1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
|
/**************************************************************************
*
* Copyright 2015 VMware, Inc
* Copyright 2011 Zack Rusin
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
**************************************************************************/
#include "trace_ostream.hpp"
#include <fstream>
#include <assert.h>
#include <string.h>
#include <snappy.h>
#include "os.hpp"
#include "trace_snappy.hpp"
#define SNAPPY_CHUNK_SIZE (1 * 1024 * 1024)
using namespace trace;
class SnappyOutStream : public OutStream {
public:
SnappyOutStream(const char *filename);
~SnappyOutStream();
SnappyOutStream(void);
bool write(const void *buffer, size_t length) override;
void flush(void) override;
bool isOpen(void) {
return m_stream.is_open();
}
private:
void close(void);
inline size_t usedCacheSize(void) const
{
assert(m_cachePtr >= m_cache);
return m_cachePtr - m_cache;
}
inline size_t freeCacheSize(void) const
{
assert(m_cacheSize >= usedCacheSize());
if (m_cacheSize > 0) {
return m_cacheSize - usedCacheSize();
} else {
return 0;
}
}
inline bool endOfData(void) const
{
return m_stream.eof() && freeCacheSize() == 0;
}
void flushWriteCache(void);
void createCache(size_t size);
void writeCompressedLength(size_t length);
private:
std::ofstream m_stream;
size_t m_cacheMaxSize;
size_t m_cacheSize;
char *m_cache;
char *m_cachePtr;
char *m_compressedCache;
};
SnappyOutStream::SnappyOutStream(const char *filename)
: m_cacheMaxSize(SNAPPY_CHUNK_SIZE),
m_cacheSize(m_cacheMaxSize),
m_cache(new char [m_cacheMaxSize]),
m_cachePtr(m_cache)
{
size_t maxCompressedLength =
snappy::MaxCompressedLength(SNAPPY_CHUNK_SIZE);
m_compressedCache = new char[maxCompressedLength];
std::ios_base::openmode fmode = std::fstream::binary
| std::fstream::out
| std::fstream::trunc;
m_stream.open(filename, fmode);
if (m_stream.is_open()) {
m_stream << SNAPPY_BYTE1;
m_stream << SNAPPY_BYTE2;
m_stream.flush();
}
}
SnappyOutStream::~SnappyOutStream()
{
close();
delete [] m_compressedCache;
delete [] m_cache;
}
bool SnappyOutStream::write(const void *buffer, size_t length)
{
if (freeCacheSize() > length) {
memcpy(m_cachePtr, buffer, length);
m_cachePtr += length;
} else if (freeCacheSize() == length) {
memcpy(m_cachePtr, buffer, length);
m_cachePtr += length;
flushWriteCache();
} else {
size_t sizeToWrite = length;
while (sizeToWrite >= freeCacheSize()) {
size_t endSize = freeCacheSize();
size_t offset = length - sizeToWrite;
memcpy(m_cachePtr, (const char*)buffer + offset, endSize);
sizeToWrite -= endSize;
m_cachePtr += endSize;
flushWriteCache();
}
if (sizeToWrite) {
size_t offset = length - sizeToWrite;
memcpy(m_cachePtr, (const char*)buffer + offset, sizeToWrite);
m_cachePtr += sizeToWrite;
}
}
return true;
}
void SnappyOutStream::close(void)
{
flushWriteCache();
m_stream.close();
delete [] m_cache;
m_cache = NULL;
m_cachePtr = NULL;
}
void SnappyOutStream::flush(void)
{
flushWriteCache();
m_stream.flush();
}
void SnappyOutStream::flushWriteCache(void)
{
size_t inputLength = usedCacheSize();
if (inputLength) {
size_t compressedLength;
::snappy::RawCompress(m_cache, inputLength,
m_compressedCache, &compressedLength);
writeCompressedLength(compressedLength);
m_stream.write(m_compressedCache, compressedLength);
m_cachePtr = m_cache;
}
assert(m_cachePtr == m_cache);
}
void SnappyOutStream::writeCompressedLength(size_t length)
{
unsigned char buf[4];
buf[0] = length & 0xff; length >>= 8;
buf[1] = length & 0xff; length >>= 8;
buf[2] = length & 0xff; length >>= 8;
buf[3] = length & 0xff; length >>= 8;
assert(length == 0);
m_stream.write((const char *)buf, sizeof buf);
}
OutStream *
trace::createSnappyStream(const char *filename)
{
SnappyOutStream *outStream = new SnappyOutStream(filename);
if (!outStream->isOpen()) {
os::log("error: could not open %s for writing\n", filename);
delete outStream;
outStream = nullptr;
}
return outStream;
}
|
