protoio.cc revision 9705:177e8d8e50fc 
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#include "base/misc.hh"
41#include "proto/protoio.hh"
42
43using namespace std;
44using namespace google::protobuf;
45
46ProtoOutputStream::ProtoOutputStream(const string& filename) :
47    fileStream(filename.c_str(), ios::out | ios::binary | ios::trunc),
48    wrappedFileStream(NULL), gzipStream(NULL), zeroCopyStream(NULL)
49{
50    if (!fileStream.good())
51        panic("Could not open %s for writing\n", filename);
52
53    // Wrap the output file in a zero copy stream, that in turn is
54    // wrapped in a gzip stream if the filename ends with .gz. The
55    // latter stream is in turn wrapped in a coded stream
56    wrappedFileStream = new io::OstreamOutputStream(&fileStream);
57    if (filename.find_last_of('.') != string::npos &&
58        filename.substr(filename.find_last_of('.') + 1) == "gz") {
59        gzipStream = new io::GzipOutputStream(wrappedFileStream);
60        zeroCopyStream = gzipStream;
61    } else {
62        zeroCopyStream = wrappedFileStream;
63    }
64
65    // Write the magic number to the file
66    io::CodedOutputStream codedStream(zeroCopyStream);
67    codedStream.WriteLittleEndian32(magicNumber);
68
69    // Note that each type of stream (packet, instruction etc) should
70    // add its own header and perform the appropriate checks
71}
72
73ProtoOutputStream::~ProtoOutputStream()
74{
75    // As the compression is optional, see if the stream exists
76    if (gzipStream != NULL)
77        delete gzipStream;
78    delete wrappedFileStream;
79    fileStream.close();
80}
81
82void
83ProtoOutputStream::write(const Message& msg)
84{
85    // Due to the byte limit of the coded stream we create it for
86    // every single mesage (based on forum discussions around the size
87    // limitation)
88    io::CodedOutputStream codedStream(zeroCopyStream);
89
90    // Write the size of the message to the stream
91    codedStream.WriteVarint32(msg.ByteSize());
92
93    // Write the message itself to the stream
94    msg.SerializeWithCachedSizes(&codedStream);
95}
96
97ProtoInputStream::ProtoInputStream(const string& filename) :
98    fileStream(filename.c_str(), ios::in | ios::binary), fileName(filename),
99    useGzip(false),
100    wrappedFileStream(NULL), gzipStream(NULL), zeroCopyStream(NULL)
101{
102    if (!fileStream.good())
103        panic("Could not open %s for reading\n", filename);
104
105    // check the magic number to see if this is a gzip stream
106    unsigned char bytes[2];
107    fileStream.read((char*) bytes, 2);
108    useGzip = fileStream.good() && bytes[0] == 0x1f && bytes[1] == 0x8b;
109
110    // seek to the start of the input file and clear any flags
111    fileStream.clear();
112    fileStream.seekg(0, ifstream::beg);
113
114    createStreams();
115}
116
117void
118ProtoInputStream::createStreams()
119{
120    // All streams should be NULL at this point
121    assert(wrappedFileStream == NULL && gzipStream == NULL &&
122           zeroCopyStream == NULL);
123
124    // Wrap the input file in a zero copy stream, that in turn is
125    // wrapped in a gzip stream if the filename ends with .gz. The
126    // latter stream is in turn wrapped in a coded stream
127    wrappedFileStream = new io::IstreamInputStream(&fileStream);
128    if (useGzip) {
129        gzipStream = new io::GzipInputStream(wrappedFileStream);
130        zeroCopyStream = gzipStream;
131    } else {
132        zeroCopyStream = wrappedFileStream;
133    }
134
135    uint32_t magic_check;
136    io::CodedInputStream codedStream(zeroCopyStream);
137    if (!codedStream.ReadLittleEndian32(&magic_check) ||
138        magic_check != magicNumber)
139        panic("Input file %s is not a valid gem5 proto format.\n",
140              fileName);
141}
142
143void
144ProtoInputStream::destroyStreams()
145{
146    // As the compression is optional, see if the stream exists
147    if (gzipStream != NULL) {
148        delete gzipStream;
149        gzipStream = NULL;
150    }
151    delete wrappedFileStream;
152    wrappedFileStream = NULL;
153
154    zeroCopyStream = NULL;
155}
156
157
158ProtoInputStream::~ProtoInputStream()
159{
160    destroyStreams();
161    fileStream.close();
162}
163
164
165void
166ProtoInputStream::reset()
167{
168    destroyStreams();
169    // seek to the start of the input file and clear any flags
170    fileStream.clear();
171    fileStream.seekg(0, ifstream::beg);
172    createStreams();
173}
174
175bool
176ProtoInputStream::read(Message& msg)
177{
178    // Read a message from the stream by getting the size, using it as
179    // a limit when parsing the message, then popping the limit again
180    uint32_t size;
181
182    // Due to the byte limit of the coded stream we create it for
183    // every single mesage (based on forum discussions around the size
184    // limitation)
185    io::CodedInputStream codedStream(zeroCopyStream);
186    if (codedStream.ReadVarint32(&size)) {
187        io::CodedInputStream::Limit limit = codedStream.PushLimit(size);
188        if (msg.ParseFromCodedStream(&codedStream)) {
189            codedStream.PopLimit(limit);
190            // All went well, the message is parsed and the limit is
191            // popped again
192            return true;
193        } else {
194            panic("Unable to read message from coded stream %s\n",
195                  fileName);
196        }
197    }
198
199    return false;
200}
201