protoio.hh revision 9397:6e6b8d8ab258
1/* 2 * Copyright (c) 2012 ARM Limited 3 * All rights reserved 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions are 16 * met: redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer; 18 * redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution; 21 * neither the name of the copyright holders nor the names of its 22 * contributors may be used to endorse or promote products derived from 23 * this software without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 * 37 * Authors: Andreas Hansson 38 */ 39 40 41/** 42 * @file 43 * Declaration of a wrapper for protobuf output streams. 44 */ 45 46#ifndef __PROTO_PROTOIO_HH__ 47#define __PROTO_PROTOIO_HH__ 48 49#include <google/protobuf/io/coded_stream.h> 50#include <google/protobuf/io/gzip_stream.h> 51#include <google/protobuf/io/zero_copy_stream_impl.h> 52#include <google/protobuf/message.h> 53 54#include <fstream> 55 56/** 57 * A ProtoOutputStream wraps a coded stream, potentially with 58 * compression, based on looking at the file name. Writing to the 59 * stream is done to enable interaction with the file on a per-message 60 * basis to avoid having to deal with huge data structures. The latter 61 * is made possible by encoding the length of each message in the 62 * stream. 63 */ 64class ProtoOutputStream 65{ 66 67 public: 68 69 /** 70 * Create an output stream for a given file name. If the filename 71 * ends with .gz then the file will be compressed accordinly. 72 * 73 * @param filename Path to the file to create or truncate 74 */ 75 ProtoOutputStream(const std::string& filename); 76 77 /** 78 * Destruct the output stream, and also flush and close the 79 * underlying file streams and coded streams. 80 */ 81 ~ProtoOutputStream(); 82 83 /** 84 * Write a message to the stream, preprending it with the message 85 * size. 86 * 87 * @param msg Message to write to the stream 88 */ 89 void write(const google::protobuf::Message& msg); 90 91 private: 92 93 /// Underlying file output stream 94 std::ofstream fileStream; 95 96 /// Zero Copy stream wrapping the STL output stream 97 google::protobuf::io::OstreamOutputStream* zeroCopyStream; 98 99 /// Optional Gzip stream to wrap the Zero Copy stream 100 google::protobuf::io::GzipOutputStream* gzipStream; 101 102 /// Top-level coded stream that messages are written to 103 google::protobuf::io::CodedOutputStream* codedStream; 104 105}; 106 107#endif //__PROTO_PROTOIO_HH 108