1 /*

     2  * GRP support routines for PhysicsFS.

     3  *

     4  * This driver handles BUILD engine archives ("groupfiles"). This format

     5  *  (but not this driver) was put together by Ken Silverman.

     6  *

     7  * The format is simple enough. In Ken's words:

     8  *

     9  *    What's the .GRP file format?

    10  *

    11  *     The ".grp" file format is just a collection of a lot of files stored

    12  *     into 1 big one. I tried to make the format as simple as possible: The

    13  *     first 12 bytes contains my name, "KenSilverman". The next 4 bytes is

    14  *     the number of files that were compacted into the group file. Then for

    15  *     each file, there is a 16 byte structure, where the first 12 bytes are

    16  *     the filename, and the last 4 bytes are the file's size. The rest of

    17  *     the group file is just the raw data packed one after the other in the

    18  *     same order as the list of files.

    19  *

    20  * (That info is from http://www.advsys.net/ken/build.htm ...)

    21  *

    22  * Please see the file LICENSE.txt in the source's root directory.

    23  *

    24  *  This file written by Ryan C. Gordon.

    25  */

    26 

    27 #define __PHYSICSFS_INTERNAL__

    28 #include "physfs_internal.h"

    29 

    30 #if PHYSFS_SUPPORTS_GRP

    31 

    32 static UNPKentry *grpLoadEntries(PHYSFS_Io *io, PHYSFS_uint32 fileCount)

    33 {

    34     PHYSFS_uint32 location = 16;  /* sizeof sig. */

    35     UNPKentry *entries = NULL;

    36     UNPKentry *entry = NULL;

    37     char *ptr = NULL;

    38 

    39     entries = (UNPKentry *) allocator.Malloc(sizeof (UNPKentry) * fileCount);

    40     BAIL_IF_MACRO(entries == NULL, PHYSFS_ERR_OUT_OF_MEMORY, NULL);

    41 

    42     location += (16 * fileCount);

    43 

    44     for (entry = entries; fileCount > 0; fileCount--, entry++)

    45     {

    46         GOTO_IF_MACRO(!__PHYSFS_readAll(io, &entry->name, 12), ERRPASS, failed);

    47         GOTO_IF_MACRO(!__PHYSFS_readAll(io, &entry->size, 4), ERRPASS, failed);

    48         entry->name[12] = '\0';  /* name isn't null-terminated in file. */

    49         if ((ptr = strchr(entry->name, ' ')) != NULL)

    50             *ptr = '\0';  /* trim extra spaces. */

    51 

    52         entry->size = PHYSFS_swapULE32(entry->size);

    53         entry->startPos = location;

    54         location += entry->size;

    55     } /* for */

    56 

    57     return entries;

    58 

    59 failed:

    60     allocator.Free(entries);

    61     return NULL;

    62 } /* grpLoadEntries */

    63 

    64 

    65 static void *GRP_openArchive(PHYSFS_Io *io, const char *name, int forWriting)

    66 {

    67     PHYSFS_uint8 buf[12];

    68     PHYSFS_uint32 count = 0;

    69     UNPKentry *entries = NULL;

    70 

    71     assert(io != NULL);  /* shouldn't ever happen. */

    72 

    73     BAIL_IF_MACRO(forWriting, PHYSFS_ERR_READ_ONLY, NULL);

    74 

    75     BAIL_IF_MACRO(!__PHYSFS_readAll(io, buf, sizeof (buf)), ERRPASS, NULL);

    76     if (memcmp(buf, "KenSilverman", sizeof (buf)) != 0)

    77         BAIL_MACRO(PHYSFS_ERR_UNSUPPORTED, NULL);

    78 

    79     BAIL_IF_MACRO(!__PHYSFS_readAll(io, &count, sizeof(count)), ERRPASS, NULL);

    80     count = PHYSFS_swapULE32(count);

    81 

    82     entries = grpLoadEntries(io, count);

    83     BAIL_IF_MACRO(!entries, ERRPASS, NULL);

    84     return UNPK_openArchive(io, entries, count);

    85 } /* GRP_openArchive */

    86 

    87 

    88 const PHYSFS_Archiver __PHYSFS_Archiver_GRP =

    89 {

    90     {

    91         "GRP",

    92         "Build engine Groupfile format",

    93         "Ryan C. Gordon <icculus@icculus.org>",

    94         "http://icculus.org/physfs/",

    95     },

    96     GRP_openArchive,        /* openArchive() method    */

    97     UNPK_enumerateFiles,    /* enumerateFiles() method */

    98     UNPK_openRead,          /* openRead() method       */

    99     UNPK_openWrite,         /* openWrite() method      */

   100     UNPK_openAppend,        /* openAppend() method     */

   101     UNPK_remove,            /* remove() method         */

   102     UNPK_mkdir,             /* mkdir() method          */

   103     UNPK_closeArchive,      /* closeArchive() method   */

   104     UNPK_stat               /* stat() method           */

   105 };

   106 

   107 #endif  /* defined PHYSFS_SUPPORTS_GRP */

   108 

   109 /* end of grp.c ... */

   110