1// Copyright 2013 Google Inc. All Rights Reserved.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7// http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14//
15// API for Brotli compression
16
17#ifndef BROTLI_ENC_ENCODE_H_
18#define BROTLI_ENC_ENCODE_H_
19
20#include <stddef.h>
21#include <stdint.h>
22#include <string>
23#include <vector>
24#include "./hash.h"
25#include "./ringbuffer.h"
26#include "./static_dict.h"
27
28namespace brotli {
29
30struct BrotliParams {
31  enum Mode {
32    MODE_TEXT = 0,
33    MODE_FONT = 1,
34  };
35  Mode mode;
36
37  BrotliParams() : mode(MODE_TEXT) {}
38};
39
40class BrotliCompressor {
41 public:
42  explicit BrotliCompressor(BrotliParams params);
43  ~BrotliCompressor();
44
45  // Writes the stream header into the internal output buffer.
46  void WriteStreamHeader();
47
48  // Encodes the data in input_buffer as a meta-block and writes it to
49  // encoded_buffer and sets *encoded_size to the number of bytes that was
50  // written.
51  void WriteMetaBlock(const size_t input_size,
52                      const uint8_t* input_buffer,
53                      const bool is_last,
54                      size_t* encoded_size,
55                      uint8_t* encoded_buffer);
56
57  // Writes a zero-length meta-block with end-of-input bit set to the
58  // internal output buffer and copies the output buffer to encoded_buffer and
59  // sets *encoded_size to the number of bytes written.
60  void FinishStream(size_t* encoded_size, uint8_t* encoded_buffer);
61
62
63 private:
64  // Initializes the hasher with the hashes of dictionary words.
65  void StoreDictionaryWordHashes();
66
67  BrotliParams params_;
68  int window_bits_;
69  std::unique_ptr<Hashers> hashers_;
70  Hashers::Type hash_type_;
71  int dist_ringbuffer_[4];
72  size_t dist_ringbuffer_idx_;
73  size_t input_pos_;
74  RingBuffer ringbuffer_;
75  std::vector<float> literal_cost_;
76  int storage_ix_;
77  uint8_t* storage_;
78  static StaticDictionary *static_dictionary_;
79};
80
81// Compresses the data in input_buffer into encoded_buffer, and sets
82// *encoded_size to the compressed length.
83// Returns 0 if there was an error and 1 otherwise.
84int BrotliCompressBuffer(BrotliParams params,
85                         size_t input_size,
86                         const uint8_t* input_buffer,
87                         size_t* encoded_size,
88                         uint8_t* encoded_buffer);
89
90
91}  // namespace brotli
92
93#endif  // BROTLI_ENC_ENCODE_H_
94