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authorLibravatarLarge Libravatar Bram Stein <steinadobecom>2014-11-06 16:22:16 +0100
committerLibravatarLarge Libravatar Bram Stein <steinadobecom>2014-11-06 16:22:16 +0100
commite67716a2725037220a1d1226e12ff6212f1e5031 (patch)
tree97f71a6b06acade510d43491caf6389e5fafbc22 /cache.h
parent64833aa89615b59b25f887443dfd344f24bbe3dc (diff)
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Add Zopfli files.

Diffstat (limited to 'cache.h')
-rw-r--r--cache.h66
1 files changed, 66 insertions, 0 deletions
diff --git a/cache.h b/cache.h
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+/*
+Copyright 2011 Google Inc. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+Author: lode.vandevenne@gmail.com (Lode Vandevenne)
+Author: jyrki.alakuijala@gmail.com (Jyrki Alakuijala)
+*/
+
+/*
+The cache that speeds up ZopfliFindLongestMatch of lz77.c.
+*/
+
+#ifndef ZOPFLI_CACHE_H_
+#define ZOPFLI_CACHE_H_
+
+#include "util.h"
+
+#ifdef ZOPFLI_LONGEST_MATCH_CACHE
+
+/*
+Cache used by ZopfliFindLongestMatch to remember previously found length/dist
+values.
+This is needed because the squeeze runs will ask these values multiple times for
+the same position.
+Uses large amounts of memory, since it has to remember the distance belonging
+to every possible shorter-than-the-best length (the so called "sublen" array).
+*/
+typedef struct ZopfliLongestMatchCache {
+ unsigned short* length;
+ unsigned short* dist;
+ unsigned char* sublen;
+} ZopfliLongestMatchCache;
+
+/* Initializes the ZopfliLongestMatchCache. */
+void ZopfliInitCache(size_t blocksize, ZopfliLongestMatchCache* lmc);
+
+/* Frees up the memory of the ZopfliLongestMatchCache. */
+void ZopfliCleanCache(ZopfliLongestMatchCache* lmc);
+
+/* Stores sublen array in the cache. */
+void ZopfliSublenToCache(const unsigned short* sublen,
+ size_t pos, size_t length,
+ ZopfliLongestMatchCache* lmc);
+
+/* Extracts sublen array from the cache. */
+void ZopfliCacheToSublen(const ZopfliLongestMatchCache* lmc,
+ size_t pos, size_t length,
+ unsigned short* sublen);
+/* Returns the length up to which could be stored in the cache. */
+unsigned ZopfliMaxCachedSublen(const ZopfliLongestMatchCache* lmc,
+ size_t pos, size_t length);
+
+#endif /* ZOPFLI_LONGEST_MATCH_CACHE */
+
+#endif /* ZOPFLI_CACHE_H_ */