thirdparty/freetype-2.3.12/src/gzip/ftgzip.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftgzip.c                                                               */
   4 /*                                                                         */
   5 /*    FreeType support for .gz compressed files.                           */
   6 /*                                                                         */
   7 /*  This optional component relies on zlib.  It should mainly be used to   */
   8 /*  parse compressed PCF fonts, as found with many X11 server              */
   9 /*  distributions.                                                         */
  10 /*                                                                         */
  11 /*  Copyright 2002, 2003, 2004, 2005, 2006, 2009 by                        */
  12 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
  13 /*                                                                         */
  14 /*  This file is part of the FreeType project, and may only be used,       */
  15 /*  modified, and distributed under the terms of the FreeType project      */
  16 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  17 /*  this file you indicate that you have read the license and              */
  18 /*  understand and accept it fully.                                        */
  19 /*                                                                         */
  20 /***************************************************************************/
  21
  22
  23 #include <ft2build.h>
  24 #include FT_INTERNAL_MEMORY_H
  25 #include FT_INTERNAL_STREAM_H
  26 #include FT_INTERNAL_DEBUG_H
  27 #include FT_GZIP_H
  28 #include FT_CONFIG_STANDARD_LIBRARY_H
  29
  30
  31 #include FT_MODULE_ERRORS_H
  32
  33 #undef __FTERRORS_H__
  34
  35 #define FT_ERR_PREFIX  Gzip_Err_
  36 #define FT_ERR_BASE    FT_Mod_Err_Gzip
  37
  38 #include FT_ERRORS_H
  39
  40
  41 #ifdef FT_CONFIG_OPTION_USE_ZLIB
  42
  43 #ifdef FT_CONFIG_OPTION_PIC
  44 #error "gzip code does not support PIC yet"
  45 #endif
  46
  47 #ifdef FT_CONFIG_OPTION_SYSTEM_ZLIB
  48
  49 #include <zlib.h>
  50
  51 #else /* !FT_CONFIG_OPTION_SYSTEM_ZLIB */
  52
  53  /* In this case, we include our own modified sources of the ZLib    */
  54  /* within the "ftgzip" component.  The modifications were necessary */
  55  /* to #include all files without conflicts, as well as preventing   */
  56  /* the definition of "extern" functions that may cause linking      */
  57  /* conflicts when a program is linked with both FreeType and the    */
  58  /* original ZLib.                                                   */
  59
  60 #define NO_DUMMY_DECL
  61 #ifndef USE_ZLIB_ZCALLOC
  62 #define MY_ZCALLOC /* prevent all zcalloc() & zfree() in zutils.c */
  63 #endif
  64
  65 #include "zlib.h"
  66
  67 #undef  SLOW
  68 #define SLOW  1  /* we can't use asm-optimized sources here! */
  69
  70   /* Urgh.  `inflate_mask' must not be declared twice -- C++ doesn't like
  71      this.  We temporarily disable it and load all necessary header files. */
  72 #define NO_INFLATE_MASK
  73 #include "zutil.h"
  74 #include "inftrees.h"
  75 #include "infblock.h"
  76 #include "infcodes.h"
  77 #include "infutil.h"
  78 #undef  NO_INFLATE_MASK
  79
  80   /* infutil.c must be included before infcodes.c */
  81 #include "zutil.c"
  82 #include "inftrees.c"
  83 #include "infutil.c"
  84 #include "infcodes.c"
  85 #include "infblock.c"
  86 #include "inflate.c"
  87 #include "adler32.c"
  88
  89 #endif /* !FT_CONFIG_OPTION_SYSTEM_ZLIB */
  90
  91
  92 /***************************************************************************/
  93 /***************************************************************************/
  94 /*****                                                                 *****/
  95 /*****            Z L I B   M E M O R Y   M A N A G E M E N T          *****/
  96 /*****                                                                 *****/
  97 /***************************************************************************/
  98 /***************************************************************************/
  99
 100   /* it is better to use FreeType memory routines instead of raw
 101      'malloc/free' */
 102
 103   static voidpf
 104   ft_gzip_alloc( FT_Memory  memory,
 105                  uInt       items,
 106                  uInt       size )
 107   {
 108     FT_ULong    sz = (FT_ULong)size * items;
 109     FT_Error    error;
 110     FT_Pointer  p;
 111
 112
 113     (void)FT_ALLOC( p, sz );
 114     return p;
 115   }
 116
 117
 118   static void
 119   ft_gzip_free( FT_Memory  memory,
 120                 voidpf     address )
 121   {
 122     FT_MEM_FREE( address );
 123   }
 124
 125
 126 #if !defined( FT_CONFIG_OPTION_SYSTEM_ZLIB ) && !defined( USE_ZLIB_ZCALLOC )
 127
 128   local voidpf
 129   zcalloc ( voidpf    opaque,
 130             unsigned  items,
 131             unsigned  size )
 132   {
 133     return ft_gzip_alloc( (FT_Memory)opaque, items, size );
 134   }
 135
 136   local void
 137   zcfree( voidpf  opaque,
 138           voidpf  ptr )
 139   {
 140     ft_gzip_free( (FT_Memory)opaque, ptr );
 141   }
 142
 143 #endif /* !SYSTEM_ZLIB && !USE_ZLIB_ZCALLOC */
 144
 145
 146 /***************************************************************************/
 147 /***************************************************************************/
 148 /*****                                                                 *****/
 149 /*****               Z L I B   F I L E   D E S C R I P T O R           *****/
 150 /*****                                                                 *****/
 151 /***************************************************************************/
 152 /***************************************************************************/
 153
 154 #define FT_GZIP_BUFFER_SIZE  4096
 155
 156   typedef struct  FT_GZipFileRec_
 157   {
 158     FT_Stream  source;         /* parent/source stream        */
 159     FT_Stream  stream;         /* embedding stream            */
 160     FT_Memory  memory;         /* memory allocator            */
 161     z_stream   zstream;        /* zlib input stream           */
 162
 163     FT_ULong   start;          /* starting position, after .gz header */
 164     FT_Byte    input[FT_GZIP_BUFFER_SIZE];   /* input read buffer  */
 165
 166     FT_Byte    buffer[FT_GZIP_BUFFER_SIZE];  /* output buffer      */
 167     FT_ULong   pos;                          /* position in output */
 168     FT_Byte*   cursor;
 169     FT_Byte*   limit;
 170
 171   } FT_GZipFileRec, *FT_GZipFile;
 172
 173
 174   /* gzip flag byte */
 175 #define FT_GZIP_ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */
 176 #define FT_GZIP_HEAD_CRC     0x02 /* bit 1 set: header CRC present */
 177 #define FT_GZIP_EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 178 #define FT_GZIP_ORIG_NAME    0x08 /* bit 3 set: original file name present */
 179 #define FT_GZIP_COMMENT      0x10 /* bit 4 set: file comment present */
 180 #define FT_GZIP_RESERVED     0xE0 /* bits 5..7: reserved */
 181
 182
 183   /* check and skip .gz header - we don't support `transparent' compression */
 184   static FT_Error
 185   ft_gzip_check_header( FT_Stream  stream )
 186   {
 187     FT_Error  error;
 188     FT_Byte   head[4];
 189
 190
 191     if ( FT_STREAM_SEEK( 0 )       ||
 192          FT_STREAM_READ( head, 4 ) )
 193       goto Exit;
 194
 195     /* head[0] && head[1] are the magic numbers;    */
 196     /* head[2] is the method, and head[3] the flags */
 197     if ( head[0] != 0x1f              ||
 198          head[1] != 0x8b              ||
 199          head[2] != Z_DEFLATED        ||
 200         (head[3] & FT_GZIP_RESERVED)  )
 201     {
 202       error = Gzip_Err_Invalid_File_Format;
 203       goto Exit;
 204     }
 205
 206     /* skip time, xflags and os code */
 207     (void)FT_STREAM_SKIP( 6 );
 208
 209     /* skip the extra field */
 210     if ( head[3] & FT_GZIP_EXTRA_FIELD )
 211     {
 212       FT_UInt  len;
 213
 214
 215       if ( FT_READ_USHORT_LE( len ) ||
 216            FT_STREAM_SKIP( len )    )
 217         goto Exit;
 218     }
 219
 220     /* skip original file name */
 221     if ( head[3] & FT_GZIP_ORIG_NAME )
 222       for (;;)
 223       {
 224         FT_UInt  c;
 225
 226
 227         if ( FT_READ_BYTE( c ) )
 228           goto Exit;
 229
 230         if ( c == 0 )
 231           break;
 232       }
 233
 234     /* skip .gz comment */
 235     if ( head[3] & FT_GZIP_COMMENT )
 236       for (;;)
 237       {
 238         FT_UInt  c;
 239
 240
 241         if ( FT_READ_BYTE( c ) )
 242           goto Exit;
 243
 244         if ( c == 0 )
 245           break;
 246       }
 247
 248     /* skip CRC */
 249     if ( head[3] & FT_GZIP_HEAD_CRC )
 250       if ( FT_STREAM_SKIP( 2 ) )
 251         goto Exit;
 252
 253   Exit:
 254     return error;
 255   }
 256
 257
 258   static FT_Error
 259   ft_gzip_file_init( FT_GZipFile  zip,
 260                      FT_Stream    stream,
 261                      FT_Stream    source )
 262   {
 263     z_stream*  zstream = &zip->zstream;
 264     FT_Error   error   = Gzip_Err_Ok;
 265
 266
 267     zip->stream = stream;
 268     zip->source = source;
 269     zip->memory = stream->memory;
 270
 271     zip->limit  = zip->buffer + FT_GZIP_BUFFER_SIZE;
 272     zip->cursor = zip->limit;
 273     zip->pos    = 0;
 274
 275     /* check and skip .gz header */
 276     {
 277       stream = source;
 278
 279       error = ft_gzip_check_header( stream );
 280       if ( error )
 281         goto Exit;
 282
 283       zip->start = FT_STREAM_POS();
 284     }
 285
 286     /* initialize zlib -- there is no zlib header in the compressed stream */
 287     zstream->zalloc = (alloc_func)ft_gzip_alloc;
 288     zstream->zfree  = (free_func) ft_gzip_free;
 289     zstream->opaque = stream->memory;
 290
 291     zstream->avail_in = 0;
 292     zstream->next_in  = zip->buffer;
 293
 294     if ( inflateInit2( zstream, -MAX_WBITS ) != Z_OK ||
 295          zstream->next_in == NULL                     )
 296       error = Gzip_Err_Invalid_File_Format;
 297
 298   Exit:
 299     return error;
 300   }
 301
 302
 303   static void
 304   ft_gzip_file_done( FT_GZipFile  zip )
 305   {
 306     z_stream*  zstream = &zip->zstream;
 307
 308
 309     inflateEnd( zstream );
 310
 311     /* clear the rest */
 312     zstream->zalloc    = NULL;
 313     zstream->zfree     = NULL;
 314     zstream->opaque    = NULL;
 315     zstream->next_in   = NULL;
 316     zstream->next_out  = NULL;
 317     zstream->avail_in  = 0;
 318     zstream->avail_out = 0;
 319
 320     zip->memory = NULL;
 321     zip->source = NULL;
 322     zip->stream = NULL;
 323   }
 324
 325
 326   static FT_Error
 327   ft_gzip_file_reset( FT_GZipFile  zip )
 328   {
 329     FT_Stream  stream = zip->source;
 330     FT_Error   error;
 331
 332
 333     if ( !FT_STREAM_SEEK( zip->start ) )
 334     {
 335       z_stream*  zstream = &zip->zstream;
 336
 337
 338       inflateReset( zstream );
 339
 340       zstream->avail_in  = 0;
 341       zstream->next_in   = zip->input;
 342       zstream->avail_out = 0;
 343       zstream->next_out  = zip->buffer;
 344
 345       zip->limit  = zip->buffer + FT_GZIP_BUFFER_SIZE;
 346       zip->cursor = zip->limit;
 347       zip->pos    = 0;
 348     }
 349
 350     return error;
 351   }
 352
 353
 354   static FT_Error
 355   ft_gzip_file_fill_input( FT_GZipFile  zip )
 356   {
 357     z_stream*  zstream = &zip->zstream;
 358     FT_Stream  stream  = zip->source;
 359     FT_ULong   size;
 360
 361
 362     if ( stream->read )
 363     {
 364       size = stream->read( stream, stream->pos, zip->input,
 365                            FT_GZIP_BUFFER_SIZE );
 366       if ( size == 0 )
 367         return Gzip_Err_Invalid_Stream_Operation;
 368     }
 369     else
 370     {
 371       size = stream->size - stream->pos;
 372       if ( size > FT_GZIP_BUFFER_SIZE )
 373         size = FT_GZIP_BUFFER_SIZE;
 374
 375       if ( size == 0 )
 376         return Gzip_Err_Invalid_Stream_Operation;
 377
 378       FT_MEM_COPY( zip->input, stream->base + stream->pos, size );
 379     }
 380     stream->pos += size;
 381
 382     zstream->next_in  = zip->input;
 383     zstream->avail_in = size;
 384
 385     return Gzip_Err_Ok;
 386   }
 387
 388
 389   static FT_Error
 390   ft_gzip_file_fill_output( FT_GZipFile  zip )
 391   {
 392     z_stream*  zstream = &zip->zstream;
 393     FT_Error   error   = 0;
 394
 395
 396     zip->cursor        = zip->buffer;
 397     zstream->next_out  = zip->cursor;
 398     zstream->avail_out = FT_GZIP_BUFFER_SIZE;
 399
 400     while ( zstream->avail_out > 0 )
 401     {
 402       int  err;
 403
 404
 405       if ( zstream->avail_in == 0 )
 406       {
 407         error = ft_gzip_file_fill_input( zip );
 408         if ( error )
 409           break;
 410       }
 411
 412       err = inflate( zstream, Z_NO_FLUSH );
 413
 414       if ( err == Z_STREAM_END )
 415       {
 416         zip->limit = zstream->next_out;
 417         if ( zip->limit == zip->cursor )
 418           error = Gzip_Err_Invalid_Stream_Operation;
 419         break;
 420       }
 421       else if ( err != Z_OK )
 422       {
 423         error = Gzip_Err_Invalid_Stream_Operation;
 424         break;
 425       }
 426     }
 427
 428     return error;
 429   }
 430
 431
 432   /* fill output buffer; `count' must be <= FT_GZIP_BUFFER_SIZE */
 433   static FT_Error
 434   ft_gzip_file_skip_output( FT_GZipFile  zip,
 435                             FT_ULong     count )
 436   {
 437     FT_Error  error = Gzip_Err_Ok;
 438     FT_ULong  delta;
 439
 440
 441     for (;;)
 442     {
 443       delta = (FT_ULong)( zip->limit - zip->cursor );
 444       if ( delta >= count )
 445         delta = count;
 446
 447       zip->cursor += delta;
 448       zip->pos    += delta;
 449
 450       count -= delta;
 451       if ( count == 0 )
 452         break;
 453
 454       error = ft_gzip_file_fill_output( zip );
 455       if ( error )
 456         break;
 457     }
 458
 459     return error;
 460   }
 461
 462
 463   static FT_ULong
 464   ft_gzip_file_io( FT_GZipFile  zip,
 465                    FT_ULong     pos,
 466                    FT_Byte*     buffer,
 467                    FT_ULong     count )
 468   {
 469     FT_ULong  result = 0;
 470     FT_Error  error;
 471
 472
 473     /* Reset inflate stream if we're seeking backwards.        */
 474     /* Yes, that is not too efficient, but it saves memory :-) */
 475     if ( pos < zip->pos )
 476     {
 477       error = ft_gzip_file_reset( zip );
 478       if ( error )
 479         goto Exit;
 480     }
 481
 482     /* skip unwanted bytes */
 483     if ( pos > zip->pos )
 484     {
 485       error = ft_gzip_file_skip_output( zip, (FT_ULong)( pos - zip->pos ) );
 486       if ( error )
 487         goto Exit;
 488     }
 489
 490     if ( count == 0 )
 491       goto Exit;
 492
 493     /* now read the data */
 494     for (;;)
 495     {
 496       FT_ULong  delta;
 497
 498
 499       delta = (FT_ULong)( zip->limit - zip->cursor );
 500       if ( delta >= count )
 501         delta = count;
 502
 503       FT_MEM_COPY( buffer, zip->cursor, delta );
 504       buffer      += delta;
 505       result      += delta;
 506       zip->cursor += delta;
 507       zip->pos    += delta;
 508
 509       count -= delta;
 510       if ( count == 0 )
 511         break;
 512
 513       error = ft_gzip_file_fill_output( zip );
 514       if ( error )
 515         break;
 516     }
 517
 518   Exit:
 519     return result;
 520   }
 521
 522
 523 /***************************************************************************/
 524 /***************************************************************************/
 525 /*****                                                                 *****/
 526 /*****               G Z   E M B E D D I N G   S T R E A M             *****/
 527 /*****                                                                 *****/
 528 /***************************************************************************/
 529 /***************************************************************************/
 530
 531   static void
 532   ft_gzip_stream_close( FT_Stream  stream )
 533   {
 534     FT_GZipFile  zip    = (FT_GZipFile)stream->descriptor.pointer;
 535     FT_Memory    memory = stream->memory;
 536
 537
 538     if ( zip )
 539     {
 540       /* finalize gzip file descriptor */
 541       ft_gzip_file_done( zip );
 542
 543       FT_FREE( zip );
 544
 545       stream->descriptor.pointer = NULL;
 546     }
 547   }
 548
 549
 550   static FT_ULong
 551   ft_gzip_stream_io( FT_Stream  stream,
 552                      FT_ULong   pos,
 553                      FT_Byte*   buffer,
 554                      FT_ULong   count )
 555   {
 556     FT_GZipFile  zip = (FT_GZipFile)stream->descriptor.pointer;
 557
 558
 559     return ft_gzip_file_io( zip, pos, buffer, count );
 560   }
 561
 562
 563   static FT_ULong
 564   ft_gzip_get_uncompressed_size( FT_Stream  stream )
 565   {
 566     FT_Error  error;
 567     FT_ULong  old_pos;
 568     FT_ULong  result = 0;
 569
 570
 571     old_pos = stream->pos;
 572     if ( !FT_Stream_Seek( stream, stream->size - 4 ) )
 573     {
 574       result = (FT_ULong)FT_Stream_ReadLong( stream, &error );
 575       if ( error )
 576         result = 0;
 577
 578       (void)FT_Stream_Seek( stream, old_pos );
 579     }
 580
 581     return result;
 582   }
 583
 584
 585   FT_EXPORT_DEF( FT_Error )
 586   FT_Stream_OpenGzip( FT_Stream  stream,
 587                       FT_Stream  source )
 588   {
 589     FT_Error     error;
 590     FT_Memory    memory = source->memory;
 591     FT_GZipFile  zip;
 592
 593
 594     /*
 595      *  check the header right now; this prevents allocating un-necessary
 596      *  objects when we don't need them
 597      */
 598     error = ft_gzip_check_header( source );
 599     if ( error )
 600       goto Exit;
 601
 602     FT_ZERO( stream );
 603     stream->memory = memory;
 604
 605     if ( !FT_QNEW( zip ) )
 606     {
 607       error = ft_gzip_file_init( zip, stream, source );
 608       if ( error )
 609       {
 610         FT_FREE( zip );
 611         goto Exit;
 612       }
 613
 614       stream->descriptor.pointer = zip;
 615     }
 616
 617     /*
 618      *  We use the following trick to try to dramatically improve the
 619      *  performance while dealing with small files.  If the original stream
 620      *  size is less than a certain threshold, we try to load the whole font
 621      *  file into memory.  This saves us from using the 32KB buffer needed
 622      *  to inflate the file, plus the two 4KB intermediate input/output
 623      *  buffers used in the `FT_GZipFile' structure.
 624      */
 625     {
 626       FT_ULong  zip_size = ft_gzip_get_uncompressed_size( source );
 627
 628
 629       if ( zip_size != 0 && zip_size < 40 * 1024 )
 630       {
 631         FT_Byte*  zip_buff;
 632
 633
 634         if ( !FT_ALLOC( zip_buff, zip_size ) )
 635         {
 636           FT_ULong  count;
 637
 638
 639           count = ft_gzip_file_io( zip, 0, zip_buff, zip_size );
 640           if ( count == zip_size )
 641           {
 642             ft_gzip_file_done( zip );
 643             FT_FREE( zip );
 644
 645             stream->descriptor.pointer = NULL;
 646
 647             stream->size  = zip_size;
 648             stream->pos   = 0;
 649             stream->base  = zip_buff;
 650             stream->read  = NULL;
 651             stream->close = ft_gzip_stream_close;
 652
 653             goto Exit;
 654           }
 655
 656           ft_gzip_file_io( zip, 0, NULL, 0 );
 657           FT_FREE( zip_buff );
 658         }
 659         error = 0;
 660       }
 661     }
 662
 663     stream->size  = 0x7FFFFFFFL;  /* don't know the real size! */
 664     stream->pos   = 0;
 665     stream->base  = 0;
 666     stream->read  = ft_gzip_stream_io;
 667     stream->close = ft_gzip_stream_close;
 668
 669   Exit:
 670     return error;
 671   }
 672
 673 #else  /* !FT_CONFIG_OPTION_USE_ZLIB */
 674
 675   FT_EXPORT_DEF( FT_Error )
 676   FT_Stream_OpenGzip( FT_Stream  stream,
 677                       FT_Stream  source )
 678   {
 679     FT_UNUSED( stream );
 680     FT_UNUSED( source );
 681
 682     return Gzip_Err_Unimplemented_Feature;
 683   }
 684
 685 #endif /* !FT_CONFIG_OPTION_USE_ZLIB */
 686
 687
 688 /* END */