Update brotli to v1.0.0-snapshot.

third_party/brotli/enc/encode.h

-/* Copyright 2013 Google Inc. All Rights Reserved.
-
-   Distributed under MIT license.
-   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
-*/
-
-// API for Brotli compression
-
-#ifndef BROTLI_ENC_ENCODE_H_
-#define BROTLI_ENC_ENCODE_H_
-
-#include <string>
-#include <vector>
-#include "./command.h"
-#include "./hash.h"
-#include "./ringbuffer.h"
-#include "./static_dict.h"
-#include "./streams.h"
-#include "./types.h"
-
-namespace brotli {
-
-static const int kMaxWindowBits = 24;
-static const int kMinWindowBits = 10;
-static const int kMinInputBlockBits = 16;
-static const int kMaxInputBlockBits = 24;
-
-struct BrotliParams {
-  BrotliParams(void)
-      : mode(MODE_GENERIC),
-        quality(11),
-        lgwin(22),
-        lgblock(0),
-        enable_dictionary(true),
-        enable_transforms(false),
-        greedy_block_split(false),
-        enable_context_modeling(true) {}
-
-  enum Mode {
-    // Default compression mode. The compressor does not know anything in
-    // advance about the properties of the input.
-    MODE_GENERIC = 0,
-    // Compression mode for UTF-8 format text input.
-    MODE_TEXT = 1,
-    // Compression mode used in WOFF 2.0.
-    MODE_FONT = 2
-  };
-  Mode mode;
-
-  // Controls the compression-speed vs compression-density tradeoffs. The higher
-  // the quality, the slower the compression. Range is 0 to 11.
-  int quality;
-  // Base 2 logarithm of the sliding window size. Range is 10 to 24.
-  int lgwin;
-  // Base 2 logarithm of the maximum input block size. Range is 16 to 24.
-  // If set to 0, the value will be set based on the quality.
-  int lgblock;
-
-  // These settings are deprecated and will be ignored.
-  // All speed vs. size compromises are controlled by the quality param.
-  bool enable_dictionary;
-  bool enable_transforms;
-  bool greedy_block_split;
-  bool enable_context_modeling;
-};
-
-// An instance can not be reused for multiple brotli streams.
-class BrotliCompressor {
- public:
-  explicit BrotliCompressor(BrotliParams params);
-  ~BrotliCompressor(void);
-
-  // The maximum input size that can be processed at once.
-  size_t input_block_size(void) const { return size_t(1) << params_.lgblock; }
-
-  // Encodes the data in input_buffer as a meta-block and writes it to
-  // encoded_buffer (*encoded_size should be set to the size of
-  // encoded_buffer) and sets *encoded_size to the number of bytes that
-  // was written. The input_size must be <= input_block_size().
-  // Returns 0 if there was an error and 1 otherwise.
-  bool WriteMetaBlock(const size_t input_size,
-                      const uint8_t* input_buffer,
-                      const bool is_last,
-                      size_t* encoded_size,
-                      uint8_t* encoded_buffer);
-
-  // Writes a metadata meta-block containing the given input to encoded_buffer.
-  // *encoded_size should be set to the size of the encoded_buffer.
-  // Sets *encoded_size to the number of bytes that was written.
-  // Note that the given input data will not be part of the sliding window and
-  // thus no backward references can be made to this data from subsequent
-  // metablocks.
-  bool WriteMetadata(const size_t input_size,
-                     const uint8_t* input_buffer,
-                     const bool is_last,
-                     size_t* encoded_size,
-                     uint8_t* encoded_buffer);
-
-  // Writes a zero-length meta-block with end-of-input bit set to the
-  // internal output buffer and copies the output buffer to encoded_buffer
-  // (*encoded_size should be set to the size of encoded_buffer) and sets
-  // *encoded_size to the number of bytes written. Returns false if there was
-  // an error and true otherwise.
-  bool FinishStream(size_t* encoded_size, uint8_t* encoded_buffer);
-
-  // Copies the given input data to the internal ring buffer of the compressor.
-  // No processing of the data occurs at this time and this function can be
-  // called multiple times before calling WriteBrotliData() to process the
-  // accumulated input. At most input_block_size() bytes of input data can be
-  // copied to the ring buffer, otherwise the next WriteBrotliData() will fail.
-  void CopyInputToRingBuffer(const size_t input_size,
-                             const uint8_t* input_buffer);
-
-  // Processes the accumulated input data and sets *out_size to the length of
-  // the new output meta-block, or to zero if no new output meta-block was
-  // created (in this case the processed input data is buffered internally).
-  // If *out_size is positive, *output points to the start of the output data.
-  // If is_last or force_flush is true, an output meta-block is always created.
-  // Returns false if the size of the input data is larger than
-  // input_block_size().
-  bool WriteBrotliData(const bool is_last, const bool force_flush,
-                       size_t* out_size, uint8_t** output);
-
-  // Fills the new state with a dictionary for LZ77, warming up the ringbuffer,
-  // e.g. for custom static dictionaries for data formats.
-  // Not to be confused with the built-in transformable dictionary of Brotli.
-  // To decode, use BrotliSetCustomDictionary of the decoder with the same
-  // dictionary.
-  void BrotliSetCustomDictionary(size_t size, const uint8_t* dict);
-
-  // No-op, but we keep it here for API backward-compatibility.
-  void WriteStreamHeader(void) {}
-
- private:
-  uint8_t* GetBrotliStorage(size_t size);
-
-  // Allocates and clears a hash table using memory in "*this",
-  // stores the number of buckets in "*table_size" and returns a pointer to
-  // the base of the hash table.
-  int* GetHashTable(int quality,
-                    size_t input_size, size_t* table_size);
-
-  BrotliParams params_;
-  Hashers* hashers_;
-  int hash_type_;
-  uint64_t input_pos_;
-  RingBuffer* ringbuffer_;
-  size_t cmd_alloc_size_;
-  Command* commands_;
-  size_t num_commands_;
-  size_t num_literals_;
-  size_t last_insert_len_;
-  uint64_t last_flush_pos_;
-  uint64_t last_processed_pos_;
-  int dist_cache_[4];
-  int saved_dist_cache_[4];
-  uint8_t last_byte_;
-  uint8_t last_byte_bits_;
-  uint8_t prev_byte_;
-  uint8_t prev_byte2_;
-  size_t storage_size_;
-  uint8_t* storage_;
-  // Hash table for quality 0 mode.
-  int small_table_[1 << 10];  // 2KB
-  int* large_table_;          // Allocated only when needed
-  // Command and distance prefix codes (each 64 symbols, stored back-to-back)
-  // used for the next block in quality 0. The command prefix code is over a
-  // smaller alphabet with the following 64 symbols:
-  //    0 - 15: insert length code 0, copy length code 0 - 15, same distance
-  //   16 - 39: insert length code 0, copy length code 0 - 23
-  //   40 - 63: insert length code 0 - 23, copy length code 0
-  // Note that symbols 16 and 40 represent the same code in the full alphabet,
-  // but we do not use either of them in quality 0.
-  uint8_t cmd_depths_[128];
-  uint16_t cmd_bits_[128];
-  // The compressed form of the command and distance prefix codes for the next
-  // block in quality 0.
-  uint8_t cmd_code_[512];
-  size_t cmd_code_numbits_;
-  // Command and literal buffers for quality 1.
-  uint32_t* command_buf_;
-  uint8_t* literal_buf_;
-
-  int is_last_block_emitted_;
-};
-
-// Compresses the data in input_buffer into encoded_buffer, and sets
-// *encoded_size to the compressed length.
-// Returns 0 if there was an error and 1 otherwise.
-int BrotliCompressBuffer(BrotliParams params,
-                         size_t input_size,
-                         const uint8_t* input_buffer,
-                         size_t* encoded_size,
-                         uint8_t* encoded_buffer);
-
-// Same as above, but uses the specified input and output classes instead
-// of reading from and writing to pre-allocated memory buffers.
-int BrotliCompress(BrotliParams params, BrotliIn* in, BrotliOut* out);
-
-// Before compressing the data, sets a custom LZ77 dictionary with
-// BrotliCompressor::BrotliSetCustomDictionary.
-int BrotliCompressWithCustomDictionary(size_t dictsize, const uint8_t* dict,
-                                       BrotliParams params,
-                                       BrotliIn* in, BrotliOut* out);
-
-
-}  // namespace brotli
-
-#endif  // BROTLI_ENC_ENCODE_H_