protoio.cc revision 9399:f7582cce2459 
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    zeroCopyStream(NULL), gzipStream(NULL), codedStream(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    zeroCopyStream = 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(zeroCopyStream);
60        codedStream = new io::CodedOutputStream(gzipStream);
61    } else {
62        codedStream = new io::CodedOutputStream(zeroCopyStream);
63    }
64
65    // Write the magic number to the file
66    codedStream->WriteLittleEndian32(magicNumber);
67
68    // Note that each type of stream (packet, instruction etc) should
69    // add its own header and perform the appropriate checks
70}
71
72ProtoOutputStream::~ProtoOutputStream()
73{
74    delete codedStream;
75    // As the compression is optional, see if the stream exists
76    if (gzipStream != NULL)
77        delete gzipStream;
78    delete zeroCopyStream;
79    fileStream.close();
80}
81
82void
83ProtoOutputStream::write(const Message& msg)
84{
85    // Write the size of the message to the stream
86    codedStream->WriteVarint32(msg.ByteSize());
87
88    // Write the message itself to the stream
89    if (!msg.SerializeToCodedStream(codedStream))
90        panic("Unable to write message to coded stream\n");
91}
92
93ProtoInputStream::ProtoInputStream(const string& filename) :
94    fileStream(filename, ios::in | ios::binary), fileName(filename),
95    useGzip(false),
96    zeroCopyStream(NULL), gzipStream(NULL), codedStream(NULL)
97{
98    if (!fileStream.good())
99        panic("Could not open %s for reading\n", filename);
100
101    // check the magic number to see if this is a gzip stream
102    unsigned char bytes[2];
103    fileStream.read((char*) bytes, 2);
104    useGzip = fileStream.good() && bytes[0] == 0x1f && bytes[1] == 0x8b;
105
106    // seek to the start of the input file and clear any flags
107    fileStream.clear();
108    fileStream.seekg(0, ifstream::beg);
109
110    createStreams();
111}
112
113void
114ProtoInputStream::createStreams()
115{
116    // All streams should be NULL at this point
117    assert(zeroCopyStream == NULL && gzipStream == NULL &&
118           codedStream == NULL);
119
120    // Wrap the input file in a zero copy stream, that in turn is
121    // wrapped in a gzip stream if the filename ends with .gz. The
122    // latter stream is in turn wrapped in a coded stream
123    zeroCopyStream = new io::IstreamInputStream(&fileStream);
124    if (useGzip) {
125        gzipStream = new io::GzipInputStream(zeroCopyStream);
126        codedStream = new io::CodedInputStream(gzipStream);
127    } else {
128        codedStream = new io::CodedInputStream(zeroCopyStream);
129    }
130
131    uint32_t magic_check;
132    if (!codedStream->ReadLittleEndian32(&magic_check) ||
133        magic_check != magicNumber)
134        panic("Input file %s is not a valid gem5 proto format.\n",
135              fileName);
136}
137
138void
139ProtoInputStream::destroyStreams()
140{
141    delete codedStream;
142    codedStream = NULL;
143    // As the compression is optional, see if the stream exists
144    if (gzipStream != NULL) {
145        delete gzipStream;
146        gzipStream = NULL;
147    }
148    delete zeroCopyStream;
149    zeroCopyStream = NULL;
150}
151
152
153ProtoInputStream::~ProtoInputStream()
154{
155    destroyStreams();
156    fileStream.close();
157}
158
159
160void
161ProtoInputStream::reset()
162{
163    destroyStreams();
164    // seek to the start of the input file and clear any flags
165    fileStream.clear();
166    fileStream.seekg(0, ifstream::beg);
167    createStreams();
168}
169
170bool
171ProtoInputStream::read(Message& msg)
172{
173    // Read a message from the stream by getting the size, using it as
174    // a limit when parsing the message, then popping the limit again
175    uint32_t size;
176    if (codedStream->ReadVarint32(&size)) {
177        io::CodedInputStream::Limit limit = codedStream->PushLimit(size);
178        if (msg.ParseFromCodedStream(codedStream)) {
179            codedStream->PopLimit(limit);
180            // All went well, the message is parsed and the limit is
181            // popped again
182            return true;
183        } else {
184            panic("Unable to read message from coded stream %s\n",
185                  fileName);
186        }
187    }
188
189    return false;
190}
191