// This file contains the declaration of classes 
// LzipInputStream and LzipOutputStream used to compress
// and decompress Google's Protocol Buffer Streams using
// the Lempel-Ziv-Markow-Algorithm.
//
// Derived from http://protobuf.googlecode.com/svn/tags/2.2.0/src/google/protobuf/io/gzip_stream.h
// Copyright 2009 by Jacob Rief <address@hidden>
// Evaluation copy - don't use in production code

#ifndef GOOGLE_PROTOBUF_IO_LZIP_STREAM_H__
#define GOOGLE_PROTOBUF_IO_LZIP_STREAM_H__

#include <stdint.h>
#include <lzlib.h>
#include <limits>
#include <google/protobuf/io/zero_copy_stream.h>

namespace google {
namespace protobuf {
namespace io {

// A ZeroCopyInputStream that reads compressed data through lzib
class LIBPROTOBUF_EXPORT LzipInputStream : public ZeroCopyInputStream {
 public:
  explicit LzipInputStream(ZeroCopyInputStream* sub_stream);

  virtual ~LzipInputStream();

  // Releases the decoder. 
  bool Close();

  // --- implements ZeroCopyInputStream ---
  bool Next(const void** data, int* size);
  void BackUp(int count);
  bool Skip(int count);
  int64 ByteCount() const;

 private:
  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(LzipInputStream);

  void Decompress();

  // compressed input stream
  ZeroCopyInputStream* sub_stream_;
  bool finished_;

  // plain text output stream
  const int output_buffer_length_;
  void* const output_buffer_;
  uint8_t* output_position_;
  uint8_t* next_out_;
  int avail_out_;

  // Lzip decoder
  void* decoder_;
  LZ_errno errno_;
};

class LIBPROTOBUF_EXPORT LzipOutputStream : public ZeroCopyOutputStream {
 public:
  // Create a LzipOutputStream with default options.
  explicit LzipOutputStream(ZeroCopyOutputStream* sub_stream, size_t compression_level = 5, int64_t member_size = std::numeric_limits<long long>::max());

  virtual ~LzipOutputStream();

  // Flushes data written so far to zipped data in the underlying stream.
  // It is the caller's responsibility to flush the underlying stream if
  // necessary.
  // Compression may be less efficient stopping and starting around flushes.
  // Returns true if no error.
  bool Flush();

  // Writes out all data and closes the lzip stream.
  // It is the caller's responsibility to close the underlying stream if
  // necessary.
  // Returns true if no error.
  bool Close();

  // --- implements ZeroCopyOutputStream ---
  bool Next(void** data, int* size);
  void BackUp(int count);
  int64 ByteCount() const;

 private:
  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(LzipOutputStream);

  void Compress(bool flush = false);

  // plain text input stream
  const int input_buffer_length_;
  void* const input_buffer_;
  uint8_t* input_position_;
  uint8_t* const input_buffer_end_;

  // compressed output stream
  ZeroCopyOutputStream* sub_stream_;
  bool finished_;

  // Lzip encoder
  struct Options {
    int dictionary_size; // 4KiB..512MiB
    int match_len_limit; // 5..273
  };
  static const Options options[9];

  void* encoder_;
  int member_size_;
  LZ_errno errno_;
};

}  // namespace io
}  // namespace protobuf
}  // namespace google

#endif  // GOOGLE_PROTOBUF_IO_LZIP_STREAM_H__