| /* |
| * 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. |
| */ |
| |
| // Author: bmcquade@google.com (Bryan McQuade) |
| |
| #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(); |
| |
| // Should be called once, before inflating any data. |
| bool Init(); |
| |
| // Should be called once, after inflating is finished. |
| void ShutDown(); |
| |
| // Does the inflater still have input that has not yet been |
| // consumed? If true, the caller should call InflateBytes(). If |
| // false, the gzip inflater is ready for additional input. |
| bool HasUnconsumedInput() const; |
| |
| // Pass a gzip-compressed buffer to the gzip inflater. The gzip |
| // inflater will inflate the buffer via InflateBytes(). SetInput |
| // should not be called if HasUnconsumedInput() is true, and the |
| // buffer passed into SetInput should not be modified by the caller |
| // until HasUnconsumedInput() returns false. |
| bool SetInput(const void *in, size_t in_size); |
| |
| // Decompress the input passed in via SetInput. Should be called |
| // until HasUnconsumedInput returns false. Returns the number of |
| // bytes inflated, or -1 if an error was encountered while |
| // inflating. |
| int InflateBytes(char *buf, size_t buf_size); |
| |
| // Has the entire input been inflated? |
| bool finished() const { return finished_; } |
| |
| // Was an error encountered during inflating? |
| bool error() const { return error_; } |
| |
| // Deflates a stringpiece, writing output to Writer. Returns false |
| // if there was some kind of failure, though none are expected. |
| static bool Deflate(StringPiece in, InflateType format, Writer* writer); |
| static bool Deflate(StringPiece in, InflateType format, int compression_level, |
| Writer* writer); |
| |
| // Inflates a stringpiece, writing output to Writer. Returns false |
| // if there was some kind of failure, such as a corrupt input. |
| static bool Inflate(StringPiece in, InflateType format, Writer* writer); |
| |
| // Checks whether in starts with the gzip file signature. |
| static bool HasGzipMagicBytes(StringPiece in); |
| |
| private: |
| friend class GzipInflaterTestPeer; |
| |
| enum StreamFormat { |
| FORMAT_GZIP, // RFC1952 |
| FORMAT_ZLIB_STREAM, // RFC1950 |
| FORMAT_RAW_INFLATE, // RFC1951 |
| }; |
| |
| 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_; |
| |
| DISALLOW_COPY_AND_ASSIGN(GzipInflater); |
| }; |
| |
| } // namespace net_instaweb |
| |
| #endif // PAGESPEED_KERNEL_UTIL_GZIP_INFLATER_H_ |