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
|
// *****************************************************************************
// * This file is part of the FreeFileSync project. It is distributed under *
// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0 *
// * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *
// *****************************************************************************
#include "zlib_wrap.h"
//Windows: use the SAME zlib version that wxWidgets is linking against! //C:\Data\Projects\wxWidgets\Source\src\zlib\zlib.h
//Linux/macOS: use zlib system header for both wxWidgets and libcurl (zlib is required for HTTP, SFTP)
// => don't compile wxWidgets with: --with-zlib=builtin
#include <zlib.h> //https://www.zlib.net/manual.html
#include <zen/scope_guard.h>
using namespace zen;
namespace
{
std::wstring formatZlibStatusCode(int sc)
{
switch (sc)
{
ZEN_CHECK_CASE_FOR_CONSTANT(Z_OK);
ZEN_CHECK_CASE_FOR_CONSTANT(Z_STREAM_END);
ZEN_CHECK_CASE_FOR_CONSTANT(Z_NEED_DICT);
ZEN_CHECK_CASE_FOR_CONSTANT(Z_ERRNO);
ZEN_CHECK_CASE_FOR_CONSTANT(Z_STREAM_ERROR);
ZEN_CHECK_CASE_FOR_CONSTANT(Z_DATA_ERROR);
ZEN_CHECK_CASE_FOR_CONSTANT(Z_MEM_ERROR);
ZEN_CHECK_CASE_FOR_CONSTANT(Z_BUF_ERROR);
ZEN_CHECK_CASE_FOR_CONSTANT(Z_VERSION_ERROR);
default:
return replaceCpy<std::wstring>(L"zlib status %x", L"%x", numberTo<std::wstring>(sc));
}
}
}
size_t zen::impl::zlib_compressBound(size_t len)
{
return ::compressBound(static_cast<uLong>(len)); //upper limit for buffer size, larger than input size!!!
}
size_t zen::impl::zlib_compress(const void* src, size_t srcLen, void* trg, size_t trgLen, int level) //throw SysError
{
uLongf bufferSize = static_cast<uLong>(trgLen);
const int rv = ::compress2(static_cast<Bytef*>(trg), //Bytef* dest,
&bufferSize, //uLongf* destLen,
static_cast<const Bytef*>(src), //const Bytef* source,
static_cast<uLong>(srcLen), //uLong sourceLen,
level); //int level
// Z_OK: success
// Z_MEM_ERROR: not enough memory
// Z_BUF_ERROR: not enough room in the output buffer
if (rv != Z_OK || bufferSize > trgLen)
throw SysError(formatSystemError(L"zlib compress2", formatZlibStatusCode(rv), L""));
return bufferSize;
}
size_t zen::impl::zlib_decompress(const void* src, size_t srcLen, void* trg, size_t trgLen) //throw SysError
{
uLongf bufferSize = static_cast<uLong>(trgLen);
const int rv = ::uncompress(static_cast<Bytef*>(trg), //Bytef* dest,
&bufferSize, //uLongf* destLen,
static_cast<const Bytef*>(src), //const Bytef* source,
static_cast<uLong>(srcLen)); //uLong sourceLen
// Z_OK: success
// Z_MEM_ERROR: not enough memory
// Z_BUF_ERROR: not enough room in the output buffer
// Z_DATA_ERROR: input data was corrupted or incomplete
if (rv != Z_OK || bufferSize > trgLen)
throw SysError(formatSystemError(L"zlib uncompress", formatZlibStatusCode(rv), L""));
return bufferSize;
}
class InputStreamAsGzip::Impl
{
public:
Impl(const std::function<size_t(void* buffer, size_t bytesToRead)>& readBlock /*throw X*/) : //throw SysError; returning 0 signals EOF: Posix read() semantics
readBlock_(readBlock)
{
const int windowBits = MAX_WBITS + 16; //"add 16 to windowBits to write a simple gzip header"
//"memLevel=1 uses minimum memory but is slow and reduces compression ratio; memLevel=9 uses maximum memory for optimal speed.
const int memLevel = 9; //test; 280 MB installer file: level 9 shrinks runtime by ~8% compared to level 8 (==DEF_MEM_LEVEL) at the cost of 128 KB extra memory
static_assert(memLevel <= MAX_MEM_LEVEL);
const int rv = ::deflateInit2(&gzipStream_, //z_streamp strm
3 /*see db_file.cpp*/, //int level
Z_DEFLATED, //int method
windowBits, //int windowBits
memLevel, //int memLevel
Z_DEFAULT_STRATEGY); //int strategy
if (rv != Z_OK)
throw SysError(formatSystemError(L"zlib deflateInit2", formatZlibStatusCode(rv), L""));
}
~Impl()
{
[[maybe_unused]] const int rv = ::deflateEnd(&gzipStream_);
assert(rv == Z_OK);
}
size_t read(void* buffer, size_t bytesToRead) //throw SysError, X; return "bytesToRead" bytes unless end of stream!
{
if (bytesToRead == 0) //"read() with a count of 0 returns zero" => indistinguishable from end of file! => check!
throw std::logic_error("Contract violation! " + std::string(__FILE__) + ':' + numberTo<std::string>(__LINE__));
gzipStream_.next_out = static_cast<Bytef*>(buffer);
gzipStream_.avail_out = static_cast<uInt>(bytesToRead);
for (;;)
{
if (gzipStream_.avail_in == 0 && !eof_)
{
if (bufIn_.size() < bytesToRead)
bufIn_.resize(bytesToRead);
const size_t bytesRead = readBlock_(&bufIn_[0], bufIn_.size()); //throw X; returning 0 signals EOF: Posix read() semantics
gzipStream_.next_in = reinterpret_cast<z_const Bytef*>(&bufIn_[0]);
gzipStream_.avail_in = static_cast<uInt>(bytesRead);
if (bytesRead == 0)
eof_ = true;
}
const int rv = ::deflate(&gzipStream_, eof_ ? Z_FINISH : Z_NO_FLUSH);
if (rv == Z_STREAM_END)
return bytesToRead - gzipStream_.avail_out;
if (rv != Z_OK)
throw SysError(formatSystemError(L"zlib deflate", formatZlibStatusCode(rv), L""));
if (gzipStream_.avail_out == 0)
return bytesToRead;
}
}
private:
const std::function<size_t(void* buffer, size_t bytesToRead)> readBlock_; //throw X
bool eof_ = false;
std::vector<std::byte> bufIn_;
z_stream gzipStream_ = {};
};
zen::InputStreamAsGzip::InputStreamAsGzip(const std::function<size_t(void* buffer, size_t bytesToRead)>& readBlock /*throw X*/) : pimpl_(std::make_unique<Impl>(readBlock)) {} //throw SysError
zen::InputStreamAsGzip::~InputStreamAsGzip() {}
size_t zen::InputStreamAsGzip::read(void* buffer, size_t bytesToRead) { return pimpl_->read(buffer, bytesToRead); } //throw SysError, X
std::string zen::compressAsGzip(const void* buffer, size_t bufSize) //throw SysError
{
struct MemoryStreamAsGzip : InputStreamAsGzip
{
explicit MemoryStreamAsGzip(const std::function<size_t(void* buffer, size_t bytesToRead)>& readBlock /*throw X*/) : InputStreamAsGzip(readBlock) {} //throw SysError
static size_t getBlockSize() { return 128 * 1024; } //InputStreamAsGzip has no idea what it's wrapping => has no getBlockSize() member!
};
MemoryStreamAsGzip gzipStream([&](void* bufIn, size_t bytesToRead) //throw SysError
{
const size_t bytesRead = std::min(bufSize, bytesToRead);
std::memcpy(bufIn, buffer, bytesRead);
buffer = static_cast<const char*>(buffer) + bytesRead;
bufSize -= bytesRead;
return bytesRead; //returning 0 signals EOF: Posix read() semantics
});
return bufferedLoad<std::string>(gzipStream); //throw SysError
}
|
