src/mesa/shader/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 "shader/prog_cache.h"
  33
  34
  35 struct cache_item
  36 {
  37    GLuint hash;
  38    void *key;
  39    struct gl_program *program;
  40    struct cache_item *next;
  41 };
  42
  43 struct gl_program_cache
  44 {
  45    struct cache_item **items;
  46    GLuint size, n_items;
  47 };
  48
  49
  50
  51 /**
  52  * Compute hash index from state key.
  53  */
  54 static GLuint
  55 hash_key(const void *key, GLuint key_size)
  56 {
  57    const GLuint *ikey = (const GLuint *) key;
  58    GLuint hash = 0, i;
  59
  60    assert(key_size >= 4);
  61
  62    /* Make a slightly better attempt at a hash function:
  63     */
  64    for (i = 0; i < key_size / sizeof(*ikey); i++)
  65    {
  66       hash += ikey[i];
  67       hash += (hash << 10);
  68       hash ^= (hash >> 6);
  69    }
  70
  71    return hash;
  72 }
  73
  74
  75 /**
  76  * Rebuild/expand the hash table to accomodate more entries
  77  */
  78 static void
  79 rehash(struct gl_program_cache *cache)
  80 {
  81    struct cache_item **items;
  82    struct cache_item *c, *next;
  83    GLuint size, i;
  84
  85    size = cache->size * 3;
  86    items = (struct cache_item**) _mesa_malloc(size * sizeof(*items));
  87    _mesa_memset(items, 0, size * sizeof(*items));
  88
  89    for (i = 0; i < cache->size; i++)
  90       for (c = cache->items[i]; c; c = next) {
  91          next = c->next;
  92          c->next = items[c->hash % size];
  93          items[c->hash % size] = c;
  94       }
  95
  96    _mesa_free(cache->items);
  97    cache->items = items;
  98    cache->size = size;
  99 }
 100
 101
 102 static void
 103 clear_cache(GLcontext *ctx, struct gl_program_cache *cache)
 104 {
 105    struct cache_item *c, *next;
 106    GLuint i;
 107
 108    for (i = 0; i < cache->size; i++) {
 109       for (c = cache->items[i]; c; c = next) {
 110          next = c->next;
 111          _mesa_free(c->key);
 112          ctx->Driver.DeleteProgram(ctx, c->program);
 113          _mesa_free(c);
 114       }
 115       cache->items[i] = NULL;
 116    }
 117
 118
 119    cache->n_items = 0;
 120 }
 121
 122
 123
 124 struct gl_program_cache *
 125 _mesa_new_program_cache(void)
 126 {
 127    struct gl_program_cache *cache = CALLOC_STRUCT(gl_program_cache);
 128    if (cache) {
 129       cache->size = 17;
 130       cache->items = (struct cache_item **)
 131          _mesa_calloc(cache->size * sizeof(struct cache_item));
 132       if (!cache->items) {
 133          _mesa_free(cache);
 134          return NULL;
 135       }
 136    }
 137    return cache;
 138 }
 139
 140
 141 void
 142 _mesa_delete_program_cache(GLcontext *ctx, struct gl_program_cache *cache)
 143 {
 144    clear_cache(ctx, cache);
 145    _mesa_free(cache->items);
 146    _mesa_free(cache);
 147 }
 148
 149
 150 struct gl_program *
 151 _mesa_search_program_cache(const struct gl_program_cache *cache,
 152                            const void *key, GLuint keysize)
 153 {
 154    const GLuint hash = hash_key(key, keysize);
 155    struct cache_item *c;
 156
 157    for (c = cache->items[hash % cache->size]; c; c = c->next) {
 158       if (c->hash == hash && memcmp(c->key, key, keysize) == 0)
 159          return c->program;
 160    }
 161
 162    return NULL;
 163 }
 164
 165
 166 void
 167 _mesa_program_cache_insert(GLcontext *ctx,
 168                            struct gl_program_cache *cache,
 169                            const void *key, GLuint keysize,
 170                            struct gl_program *program)
 171 {
 172    const GLuint hash = hash_key(key, keysize);
 173    struct cache_item *c = CALLOC_STRUCT(cache_item);
 174
 175    c->hash = hash;
 176
 177    c->key = _mesa_malloc(keysize);
 178    memcpy(c->key, key, keysize);
 179
 180    c->program = program;
 181
 182    if (cache->n_items > cache->size * 1.5) {
 183       if (cache->size < 1000)
 184          rehash(cache);
 185       else
 186          clear_cache(ctx, cache);
 187    }
 188
 189    cache->n_items++;
 190    c->next = cache->items[hash % cache->size];
 191    cache->items[hash % cache->size] = c;
 192 }