1 /* |
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2 * HOG support routines for PhysicsFS. |
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3 * |
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4 * This driver handles Descent I/II HOG archives. |
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5 * |
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6 * The format is very simple: |
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7 * |
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8 * The file always starts with the 3-byte signature "DHF" (Descent |
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9 * HOG file). After that the files of a HOG are just attached after |
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10 * another, divided by a 17 bytes header, which specifies the name |
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11 * and length (in bytes) of the forthcoming file! So you just read |
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12 * the header with its information of how big the following file is, |
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13 * and then skip exact that number of bytes to get to the next file |
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14 * in that HOG. |
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15 * |
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16 * char sig[3] = {'D', 'H', 'F'}; // "DHF"=Descent HOG File |
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17 * |
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18 * struct { |
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19 * char file_name[13]; // Filename, padded to 13 bytes with 0s |
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20 * int file_size; // filesize in bytes |
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21 * char data[file_size]; // The file data |
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22 * } FILE_STRUCT; // Repeated until the end of the file. |
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23 * |
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24 * (That info is from http://www.descent2.com/ddn/specs/hog/) |
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25 * |
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26 * Please see the file LICENSE.txt in the source's root directory. |
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27 * |
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28 * This file written by Bradley Bell. |
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29 * Based on grp.c by Ryan C. Gordon. |
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30 */ |
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31 |
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32 #define __PHYSICSFS_INTERNAL__ |
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33 #include "physfs_internal.h" |
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34 |
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35 #if PHYSFS_SUPPORTS_HOG |
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36 |
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37 static UNPKentry *hogLoadEntries(PHYSFS_Io *io, PHYSFS_uint32 *_entCount) |
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38 { |
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39 const PHYSFS_uint64 iolen = io->length(io); |
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40 PHYSFS_uint32 entCount = 0; |
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41 void *ptr = NULL; |
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42 UNPKentry *entries = NULL; |
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43 UNPKentry *entry = NULL; |
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44 PHYSFS_uint32 size = 0; |
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45 PHYSFS_uint32 pos = 3; |
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46 |
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47 while (pos < iolen) |
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48 { |
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49 entCount++; |
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50 ptr = allocator.Realloc(ptr, sizeof (UNPKentry) * entCount); |
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51 GOTO_IF_MACRO(ptr == NULL, PHYSFS_ERR_OUT_OF_MEMORY, failed); |
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52 entries = (UNPKentry *) ptr; |
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53 entry = &entries[entCount-1]; |
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54 |
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55 GOTO_IF_MACRO(!__PHYSFS_readAll(io, &entry->name, 13), ERRPASS, failed); |
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56 pos += 13; |
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57 GOTO_IF_MACRO(!__PHYSFS_readAll(io, &size, 4), ERRPASS, failed); |
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58 pos += 4; |
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59 |
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60 entry->size = PHYSFS_swapULE32(size); |
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61 entry->startPos = pos; |
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62 pos += size; |
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63 |
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64 /* skip over entry */ |
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65 GOTO_IF_MACRO(!io->seek(io, pos), ERRPASS, failed); |
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66 } /* while */ |
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67 |
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68 *_entCount = entCount; |
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69 return entries; |
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70 |
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71 failed: |
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72 allocator.Free(entries); |
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73 return NULL; |
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74 } /* hogLoadEntries */ |
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75 |
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76 |
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77 static void *HOG_openArchive(PHYSFS_Io *io, const char *name, int forWriting) |
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78 { |
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79 PHYSFS_uint8 buf[3]; |
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80 PHYSFS_uint32 count = 0; |
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81 UNPKentry *entries = NULL; |
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82 |
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83 assert(io != NULL); /* shouldn't ever happen. */ |
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84 BAIL_IF_MACRO(forWriting, PHYSFS_ERR_READ_ONLY, NULL); |
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85 BAIL_IF_MACRO(!__PHYSFS_readAll(io, buf, 3), ERRPASS, NULL); |
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86 BAIL_IF_MACRO(memcmp(buf, "DHF", 3) != 0, PHYSFS_ERR_UNSUPPORTED, NULL); |
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87 |
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88 entries = hogLoadEntries(io, &count); |
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89 BAIL_IF_MACRO(!entries, ERRPASS, NULL); |
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90 return UNPK_openArchive(io, entries, count); |
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91 } /* HOG_openArchive */ |
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92 |
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93 |
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94 const PHYSFS_Archiver __PHYSFS_Archiver_HOG = |
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95 { |
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96 { |
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97 "HOG", |
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98 "Descent I/II HOG file format", |
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99 "Bradley Bell <btb@icculus.org>", |
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100 "http://icculus.org/physfs/", |
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101 }, |
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102 HOG_openArchive, /* openArchive() method */ |
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103 UNPK_enumerateFiles, /* enumerateFiles() method */ |
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104 UNPK_openRead, /* openRead() method */ |
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105 UNPK_openWrite, /* openWrite() method */ |
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106 UNPK_openAppend, /* openAppend() method */ |
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107 UNPK_remove, /* remove() method */ |
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108 UNPK_mkdir, /* mkdir() method */ |
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109 UNPK_closeArchive, /* closeArchive() method */ |
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110 UNPK_stat /* stat() method */ |
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111 }; |
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112 |
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113 #endif /* defined PHYSFS_SUPPORTS_HOG */ |
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114 |
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115 /* end of hog.c ... */ |
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116 |
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