Zoltan Szabadka
1571db36a9
This commit contains a batch of changes that were made to the Brotli compression algorithm in the last three weeks. Most important changes: * Added UTF8 context model for good text compression. * Simplified context modeling by having only 4 context modes. * Per-block context mode selection. * Faster backward copying and bit reading functions. * More efficient histogram coding. * Streaming support for the decoder and encoder.
103 lines
3.3 KiB
C
103 lines
3.3 KiB
C
// Copyright 2013 Google Inc. All Rights Reserved.
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//
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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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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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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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// Functions for streaming input and output.
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#ifndef BROTLI_DEC_STREAMS_H_
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#define BROTLI_DEC_STREAMS_H_
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#include <stdio.h>
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#include "./types.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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// Function pointer type used to read len bytes into buf. Returns the
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// number of bytes read or -1 on error.
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typedef int (*BrotliInputFunction)(void* data, uint8_t* buf, size_t len);
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// Input callback function with associated data.
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typedef struct {
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BrotliInputFunction cb_;
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void* data_;
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} BrotliInput;
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// Reads len bytes into buf, using the in callback.
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static BROTLI_INLINE int BrotliRead(BrotliInput in, uint8_t* buf, size_t len) {
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return in.cb_(in.data_, buf, len);
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}
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// Function pointer type used to write len bytes into buf. Returns the
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// number of bytes written or -1 on error.
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typedef int (*BrotliOutputFunction)(void* data, const uint8_t* buf, size_t len);
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// Output callback function with associated data.
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typedef struct {
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BrotliOutputFunction cb_;
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void* data_;
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} BrotliOutput;
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// Writes len bytes into buf, using the out callback.
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static BROTLI_INLINE int BrotliWrite(BrotliOutput out,
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const uint8_t* buf, size_t len) {
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return out.cb_(out.data_, buf, len);
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}
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// Memory region with position.
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typedef struct {
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const uint8_t* buffer;
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size_t length;
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size_t pos;
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} BrotliMemInput;
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// Input callback where *data is a BrotliMemInput struct.
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int BrotliMemInputFunction(void* data, uint8_t* buf, size_t count);
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// Returns an input callback that wraps the given memory region.
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BrotliInput BrotliInitMemInput(const uint8_t* buffer, size_t length,
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BrotliMemInput* mem_input);
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// Output buffer with position.
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typedef struct {
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uint8_t* buffer;
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size_t length;
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size_t pos;
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} BrotliMemOutput;
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// Output callback where *data is a BrotliMemOutput struct.
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int BrotliMemOutputFunction(void* data, const uint8_t* buf, size_t count);
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// Returns an output callback that wraps the given memory region.
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BrotliOutput BrotliInitMemOutput(uint8_t* buffer, size_t length,
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BrotliMemOutput* mem_output);
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// Input callback that reads from standard input.
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int BrotliStdinInputFunction(void* data, uint8_t* buf, size_t count);
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BrotliInput BrotliStdinInput();
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// Output callback that writes to standard output.
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int BrotliStdoutOutputFunction(void* data, const uint8_t* buf, size_t count);
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BrotliOutput BrotliStdoutOutput();
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// Output callback that writes to a file.
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int BrotliFileOutputFunction(void* data, const uint8_t* buf, size_t count);
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BrotliOutput BrotliFileOutput(FILE* f);
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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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#endif // BROTLI_DEC_STREAMS_H_
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