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   1 /***************************************************************************
   2  *             chm_lib.c - CHM archive manipulation routines               *
   3  *                           -------------------                           *
   4  *                                                                         *
   5  *  author:     Jed Wing <jedwin@ugcs.caltech.edu>                         *
   6  *  version:    0.3                                                        *
   7  *  notes:      These routines are meant for the manipulation of microsoft *
   8  *              .chm (compiled html help) files, but may likely be used    *
   9  *              for the manipulation of any ITSS archive, if ever ITSS     *
  10  *              archives are used for any other purpose.                   *
  11  *                                                                         *
  12  *              Note also that the section names are statically handled.   *
  13  *              To be entirely correct, the section names should be read   *
  14  *              from the section names meta-file, and then the various     *
  15  *              content sections and the "transforms" to apply to the data *
  16  *              they contain should be inferred from the section name and  *
  17  *              the meta-files referenced using that name; however, all of *
  18  *              the files I've been able to get my hands on appear to have *
  19  *              only two sections: Uncompressed and MSCompressed.          *
  20  *              Additionally, the ITSS.DLL file included with Windows does *
  21  *              not appear to handle any different transforms than the     *
  22  *              simple LZX-transform.  Furthermore, the list of transforms *
  23  *              to apply is broken, in that only half the required space   *
  24  *              is allocated for the list.  (It appears as though the      *
  25  *              space is allocated for ASCII strings, but the strings are  *
  26  *              written as unicode.  As a result, only the first half of   *
  27  *              the string appears.)  So this is probably not too big of   *
  28  *              a deal, at least until CHM v4 (MS .lit files), which also  *
  29  *              incorporate encryption, of some description.               *
  30  *                                                                         *
  31  ***************************************************************************/
  32
  33 /***************************************************************************
  34  *                                                                         *
  35  *   This library is free software; you can redistribute it and/or modify  *
  36  *   it under the terms of the GNU Lesser General Public License as        *
  37  *   published by the Free Software Foundation; either version 2.1 of the  *
  38  *   License, or (at your option) any later version.                       *
  39  *                                                                         *
  40  ***************************************************************************/
  41
  42 /***************************************************************************
  43  *                                                                         *
  44  * Adapted for Wine by Mike McCormack                                      *
  45  *                                                                         *
  46  ***************************************************************************/
  47
  48 #include "config.h"
  49 #include "wine/port.h"
  50
  51 #include <stdarg.h>
  52 #include <stdio.h>
  53 #include <stdlib.h>
  54 #include <string.h>
  55
  56 #include "windef.h"
  57 #include "winbase.h"
  58 #include "wine/unicode.h"
  59
  60 #include "chm_lib.h"
  61 #include "lzx.h"
  62
  63 #define CHM_ACQUIRE_LOCK(a) do {                        \
  64         EnterCriticalSection(&(a));                     \
  65     } while(0)
  66 #define CHM_RELEASE_LOCK(a) do {                        \
  67         LeaveCriticalSection(&(a));                     \
  68     } while(0)
  69
  70 #define CHM_NULL_FD (INVALID_HANDLE_VALUE)
  71 #define CHM_CLOSE_FILE(fd) CloseHandle((fd))
  72
  73 /*
  74  * defines related to tuning
  75  */
  76 #ifndef CHM_MAX_BLOCKS_CACHED
  77 #define CHM_MAX_BLOCKS_CACHED 5
  78 #endif
  79
  80 /*
  81  * architecture specific defines
  82  *
  83  * Note: as soon as C99 is more widespread, the below defines should
  84  * probably just use the C99 sized-int types.
  85  *
  86  * The following settings will probably work for many platforms.  The sizes
  87  * don't have to be exactly correct, but the types must accommodate at least as
  88  * many bits as they specify.
  89  */
  90
  91 /* i386, 32-bit, Windows */
  92 typedef BYTE   UChar;
  93 typedef SHORT  Int16;
  94 typedef USHORT UInt16;
  95 typedef LONG   Int32;
  96 typedef DWORD      UInt32;
  97 typedef LONGLONG   Int64;
  98 typedef ULONGLONG  UInt64;
  99
 100 /* utilities for unmarshalling data */
 101 static int _unmarshal_char_array(unsigned char **pData,
 102                                  unsigned long *pLenRemain,
 103                                  char *dest,
 104                                  int count)
 105 {
 106     if (count <= 0  ||  (unsigned int)count > *pLenRemain)
 107         return 0;
 108     memcpy(dest, (*pData), count);
 109     *pData += count;
 110     *pLenRemain -= count;
 111     return 1;
 112 }
 113
 114 static int _unmarshal_uchar_array(unsigned char **pData,
 115                                   unsigned long *pLenRemain,
 116                                   unsigned char *dest,
 117                                   int count)
 118 {
 119         if (count <= 0  ||  (unsigned int)count > *pLenRemain)
 120         return 0;
 121     memcpy(dest, (*pData), count);
 122     *pData += count;
 123     *pLenRemain -= count;
 124     return 1;
 125 }
 126
 127 static int _unmarshal_int32(unsigned char **pData,
 128                             unsigned long *pLenRemain,
 129                             Int32 *dest)
 130 {
 131     if (4 > *pLenRemain)
 132         return 0;
 133     *dest = (*pData)[0] | (*pData)[1]<<8 | (*pData)[2]<<16 | (*pData)[3]<<24;
 134     *pData += 4;
 135     *pLenRemain -= 4;
 136     return 1;
 137 }
 138
 139 static int _unmarshal_uint32(unsigned char **pData,
 140                              unsigned long *pLenRemain,
 141                              UInt32 *dest)
 142 {
 143     if (4 > *pLenRemain)
 144         return 0;
 145     *dest = (*pData)[0] | (*pData)[1]<<8 | (*pData)[2]<<16 | (*pData)[3]<<24;
 146     *pData += 4;
 147     *pLenRemain -= 4;
 148     return 1;
 149 }
 150
 151 static int _unmarshal_int64(unsigned char **pData,
 152                             unsigned long *pLenRemain,
 153                             Int64 *dest)
 154 {
 155     Int64 temp;
 156     int i;
 157     if (8 > *pLenRemain)
 158         return 0;
 159     temp=0;
 160     for(i=8; i>0; i--)
 161     {
 162         temp <<= 8;
 163         temp |= (*pData)[i-1];
 164     }
 165     *dest = temp;
 166     *pData += 8;
 167     *pLenRemain -= 8;
 168     return 1;
 169 }
 170
 171 static int _unmarshal_uint64(unsigned char **pData,
 172                              unsigned long *pLenRemain,
 173                              UInt64 *dest)
 174 {
 175     UInt64 temp;
 176     int i;
 177     if (8 > *pLenRemain)
 178         return 0;
 179     temp=0;
 180     for(i=8; i>0; i--)
 181     {
 182         temp <<= 8;
 183         temp |= (*pData)[i-1];
 184     }
 185     *dest = temp;
 186     *pData += 8;
 187     *pLenRemain -= 8;
 188     return 1;
 189 }
 190
 191 static int _unmarshal_uuid(unsigned char **pData,
 192                            unsigned long *pDataLen,
 193                            unsigned char *dest)
 194 {
 195     return _unmarshal_uchar_array(pData, pDataLen, dest, 16);
 196 }
 197
 198 /* names of sections essential to decompression */
 199 static const WCHAR _CHMU_RESET_TABLE[] = {
 200 ':',':','D','a','t','a','S','p','a','c','e','/',
 201         'S','t','o','r','a','g','e','/',
 202         'M','S','C','o','m','p','r','e','s','s','e','d','/',
 203         'T','r','a','n','s','f','o','r','m','/',
 204         '{','7','F','C','2','8','9','4','0','-','9','D','3','1',
 205           '-','1','1','D','0','-','9','B','2','7','-',
 206           '0','0','A','0','C','9','1','E','9','C','7','C','}','/',
 207         'I','n','s','t','a','n','c','e','D','a','t','a','/',
 208         'R','e','s','e','t','T','a','b','l','e',0
 209 };
 210 static const WCHAR _CHMU_LZXC_CONTROLDATA[] = {
 211 ':',':','D','a','t','a','S','p','a','c','e','/',
 212         'S','t','o','r','a','g','e','/',
 213         'M','S','C','o','m','p','r','e','s','s','e','d','/',
 214         'C','o','n','t','r','o','l','D','a','t','a',0
 215 };
 216 static const WCHAR _CHMU_CONTENT[] = {
 217 ':',':','D','a','t','a','S','p','a','c','e','/',
 218         'S','t','o','r','a','g','e','/',
 219         'M','S','C','o','m','p','r','e','s','s','e','d','/',
 220         'C','o','n','t','e','n','t',0
 221 };
 222 static const WCHAR _CHMU_SPANINFO[] = {
 223 ':',':','D','a','t','a','S','p','a','c','e','/',
 224         'S','t','o','r','a','g','e','/',
 225         'M','S','C','o','m','p','r','e','s','s','e','d','/',
 226         'S','p','a','n','I','n','f','o',
 227 };
 228
 229 /*
 230  * structures local to this module
 231  */
 232
 233 /* structure of ITSF headers */
 234 #define _CHM_ITSF_V2_LEN (0x58)
 235 #define _CHM_ITSF_V3_LEN (0x60)
 236 struct chmItsfHeader
 237 {
 238     char        signature[4];           /*  0 (ITSF) */
 239     Int32       version;                /*  4 */
 240     Int32       header_len;             /*  8 */
 241     Int32       unknown_000c;           /*  c */
 242     UInt32      last_modified;          /* 10 */
 243     UInt32      lang_id;                /* 14 */
 244     UChar       dir_uuid[16];           /* 18 */
 245     UChar       stream_uuid[16];        /* 28 */
 246     UInt64      unknown_offset;         /* 38 */
 247     UInt64      unknown_len;            /* 40 */
 248     UInt64      dir_offset;             /* 48 */
 249     UInt64      dir_len;                /* 50 */
 250     UInt64      data_offset;            /* 58 (Not present before V3) */
 251 }; /* __attribute__ ((aligned (1))); */
 252
 253 static int _unmarshal_itsf_header(unsigned char **pData,
 254                                   unsigned long *pDataLen,
 255                                   struct chmItsfHeader *dest)
 256 {
 257     /* we only know how to deal with the 0x58 and 0x60 byte structures */
 258     if (*pDataLen != _CHM_ITSF_V2_LEN  &&  *pDataLen != _CHM_ITSF_V3_LEN)
 259         return 0;
 260
 261     /* unmarshal common fields */
 262     _unmarshal_char_array(pData, pDataLen,  dest->signature, 4);
 263     _unmarshal_int32     (pData, pDataLen, &dest->version);
 264     _unmarshal_int32     (pData, pDataLen, &dest->header_len);
 265     _unmarshal_int32     (pData, pDataLen, &dest->unknown_000c);
 266     _unmarshal_uint32    (pData, pDataLen, &dest->last_modified);
 267     _unmarshal_uint32    (pData, pDataLen, &dest->lang_id);
 268     _unmarshal_uuid      (pData, pDataLen,  dest->dir_uuid);
 269     _unmarshal_uuid      (pData, pDataLen,  dest->stream_uuid);
 270     _unmarshal_uint64    (pData, pDataLen, &dest->unknown_offset);
 271     _unmarshal_uint64    (pData, pDataLen, &dest->unknown_len);
 272     _unmarshal_uint64    (pData, pDataLen, &dest->dir_offset);
 273     _unmarshal_uint64    (pData, pDataLen, &dest->dir_len);
 274
 275     /* error check the data */
 276     /* XXX: should also check UUIDs, probably, though with a version 3 file,
 277      * current MS tools do not seem to use them.
 278      */
 279     if (memcmp(dest->signature, "ITSF", 4) != 0)
 280         return 0;
 281     if (dest->version == 2)
 282     {
 283         if (dest->header_len < _CHM_ITSF_V2_LEN)
 284             return 0;
 285     }
 286     else if (dest->version == 3)
 287     {
 288         if (dest->header_len < _CHM_ITSF_V3_LEN)
 289             return 0;
 290     }
 291     else
 292         return 0;
 293
 294     /* now, if we have a V3 structure, unmarshal the rest.
 295      * otherwise, compute it
 296      */
 297     if (dest->version == 3)
 298     {
 299         if (*pDataLen != 0)
 300             _unmarshal_uint64(pData, pDataLen, &dest->data_offset);
 301         else
 302             return 0;
 303     }
 304     else
 305         dest->data_offset = dest->dir_offset + dest->dir_len;
 306
 307     return 1;
 308 }
 309
 310 /* structure of ITSP headers */
 311 #define _CHM_ITSP_V1_LEN (0x54)
 312 struct chmItspHeader
 313 {
 314     char        signature[4];           /*  0 (ITSP) */
 315     Int32       version;                /*  4 */
 316     Int32       header_len;             /*  8 */
 317     Int32       unknown_000c;           /*  c */
 318     UInt32      block_len;              /* 10 */
 319     Int32       blockidx_intvl;         /* 14 */
 320     Int32       index_depth;            /* 18 */
 321     Int32       index_root;             /* 1c */
 322     Int32       index_head;             /* 20 */
 323     Int32       unknown_0024;           /* 24 */
 324     UInt32      num_blocks;             /* 28 */
 325     Int32       unknown_002c;           /* 2c */
 326     UInt32      lang_id;                /* 30 */
 327     UChar       system_uuid[16];        /* 34 */
 328     UChar       unknown_0044[16];       /* 44 */
 329 }; /* __attribute__ ((aligned (1))); */
 330
 331 static int _unmarshal_itsp_header(unsigned char **pData,
 332                                   unsigned long *pDataLen,
 333                                   struct chmItspHeader *dest)
 334 {
 335     /* we only know how to deal with a 0x54 byte structures */
 336     if (*pDataLen != _CHM_ITSP_V1_LEN)
 337         return 0;
 338
 339     /* unmarshal fields */
 340     _unmarshal_char_array(pData, pDataLen,  dest->signature, 4);
 341     _unmarshal_int32     (pData, pDataLen, &dest->version);
 342     _unmarshal_int32     (pData, pDataLen, &dest->header_len);
 343     _unmarshal_int32     (pData, pDataLen, &dest->unknown_000c);
 344     _unmarshal_uint32    (pData, pDataLen, &dest->block_len);
 345     _unmarshal_int32     (pData, pDataLen, &dest->blockidx_intvl);
 346     _unmarshal_int32     (pData, pDataLen, &dest->index_depth);
 347     _unmarshal_int32     (pData, pDataLen, &dest->index_root);
 348     _unmarshal_int32     (pData, pDataLen, &dest->index_head);
 349     _unmarshal_int32     (pData, pDataLen, &dest->unknown_0024);
 350     _unmarshal_uint32    (pData, pDataLen, &dest->num_blocks);
 351     _unmarshal_int32     (pData, pDataLen, &dest->unknown_002c);
 352     _unmarshal_uint32    (pData, pDataLen, &dest->lang_id);
 353     _unmarshal_uuid      (pData, pDataLen,  dest->system_uuid);
 354     _unmarshal_uchar_array(pData, pDataLen, dest->unknown_0044, 16);
 355
 356     /* error check the data */
 357     if (memcmp(dest->signature, "ITSP", 4) != 0)
 358         return 0;
 359     if (dest->version != 1)
 360         return 0;
 361     if (dest->header_len != _CHM_ITSP_V1_LEN)
 362         return 0;
 363
 364     return 1;
 365 }
 366
 367 /* structure of PMGL headers */
 368 static const char _chm_pmgl_marker[4] = "PMGL";
 369 #define _CHM_PMGL_LEN (0x14)
 370 struct chmPmglHeader
 371 {
 372     char        signature[4];           /*  0 (PMGL) */
 373     UInt32      free_space;             /*  4 */
 374     UInt32      unknown_0008;           /*  8 */
 375     Int32       block_prev;             /*  c */
 376     Int32       block_next;             /* 10 */
 377 }; /* __attribute__ ((aligned (1))); */
 378
 379 static int _unmarshal_pmgl_header(unsigned char **pData,
 380                                   unsigned long *pDataLen,
 381                                   struct chmPmglHeader *dest)
 382 {
 383     /* we only know how to deal with a 0x14 byte structures */
 384     if (*pDataLen != _CHM_PMGL_LEN)
 385         return 0;
 386
 387     /* unmarshal fields */
 388     _unmarshal_char_array(pData, pDataLen,  dest->signature, 4);
 389     _unmarshal_uint32    (pData, pDataLen, &dest->free_space);
 390     _unmarshal_uint32    (pData, pDataLen, &dest->unknown_0008);
 391     _unmarshal_int32     (pData, pDataLen, &dest->block_prev);
 392     _unmarshal_int32     (pData, pDataLen, &dest->block_next);
 393
 394     /* check structure */
 395     if (memcmp(dest->signature, _chm_pmgl_marker, 4) != 0)
 396         return 0;
 397
 398     return 1;
 399 }
 400
 401 /* structure of PMGI headers */
 402 static const char _chm_pmgi_marker[4] = "PMGI";
 403 #define _CHM_PMGI_LEN (0x08)
 404 struct chmPmgiHeader
 405 {
 406     char        signature[4];           /*  0 (PMGI) */
 407     UInt32      free_space;             /*  4 */
 408 }; /* __attribute__ ((aligned (1))); */
 409
 410 static int _unmarshal_pmgi_header(unsigned char **pData,
 411                                   unsigned long *pDataLen,
 412                                   struct chmPmgiHeader *dest)
 413 {
 414     /* we only know how to deal with a 0x8 byte structures */
 415     if (*pDataLen != _CHM_PMGI_LEN)
 416         return 0;
 417
 418     /* unmarshal fields */
 419     _unmarshal_char_array(pData, pDataLen,  dest->signature, 4);
 420     _unmarshal_uint32    (pData, pDataLen, &dest->free_space);
 421
 422     /* check structure */
 423     if (memcmp(dest->signature, _chm_pmgi_marker, 4) != 0)
 424         return 0;
 425
 426     return 1;
 427 }
 428
 429 /* structure of LZXC reset table */
 430 #define _CHM_LZXC_RESETTABLE_V1_LEN (0x28)
 431 struct chmLzxcResetTable
 432 {
 433     UInt32      version;
 434     UInt32      block_count;
 435     UInt32      unknown;
 436     UInt32      table_offset;
 437     UInt64      uncompressed_len;
 438     UInt64      compressed_len;
 439     UInt64      block_len;
 440 }; /* __attribute__ ((aligned (1))); */
 441
 442 static int _unmarshal_lzxc_reset_table(unsigned char **pData,
 443                                        unsigned long *pDataLen,
 444                                        struct chmLzxcResetTable *dest)
 445 {
 446     /* we only know how to deal with a 0x28 byte structures */
 447     if (*pDataLen != _CHM_LZXC_RESETTABLE_V1_LEN)
 448         return 0;
 449
 450     /* unmarshal fields */
 451     _unmarshal_uint32    (pData, pDataLen, &dest->version);
 452     _unmarshal_uint32    (pData, pDataLen, &dest->block_count);
 453     _unmarshal_uint32    (pData, pDataLen, &dest->unknown);
 454     _unmarshal_uint32    (pData, pDataLen, &dest->table_offset);
 455     _unmarshal_uint64    (pData, pDataLen, &dest->uncompressed_len);
 456     _unmarshal_uint64    (pData, pDataLen, &dest->compressed_len);
 457     _unmarshal_uint64    (pData, pDataLen, &dest->block_len);
 458
 459     /* check structure */
 460     if (dest->version != 2)
 461         return 0;
 462
 463     return 1;
 464 }
 465
 466 /* structure of LZXC control data block */
 467 #define _CHM_LZXC_MIN_LEN (0x18)
 468 #define _CHM_LZXC_V2_LEN (0x1c)
 469 struct chmLzxcControlData
 470 {
 471     UInt32      size;                   /*  0        */
 472     char        signature[4];           /*  4 (LZXC) */
 473     UInt32      version;                /*  8        */
 474     UInt32      resetInterval;          /*  c        */
 475     UInt32      windowSize;             /* 10        */
 476     UInt32      windowsPerReset;        /* 14        */
 477     UInt32      unknown_18;             /* 18        */
 478 };
 479
 480 static int _unmarshal_lzxc_control_data(unsigned char **pData,
 481                                         unsigned long *pDataLen,
 482                                         struct chmLzxcControlData *dest)
 483 {
 484     /* we want at least 0x18 bytes */
 485     if (*pDataLen < _CHM_LZXC_MIN_LEN)
 486         return 0;
 487
 488     /* unmarshal fields */
 489     _unmarshal_uint32    (pData, pDataLen, &dest->size);
 490     _unmarshal_char_array(pData, pDataLen,  dest->signature, 4);
 491     _unmarshal_uint32    (pData, pDataLen, &dest->version);
 492     _unmarshal_uint32    (pData, pDataLen, &dest->resetInterval);
 493     _unmarshal_uint32    (pData, pDataLen, &dest->windowSize);
 494     _unmarshal_uint32    (pData, pDataLen, &dest->windowsPerReset);
 495
 496     if (*pDataLen >= _CHM_LZXC_V2_LEN)
 497         _unmarshal_uint32    (pData, pDataLen, &dest->unknown_18);
 498     else
 499         dest->unknown_18 = 0;
 500
 501     if (dest->version == 2)
 502     {
 503         dest->resetInterval *= 0x8000;
 504         dest->windowSize *= 0x8000;
 505     }
 506     if (dest->windowSize == 0  ||  dest->resetInterval == 0)
 507         return 0;
 508
 509     /* for now, only support resetInterval a multiple of windowSize/2 */
 510     if (dest->windowSize == 1)
 511         return 0;
 512     if ((dest->resetInterval % (dest->windowSize/2)) != 0)
 513         return 0;
 514
 515     /* check structure */
 516     if (memcmp(dest->signature, "LZXC", 4) != 0)
 517         return 0;
 518
 519     return 1;
 520 }
 521
 522 /* the structure used for chm file handles */
 523 struct chmFile
 524 {
 525     HANDLE              fd;
 526
 527     CRITICAL_SECTION    mutex;
 528     CRITICAL_SECTION    lzx_mutex;
 529     CRITICAL_SECTION    cache_mutex;
 530
 531     UInt64              dir_offset;
 532     UInt64              dir_len;
 533     UInt64              data_offset;
 534     Int32               index_root;
 535     Int32               index_head;
 536     UInt32              block_len;
 537
 538     UInt64              span;
 539     struct chmUnitInfo  rt_unit;
 540     struct chmUnitInfo  cn_unit;
 541     struct chmLzxcResetTable reset_table;
 542
 543     /* LZX control data */
 544     int                 compression_enabled;
 545     UInt32              window_size;
 546     UInt32              reset_interval;
 547     UInt32              reset_blkcount;
 548
 549     /* decompressor state */
 550     struct LZXstate    *lzx_state;
 551     int                 lzx_last_block;
 552
 553     /* cache for decompressed blocks */
 554     UChar             **cache_blocks;
 555     Int64              *cache_block_indices;
 556     Int32               cache_num_blocks;
 557 };
 558
 559 /*
 560  * utility functions local to this module
 561  */
 562
 563 /* utility function to handle differences between {pread,read}(64)? */
 564 static Int64 _chm_fetch_bytes(struct chmFile *h,
 565                               UChar *buf,
 566                               UInt64 os,
 567                               Int64 len)
 568 {
 569     Int64 readLen=0;
 570     if (h->fd  ==  CHM_NULL_FD)
 571         return readLen;
 572
 573     CHM_ACQUIRE_LOCK(h->mutex);
 574     /* NOTE: this might be better done with CreateFileMapping, et cetera... */
 575     {
 576         DWORD origOffsetLo=0, origOffsetHi=0;
 577         DWORD offsetLo, offsetHi;
 578         DWORD actualLen=0;
 579
 580         /* awkward Win32 Seek/Tell */
 581         offsetLo = (unsigned long)(os & 0xffffffffL);
 582         offsetHi = (unsigned long)((os >> 32) & 0xffffffffL);
 583         origOffsetLo = SetFilePointer(h->fd, 0, &origOffsetHi, FILE_CURRENT);
 584         offsetLo = SetFilePointer(h->fd, offsetLo, &offsetHi, FILE_BEGIN);
 585
 586         /* read the data */
 587         if (ReadFile(h->fd,
 588                      buf,
 589                      (DWORD)len,
 590                      &actualLen,
 591                      NULL))
 592             readLen = actualLen;
 593         else
 594             readLen = 0;
 595
 596         /* restore original position */
 597         SetFilePointer(h->fd, origOffsetLo, &origOffsetHi, FILE_BEGIN);
 598     }
 599     CHM_RELEASE_LOCK(h->mutex);
 600     return readLen;
 601 }
 602
 603 /* open an ITS archive */
 604 struct chmFile *chm_openW(const WCHAR *filename)
 605 {
 606     unsigned char               sbuffer[256];
 607     unsigned long               sremain;
 608     unsigned char              *sbufpos;
 609     struct chmFile             *newHandle=NULL;
 610     struct chmItsfHeader        itsfHeader;
 611     struct chmItspHeader        itspHeader;
 612 #if 0
 613     struct chmUnitInfo          uiSpan;
 614 #endif
 615     struct chmUnitInfo          uiLzxc;
 616     struct chmLzxcControlData   ctlData;
 617
 618     /* allocate handle */
 619     newHandle = (struct chmFile *)malloc(sizeof(struct chmFile));
 620     newHandle->fd = CHM_NULL_FD;
 621     newHandle->lzx_state = NULL;
 622     newHandle->cache_blocks = NULL;
 623     newHandle->cache_block_indices = NULL;
 624     newHandle->cache_num_blocks = 0;
 625
 626     /* open file */
 627     if ((newHandle->fd=CreateFileW(filename,
 628                                    GENERIC_READ,
 629                                    FILE_SHARE_READ,
 630                                    NULL,
 631                                    OPEN_EXISTING,
 632                                    FILE_ATTRIBUTE_NORMAL,
 633                                    NULL)) == CHM_NULL_FD)
 634     {
 635         free(newHandle);
 636         return NULL;
 637     }
 638
 639     /* initialize mutexes, if needed */
 640     InitializeCriticalSection(&newHandle->mutex);
 641     InitializeCriticalSection(&newHandle->lzx_mutex);
 642     InitializeCriticalSection(&newHandle->cache_mutex);
 643
 644     /* read and verify header */
 645     sremain = _CHM_ITSF_V3_LEN;
 646     sbufpos = sbuffer;
 647     if (_chm_fetch_bytes(newHandle, sbuffer, (UInt64)0, sremain) != sremain    ||
 648         !_unmarshal_itsf_header(&sbufpos, &sremain, &itsfHeader))
 649     {
 650         chm_close(newHandle);
 651         return NULL;
 652     }
 653
 654     /* stash important values from header */
 655     newHandle->dir_offset  = itsfHeader.dir_offset;
 656     newHandle->dir_len     = itsfHeader.dir_len;
 657     newHandle->data_offset = itsfHeader.data_offset;
 658
 659     /* now, read and verify the directory header chunk */
 660     sremain = _CHM_ITSP_V1_LEN;
 661     sbufpos = sbuffer;
 662     if (_chm_fetch_bytes(newHandle, sbuffer,
 663                          (UInt64)itsfHeader.dir_offset, sremain) != sremain       ||
 664         !_unmarshal_itsp_header(&sbufpos, &sremain, &itspHeader))
 665     {
 666         chm_close(newHandle);
 667         return NULL;
 668     }
 669
 670     /* grab essential information from ITSP header */
 671     newHandle->dir_offset += itspHeader.header_len;
 672     newHandle->dir_len    -= itspHeader.header_len;
 673     newHandle->index_root  = itspHeader.index_root;
 674     newHandle->index_head  = itspHeader.index_head;
 675     newHandle->block_len   = itspHeader.block_len;
 676
 677     /* if the index root is -1, this means we don't have any PMGI blocks.
 678      * as a result, we must use the sole PMGL block as the index root
 679      */
 680     if (newHandle->index_root == -1)
 681         newHandle->index_root = newHandle->index_head;
 682
 683     /* By default, compression is enabled. */
 684     newHandle->compression_enabled = 1;
 685
 686 /* Jed, Sun Jun 27: 'span' doesn't seem to be used anywhere?! */
 687 #if 0
 688     /* fetch span */
 689     if (CHM_RESOLVE_SUCCESS != chm_resolve_object(newHandle,
 690                                                   _CHMU_SPANINFO,
 691                                                   &uiSpan)                ||
 692         uiSpan.space == CHM_COMPRESSED)
 693     {
 694         chm_close(newHandle);
 695         return NULL;
 696     }
 697
 698     /* N.B.: we've already checked that uiSpan is in the uncompressed section,
 699      *       so this should not require attempting to decompress, which may
 700      *       rely on having a valid "span"
 701      */
 702     sremain = 8;
 703     sbufpos = sbuffer;
 704     if (chm_retrieve_object(newHandle, &uiSpan, sbuffer,
 705                             0, sremain) != sremain                        ||
 706         !_unmarshal_uint64(&sbufpos, &sremain, &newHandle->span))
 707     {
 708         chm_close(newHandle);
 709         return NULL;
 710     }
 711 #endif
 712
 713     /* prefetch most commonly needed unit infos */
 714     if (CHM_RESOLVE_SUCCESS != chm_resolve_object(newHandle,
 715                                                   _CHMU_RESET_TABLE,
 716                                                   &newHandle->rt_unit)    ||
 717         newHandle->rt_unit.space == CHM_COMPRESSED                        ||
 718         CHM_RESOLVE_SUCCESS != chm_resolve_object(newHandle,
 719                                                   _CHMU_CONTENT,
 720                                                   &newHandle->cn_unit)    ||
 721         newHandle->cn_unit.space == CHM_COMPRESSED                        ||
 722         CHM_RESOLVE_SUCCESS != chm_resolve_object(newHandle,
 723                                                   _CHMU_LZXC_CONTROLDATA,
 724                                                   &uiLzxc)                ||
 725         uiLzxc.space == CHM_COMPRESSED)
 726     {
 727         newHandle->compression_enabled = 0;
 728     }
 729
 730     /* read reset table info */
 731     if (newHandle->compression_enabled)
 732     {
 733         sremain = _CHM_LZXC_RESETTABLE_V1_LEN;
 734         sbufpos = sbuffer;
 735         if (chm_retrieve_object(newHandle, &newHandle->rt_unit, sbuffer,
 736                                 0, sremain) != sremain                        ||
 737             !_unmarshal_lzxc_reset_table(&sbufpos, &sremain,
 738                                          &newHandle->reset_table))
 739         {
 740             newHandle->compression_enabled = 0;
 741         }
 742     }
 743
 744     /* read control data */
 745     if (newHandle->compression_enabled)
 746     {
 747         sremain = (unsigned long)uiLzxc.length;
 748         sbufpos = sbuffer;
 749         if (chm_retrieve_object(newHandle, &uiLzxc, sbuffer,
 750                                 0, sremain) != sremain                       ||
 751             !_unmarshal_lzxc_control_data(&sbufpos, &sremain,
 752                                           &ctlData))
 753         {
 754             newHandle->compression_enabled = 0;
 755         }
 756
 757         newHandle->window_size = ctlData.windowSize;
 758         newHandle->reset_interval = ctlData.resetInterval;
 759
 760 /* Jed, Mon Jun 28: Experimentally, it appears that the reset block count */
 761 /*       must be multiplied by this formerly unknown ctrl data field in   */
 762 /*       order to decompress some files.                                  */
 763 #if 0
 764         newHandle->reset_blkcount = newHandle->reset_interval /
 765                     (newHandle->window_size / 2);
 766 #else
 767         newHandle->reset_blkcount = newHandle->reset_interval    /
 768                                     (newHandle->window_size / 2) *
 769                                     ctlData.windowsPerReset;
 770 #endif
 771     }
 772
 773     /* initialize cache */
 774     chm_set_param(newHandle, CHM_PARAM_MAX_BLOCKS_CACHED,
 775                   CHM_MAX_BLOCKS_CACHED);
 776
 777     return newHandle;
 778 }
 779
 780 /* close an ITS archive */
 781 void chm_close(struct chmFile *h)
 782 {
 783     if (h != NULL)
 784     {
 785         if (h->fd != CHM_NULL_FD)
 786             CHM_CLOSE_FILE(h->fd);
 787         h->fd = CHM_NULL_FD;
 788
 789         DeleteCriticalSection(&h->mutex);
 790         DeleteCriticalSection(&h->lzx_mutex);
 791         DeleteCriticalSection(&h->cache_mutex);
 792
 793         if (h->lzx_state)
 794             LZXteardown(h->lzx_state);
 795         h->lzx_state = NULL;
 796
 797         if (h->cache_blocks)
 798         {
 799             int i;
 800             for (i=0; i<h->cache_num_blocks; i++)
 801             {
 802                 if (h->cache_blocks[i])
 803                     free(h->cache_blocks[i]);
 804             }
 805             free(h->cache_blocks);
 806             h->cache_blocks = NULL;
 807         }
 808
 809         if (h->cache_block_indices)
 810             free(h->cache_block_indices);
 811         h->cache_block_indices = NULL;
 812
 813         free(h);
 814     }
 815 }
 816
 817 /*
 818  * set a parameter on the file handle.
 819  * valid parameter types:
 820  *          CHM_PARAM_MAX_BLOCKS_CACHED:
 821  *                 how many decompressed blocks should be cached?  A simple
 822  *                 caching scheme is used, wherein the index of the block is
 823  *                 used as a hash value, and hash collision results in the
 824  *                 invalidation of the previously cached block.
 825  */
 826 void chm_set_param(struct chmFile *h,
 827                    int paramType,
 828                    int paramVal)
 829 {
 830     switch (paramType)
 831     {
 832         case CHM_PARAM_MAX_BLOCKS_CACHED:
 833             CHM_ACQUIRE_LOCK(h->cache_mutex);
 834             if (paramVal != h->cache_num_blocks)
 835             {
 836                 UChar **newBlocks;
 837                 UInt64 *newIndices;
 838                 int     i;
 839
 840                 /* allocate new cached blocks */
 841                 newBlocks = (UChar **)malloc(paramVal * sizeof (UChar *));
 842                 newIndices = (UInt64 *)malloc(paramVal * sizeof (UInt64));
 843                 for (i=0; i<paramVal; i++)
 844                 {
 845                     newBlocks[i] = NULL;
 846                     newIndices[i] = 0;
 847                 }
 848
 849                 /* re-distribute old cached blocks */
 850                 if (h->cache_blocks)
 851                 {
 852                     for (i=0; i<h->cache_num_blocks; i++)
 853                     {
 854                         int newSlot = (int)(h->cache_block_indices[i] % paramVal);
 855
 856                         if (h->cache_blocks[i])
 857                         {
 858                             /* in case of collision, destroy newcomer */
 859                             if (newBlocks[newSlot])
 860                             {
 861                                 free(h->cache_blocks[i]);
 862                                 h->cache_blocks[i] = NULL;
 863                             }
 864                             else
 865                             {
 866                                 newBlocks[newSlot] = h->cache_blocks[i];
 867                                 newIndices[newSlot] =
 868                                             h->cache_block_indices[i];
 869                             }
 870                         }
 871                     }
 872
 873                     free(h->cache_blocks);
 874                     free(h->cache_block_indices);
 875                 }
 876
 877                 /* now, set new values */
 878                 h->cache_blocks = newBlocks;
 879                 h->cache_block_indices = newIndices;
 880                 h->cache_num_blocks = paramVal;
 881             }
 882             CHM_RELEASE_LOCK(h->cache_mutex);
 883             break;
 884
 885         default:
 886             break;
 887     }
 888 }
 889
 890 /*
 891  * helper methods for chm_resolve_object
 892  */
 893
 894 /* skip a compressed dword */
 895 static void _chm_skip_cword(UChar **pEntry)
 896 {
 897     while (*(*pEntry)++ >= 0x80)
 898         ;
 899 }
 900
 901 /* skip the data from a PMGL entry */
 902 static void _chm_skip_PMGL_entry_data(UChar **pEntry)
 903 {
 904     _chm_skip_cword(pEntry);
 905     _chm_skip_cword(pEntry);
 906     _chm_skip_cword(pEntry);
 907 }
 908
 909 /* parse a compressed dword */
 910 static UInt64 _chm_parse_cword(UChar **pEntry)
 911 {
 912     UInt64 accum = 0;
 913     UChar temp;
 914     while ((temp=*(*pEntry)++) >= 0x80)
 915     {
 916         accum <<= 7;
 917         accum += temp & 0x7f;
 918     }
 919
 920     return (accum << 7) + temp;
 921 }
 922
 923 /* parse a utf-8 string into an ASCII char buffer */
 924 static int _chm_parse_UTF8(UChar **pEntry, UInt64 count, WCHAR *path)
 925 {
 926     /* MJM - Modified to return real Unicode strings */
 927     while (count != 0)
 928     {
 929         *path++ = (*(*pEntry)++);
 930         --count;
 931     }
 932
 933     *path = '\0';
 934     return 1;
 935 }
 936
 937 /* parse a PMGL entry into a chmUnitInfo struct; return 1 on success. */
 938 static int _chm_parse_PMGL_entry(UChar **pEntry, struct chmUnitInfo *ui)
 939 {
 940     UInt64 strLen;
 941
 942     /* parse str len */
 943     strLen = _chm_parse_cword(pEntry);
 944     if (strLen > CHM_MAX_PATHLEN)
 945         return 0;
 946
 947     /* parse path */
 948     if (! _chm_parse_UTF8(pEntry, strLen, ui->path))
 949         return 0;
 950
 951     /* parse info */
 952     ui->space  = (int)_chm_parse_cword(pEntry);
 953     ui->start  = _chm_parse_cword(pEntry);
 954     ui->length = _chm_parse_cword(pEntry);
 955     return 1;
 956 }
 957
 958 /* find an exact entry in PMGL; return NULL if we fail */
 959 static UChar *_chm_find_in_PMGL(UChar *page_buf,
 960                          UInt32 block_len,
 961                          const WCHAR *objPath)
 962 {
 963     /* XXX: modify this to do a binary search using the nice index structure
 964      *      that is provided for us.
 965      */
 966     struct chmPmglHeader header;
 967     UInt32 hremain;
 968     UChar *end;
 969     UChar *cur;
 970     UChar *temp;
 971     UInt64 strLen;
 972     WCHAR buffer[CHM_MAX_PATHLEN+1];
 973
 974     /* figure out where to start and end */
 975     cur = page_buf;
 976     hremain = _CHM_PMGL_LEN;
 977     if (! _unmarshal_pmgl_header(&cur, &hremain, &header))
 978         return NULL;
 979     end = page_buf + block_len - (header.free_space);
 980
 981     /* now, scan progressively */
 982     while (cur < end)
 983     {
 984         /* grab the name */
 985         temp = cur;
 986         strLen = _chm_parse_cword(&cur);
 987         if (! _chm_parse_UTF8(&cur, strLen, buffer))
 988             return NULL;
 989
 990         /* check if it is the right name */
 991         if (! strcmpiW(buffer, objPath))
 992             return temp;
 993
 994         _chm_skip_PMGL_entry_data(&cur);
 995     }
 996
 997     return NULL;
 998 }
 999
1000 /* find which block should be searched next for the entry; -1 if no block */
1001 static Int32 _chm_find_in_PMGI(UChar *page_buf,
1002                         UInt32 block_len,
1003                         const WCHAR *objPath)
1004 {
1005     /* XXX: modify this to do a binary search using the nice index structure
1006      *      that is provided for us
1007      */
1008     struct chmPmgiHeader header;
1009     UInt32 hremain;
1010     int page=-1;
1011     UChar *end;
1012     UChar *cur;
1013     UInt64 strLen;
1014     WCHAR buffer[CHM_MAX_PATHLEN+1];
1015
1016     /* figure out where to start and end */
1017     cur = page_buf;
1018     hremain = _CHM_PMGI_LEN;
1019     if (! _unmarshal_pmgi_header(&cur, &hremain, &header))
1020         return -1;
1021     end = page_buf + block_len - (header.free_space);
1022
1023     /* now, scan progressively */
1024     while (cur < end)
1025     {
1026         /* grab the name */
1027         strLen = _chm_parse_cword(&cur);
1028         if (! _chm_parse_UTF8(&cur, strLen, buffer))
1029             return -1;
1030
1031         /* check if it is the right name */
1032         if (strcmpiW(buffer, objPath) > 0)
1033             return page;
1034
1035         /* load next value for path */
1036         page = (int)_chm_parse_cword(&cur);
1037     }
1038
1039     return page;
1040 }
1041
1042 /* resolve a particular object from the archive */
1043 int chm_resolve_object(struct chmFile *h,
1044                        const WCHAR *objPath,
1045                        struct chmUnitInfo *ui)
1046 {
1047     /*
1048      * XXX: implement caching scheme for dir pages
1049      */
1050
1051     Int32 curPage;
1052
1053     /* buffer to hold whatever page we're looking at */
1054     UChar *page_buf = HeapAlloc(GetProcessHeap(), 0, h->block_len);
1055
1056     /* starting page */
1057     curPage = h->index_root;
1058
1059     /* until we have either returned or given up */
1060     while (curPage != -1)
1061     {
1062
1063         /* try to fetch the index page */
1064         if (_chm_fetch_bytes(h, page_buf,
1065                              (UInt64)h->dir_offset + (UInt64)curPage*h->block_len,
1066                              h->block_len) != h->block_len)
1067         {
1068             HeapFree(GetProcessHeap(), 0, page_buf);
1069             return CHM_RESOLVE_FAILURE;
1070         }
1071
1072         /* now, if it is a leaf node: */
1073         if (memcmp(page_buf, _chm_pmgl_marker, 4) == 0)
1074         {
1075             /* scan block */
1076             UChar *pEntry = _chm_find_in_PMGL(page_buf,
1077                                               h->block_len,
1078                                               objPath);
1079             if (pEntry == NULL)
1080             {
1081                 HeapFree(GetProcessHeap(), 0, page_buf);
1082                 return CHM_RESOLVE_FAILURE;
1083             }
1084
1085             /* parse entry and return */
1086             _chm_parse_PMGL_entry(&pEntry, ui);
1087             HeapFree(GetProcessHeap(), 0, page_buf);
1088             return CHM_RESOLVE_SUCCESS;
1089         }
1090
1091         /* else, if it is a branch node: */
1092         else if (memcmp(page_buf, _chm_pmgi_marker, 4) == 0)
1093             curPage = _chm_find_in_PMGI(page_buf, h->block_len, objPath);
1094
1095         /* else, we are confused.  give up. */
1096         else
1097         {
1098             HeapFree(GetProcessHeap(), 0, page_buf);
1099             return CHM_RESOLVE_FAILURE;
1100         }
1101     }
1102
1103     /* didn't find anything.  fail. */
1104     HeapFree(GetProcessHeap(), 0, page_buf);
1105     return CHM_RESOLVE_FAILURE;
1106 }
1107
1108 /*
1109  * utility methods for dealing with compressed data
1110  */
1111
1112 /* get the bounds of a compressed block.  return 0 on failure */
1113 static int _chm_get_cmpblock_bounds(struct chmFile *h,
1114                              UInt64 block,
1115                              UInt64 *start,
1116                              Int64 *len)
1117 {
1118     UChar buffer[8], *dummy;
1119     UInt32 remain;
1120
1121     /* for all but the last block, use the reset table */
1122     if (block < h->reset_table.block_count-1)
1123     {
1124         /* unpack the start address */
1125         dummy = buffer;
1126         remain = 8;
1127         if (_chm_fetch_bytes(h, buffer,
1128                              (UInt64)h->data_offset
1129                                 + (UInt64)h->rt_unit.start
1130                                 + (UInt64)h->reset_table.table_offset
1131                                 + (UInt64)block*8,
1132                              remain) != remain                            ||
1133             !_unmarshal_uint64(&dummy, &remain, start))
1134             return 0;
1135
1136         /* unpack the end address */
1137         dummy = buffer;
1138         remain = 8;
1139         if (_chm_fetch_bytes(h, buffer,
1140                          (UInt64)h->data_offset
1141                                 + (UInt64)h->rt_unit.start
1142                                 + (UInt64)h->reset_table.table_offset
1143                                 + (UInt64)block*8 + 8,
1144                          remain) != remain                                ||
1145             !_unmarshal_int64(&dummy, &remain, len))
1146             return 0;
1147     }
1148
1149     /* for the last block, use the span in addition to the reset table */
1150     else
1151     {
1152         /* unpack the start address */
1153         dummy = buffer;
1154         remain = 8;
1155         if (_chm_fetch_bytes(h, buffer,
1156                              (UInt64)h->data_offset
1157                                 + (UInt64)h->rt_unit.start
1158                                 + (UInt64)h->reset_table.table_offset
1159                                 + (UInt64)block*8,
1160                              remain) != remain                            ||
1161             !_unmarshal_uint64(&dummy, &remain, start))
1162             return 0;
1163
1164         *len = h->reset_table.compressed_len;
1165     }
1166
1167     /* compute the length and absolute start address */
1168     *len -= *start;
1169     *start += h->data_offset + h->cn_unit.start;
1170
1171     return 1;
1172 }
1173
1174 /* decompress the block.  must have lzx_mutex. */
1175 static Int64 _chm_decompress_block(struct chmFile *h,
1176                                    UInt64 block,
1177                                    UChar **ubuffer)
1178 {
1179     UChar *cbuffer = HeapAlloc( GetProcessHeap(), 0,
1180                               ((unsigned int)h->reset_table.block_len + 6144));
1181     UInt64 cmpStart;                                    /* compressed start  */
1182     Int64 cmpLen;                                       /* compressed len    */
1183     int indexSlot;                                      /* cache index slot  */
1184     UChar *lbuffer;                                     /* local buffer ptr  */
1185     UInt32 blockAlign = (UInt32)(block % h->reset_blkcount); /* reset intvl. aln. */
1186     UInt32 i;                                           /* local loop index  */
1187
1188     /* let the caching system pull its weight! */
1189     if (block - blockAlign <= h->lzx_last_block  &&
1190         block              >= h->lzx_last_block)
1191         blockAlign = (block - h->lzx_last_block);
1192
1193     /* check if we need previous blocks */
1194     if (blockAlign != 0)
1195     {
1196         /* fetch all required previous blocks since last reset */
1197         for (i = blockAlign; i > 0; i--)
1198         {
1199             UInt32 curBlockIdx = block - i;
1200
1201             /* check if we most recently decompressed the previous block */
1202             if (h->lzx_last_block != curBlockIdx)
1203             {
1204                 if ((curBlockIdx % h->reset_blkcount) == 0)
1205                 {
1206 #ifdef CHM_DEBUG
1207                     fprintf(stderr, "***RESET (1)***\n");
1208 #endif
1209                     LZXreset(h->lzx_state);
1210                 }
1211
1212                 indexSlot = (int)((curBlockIdx) % h->cache_num_blocks);
1213                 h->cache_block_indices[indexSlot] = curBlockIdx;
1214                 if (! h->cache_blocks[indexSlot])
1215                     h->cache_blocks[indexSlot] = (UChar *)malloc(
1216                                                                  (unsigned int)(h->reset_table.block_len));
1217                 lbuffer = h->cache_blocks[indexSlot];
1218
1219                 /* decompress the previous block */
1220 #ifdef CHM_DEBUG
1221                 fprintf(stderr, "Decompressing block #%4d (EXTRA)\n", curBlockIdx);
1222 #endif
1223                 if (!_chm_get_cmpblock_bounds(h, curBlockIdx, &cmpStart, &cmpLen) ||
1224                     _chm_fetch_bytes(h, cbuffer, cmpStart, cmpLen) != cmpLen      ||
1225                     LZXdecompress(h->lzx_state, cbuffer, lbuffer, (int)cmpLen,
1226                                   (int)h->reset_table.block_len) != DECR_OK)
1227                 {
1228 #ifdef CHM_DEBUG
1229                     fprintf(stderr, "   (DECOMPRESS FAILED!)\n");
1230 #endif
1231                     HeapFree(GetProcessHeap(), 0, cbuffer);
1232                     return (Int64)0;
1233                 }
1234
1235                 h->lzx_last_block = (int)curBlockIdx;
1236             }
1237         }
1238     }
1239     else
1240     {
1241         if ((block % h->reset_blkcount) == 0)
1242         {
1243 #ifdef CHM_DEBUG
1244             fprintf(stderr, "***RESET (2)***\n");
1245 #endif
1246             LZXreset(h->lzx_state);
1247         }
1248     }
1249
1250     /* allocate slot in cache */
1251     indexSlot = (int)(block % h->cache_num_blocks);
1252     h->cache_block_indices[indexSlot] = block;
1253     if (! h->cache_blocks[indexSlot])
1254         h->cache_blocks[indexSlot] = (UChar *)malloc(
1255                                           ((unsigned int)h->reset_table.block_len));
1256     lbuffer = h->cache_blocks[indexSlot];
1257     *ubuffer = lbuffer;
1258
1259     /* decompress the block we actually want */
1260 #ifdef CHM_DEBUG
1261     fprintf(stderr, "Decompressing block #%4d (REAL )\n", block);
1262 #endif
1263     if (! _chm_get_cmpblock_bounds(h, block, &cmpStart, &cmpLen)          ||
1264         _chm_fetch_bytes(h, cbuffer, cmpStart, cmpLen) != cmpLen          ||
1265         LZXdecompress(h->lzx_state, cbuffer, lbuffer, (int)cmpLen,
1266                       (int)h->reset_table.block_len) != DECR_OK)
1267     {
1268 #ifdef CHM_DEBUG
1269         fprintf(stderr, "   (DECOMPRESS FAILED!)\n");
1270 #endif
1271         HeapFree(GetProcessHeap(), 0, cbuffer);
1272         return (Int64)0;
1273     }
1274     h->lzx_last_block = (int)block;
1275
1276     /* XXX: modify LZX routines to return the length of the data they
1277      * decompressed and return that instead, for an extra sanity check.
1278      */
1279     HeapFree(GetProcessHeap(), 0, cbuffer);
1280     return h->reset_table.block_len;
1281 }
1282
1283 /* grab a region from a compressed block */
1284 static Int64 _chm_decompress_region(struct chmFile *h,
1285                                     UChar *buf,
1286                                     UInt64 start,
1287                                     Int64 len)
1288 {
1289     UInt64 nBlock, nOffset;
1290     UInt64 nLen;
1291     UInt64 gotLen;
1292     UChar *ubuffer;
1293
1294         if (len <= 0)
1295                 return (Int64)0;
1296
1297     /* figure out what we need to read */
1298     nBlock = start / h->reset_table.block_len;
1299     nOffset = start % h->reset_table.block_len;
1300     nLen = len;
1301     if (nLen > (h->reset_table.block_len - nOffset))
1302         nLen = h->reset_table.block_len - nOffset;
1303
1304     /* if block is cached, return data from it. */
1305     CHM_ACQUIRE_LOCK(h->lzx_mutex);
1306     CHM_ACQUIRE_LOCK(h->cache_mutex);
1307     if (h->cache_block_indices[nBlock % h->cache_num_blocks] == nBlock    &&
1308         h->cache_blocks[nBlock % h->cache_num_blocks] != NULL)
1309     {
1310         memcpy(buf,
1311                h->cache_blocks[nBlock % h->cache_num_blocks] + nOffset,
1312                (unsigned int)nLen);
1313         CHM_RELEASE_LOCK(h->cache_mutex);
1314         CHM_RELEASE_LOCK(h->lzx_mutex);
1315         return nLen;
1316     }
1317     CHM_RELEASE_LOCK(h->cache_mutex);
1318
1319     /* data request not satisfied, so... start up the decompressor machine */
1320     if (! h->lzx_state)
1321     {
1322         int window_size = ffs(h->window_size) - 1;
1323         h->lzx_last_block = -1;
1324         h->lzx_state = LZXinit(window_size);
1325     }
1326
1327     /* decompress some data */
1328     gotLen = _chm_decompress_block(h, nBlock, &ubuffer);
1329     if (gotLen < nLen)
1330         nLen = gotLen;
1331     memcpy(buf, ubuffer+nOffset, (unsigned int)nLen);
1332     CHM_RELEASE_LOCK(h->lzx_mutex);
1333     return nLen;
1334 }
1335
1336 /* retrieve (part of) an object */
1337 LONGINT64 chm_retrieve_object(struct chmFile *h,
1338                                struct chmUnitInfo *ui,
1339                                unsigned char *buf,
1340                                LONGUINT64 addr,
1341                                LONGINT64 len)
1342 {
1343     /* must be valid file handle */
1344     if (h == NULL)
1345         return (Int64)0;
1346
1347     /* starting address must be in correct range */
1348     if (addr < 0  ||  addr >= ui->length)
1349         return (Int64)0;
1350
1351     /* clip length */
1352     if (addr + len > ui->length)
1353         len = ui->length - addr;
1354
1355     /* if the file is uncompressed, it's simple */
1356     if (ui->space == CHM_UNCOMPRESSED)
1357     {
1358         /* read data */
1359         return _chm_fetch_bytes(h,
1360                                 buf,
1361                                 (UInt64)h->data_offset + (UInt64)ui->start + (UInt64)addr,
1362                                 len);
1363     }
1364
1365     /* else if the file is compressed, it's a little trickier */
1366     else /* ui->space == CHM_COMPRESSED */
1367     {
1368         Int64 swath=0, total=0;
1369
1370         /* if compression is not enabled for this file... */
1371         if (! h->compression_enabled)
1372             return total;
1373
1374         do {
1375
1376             /* swill another mouthful */
1377             swath = _chm_decompress_region(h, buf, ui->start + addr, len);
1378
1379             /* if we didn't get any... */
1380             if (swath == 0)
1381                 return total;
1382
1383             /* update stats */
1384             total += swath;
1385             len -= swath;
1386             addr += swath;
1387             buf += swath;
1388
1389         } while (len != 0);
1390
1391         return total;
1392     }
1393 }
1394
1395 /* enumerate the objects in the .chm archive */
1396 int chm_enumerate(struct chmFile *h,
1397                   int what,
1398                   CHM_ENUMERATOR e,
1399                   void *context)
1400 {
1401     Int32 curPage;
1402
1403     /* buffer to hold whatever page we're looking at */
1404     UChar *page_buf = HeapAlloc(GetProcessHeap(), 0, (unsigned int)h->block_len);
1405     struct chmPmglHeader header;
1406     UChar *end;
1407     UChar *cur;
1408     unsigned long lenRemain;
1409     UInt64 ui_path_len;
1410
1411     /* the current ui */
1412     struct chmUnitInfo ui;
1413     int flag;
1414
1415     /* starting page */
1416     curPage = h->index_head;
1417
1418     /* until we have either returned or given up */
1419     while (curPage != -1)
1420     {
1421
1422         /* try to fetch the index page */
1423         if (_chm_fetch_bytes(h,
1424                              page_buf,
1425                              (UInt64)h->dir_offset + (UInt64)curPage*h->block_len,
1426                              h->block_len) != h->block_len)
1427         {
1428             HeapFree(GetProcessHeap(), 0, page_buf);
1429             return 0;
1430         }
1431
1432         /* figure out start and end for this page */
1433         cur = page_buf;
1434         lenRemain = _CHM_PMGL_LEN;
1435         if (! _unmarshal_pmgl_header(&cur, &lenRemain, &header))
1436         {
1437             HeapFree(GetProcessHeap(), 0, page_buf);
1438             return 0;
1439         }
1440         end = page_buf + h->block_len - (header.free_space);
1441
1442         /* loop over this page */
1443         while (cur < end)
1444         {
1445             if (! _chm_parse_PMGL_entry(&cur, &ui))
1446             {
1447                 HeapFree(GetProcessHeap(), 0, page_buf);
1448                 return 0;
1449             }
1450
1451             /* get the length of the path */
1452             ui_path_len = strlenW(ui.path)-1;
1453
1454             /* check for DIRS */
1455             if (ui.path[ui_path_len] == '/'  &&  !(what & CHM_ENUMERATE_DIRS))
1456                 continue;
1457
1458             /* check for FILES */
1459             if (ui.path[ui_path_len] != '/'  &&  !(what & CHM_ENUMERATE_FILES))
1460                 continue;
1461
1462             /* check for NORMAL vs. META */
1463             if (ui.path[0] == '/')
1464             {
1465
1466                 /* check for NORMAL vs. SPECIAL */
1467                 if (ui.path[1] == '#'  ||  ui.path[1] == '$')
1468                     flag = CHM_ENUMERATE_SPECIAL;
1469                 else
1470                     flag = CHM_ENUMERATE_NORMAL;
1471             }
1472             else
1473                 flag = CHM_ENUMERATE_META;
1474             if (! (what & flag))
1475                 continue;
1476
1477             /* call the enumerator */
1478             {
1479                 int status = (*e)(h, &ui, context);
1480                 switch (status)
1481                 {
1482                     case CHM_ENUMERATOR_FAILURE:
1483                         HeapFree(GetProcessHeap(), 0, page_buf);
1484                         return 0;
1485                     case CHM_ENUMERATOR_CONTINUE:
1486                         break;
1487                     case CHM_ENUMERATOR_SUCCESS:
1488                         HeapFree(GetProcessHeap(), 0, page_buf);
1489                         return 1;
1490                     default:
1491                         break;
1492                 }
1493             }
1494         }
1495
1496         /* advance to next page */
1497         curPage = header.block_next;
1498     }
1499
1500     HeapFree(GetProcessHeap(), 0, page_buf);
1501     return 1;
1502 }
1503
1504 int chm_enumerate_dir(struct chmFile *h,
1505                       const WCHAR *prefix,
1506                       int what,
1507                       CHM_ENUMERATOR e,
1508                       void *context)
1509 {
1510     /*
1511      * XXX: do this efficiently (i.e. using the tree index)
1512      */
1513
1514     Int32 curPage;
1515
1516     /* buffer to hold whatever page we're looking at */
1517     UChar *page_buf = HeapAlloc(GetProcessHeap(), 0, (unsigned int)h->block_len);
1518     struct chmPmglHeader header;
1519     UChar *end;
1520     UChar *cur;
1521     unsigned long lenRemain;
1522
1523     /* set to 1 once we've started */
1524     int it_has_begun=0;
1525
1526     /* the current ui */
1527     struct chmUnitInfo ui;
1528     int flag;
1529     UInt64 ui_path_len;
1530
1531     /* the length of the prefix */
1532     WCHAR prefixRectified[CHM_MAX_PATHLEN+1];
1533     int prefixLen;
1534     WCHAR lastPath[CHM_MAX_PATHLEN];
1535     int lastPathLen;
1536
1537     /* starting page */
1538     curPage = h->index_head;
1539
1540     /* initialize pathname state */
1541     strncpyW(prefixRectified, prefix, CHM_MAX_PATHLEN);
1542     prefixLen = strlenW(prefixRectified);
1543     if (prefixLen != 0)
1544     {
1545         if (prefixRectified[prefixLen-1] != '/')
1546         {
1547             prefixRectified[prefixLen] = '/';
1548             prefixRectified[prefixLen+1] = '\0';
1549             ++prefixLen;
1550         }
1551     }
1552     lastPath[0] = '\0';
1553     lastPathLen = -1;
1554
1555     /* until we have either returned or given up */
1556     while (curPage != -1)
1557     {
1558
1559         /* try to fetch the index page */
1560         if (_chm_fetch_bytes(h,
1561                              page_buf,
1562                              (UInt64)h->dir_offset + (UInt64)curPage*h->block_len,
1563                              h->block_len) != h->block_len)
1564         {
1565             HeapFree(GetProcessHeap(), 0, page_buf);
1566             return 0;
1567         }
1568
1569         /* figure out start and end for this page */
1570         cur = page_buf;
1571         lenRemain = _CHM_PMGL_LEN;
1572         if (! _unmarshal_pmgl_header(&cur, &lenRemain, &header))
1573         {
1574             HeapFree(GetProcessHeap(), 0, page_buf);
1575             return 0;
1576         }
1577         end = page_buf + h->block_len - (header.free_space);
1578
1579         /* loop over this page */
1580         while (cur < end)
1581         {
1582             if (! _chm_parse_PMGL_entry(&cur, &ui))
1583             {
1584                 HeapFree(GetProcessHeap(), 0, page_buf);
1585                 return 0;
1586             }
1587
1588             /* check if we should start */
1589             if (! it_has_begun)
1590             {
1591                 if (ui.length == 0  &&  strncmpiW(ui.path, prefixRectified, prefixLen) == 0)
1592                     it_has_begun = 1;
1593                 else
1594                     continue;
1595
1596                 if (ui.path[prefixLen] == '\0')
1597                     continue;
1598             }
1599
1600             /* check if we should stop */
1601             else
1602             {
1603                 if (strncmpiW(ui.path, prefixRectified, prefixLen) != 0)
1604                 {
1605                     HeapFree(GetProcessHeap(), 0, page_buf);
1606                     return 1;
1607                 }
1608             }
1609
1610             /* check if we should include this path */
1611             if (lastPathLen != -1)
1612             {
1613                 if (strncmpiW(ui.path, lastPath, lastPathLen) == 0)
1614                     continue;
1615             }
1616             strcpyW(lastPath, ui.path);
1617             lastPathLen = strlenW(lastPath);
1618
1619             /* get the length of the path */
1620             ui_path_len = strlenW(ui.path)-1;
1621
1622             /* check for DIRS */
1623             if (ui.path[ui_path_len] == '/'  &&  !(what & CHM_ENUMERATE_DIRS))
1624                 continue;
1625
1626             /* check for FILES */
1627             if (ui.path[ui_path_len] != '/'  &&  !(what & CHM_ENUMERATE_FILES))
1628                 continue;
1629
1630             /* check for NORMAL vs. META */
1631             if (ui.path[0] == '/')
1632             {
1633
1634                 /* check for NORMAL vs. SPECIAL */
1635                 if (ui.path[1] == '#'  ||  ui.path[1] == '$')
1636                     flag = CHM_ENUMERATE_SPECIAL;
1637                 else
1638                     flag = CHM_ENUMERATE_NORMAL;
1639             }
1640             else
1641                 flag = CHM_ENUMERATE_META;
1642             if (! (what & flag))
1643                 continue;
1644
1645             /* call the enumerator */
1646             {
1647                 int status = (*e)(h, &ui, context);
1648                 switch (status)
1649                 {
1650                     case CHM_ENUMERATOR_FAILURE:
1651                         HeapFree(GetProcessHeap(), 0, page_buf);
1652                         return 0;
1653                     case CHM_ENUMERATOR_CONTINUE:
1654                         break;
1655                     case CHM_ENUMERATOR_SUCCESS:
1656                         HeapFree(GetProcessHeap(), 0, page_buf);
1657                         return 1;
1658                     default:
1659                         break;
1660                 }
1661             }
1662         }
1663
1664         /* advance to next page */
1665         curPage = header.block_next;
1666     }
1667
1668     HeapFree(GetProcessHeap(), 0, page_buf);
1669     return 1;
1670 }