src/common/wadres.c

   1 #include <stdint.h>
   2 #include <string.h>
   3 #include <stdlib.h>
   4 #include <assert.h>
   5
   6 #include "wadres.h"
   7 #include "streams.h"
   8 #include "cp866.h"
   9
  10 typedef struct Entry {
  11   long offset, size;
  12   char name[8];
  13   int f;
  14 } Entry;
  15
  16 typedef struct Block {
  17   int id;
  18   int ref;
  19   char data[];
  20 } Block;
  21
  22 static int n_wads;
  23 static int n_resources;
  24 static Stream *wads[MAX_WADS];
  25 static Entry resources[MAX_RESOURCES];
  26 static Block *blocks[MAX_RESOURCES];
  27
  28 static int check_header (Stream *r) {
  29   assert(r != NULL);
  30   char ident[4];
  31   stream_setpos(r, 0); // !!!
  32   stream_read(ident, 4, 1, r);
  33   return (memcmp(ident, "IWAD", 4) == 0) || (memcmp(ident, "PWAD", 4) == 0);
  34 }
  35
  36 int WADRES_addwad (Stream *r) {
  37   assert(r != NULL);
  38   if (n_wads < MAX_WADS && check_header(r)) {
  39     wads[n_wads] = r;
  40     n_wads += 1;
  41     return 1;
  42   } else {
  43     return 0;
  44   }
  45 }
  46
  47 static int WADRES_addresource (const Entry *e) {
  48   assert(e != NULL);
  49   for (int i = 0; i < n_resources; ++i) {
  50     if (cp866_strncasecmp(resources[i].name, e->name, 8) == 0) {
  51       memcpy(&resources[i], e, sizeof(Entry));
  52       return i;
  53     }
  54   }
  55   if (n_resources < MAX_RESOURCES) {
  56     memcpy(&resources[n_resources], e, sizeof(Entry));
  57     n_resources += 1;
  58     return n_resources - 1;
  59   }
  60   return -1;
  61 }
  62
  63 static int WADRES_read (int f) {
  64   Stream *r = wads[f];
  65   stream_setpos(r, 4); // skip magic
  66   int32_t n = stream_read32(r);
  67   int32_t dir = stream_read32(r);
  68   stream_setpos(r, dir);
  69   int ok = 1;
  70   for (int32_t i = 0; ok && i < n; ++i) {
  71     Entry e;
  72     e.offset = stream_read32(r);
  73     e.size = stream_read32(r);
  74     e.f = f;
  75     stream_read(e.name, 8, 1, r);
  76     ok = WADRES_addresource(&e) != -1;
  77   }
  78   return ok;
  79 }
  80
  81 int WADRES_rehash (void) {
  82   int ok = 1;
  83   for (int i = 0; i < n_wads; ++i) {
  84     if (!WADRES_read(i)) {
  85       ok = 0;
  86     }
  87   }
  88   return ok;
  89 }
  90
  91 int WADRES_find (const char name[8]) {
  92   int i = n_resources - 1;
  93   while (i >= 0 && cp866_strncasecmp(name, resources[i].name, 8) != 0) {
  94     i -= 1;
  95   }
  96   return i;
  97 }
  98
  99 int WADRES_maxids (void) {
 100   return n_resources;
 101 }
 102
 103 Stream *WADRES_getbasereader (int id) {
 104   assert(id >= 0 && id < n_resources);
 105   return wads[resources[id].f];
 106 }
 107
 108 long WADRES_getoffset (int id) {
 109   assert(id >= 0 && id < n_resources);
 110   return resources[id].offset;
 111 }
 112
 113 long WADRES_getsize (int id) {
 114   assert(id >= 0 && id < n_resources);
 115   return resources[id].size;
 116 }
 117
 118 void WADRES_getname (int id, char *name) {
 119   assert(id >= 0 && id < n_resources);
 120   strncpy(name, resources[id].name, 8);
 121 }
 122
 123 void WADRES_getdata (int id, void *data) {
 124   assert(id >= 0 && id < n_resources);
 125   Stream *r = wads[resources[id].f];
 126   long pos = stream_getpos(r);
 127   stream_setpos(r, resources[id].offset);
 128   stream_read(data, resources[id].size, 1, r);
 129   stream_setpos(r, pos);
 130 }
 131
 132 void *WADRES_lock (int id) {
 133   assert(id >= -1 && id < MAX_RESOURCES);
 134   if (id >= 0) {
 135     Block *x = blocks[id];
 136     if (x) {
 137       x->ref += 1;
 138       return x->data;
 139     } else {
 140       x = malloc(sizeof(Block) + WADRES_getsize(id));
 141       if (x) {
 142         x->id = id;
 143         x->ref = 1;
 144         WADRES_getdata(id, x->data);
 145         blocks[id] = x;
 146         return x->data;
 147       }
 148     }
 149   }
 150   return NULL;
 151 }
 152
 153 void WADRES_unlock (void *data) {
 154   if (data) {
 155     Block *x = data - sizeof(Block);
 156     int id = x->id;
 157     assert(id >= 0 && id < MAX_RESOURCES);
 158     x->ref -= 1;
 159     assert(x->ref >= 0);
 160 #if 0
 161     if (x->ref == 0) {
 162       blocks[id] = NULL;
 163       free(x);
 164     }
 165 #endif
 166   }
 167 }
 168
 169 int WADRES_locked (int id) {
 170   assert(id >= -1 && id < MAX_RESOURCES);
 171   return (id >= 0) && (blocks[id] != NULL) && (blocks[id]->ref >= 1);
 172 }
 173
 174 int WADRES_was_locked (int id) {
 175   assert(id >= -1 && id < MAX_RESOURCES);
 176   return (id >= 0) && (blocks[id] != NULL) && (blocks[id]->ref >= 0);
 177 }