Improved directory structure with the source code under src

1 files changed, 119 insertions, 0 deletions

diff --git a/src/zopfli/cache.c b/src/zopfli/cache.c
new file mode 100644
index 0000000..88a49ac
--- /dev/null
+++ b/src/zopfli/cache.c
@@ -0,0 +1,119 @@
+/*
+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)
+*/
+
+#include "cache.h"
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef ZOPFLI_LONGEST_MATCH_CACHE
+
+void ZopfliInitCache(size_t blocksize, ZopfliLongestMatchCache* lmc) {
+  size_t i;
+  lmc->length = (unsigned short*)malloc(sizeof(unsigned short) * blocksize);
+  lmc->dist = (unsigned short*)malloc(sizeof(unsigned short) * blocksize);
+  /* Rather large amount of memory. */
+  lmc->sublen = (unsigned char*)malloc(ZOPFLI_CACHE_LENGTH * 3 * blocksize);
+
+  /* length > 0 and dist 0 is invalid combination, which indicates on purpose
+  that this cache value is not filled in yet. */
+  for (i = 0; i < blocksize; i++) lmc->length[i] = 1;
+  for (i = 0; i < blocksize; i++) lmc->dist[i] = 0;
+  for (i = 0; i < ZOPFLI_CACHE_LENGTH * blocksize * 3; i++) lmc->sublen[i] = 0;
+}
+
+void ZopfliCleanCache(ZopfliLongestMatchCache* lmc) {
+  free(lmc->length);
+  free(lmc->dist);
+  free(lmc->sublen);
+}
+
+void ZopfliSublenToCache(const unsigned short* sublen,
+                         size_t pos, size_t length,
+                         ZopfliLongestMatchCache* lmc) {
+  size_t i;
+  size_t j = 0;
+  unsigned bestlength = 0;
+  unsigned char* cache;
+
+#if ZOPFLI_CACHE_LENGTH == 0
+  return;
+#endif
+
+  cache = &lmc->sublen[ZOPFLI_CACHE_LENGTH * pos * 3];
+  if (length < 3) return;
+  for (i = 3; i <= length; i++) {
+    if (i == length || sublen[i] != sublen[i + 1]) {
+      cache[j * 3] = i - 3;
+      cache[j * 3 + 1] = sublen[i] % 256;
+      cache[j * 3 + 2] = (sublen[i] >> 8) % 256;
+      bestlength = i;
+      j++;
+      if (j >= ZOPFLI_CACHE_LENGTH) break;
+    }
+  }
+  if (j < ZOPFLI_CACHE_LENGTH) {
+    assert(bestlength == length);
+    cache[(ZOPFLI_CACHE_LENGTH - 1) * 3] = bestlength - 3;
+  } else {
+    assert(bestlength <= length);
+  }
+  assert(bestlength == ZopfliMaxCachedSublen(lmc, pos, length));
+}
+
+void ZopfliCacheToSublen(const ZopfliLongestMatchCache* lmc,
+                         size_t pos, size_t length,
+                         unsigned short* sublen) {
+  size_t i, j;
+  unsigned maxlength = ZopfliMaxCachedSublen(lmc, pos, length);
+  unsigned prevlength = 0;
+  unsigned char* cache;
+#if ZOPFLI_CACHE_LENGTH == 0
+  return;
+#endif
+  if (length < 3) return;
+  cache = &lmc->sublen[ZOPFLI_CACHE_LENGTH * pos * 3];
+  for (j = 0; j < ZOPFLI_CACHE_LENGTH; j++) {
+    unsigned length = cache[j * 3] + 3;
+    unsigned dist = cache[j * 3 + 1] + 256 * cache[j * 3 + 2];
+    for (i = prevlength; i <= length; i++) {
+      sublen[i] = dist;
+    }
+    if (length == maxlength) break;
+    prevlength = length + 1;
+  }
+}
+
+/*
+Returns the length up to which could be stored in the cache.
+*/
+unsigned ZopfliMaxCachedSublen(const ZopfliLongestMatchCache* lmc,
+                               size_t pos, size_t length) {
+  unsigned char* cache;
+#if ZOPFLI_CACHE_LENGTH == 0
+  return 0;
+#endif
+  cache = &lmc->sublen[ZOPFLI_CACHE_LENGTH * pos * 3];
+  (void)length;
+  if (cache[1] == 0 && cache[2] == 0) return 0;  /* No sublen cached. */
+  return cache[(ZOPFLI_CACHE_LENGTH - 1) * 3] + 3;
+}
+
+#endif  /* ZOPFLI_LONGEST_MATCH_CACHE */