	p = reads;
490	}
491	else
492	{
493	p = stream->base + stream->pos;
494	}
495
496	if ( p )
497	result = FT_NEXT_SHORT( p );
498	}
499	else
500	goto Fail;
501
502	stream->pos += 2;
503
504	return result;
505
506	Fail:
507	*error = FT_Err_Invalid_Stream_Operation;
508	FT_ERROR(( "FT_Stream_ReadShort:" ));
509	FT_ERROR(( " invalid i/o; pos = 0x%lx, size = 0x%lx\n",
510	stream->pos, stream->size ));
511
512	return 0;
513	}
514
515
516	FT_BASE_DEF( FT_Short )
517	FT_Stream_ReadShortLE( FT_Stream stream,
518	FT_Error* error )
519	{
520	FT_Byte reads[2];
521	FT_Byte* p = 0;
522	FT_Short result = 0;
523
524
525	FT_ASSERT( stream );
526
527	*error = FT_Err_Ok;
528
529	if ( stream->pos + 1 < stream->size )
530	{
531	if ( stream->read )
532	{
533	if ( stream->read( stream, stream->pos, reads, 2L ) != 2L )
534	goto Fail;
535
536	p = reads;
537	}
538	else
539	{
540	p = stream->base + stream->pos;
541	}
542
543	if ( p )
544	result = FT_NEXT_SHORT_LE( p );
545	}
546	else
547	goto Fail;
548
549	stream->pos += 2;
550
551	return result;
552
553	Fail:
554	*error = FT_Err_Invalid_Stream_Operation;
555	FT_ERROR(( "FT_Stream_ReadShortLE:" ));
556	FT_ERROR(( " invalid i/o; pos = 0x%lx, size = 0x%lx\n",
557	stream->pos, stream->size ));
558
559	return 0;
560	}
561
562
563	FT_BASE_DEF( FT_Long )
564	FT_Stream_ReadOffset( FT_Stream stream,
565	FT_Error* error )
566	{
567	FT_Byte reads[3];
568	FT_Byte* p = 0;
569	FT_Long result = 0;
570
571
572	FT_ASSERT( stream );
573
574	*error = FT_Err_Ok;
575
576	if ( stream->pos + 2 < stream->size )
577	{
578	if ( stream->read )
579	{
580	if (stream->read( stream, stream->pos, reads, 3L ) != 3L )
581	goto Fail;
582
583	p = reads;
584	}
585	else
586	{
587	p = stream->base + stream->pos;
588	}
589
590	if ( p )
591	result = FT_NEXT_OFF3( p );
592	}
593	else
594	goto Fail;
595
596	stream->pos += 3;
597
598	return result;
599
600	Fail:
601	*error = FT_Err_Invalid_Stream_Operation;
602	FT_ERROR(( "FT_Stream_ReadOffset:" ));
603	FT_ERROR(( " invalid i/o; pos = 0x%lx, size = 0x%lx\n",
604	stream->pos, stream->size ));
605
606	return 0;
607	}
608
609
610	FT_BASE_DEF( FT_Long )
611	FT_Stream_ReadLong( FT_Stream stream,
612	FT_Error* error )
613	{
614	FT_Byte reads[4];
615	FT_Byte* p = 0;
616	FT_Long result = 0;
617
618
619	FT_ASSERT( stream );
620
621	*error = FT_Err_Ok;
622
623	if ( stream->pos + 3 < stream->size )
624	{
625	if ( stream->read )
626	{
627	if ( stream->read( stream, stream->pos, reads, 4L ) != 4L )
628	goto Fail;
629
630	p = reads;
631	}
632	else
633	{
634	p = stream->base + stream->pos;
635	}
636
637	if ( p )
638	result = FT_NEXT_LONG( p );
639	}
640	else
641	goto Fail;
642
643	stream->pos += 4;
644
645	return result;
646
647	Fail:
648	FT_ERROR(( "FT_Stream_ReadLong: invalid i/o; pos = 0x%lx, size = 0x%lx\n",
649	stream->pos, stream->size ));
650	*error = FT_Err_Invalid_Stream_Operation;
651
652	return 0;
653	}
654
655
656	FT_BASE_DEF( FT_Long )
657	FT_Stream_ReadLongLE( FT_Stream stream,
658	FT_Error* error )
659	{
660	FT_Byte reads[4];
661	FT_Byte* p = 0;
662	FT_Long result = 0;
663
664
665	FT_ASSERT( stream );
666
667	*error = FT_Err_Ok;
668
669	if ( stream->pos + 3 < stream->size )
670	{
671	if ( stream->read )
672	{
673	if ( stream->read( stream, stream->pos, reads, 4L ) != 4L )
674	goto Fail;
675
676	p = reads;
677	}
678	else
679	{
680	p = stream->base + stream->pos;
681	}
682
683	if ( p )
684	result = FT_NEXT_LONG_LE( p );
685	}
686	else
687	goto Fail;
688
689	stream->pos += 4;
690
691	return result;
692
693	Fail:
694	FT_ERROR(( "FT_Stream_ReadLongLE:" ));
695	FT_ERROR(( " invalid i/o; pos = 0x%lx, size = 0x%lx\n",
696	stream->pos, stream->size ));
697	*error = FT_Err_Invalid_Stream_Operation;
698
699	return 0;
700	}
701
702
703	FT_BASE_DEF( FT_Error )
704	FT_Stream_ReadFields( FT_Stream stream,
705	const FT_Frame_Field* fields,
706	void* structure )
707	{
708	FT_Error error;
709	FT_Bool frame_accessed = 0;
710	FT_Byte* cursor;
711
712	if ( !fields \|\| !stream )
713	return FT_Err_Invalid_Argument;
714
715	cursor = stream->cursor;
716
717	error = FT_Err_Ok;
718	do
719	{
720	FT_ULong value;
721	FT_Int sign_shift;
722	FT_Byte* p;
723
724
725	switch ( fields->value )
726	{
727	case ft_frame_start: /* access a new frame */
728	error = FT_Stream_EnterFrame( stream, fields->offset );
729	if ( error )
730	goto Exit;
731
732	frame_accessed = 1;
733	cursor = stream->cursor;
734	fields++;
735	continue; /* loop! */
736
737	case ft_frame_bytes: /* read a byte sequence */
738	case ft_frame_skip: /* skip some bytes */
739	{
740	FT_UInt len = fields->size;
741
742
743	if ( cursor + len > stream->limit )
744	{
745	error = FT_Err_Invalid_Stream_Operation;
746	goto Exit;
747	}
748
749	if ( fields->value == ft_frame_bytes )
750	{
751	p = (FT_Byte*)structure + fields->offset;
752	FT_MEM_COPY( p, cursor, len );
753	}
754	cursor += len;
755	fields++;
756	continue;
757	}
758
759	case ft_frame_byte:
760	case ft_frame_schar: /* read a single byte */
761	value = FT_NEXT_BYTE(cursor);
762	sign_shift = 24;
763	break;
764
765	case ft_frame_short_be:
766	case ft_frame_ushort_be: /* read a 2-byte big-endian short */
767	value = FT_NEXT_USHORT(cursor);
768	sign_shift = 16;
769	break;
770
771	case ft_frame_short_le:
772	case ft_frame_ushort_le: /* read a 2-byte little-endian short */
773	value = FT_NEXT_USHORT_LE(cursor);
774	sign_shift = 16;
775	break;
776
777	case ft_frame_long_be:
778	case ft_frame_ulong_be: /* read a 4-byte big-endian long */
779	value = FT_NEXT_ULONG(cursor);
780	sign_shift = 0;
781	break;
782
783	case ft_frame_long_le:
784	case ft_frame_ulong_le: /* read a 4-byte little-endian long */
785	value = FT_NEXT_ULONG_LE(cursor);
786	sign_shift = 0;
787	break;
788
789	case ft_frame_off3_be:
790	case ft_frame_uoff3_be: /* read a 3-byte big-endian long */
791	value = FT_NEXT_UOFF3(cursor);
792	sign_shift = 8;
793	break;
794
795	case ft_frame_off3_le:
796	case ft_frame_uoff3_le: /* read a 3-byte little-endian long */
797	value = FT_NEXT_UOFF3_LE(cursor);
798	sign_shift = 8;
799	break;
800
801	default:
802	/* otherwise, exit the loop */
803	stream->cursor = cursor;
804	goto Exit;
805	}
806
807	/* now, compute the signed value is necessary */
808	if ( fields->value & FT_FRAME_OP_SIGNED )
809	value = (FT_ULong)( (FT_Int32)( value << sign_shift ) >> sign_shift );
810
811	/* finally, store the value in the object */
812
813	p = (FT_Byte*)structure + fields->offset;
814	switch ( fields->size )
815	{
816	case (8 / FT_CHAR_BIT):
817	(FT_Byte)p = (FT_Byte)value;
818	break;
819
820	case (16 / FT_CHAR_BIT):
821	(FT_UShort)p = (FT_UShort)value;
822	break;
823
824	case (32 / FT_CHAR_BIT):
825	(FT_UInt32)p = (FT_UInt32)value;
826	break;
827
828	default: /* for 64-bit systems */
829	(FT_ULong)p = (FT_ULong)value;
830	}
831
832	/* go to next field */
833	fields++;
834	}
835	while ( 1 );
836
837	Exit:
838	/* close the frame if it was opened by this read */
839	if ( frame_accessed )
840	FT_Stream_ExitFrame( stream );
841
842	return error;
843	}
844
845
846	/* END */

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source: svn/trunk/zasc/freetype-2.3.9/ftstream.c

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