File: | lzw/ftlzw.c |
Location: | line 126, column 7 |
Description: | Value stored to 'stream' is never read |
1 | /***************************************************************************/ |
2 | /* */ |
3 | /* ftlzw.c */ |
4 | /* */ |
5 | /* FreeType support for .Z compressed files. */ |
6 | /* */ |
7 | /* This optional component relies on NetBSD's zopen(). It should mainly */ |
8 | /* be used to parse compressed PCF fonts, as found with many X11 server */ |
9 | /* distributions. */ |
10 | /* */ |
11 | /* Copyright 2004, 2005, 2006, 2009 by */ |
12 | /* Albert Chin-A-Young. */ |
13 | /* */ |
14 | /* Based on code in src/gzip/ftgzip.c, Copyright 2004 by */ |
15 | /* David Turner, Robert Wilhelm, and Werner Lemberg. */ |
16 | /* */ |
17 | /* This file is part of the FreeType project, and may only be used, */ |
18 | /* modified, and distributed under the terms of the FreeType project */ |
19 | /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ |
20 | /* this file you indicate that you have read the license and */ |
21 | /* understand and accept it fully. */ |
22 | /* */ |
23 | /***************************************************************************/ |
24 | |
25 | #include <ft2build.h> |
26 | #include FT_INTERNAL_MEMORY_H<freetype/internal/ftmemory.h> |
27 | #include FT_INTERNAL_STREAM_H<freetype/internal/ftstream.h> |
28 | #include FT_INTERNAL_DEBUG_H<freetype/internal/ftdebug.h> |
29 | #include FT_LZW_H<freetype/ftlzw.h> |
30 | #include FT_CONFIG_STANDARD_LIBRARY_H<freetype/config/ftstdlib.h> |
31 | |
32 | |
33 | #include FT_MODULE_ERRORS_H<freetype/ftmoderr.h> |
34 | |
35 | #undef __FTERRORS_H__ |
36 | |
37 | #define FT_ERR_PREFIX LZW_Err_ |
38 | #define FT_ERR_BASE FT_Mod_Err_LZW |
39 | |
40 | #include FT_ERRORS_H<freetype/fterrors.h> |
41 | |
42 | |
43 | #ifdef FT_CONFIG_OPTION_USE_LZW |
44 | |
45 | #ifdef FT_CONFIG_OPTION_PIC |
46 | #error "lzw code does not support PIC yet" |
47 | #endif |
48 | |
49 | #include "ftzopen.h" |
50 | |
51 | |
52 | /***************************************************************************/ |
53 | /***************************************************************************/ |
54 | /***** *****/ |
55 | /***** M E M O R Y M A N A G E M E N T *****/ |
56 | /***** *****/ |
57 | /***************************************************************************/ |
58 | /***************************************************************************/ |
59 | |
60 | /***************************************************************************/ |
61 | /***************************************************************************/ |
62 | /***** *****/ |
63 | /***** F I L E D E S C R I P T O R *****/ |
64 | /***** *****/ |
65 | /***************************************************************************/ |
66 | /***************************************************************************/ |
67 | |
68 | #define FT_LZW_BUFFER_SIZE4096 4096 |
69 | |
70 | typedef struct FT_LZWFileRec_ |
71 | { |
72 | FT_Stream source; /* parent/source stream */ |
73 | FT_Stream stream; /* embedding stream */ |
74 | FT_Memory memory; /* memory allocator */ |
75 | FT_LzwStateRec lzw; /* lzw decompressor state */ |
76 | |
77 | FT_Byte buffer[FT_LZW_BUFFER_SIZE4096]; /* output buffer */ |
78 | FT_ULong pos; /* position in output */ |
79 | FT_Byte* cursor; |
80 | FT_Byte* limit; |
81 | |
82 | } FT_LZWFileRec, *FT_LZWFile; |
83 | |
84 | |
85 | /* check and skip .Z header */ |
86 | static FT_Error |
87 | ft_lzw_check_header( FT_Stream stream ) |
88 | { |
89 | FT_Error error; |
90 | FT_Byte head[2]; |
91 | |
92 | |
93 | if ( FT_STREAM_SEEK( 0 )( ( error = (FT_Stream_Seek( stream, 0 )) ) != 0 ) || |
94 | FT_STREAM_READ( head, 2 )( ( error = (FT_Stream_Read( stream, (FT_Byte*)head, 2 )) ) != 0 ) ) |
95 | goto Exit; |
96 | |
97 | /* head[0] && head[1] are the magic numbers */ |
98 | if ( head[0] != 0x1f || |
99 | head[1] != 0x9d ) |
100 | error = LZW_Err_Invalid_File_Format; |
101 | |
102 | Exit: |
103 | return error; |
104 | } |
105 | |
106 | |
107 | static FT_Error |
108 | ft_lzw_file_init( FT_LZWFile zip, |
109 | FT_Stream stream, |
110 | FT_Stream source ) |
111 | { |
112 | FT_LzwState lzw = &zip->lzw; |
113 | FT_Error error = LZW_Err_Ok; |
114 | |
115 | |
116 | zip->stream = stream; |
117 | zip->source = source; |
118 | zip->memory = stream->memory; |
119 | |
120 | zip->limit = zip->buffer + FT_LZW_BUFFER_SIZE4096; |
121 | zip->cursor = zip->limit; |
122 | zip->pos = 0; |
123 | |
124 | /* check and skip .Z header */ |
125 | { |
126 | stream = source; |
Value stored to 'stream' is never read | |
127 | |
128 | error = ft_lzw_check_header( source ); |
129 | if ( error ) |
130 | goto Exit; |
131 | } |
132 | |
133 | /* initialize internal lzw variable */ |
134 | ft_lzwstate_init( lzw, source ); |
135 | |
136 | Exit: |
137 | return error; |
138 | } |
139 | |
140 | |
141 | static void |
142 | ft_lzw_file_done( FT_LZWFile zip ) |
143 | { |
144 | /* clear the rest */ |
145 | ft_lzwstate_done( &zip->lzw ); |
146 | |
147 | zip->memory = NULL((void*)0); |
148 | zip->source = NULL((void*)0); |
149 | zip->stream = NULL((void*)0); |
150 | } |
151 | |
152 | |
153 | static FT_Error |
154 | ft_lzw_file_reset( FT_LZWFile zip ) |
155 | { |
156 | FT_Stream stream = zip->source; |
157 | FT_Error error; |
158 | |
159 | |
160 | if ( !FT_STREAM_SEEK( 0 )( ( error = (FT_Stream_Seek( stream, 0 )) ) != 0 ) ) |
161 | { |
162 | ft_lzwstate_reset( &zip->lzw ); |
163 | |
164 | zip->limit = zip->buffer + FT_LZW_BUFFER_SIZE4096; |
165 | zip->cursor = zip->limit; |
166 | zip->pos = 0; |
167 | } |
168 | |
169 | return error; |
170 | } |
171 | |
172 | |
173 | static FT_Error |
174 | ft_lzw_file_fill_output( FT_LZWFile zip ) |
175 | { |
176 | FT_LzwState lzw = &zip->lzw; |
177 | FT_ULong count; |
178 | FT_Error error = 0; |
179 | |
180 | |
181 | zip->cursor = zip->buffer; |
182 | |
183 | count = ft_lzwstate_io( lzw, zip->buffer, FT_LZW_BUFFER_SIZE4096 ); |
184 | |
185 | zip->limit = zip->cursor + count; |
186 | |
187 | if ( count == 0 ) |
188 | error = LZW_Err_Invalid_Stream_Operation; |
189 | |
190 | return error; |
191 | } |
192 | |
193 | |
194 | /* fill output buffer; `count' must be <= FT_LZW_BUFFER_SIZE */ |
195 | static FT_Error |
196 | ft_lzw_file_skip_output( FT_LZWFile zip, |
197 | FT_ULong count ) |
198 | { |
199 | FT_Error error = LZW_Err_Ok; |
200 | |
201 | |
202 | /* first, we skip what we can from the output buffer */ |
203 | { |
204 | FT_ULong delta = (FT_ULong)( zip->limit - zip->cursor ); |
205 | |
206 | |
207 | if ( delta >= count ) |
208 | delta = count; |
209 | |
210 | zip->cursor += delta; |
211 | zip->pos += delta; |
212 | |
213 | count -= delta; |
214 | } |
215 | |
216 | /* next, we skip as many bytes remaining as possible */ |
217 | while ( count > 0 ) |
218 | { |
219 | FT_ULong delta = FT_LZW_BUFFER_SIZE4096; |
220 | FT_ULong numread; |
221 | |
222 | |
223 | if ( delta > count ) |
224 | delta = count; |
225 | |
226 | numread = ft_lzwstate_io( &zip->lzw, NULL((void*)0), delta ); |
227 | if ( numread < delta ) |
228 | { |
229 | /* not enough bytes */ |
230 | error = LZW_Err_Invalid_Stream_Operation; |
231 | break; |
232 | } |
233 | |
234 | zip->pos += delta; |
235 | count -= delta; |
236 | } |
237 | |
238 | return error; |
239 | } |
240 | |
241 | |
242 | static FT_ULong |
243 | ft_lzw_file_io( FT_LZWFile zip, |
244 | FT_ULong pos, |
245 | FT_Byte* buffer, |
246 | FT_ULong count ) |
247 | { |
248 | FT_ULong result = 0; |
249 | FT_Error error; |
250 | |
251 | |
252 | /* seeking backwards. */ |
253 | if ( pos < zip->pos ) |
254 | { |
255 | /* If the new position is within the output buffer, simply */ |
256 | /* decrement pointers, otherwise we reset the stream completely! */ |
257 | if ( ( zip->pos - pos ) <= (FT_ULong)( zip->cursor - zip->buffer ) ) |
258 | { |
259 | zip->cursor -= zip->pos - pos; |
260 | zip->pos = pos; |
261 | } |
262 | else |
263 | { |
264 | error = ft_lzw_file_reset( zip ); |
265 | if ( error ) |
266 | goto Exit; |
267 | } |
268 | } |
269 | |
270 | /* skip unwanted bytes */ |
271 | if ( pos > zip->pos ) |
272 | { |
273 | error = ft_lzw_file_skip_output( zip, (FT_ULong)( pos - zip->pos ) ); |
274 | if ( error ) |
275 | goto Exit; |
276 | } |
277 | |
278 | if ( count == 0 ) |
279 | goto Exit; |
280 | |
281 | /* now read the data */ |
282 | for (;;) |
283 | { |
284 | FT_ULong delta; |
285 | |
286 | |
287 | delta = (FT_ULong)( zip->limit - zip->cursor ); |
288 | if ( delta >= count ) |
289 | delta = count; |
290 | |
291 | FT_MEM_COPY( buffer + result, zip->cursor, delta )((__builtin_object_size (buffer + result, 0) != (size_t) -1) ? __builtin___memcpy_chk (buffer + result, zip->cursor, delta , __builtin_object_size (buffer + result, 0)) : __inline_memcpy_chk (buffer + result, zip->cursor, delta)); |
292 | result += delta; |
293 | zip->cursor += delta; |
294 | zip->pos += delta; |
295 | |
296 | count -= delta; |
297 | if ( count == 0 ) |
298 | break; |
299 | |
300 | error = ft_lzw_file_fill_output( zip ); |
301 | if ( error ) |
302 | break; |
303 | } |
304 | |
305 | Exit: |
306 | return result; |
307 | } |
308 | |
309 | |
310 | /***************************************************************************/ |
311 | /***************************************************************************/ |
312 | /***** *****/ |
313 | /***** L Z W E M B E D D I N G S T R E A M *****/ |
314 | /***** *****/ |
315 | /***************************************************************************/ |
316 | /***************************************************************************/ |
317 | |
318 | static void |
319 | ft_lzw_stream_close( FT_Stream stream ) |
320 | { |
321 | FT_LZWFile zip = (FT_LZWFile)stream->descriptor.pointer; |
322 | FT_Memory memory = stream->memory; |
323 | |
324 | |
325 | if ( zip ) |
326 | { |
327 | /* finalize lzw file descriptor */ |
328 | ft_lzw_file_done( zip ); |
329 | |
330 | FT_FREE( zip )do { ft_mem_free( memory, (zip) ); (zip) = ((void*)0); } while ( 0 ); |
331 | |
332 | stream->descriptor.pointer = NULL((void*)0); |
333 | } |
334 | } |
335 | |
336 | |
337 | static FT_ULong |
338 | ft_lzw_stream_io( FT_Stream stream, |
339 | FT_ULong pos, |
340 | FT_Byte* buffer, |
341 | FT_ULong count ) |
342 | { |
343 | FT_LZWFile zip = (FT_LZWFile)stream->descriptor.pointer; |
344 | |
345 | |
346 | return ft_lzw_file_io( zip, pos, buffer, count ); |
347 | } |
348 | |
349 | |
350 | FT_EXPORT_DEF( FT_Error )extern FT_Error |
351 | FT_Stream_OpenLZW( FT_Stream stream, |
352 | FT_Stream source ) |
353 | { |
354 | FT_Error error; |
355 | FT_Memory memory = source->memory; |
356 | FT_LZWFile zip; |
357 | |
358 | |
359 | /* |
360 | * Check the header right now; this prevents allocation of a huge |
361 | * LZWFile object (400 KByte of heap memory) if not necessary. |
362 | * |
363 | * Did I mention that you should never use .Z compressed font |
364 | * files? |
365 | */ |
366 | error = ft_lzw_check_header( source ); |
367 | if ( error ) |
368 | goto Exit; |
369 | |
370 | FT_ZERO( stream )((__builtin_object_size (stream, 0) != (size_t) -1) ? __builtin___memset_chk (stream, 0, sizeof ( *(stream) ), __builtin_object_size (stream , 0)) : __inline_memset_chk (stream, 0, sizeof ( *(stream) )) ); |
371 | stream->memory = memory; |
372 | |
373 | if ( !FT_NEW( zip )( ((zip) = (ft_mem_alloc( memory, (sizeof ( *(zip) )), &error ))), error != 0 ) ) |
374 | { |
375 | error = ft_lzw_file_init( zip, stream, source ); |
376 | if ( error ) |
377 | { |
378 | FT_FREE( zip )do { ft_mem_free( memory, (zip) ); (zip) = ((void*)0); } while ( 0 ); |
379 | goto Exit; |
380 | } |
381 | |
382 | stream->descriptor.pointer = zip; |
383 | } |
384 | |
385 | stream->size = 0x7FFFFFFFL; /* don't know the real size! */ |
386 | stream->pos = 0; |
387 | stream->base = 0; |
388 | stream->read = ft_lzw_stream_io; |
389 | stream->close = ft_lzw_stream_close; |
390 | |
391 | Exit: |
392 | return error; |
393 | } |
394 | |
395 | |
396 | #include "ftzopen.c" |
397 | |
398 | |
399 | #else /* !FT_CONFIG_OPTION_USE_LZW */ |
400 | |
401 | |
402 | FT_EXPORT_DEF( FT_Error )extern FT_Error |
403 | FT_Stream_OpenLZW( FT_Stream stream, |
404 | FT_Stream source ) |
405 | { |
406 | FT_UNUSED( stream )( (stream) = (stream) ); |
407 | FT_UNUSED( source )( (source) = (source) ); |
408 | |
409 | return LZW_Err_Unimplemented_Feature; |
410 | } |
411 | |
412 | |
413 | #endif /* !FT_CONFIG_OPTION_USE_LZW */ |
414 | |
415 | |
416 | /* END */ |