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83aa24dc86
* Change order of members of bit reader state structure. * Remove unused includes for assert. Add BROTLI_DCHECK macros and use it instead of assert. * Do not calculate nbits in common case of ReadSymbol. * Introduce and use PREDICT_TRUE / PREDICT_FALSE macros. * Allocate less memory in the brotli decoder if it knows the result size beforehand. Before this, the decoder would always allocate 16MB if the encoder annotated the window size as 22 bit (which is the default), even if the file is only a few KB uncompressed. Now, it'll only allocate a ringbuffer as large as needed for the result file. But only if it can know the filesize, it's not possible to know that if there are multiple metablocks or too large uncompressed metablock.
44 lines
1.3 KiB
C
44 lines
1.3 KiB
C
/* Copyright 2013 Google Inc. All Rights Reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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/* Size-checked memory allocation. */
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#include <stdlib.h>
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#include "./port.h"
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#include "./safe_malloc.h"
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#if defined(__cplusplus) || defined(c_plusplus)
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extern "C" {
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#endif
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/* Returns 0 in case of overflow of nmemb * size. */
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static int CheckSizeArgumentsOverflow(uint64_t nmemb, size_t size) {
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const uint64_t total_size = nmemb * size;
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if (nmemb == 0) return 1;
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if ((uint64_t)size > BROTLI_MAX_ALLOCABLE_MEMORY / nmemb) return 0;
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if (total_size != (size_t)total_size) return 0;
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return 1;
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}
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void* BrotliSafeMalloc(uint64_t nmemb, size_t size) {
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if (!CheckSizeArgumentsOverflow(nmemb, size)) return NULL;
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BROTLI_DCHECK(nmemb * size > 0);
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return malloc((size_t)(nmemb * size));
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}
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#if defined(__cplusplus) || defined(c_plusplus)
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} /* extern "C" */
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#endif
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