src/mesa/program/prog_cache.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28
  29 #include "main/glheader.h"
  30 #include "main/mtypes.h"
  31 #include "main/imports.h"
  32 #include "main/shaderobj.h"
  33 #include "program/prog_cache.h"
  34 #include "program/program.h"
  35
  36
  37 struct cache_item
  38 {
  39    GLuint hash;
  40    void *key;
  41    struct gl_program *program;
  42    struct cache_item *next;
  43 };
  44
  45 struct gl_program_cache
  46 {
  47    struct cache_item **items;
  48    struct cache_item *last;
  49    GLuint size, n_items;
  50 };
  51
  52
  53
  54 /**
  55  * Compute hash index from state key.
  56  */
  57 static GLuint
  58 hash_key(const void *key, GLuint key_size)
  59 {
  60    const GLuint *ikey = (const GLuint *) key;
  61    GLuint hash = 0, i;
  62
  63    assert(key_size >= 4);
  64
  65    /* Make a slightly better attempt at a hash function:
  66     */
  67    for (i = 0; i < key_size / sizeof(*ikey); i++)
  68    {
  69       hash += ikey[i];
  70       hash += (hash << 10);
  71       hash ^= (hash >> 6);
  72    }
  73
  74    return hash;
  75 }
  76
  77
  78 /**
  79  * Rebuild/expand the hash table to accomodate more entries
  80  */
  81 static void
  82 rehash(struct gl_program_cache *cache)
  83 {
  84    struct cache_item **items;
  85    struct cache_item *c, *next;
  86    GLuint size, i;
  87
  88    cache->last = NULL;
  89
  90    size = cache->size * 3;
  91    items = (struct cache_item**) malloc(size * sizeof(*items));
  92    memset(items, 0, size * sizeof(*items));
  93
  94    for (i = 0; i < cache->size; i++)
  95       for (c = cache->items[i]; c; c = next) {
  96          next = c->next;
  97          c->next = items[c->hash % size];
  98          items[c->hash % size] = c;
  99       }
 100
 101    free(cache->items);
 102    cache->items = items;
 103    cache->size = size;
 104 }
 105
 106
 107 static void
 108 clear_cache(struct gl_context *ctx, struct gl_program_cache *cache,
 109             GLboolean shader)
 110 {
 111    struct cache_item *c, *next;
 112    GLuint i;
 113
 114    cache->last = NULL;
 115
 116    for (i = 0; i < cache->size; i++) {
 117       for (c = cache->items[i]; c; c = next) {
 118          next = c->next;
 119          free(c->key);
 120          if (shader) {
 121             _mesa_reference_shader_program(ctx,
 122                                            (struct gl_shader_program **)&c->program,
 123                                            NULL);
 124          } else {
 125             _mesa_reference_program(ctx, &c->program, NULL);
 126          }
 127          free(c);
 128       }
 129       cache->items[i] = NULL;
 130    }
 131
 132
 133    cache->n_items = 0;
 134 }
 135
 136
 137
 138 struct gl_program_cache *
 139 _mesa_new_program_cache(void)
 140 {
 141    struct gl_program_cache *cache = CALLOC_STRUCT(gl_program_cache);
 142    if (cache) {
 143       cache->size = 17;
 144       cache->items = (struct cache_item **)
 145          calloc(1, cache->size * sizeof(struct cache_item));
 146       if (!cache->items) {
 147          free(cache);
 148          return NULL;
 149       }
 150    }
 151    return cache;
 152 }
 153
 154
 155 void
 156 _mesa_delete_program_cache(struct gl_context *ctx, struct gl_program_cache *cache)
 157 {
 158    clear_cache(ctx, cache, GL_FALSE);
 159    free(cache->items);
 160    free(cache);
 161 }
 162
 163 void
 164 _mesa_delete_shader_cache(struct gl_context *ctx,
 165                           struct gl_program_cache *cache)
 166 {
 167    clear_cache(ctx, cache, GL_TRUE);
 168    free(cache->items);
 169    free(cache);
 170 }
 171
 172
 173 struct gl_program *
 174 _mesa_search_program_cache(struct gl_program_cache *cache,
 175                            const void *key, GLuint keysize)
 176 {
 177    if (cache->last &&
 178        memcmp(cache->last->key, key, keysize) == 0) {
 179       return cache->last->program;
 180    }
 181    else {
 182       const GLuint hash = hash_key(key, keysize);
 183       struct cache_item *c;
 184
 185       for (c = cache->items[hash % cache->size]; c; c = c->next) {
 186          if (c->hash == hash && memcmp(c->key, key, keysize) == 0) {
 187             cache->last = c;
 188             return c->program;
 189          }
 190       }
 191
 192       return NULL;
 193    }
 194 }
 195
 196
 197 void
 198 _mesa_program_cache_insert(struct gl_context *ctx,
 199                            struct gl_program_cache *cache,
 200                            const void *key, GLuint keysize,
 201                            struct gl_program *program)
 202 {
 203    const GLuint hash = hash_key(key, keysize);
 204    struct cache_item *c = CALLOC_STRUCT(cache_item);
 205
 206    c->hash = hash;
 207
 208    c->key = malloc(keysize);
 209    memcpy(c->key, key, keysize);
 210
 211    c->program = program;  /* no refcount change */
 212
 213    if (cache->n_items > cache->size * 1.5) {
 214       if (cache->size < 1000)
 215          rehash(cache);
 216       else
 217          clear_cache(ctx, cache, GL_FALSE);
 218    }
 219
 220    cache->n_items++;
 221    c->next = cache->items[hash % cache->size];
 222    cache->items[hash % cache->size] = c;
 223 }
 224
 225 void
 226 _mesa_shader_cache_insert(struct gl_context *ctx,
 227                           struct gl_program_cache *cache,
 228                           const void *key, GLuint keysize,
 229                           struct gl_shader_program *program)
 230 {
 231    const GLuint hash = hash_key(key, keysize);
 232    struct cache_item *c = CALLOC_STRUCT(cache_item);
 233
 234    c->hash = hash;
 235
 236    c->key = malloc(keysize);
 237    memcpy(c->key, key, keysize);
 238
 239    c->program = (struct gl_program *)program;  /* no refcount change */
 240
 241    if (cache->n_items > cache->size * 1.5) {
 242       if (cache->size < 1000)
 243          rehash(cache);
 244       else
 245          clear_cache(ctx, cache, GL_TRUE);
 246    }
 247
 248    cache->n_items++;
 249    c->next = cache->items[hash % cache->size];
 250    cache->items[hash % cache->size] = c;
 251 }