|
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, 2010 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 |
|
27 #include FT_INTERNAL_STREAM_H |
|
28 #include FT_INTERNAL_DEBUG_H |
|
29 #include FT_LZW_H |
|
30 #include FT_CONFIG_STANDARD_LIBRARY_H |
|
31 |
|
32 |
|
33 #include FT_MODULE_ERRORS_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 |
|
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_SIZE 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_SIZE]; /* 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 ) || |
|
94 FT_STREAM_READ( head, 2 ) ) |
|
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_SIZE; |
|
121 zip->cursor = zip->limit; |
|
122 zip->pos = 0; |
|
123 |
|
124 /* check and skip .Z header */ |
|
125 error = ft_lzw_check_header( source ); |
|
126 if ( error ) |
|
127 goto Exit; |
|
128 |
|
129 /* initialize internal lzw variable */ |
|
130 ft_lzwstate_init( lzw, source ); |
|
131 |
|
132 Exit: |
|
133 return error; |
|
134 } |
|
135 |
|
136 |
|
137 static void |
|
138 ft_lzw_file_done( FT_LZWFile zip ) |
|
139 { |
|
140 /* clear the rest */ |
|
141 ft_lzwstate_done( &zip->lzw ); |
|
142 |
|
143 zip->memory = NULL; |
|
144 zip->source = NULL; |
|
145 zip->stream = NULL; |
|
146 } |
|
147 |
|
148 |
|
149 static FT_Error |
|
150 ft_lzw_file_reset( FT_LZWFile zip ) |
|
151 { |
|
152 FT_Stream stream = zip->source; |
|
153 FT_Error error; |
|
154 |
|
155 |
|
156 if ( !FT_STREAM_SEEK( 0 ) ) |
|
157 { |
|
158 ft_lzwstate_reset( &zip->lzw ); |
|
159 |
|
160 zip->limit = zip->buffer + FT_LZW_BUFFER_SIZE; |
|
161 zip->cursor = zip->limit; |
|
162 zip->pos = 0; |
|
163 } |
|
164 |
|
165 return error; |
|
166 } |
|
167 |
|
168 |
|
169 static FT_Error |
|
170 ft_lzw_file_fill_output( FT_LZWFile zip ) |
|
171 { |
|
172 FT_LzwState lzw = &zip->lzw; |
|
173 FT_ULong count; |
|
174 FT_Error error = LZW_Err_Ok; |
|
175 |
|
176 |
|
177 zip->cursor = zip->buffer; |
|
178 |
|
179 count = ft_lzwstate_io( lzw, zip->buffer, FT_LZW_BUFFER_SIZE ); |
|
180 |
|
181 zip->limit = zip->cursor + count; |
|
182 |
|
183 if ( count == 0 ) |
|
184 error = LZW_Err_Invalid_Stream_Operation; |
|
185 |
|
186 return error; |
|
187 } |
|
188 |
|
189 |
|
190 /* fill output buffer; `count' must be <= FT_LZW_BUFFER_SIZE */ |
|
191 static FT_Error |
|
192 ft_lzw_file_skip_output( FT_LZWFile zip, |
|
193 FT_ULong count ) |
|
194 { |
|
195 FT_Error error = LZW_Err_Ok; |
|
196 |
|
197 |
|
198 /* first, we skip what we can from the output buffer */ |
|
199 { |
|
200 FT_ULong delta = (FT_ULong)( zip->limit - zip->cursor ); |
|
201 |
|
202 |
|
203 if ( delta >= count ) |
|
204 delta = count; |
|
205 |
|
206 zip->cursor += delta; |
|
207 zip->pos += delta; |
|
208 |
|
209 count -= delta; |
|
210 } |
|
211 |
|
212 /* next, we skip as many bytes remaining as possible */ |
|
213 while ( count > 0 ) |
|
214 { |
|
215 FT_ULong delta = FT_LZW_BUFFER_SIZE; |
|
216 FT_ULong numread; |
|
217 |
|
218 |
|
219 if ( delta > count ) |
|
220 delta = count; |
|
221 |
|
222 numread = ft_lzwstate_io( &zip->lzw, NULL, delta ); |
|
223 if ( numread < delta ) |
|
224 { |
|
225 /* not enough bytes */ |
|
226 error = LZW_Err_Invalid_Stream_Operation; |
|
227 break; |
|
228 } |
|
229 |
|
230 zip->pos += delta; |
|
231 count -= delta; |
|
232 } |
|
233 |
|
234 return error; |
|
235 } |
|
236 |
|
237 |
|
238 static FT_ULong |
|
239 ft_lzw_file_io( FT_LZWFile zip, |
|
240 FT_ULong pos, |
|
241 FT_Byte* buffer, |
|
242 FT_ULong count ) |
|
243 { |
|
244 FT_ULong result = 0; |
|
245 FT_Error error; |
|
246 |
|
247 |
|
248 /* seeking backwards. */ |
|
249 if ( pos < zip->pos ) |
|
250 { |
|
251 /* If the new position is within the output buffer, simply */ |
|
252 /* decrement pointers, otherwise we reset the stream completely! */ |
|
253 if ( ( zip->pos - pos ) <= (FT_ULong)( zip->cursor - zip->buffer ) ) |
|
254 { |
|
255 zip->cursor -= zip->pos - pos; |
|
256 zip->pos = pos; |
|
257 } |
|
258 else |
|
259 { |
|
260 error = ft_lzw_file_reset( zip ); |
|
261 if ( error ) |
|
262 goto Exit; |
|
263 } |
|
264 } |
|
265 |
|
266 /* skip unwanted bytes */ |
|
267 if ( pos > zip->pos ) |
|
268 { |
|
269 error = ft_lzw_file_skip_output( zip, (FT_ULong)( pos - zip->pos ) ); |
|
270 if ( error ) |
|
271 goto Exit; |
|
272 } |
|
273 |
|
274 if ( count == 0 ) |
|
275 goto Exit; |
|
276 |
|
277 /* now read the data */ |
|
278 for (;;) |
|
279 { |
|
280 FT_ULong delta; |
|
281 |
|
282 |
|
283 delta = (FT_ULong)( zip->limit - zip->cursor ); |
|
284 if ( delta >= count ) |
|
285 delta = count; |
|
286 |
|
287 FT_MEM_COPY( buffer + result, zip->cursor, delta ); |
|
288 result += delta; |
|
289 zip->cursor += delta; |
|
290 zip->pos += delta; |
|
291 |
|
292 count -= delta; |
|
293 if ( count == 0 ) |
|
294 break; |
|
295 |
|
296 error = ft_lzw_file_fill_output( zip ); |
|
297 if ( error ) |
|
298 break; |
|
299 } |
|
300 |
|
301 Exit: |
|
302 return result; |
|
303 } |
|
304 |
|
305 |
|
306 /***************************************************************************/ |
|
307 /***************************************************************************/ |
|
308 /***** *****/ |
|
309 /***** L Z W E M B E D D I N G S T R E A M *****/ |
|
310 /***** *****/ |
|
311 /***************************************************************************/ |
|
312 /***************************************************************************/ |
|
313 |
|
314 static void |
|
315 ft_lzw_stream_close( FT_Stream stream ) |
|
316 { |
|
317 FT_LZWFile zip = (FT_LZWFile)stream->descriptor.pointer; |
|
318 FT_Memory memory = stream->memory; |
|
319 |
|
320 |
|
321 if ( zip ) |
|
322 { |
|
323 /* finalize lzw file descriptor */ |
|
324 ft_lzw_file_done( zip ); |
|
325 |
|
326 FT_FREE( zip ); |
|
327 |
|
328 stream->descriptor.pointer = NULL; |
|
329 } |
|
330 } |
|
331 |
|
332 |
|
333 static FT_ULong |
|
334 ft_lzw_stream_io( FT_Stream stream, |
|
335 FT_ULong pos, |
|
336 FT_Byte* buffer, |
|
337 FT_ULong count ) |
|
338 { |
|
339 FT_LZWFile zip = (FT_LZWFile)stream->descriptor.pointer; |
|
340 |
|
341 |
|
342 return ft_lzw_file_io( zip, pos, buffer, count ); |
|
343 } |
|
344 |
|
345 |
|
346 FT_EXPORT_DEF( FT_Error ) |
|
347 FT_Stream_OpenLZW( FT_Stream stream, |
|
348 FT_Stream source ) |
|
349 { |
|
350 FT_Error error; |
|
351 FT_Memory memory = source->memory; |
|
352 FT_LZWFile zip; |
|
353 |
|
354 |
|
355 /* |
|
356 * Check the header right now; this prevents allocation of a huge |
|
357 * LZWFile object (400 KByte of heap memory) if not necessary. |
|
358 * |
|
359 * Did I mention that you should never use .Z compressed font |
|
360 * files? |
|
361 */ |
|
362 error = ft_lzw_check_header( source ); |
|
363 if ( error ) |
|
364 goto Exit; |
|
365 |
|
366 FT_ZERO( stream ); |
|
367 stream->memory = memory; |
|
368 |
|
369 if ( !FT_NEW( zip ) ) |
|
370 { |
|
371 error = ft_lzw_file_init( zip, stream, source ); |
|
372 if ( error ) |
|
373 { |
|
374 FT_FREE( zip ); |
|
375 goto Exit; |
|
376 } |
|
377 |
|
378 stream->descriptor.pointer = zip; |
|
379 } |
|
380 |
|
381 stream->size = 0x7FFFFFFFL; /* don't know the real size! */ |
|
382 stream->pos = 0; |
|
383 stream->base = 0; |
|
384 stream->read = ft_lzw_stream_io; |
|
385 stream->close = ft_lzw_stream_close; |
|
386 |
|
387 Exit: |
|
388 return error; |
|
389 } |
|
390 |
|
391 |
|
392 #include "ftzopen.c" |
|
393 |
|
394 |
|
395 #else /* !FT_CONFIG_OPTION_USE_LZW */ |
|
396 |
|
397 |
|
398 FT_EXPORT_DEF( FT_Error ) |
|
399 FT_Stream_OpenLZW( FT_Stream stream, |
|
400 FT_Stream source ) |
|
401 { |
|
402 FT_UNUSED( stream ); |
|
403 FT_UNUSED( source ); |
|
404 |
|
405 return LZW_Err_Unimplemented_Feature; |
|
406 } |
|
407 |
|
408 |
|
409 #endif /* !FT_CONFIG_OPTION_USE_LZW */ |
|
410 |
|
411 |
|
412 /* END */ |