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417107b3dd
The new modes process the input data in independent blocks, using backward references only from within an input block. The new modes can be used by specifying quality 0 or quality 1, the old quality 1 and quality 2 modes are renamed quality 2 and quality 3, respectively, and the old quality 3 mode is removed.
41 lines
1.7 KiB
C++
41 lines
1.7 KiB
C++
/* Copyright 2015 Google Inc. All Rights Reserved.
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Distributed under MIT license.
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See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
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*/
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// Function for fast encoding of an input fragment, independently from the input
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// history. This function uses two-pass processing: in the first pass we save
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// the found backward matches and literal bytes into a buffer, and in the
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// second pass we emit them into the bit stream using prefix codes built based
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// on the actual command and literal byte histograms.
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#ifndef BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_
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#define BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_
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#include "./types.h"
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namespace brotli {
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static const size_t kCompressFragmentTwoPassBlockSize = 1 << 17;
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// Compresses "input" string to the "*storage" buffer as one or more complete
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// meta-blocks, and updates the "*storage_ix" bit position.
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//
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// If "is_last" is true, emits an additional empty last meta-block.
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//
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// REQUIRES: "input_size" is greater than zero, or "is_last" is true.
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// REQUIRES: "command_buf" and "literal_buf" point to at least
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// kCompressFragmentTwoPassBlockSize long arrays.
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// REQUIRES: All elements in "table[0..table_size-1]" are initialized to zero.
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// REQUIRES: "table_size" is a power of two
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void BrotliCompressFragmentTwoPass(const uint8_t* input, size_t input_size,
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bool is_last,
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uint32_t* command_buf, uint8_t* literal_buf,
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int* table, size_t table_size,
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size_t* storage_ix, uint8_t* storage);
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} // namespace brotli
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#endif // BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_
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