third_party/libwebp/utils/color_cache.c

   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 "./color_cache.h"
  17 #include "../utils/utils.h"
  18
  19 //------------------------------------------------------------------------------
  20 // VP8LColorCache.
  21
  22 int VP8LColorCacheInit(VP8LColorCache* const cc, int hash_bits) {
  23   const int hash_size = 1 << hash_bits;
  24   assert(cc != NULL);
  25   assert(hash_bits > 0);
  26   cc->colors_ = (uint32_t*)WebPSafeCalloc((uint64_t)hash_size,
  27                                           sizeof(*cc->colors_));
  28   if (cc->colors_ == NULL) return 0;
  29   cc->hash_shift_ = 32 - hash_bits;
  30   return 1;
  31 }
  32
  33 void VP8LColorCacheClear(VP8LColorCache* const cc) {
  34   if (cc != NULL) {
  35     WebPSafeFree(cc->colors_);
  36     cc->colors_ = NULL;
  37   }
  38 }
  39