Added brotli enc/ and tools/ directories.

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_;
+};
+
+// 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_