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 "proto/protoio.hh"
41
42#include "base/logging.hh"
43
44using namespace std;
45using namespace google::protobuf;
46
47ProtoOutputStream::ProtoOutputStream(const string& filename) :
48    fileStream(filename.c_str(), ios::out | ios::binary | ios::trunc),
49    wrappedFileStream(NULL), gzipStream(NULL), zeroCopyStream(NULL)
50{
51    if (!fileStream.good())
52        panic("Could not open %s for writing\n", filename);
53
54    // Wrap the output file in a zero copy stream, that in turn is
55    // wrapped in a gzip stream if the filename ends with .gz. The
56    // latter stream is in turn wrapped in a coded stream
57    wrappedFileStream = new io::OstreamOutputStream(&fileStream);
58    if (filename.find_last_of('.') != string::npos &&
59        filename.substr(filename.find_last_of('.') + 1) == "gz") {
60        gzipStream = new io::GzipOutputStream(wrappedFileStream);
61        zeroCopyStream = gzipStream;
62    } else {
63        zeroCopyStream = wrappedFileStream;
64    }
65
66    // Write the magic number to the file
67    io::CodedOutputStream codedStream(zeroCopyStream);
68    codedStream.WriteLittleEndian32(magicNumber);
69
70    // Note that each type of stream (packet, instruction etc) should
71    // add its own header and perform the appropriate checks
72}
73
74ProtoOutputStream::~ProtoOutputStream()
75{
76    // As the compression is optional, see if the stream exists
77    if (gzipStream != NULL)
78        delete gzipStream;
79    delete wrappedFileStream;
80    fileStream.close();
81}
82
83void
84ProtoOutputStream::write(const Message& msg)
85{
86    // Due to the byte limit of the coded stream we create it for
87    // every single mesage (based on forum discussions around the size
88    // limitation)
89    io::CodedOutputStream codedStream(zeroCopyStream);
90
91    // Write the size of the message to the stream
92    codedStream.WriteVarint32(msg.ByteSize());
93
94    // Write the message itself to the stream
95    msg.SerializeWithCachedSizes(&codedStream);
96}
97
98ProtoInputStream::ProtoInputStream(const string& filename) :
99    fileStream(filename.c_str(), ios::in | ios::binary), fileName(filename),
100    useGzip(false),
101    wrappedFileStream(NULL), gzipStream(NULL), zeroCopyStream(NULL)
102{
103    if (!fileStream.good())
104        panic("Could not open %s for reading\n", filename);
105
106    // check the magic number to see if this is a gzip stream
107    unsigned char bytes[2];
108    fileStream.read((char*) bytes, 2);
109    useGzip = fileStream.good() && bytes[0] == 0x1f && bytes[1] == 0x8b;
110
111    // seek to the start of the input file and clear any flags
112    fileStream.clear();
113    fileStream.seekg(0, ifstream::beg);
114
115    createStreams();
116}
117
118void
119ProtoInputStream::createStreams()
120{
121    // All streams should be NULL at this point
122    assert(wrappedFileStream == NULL && gzipStream == NULL &&
123           zeroCopyStream == NULL);
124
125    // Wrap the input file in a zero copy stream, that in turn is
126    // wrapped in a gzip stream if the filename ends with .gz. The
127    // latter stream is in turn wrapped in a coded stream
128    wrappedFileStream = new io::IstreamInputStream(&fileStream);
129    if (useGzip) {
130        gzipStream = new io::GzipInputStream(wrappedFileStream);
131        zeroCopyStream = gzipStream;
132    } else {
133        zeroCopyStream = wrappedFileStream;
134    }
135
136    uint32_t magic_check;
137    io::CodedInputStream codedStream(zeroCopyStream);
138    if (!codedStream.ReadLittleEndian32(&magic_check) ||
139        magic_check != magicNumber)
140        panic("Input file %s is not a valid gem5 proto format.\n",
141              fileName);
142}
143
144void
145ProtoInputStream::destroyStreams()
146{
147    // As the compression is optional, see if the stream exists
148    if (gzipStream != NULL) {
149        delete gzipStream;
150        gzipStream = NULL;
151    }
152    delete wrappedFileStream;
153    wrappedFileStream = NULL;
154
155    zeroCopyStream = NULL;
156}
157
158
159ProtoInputStream::~ProtoInputStream()
160{
161    destroyStreams();
162    fileStream.close();
163}
164
165
166void
167ProtoInputStream::reset()
168{
169    destroyStreams();
170    // seek to the start of the input file and clear any flags
171    fileStream.clear();
172    fileStream.seekg(0, ifstream::beg);
173    createStreams();
174}
175
176bool
177ProtoInputStream::read(Message& msg)
178{
179    // Read a message from the stream by getting the size, using it as
180    // a limit when parsing the message, then popping the limit again
181    uint32_t size;
182
183    // Due to the byte limit of the coded stream we create it for
184    // every single mesage (based on forum discussions around the size
185    // limitation)
186    io::CodedInputStream codedStream(zeroCopyStream);
187    if (codedStream.ReadVarint32(&size)) {
188        io::CodedInputStream::Limit limit = codedStream.PushLimit(size);
189        if (msg.ParseFromCodedStream(&codedStream)) {
190            codedStream.PopLimit(limit);
191            // All went well, the message is parsed and the limit is
192            // popped again
193            return true;
194        } else {
195            panic("Unable to read message from coded stream %s\n",
196                  fileName);
197        }
198    }
199
200    return false;
201}
202