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
37struct cache_item
38{
39   GLuint hash;
40   void *key;
41   struct gl_program *program;
42   struct cache_item *next;
43};
44
45struct 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 */
57static GLuint
58hash_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 */
81static void
82rehash(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
107static void
108clear_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
138struct 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
155void
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
163void
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
173struct 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
197void
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
225void
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}
252