gzip_inflater.h

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/*
 * Copyright 2010 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http:///www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


#ifndef PAGESPEED_KERNEL_UTIL_GZIP_INFLATER_H_
#define PAGESPEED_KERNEL_UTIL_GZIP_INFLATER_H_

#include <cstddef>
#include "pagespeed/kernel/base/basictypes.h"
#include "pagespeed/kernel/base/string_util.h"

typedef struct z_stream_s z_stream;

namespace net_instaweb {

class Writer;

class GzipInflater {
 public:
  enum InflateType {kGzip, kDeflate};

  explicit GzipInflater(InflateType type);
  ~GzipInflater();

  bool Init();

  void ShutDown();

  bool HasUnconsumedInput() const;

  bool SetInput(const void *in, size_t in_size);

  int InflateBytes(char *buf, size_t buf_size);

  bool finished() const { return finished_; }

  bool error() const { return error_; }

  static bool Deflate(StringPiece in, InflateType format, Writer* writer);
  static bool Deflate(StringPiece in, InflateType format, int compression_level,
                      Writer* writer);

  static bool Inflate(StringPiece in, InflateType format, Writer* writer);

  static bool HasGzipMagicBytes(StringPiece in);

 private:
  friend class GzipInflaterTestPeer;

  enum StreamFormat {
    FORMAT_GZIP,         
    FORMAT_ZLIB_STREAM,  
    FORMAT_RAW_INFLATE,  
  };

  static bool GetWindowBitsForFormat(
      StreamFormat format, int* out_window_bits);
  void Free();
  void SetInputInternal(const void *in, size_t in_size);
  void SwitchToRawDeflateFormat();

  z_stream *zlib_;
  StreamFormat format_;
  bool finished_;
  bool error_;

  
};

}  

#endif