1fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// Protocol Buffers - Google's data interchange format 2fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// Copyright 2008 Google Inc. All rights reserved. 3afb4b72037e3f13db208590fc782c4bc8e27f862Jeff Davidson// https://developers.google.com/protocol-buffers/ 4fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// 5fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// Redistribution and use in source and binary forms, with or without 6fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// modification, are permitted provided that the following conditions are 7fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// met: 8fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// 9fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// * Redistributions of source code must retain the above copyright 10fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// notice, this list of conditions and the following disclaimer. 11fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// * Redistributions in binary form must reproduce the above 12fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// copyright notice, this list of conditions and the following disclaimer 13fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// in the documentation and/or other materials provided with the 14fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// distribution. 15fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// * Neither the name of Google Inc. nor the names of its 16fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// contributors may be used to endorse or promote products derived from 17fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// this software without specific prior written permission. 18fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// 19fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 31fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// Author: brianolson@google.com (Brian Olson) 32fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// 33fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// This file contains the definition for classes GzipInputStream and 34fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// GzipOutputStream. 35fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// 36fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// GzipInputStream decompresses data from an underlying 37fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// ZeroCopyInputStream and provides the decompressed data as a 38fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// ZeroCopyInputStream. 39fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// 40fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// GzipOutputStream is an ZeroCopyOutputStream that compresses data to 41fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// an underlying ZeroCopyOutputStream. 42fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 43fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville#ifndef GOOGLE_PROTOBUF_IO_GZIP_STREAM_H__ 44fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville#define GOOGLE_PROTOBUF_IO_GZIP_STREAM_H__ 45fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 46a3b2a6da25a76f17c73d31def3952feb0fd2296eJeff Davidson#include <google/protobuf/stubs/common.h> 47fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville#include <google/protobuf/io/zero_copy_stream.h> 48b0575e93e4c39dec69365b850088a1eb7f82c5b3Tamas Berghammer#include <zlib.h> 49fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 50fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Savillenamespace google { 51fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Savillenamespace protobuf { 52fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Savillenamespace io { 53fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 54fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville// A ZeroCopyInputStream that reads compressed data through zlib 55fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Savilleclass LIBPROTOBUF_EXPORT GzipInputStream : public ZeroCopyInputStream { 56fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville public: 57fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Format key for constructor 58fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville enum Format { 59fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // zlib will autodetect gzip header or deflate stream 60fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville AUTO = 0, 61fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 62fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // GZIP streams have some extra header data for file attributes. 63fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville GZIP = 1, 64fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 65fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Simpler zlib stream format. 66fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville ZLIB = 2, 67fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville }; 68fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 69fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // buffer_size and format may be -1 for default of 64kB and GZIP format 70fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville explicit GzipInputStream( 71fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville ZeroCopyInputStream* sub_stream, 72fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville Format format = AUTO, 73fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville int buffer_size = -1); 74fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville virtual ~GzipInputStream(); 75fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 76fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Return last error message or NULL if no error. 77fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville inline const char* ZlibErrorMessage() const { 78fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville return zcontext_.msg; 79fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville } 80fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville inline int ZlibErrorCode() const { 81fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville return zerror_; 82fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville } 83fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 84fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // implements ZeroCopyInputStream ---------------------------------- 85fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville bool Next(const void** data, int* size); 86fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville void BackUp(int count); 87fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville bool Skip(int count); 88fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville int64 ByteCount() const; 89fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 90fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville private: 91fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville Format format_; 92fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 93fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville ZeroCopyInputStream* sub_stream_; 94fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 95fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville z_stream zcontext_; 96fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville int zerror_; 97fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 98fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville void* output_buffer_; 99fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville void* output_position_; 100fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville size_t output_buffer_length_; 101b0575e93e4c39dec69365b850088a1eb7f82c5b3Tamas Berghammer int64 byte_count_; 102fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 103fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville int Inflate(int flush); 104fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville void DoNextOutput(const void** data, int* size); 105fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 106fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(GzipInputStream); 107fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville}; 108fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 109fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 110fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Savilleclass LIBPROTOBUF_EXPORT GzipOutputStream : public ZeroCopyOutputStream { 111fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville public: 112fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Format key for constructor 113fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville enum Format { 114fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // GZIP streams have some extra header data for file attributes. 115fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville GZIP = 1, 116fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 117fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Simpler zlib stream format. 118fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville ZLIB = 2, 119fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville }; 120fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 121fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville struct Options { 122fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Defaults to GZIP. 123fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville Format format; 124fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 125fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // What size buffer to use internally. Defaults to 64kB. 126fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville int buffer_size; 127fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 128fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // A number between 0 and 9, where 0 is no compression and 9 is best 129fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // compression. Defaults to Z_DEFAULT_COMPRESSION (see zlib.h). 130fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville int compression_level; 131fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 132fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Defaults to Z_DEFAULT_STRATEGY. Can also be set to Z_FILTERED, 133fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Z_HUFFMAN_ONLY, or Z_RLE. See the documentation for deflateInit2 in 134fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // zlib.h for definitions of these constants. 135fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville int compression_strategy; 136fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 137fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville Options(); // Initializes with default values. 138fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville }; 139fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 140fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Create a GzipOutputStream with default options. 141fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville explicit GzipOutputStream(ZeroCopyOutputStream* sub_stream); 142fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 143fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Create a GzipOutputStream with the given options. 144fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville GzipOutputStream( 145fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville ZeroCopyOutputStream* sub_stream, 146fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville const Options& options); 147fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 148fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville virtual ~GzipOutputStream(); 149fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 150fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Return last error message or NULL if no error. 151fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville inline const char* ZlibErrorMessage() const { 152fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville return zcontext_.msg; 153fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville } 154fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville inline int ZlibErrorCode() const { 155fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville return zerror_; 156fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville } 157fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 158fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Flushes data written so far to zipped data in the underlying stream. 159fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // It is the caller's responsibility to flush the underlying stream if 160fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // necessary. 161fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Compression may be less efficient stopping and starting around flushes. 162fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Returns true if no error. 163a3b2a6da25a76f17c73d31def3952feb0fd2296eJeff Davidson // 164a3b2a6da25a76f17c73d31def3952feb0fd2296eJeff Davidson // Please ensure that block size is > 6. Here is an excerpt from the zlib 165a3b2a6da25a76f17c73d31def3952feb0fd2296eJeff Davidson // doc that explains why: 166a3b2a6da25a76f17c73d31def3952feb0fd2296eJeff Davidson // 167a3b2a6da25a76f17c73d31def3952feb0fd2296eJeff Davidson // In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that avail_out 168a3b2a6da25a76f17c73d31def3952feb0fd2296eJeff Davidson // is greater than six to avoid repeated flush markers due to 169a3b2a6da25a76f17c73d31def3952feb0fd2296eJeff Davidson // avail_out == 0 on return. 170fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville bool Flush(); 171fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 172fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Writes out all data and closes the gzip stream. 173fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // It is the caller's responsibility to close the underlying stream if 174fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // necessary. 175fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Returns true if no error. 176fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville bool Close(); 177fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 178fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // implements ZeroCopyOutputStream --------------------------------- 179fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville bool Next(void** data, int* size); 180fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville void BackUp(int count); 181fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville int64 ByteCount() const; 182fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 183fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville private: 184fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville ZeroCopyOutputStream* sub_stream_; 185fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Result from calling Next() on sub_stream_ 186fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville void* sub_data_; 187fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville int sub_data_size_; 188fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 189fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville z_stream zcontext_; 190fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville int zerror_; 191fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville void* input_buffer_; 192fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville size_t input_buffer_length_; 193fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 194fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Shared constructor code. 195fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville void Init(ZeroCopyOutputStream* sub_stream, const Options& options); 196fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 197fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Do some compression. 198fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Takes zlib flush mode. 199fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville // Returns zlib error code. 200fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville int Deflate(int flush); 201fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 202fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(GzipOutputStream); 203fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville}; 204fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 205fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville} // namespace io 206fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville} // namespace protobuf 207fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville 208fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville} // namespace google 209fbaaef999ba563838ebd00874ed8a1c01fbf286dWink Saville#endif // GOOGLE_PROTOBUF_IO_GZIP_STREAM_H__ 210