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1 // Copyright 2012 Google Inc. All Rights Reserved.
2 //
3 // Use of this source code is governed by a BSD-style license
4 // that can be found in the COPYING file in the root of the source
5 // tree. An additional intellectual property rights grant can be found
6 // in the file PATENTS. All contributing project authors may
7 // be found in the AUTHORS file in the root of the source tree.
8 // -----------------------------------------------------------------------------
9 //
10 // Color Cache for WebP Lossless
11 //
12 // Author: Jyrki Alakuijala (jyrki@google.com)
13 
14 #include <assert.h>
15 #include <stdlib.h>
16 #include <string.h>
17 #include "./color_cache_utils.h"
18 #include "./utils.h"
19 
20 //------------------------------------------------------------------------------
21 // VP8LColorCache.
22 
VP8LColorCacheInit(VP8LColorCache * const cc,int hash_bits)23 int VP8LColorCacheInit(VP8LColorCache* const cc, int hash_bits) {
24   const int hash_size = 1 << hash_bits;
25   assert(cc != NULL);
26   assert(hash_bits > 0);
27   cc->colors_ = (uint32_t*)WebPSafeCalloc((uint64_t)hash_size,
28                                           sizeof(*cc->colors_));
29   if (cc->colors_ == NULL) return 0;
30   cc->hash_shift_ = 32 - hash_bits;
31   cc->hash_bits_ = hash_bits;
32   return 1;
33 }
34 
VP8LColorCacheClear(VP8LColorCache * const cc)35 void VP8LColorCacheClear(VP8LColorCache* const cc) {
36   if (cc != NULL) {
37     WebPSafeFree(cc->colors_);
38     cc->colors_ = NULL;
39   }
40 }
41 
VP8LColorCacheCopy(const VP8LColorCache * const src,VP8LColorCache * const dst)42 void VP8LColorCacheCopy(const VP8LColorCache* const src,
43                         VP8LColorCache* const dst) {
44   assert(src != NULL);
45   assert(dst != NULL);
46   assert(src->hash_bits_ == dst->hash_bits_);
47   memcpy(dst->colors_, src->colors_,
48          ((size_t)1u << dst->hash_bits_) * sizeof(*dst->colors_));
49 }
50