-
Notifications
You must be signed in to change notification settings - Fork 5
/
Copy pathizstream_impl.hpp
223 lines (182 loc) · 7.6 KB
/
izstream_impl.hpp
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
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
/*
zstream-cpp Library License:
--------------------------
The zlib/libpng License Copyright (c) 2003 Jonathan de Halleux.
This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution
Author: Jonathan de Halleux, [email protected], 2003
Gero Mueller, [email protected], 2015
*/
#ifndef INPUT_ZIP_STREAM_IMPL_HPP
#define INPUT_ZIP_STREAM_IMPL_HPP
#include "izstream.hpp"
#include <sstream>
#include <cstring>
namespace zstream {
template<typename Elem, typename Tr, typename ElemA, typename ByteT,
typename ByteAT>
basic_unzip_streambuf<Elem, Tr, ElemA, ByteT, ByteAT>::basic_unzip_streambuf(
istream_reference istream_, size_t window_size_,
size_t read_buffer_size_, size_t input_buffer_size_) :
m_istream(istream_), m_input_buffer(input_buffer_size_), m_buffer(
read_buffer_size_), m_crc(0) {
// setting zalloc, zfree and opaque
m_zip_stream.zalloc = (alloc_func) 0;
m_zip_stream.zfree = (free_func) 0;
m_zip_stream.next_in = NULL;
m_zip_stream.avail_in = 0;
m_zip_stream.avail_out = 0;
m_zip_stream.next_out = NULL;
m_err = inflateInit2(&m_zip_stream, -static_cast<int>(window_size_));
this->setg(&(m_buffer[0]) + 4, // beginning of putback area
&(m_buffer[0]) + 4, // read position
&(m_buffer[0]) + 4); // end position
}
template<typename Elem, typename Tr, typename ElemA, typename ByteT,
typename ByteAT>
size_t basic_unzip_streambuf<Elem, Tr, ElemA, ByteT, ByteAT>::fill_input_buffer() {
m_zip_stream.next_in = &(m_input_buffer[0]);
m_istream.read((char_type*) (&(m_input_buffer[0])),
static_cast<std::streamsize>(m_input_buffer.size()
/ sizeof(char_type)));
return m_zip_stream.avail_in = m_istream.gcount() * sizeof(char_type);
}
template<typename Elem, typename Tr, typename ElemA, typename ByteT,
typename ByteAT>
basic_unzip_streambuf<Elem, Tr, ElemA, ByteT, ByteAT>::~basic_unzip_streambuf() {
inflateEnd(&m_zip_stream);
}
template<typename Elem, typename Tr, typename ElemA, typename ByteT,
typename ByteAT>
typename basic_unzip_streambuf<Elem, Tr, ElemA, ByteT, ByteAT>::int_type basic_unzip_streambuf<
Elem, Tr, ElemA, ByteT, ByteAT>::underflow() {
if (this->gptr() && (this->gptr() < this->egptr()))
return *reinterpret_cast<unsigned char *>(this->gptr());
int n_putback = static_cast<int>(this->gptr() - this->eback());
if (n_putback > 4)
n_putback = 4;
memcpy(&(m_buffer[0]) + (4 - n_putback), this->gptr() - n_putback,
n_putback * sizeof(char_type));
int num = unzip_from_stream(&(m_buffer[0]) + 4,
static_cast<std::streamsize>((m_buffer.size() - 4)
* sizeof(char_type)));
if (num <= 0) // ERROR or EOF
return EOF;
// reset buffer pointers
this->setg(&(m_buffer[0]) + (4 - n_putback), // beginning of putback area
&(m_buffer[0]) + 4, // read position
&(m_buffer[0]) + 4 + num); // end of buffer
// return next character
return *reinterpret_cast<unsigned char *>(this->gptr());
}
template<typename Elem, typename Tr, typename ElemA, typename ByteT,
typename ByteAT>
std::streamsize basic_unzip_streambuf<Elem, Tr, ElemA, ByteT, ByteAT>::unzip_from_stream(
char_type* buffer_, std::streamsize buffer_size_) {
m_zip_stream.next_out = (byte_buffer_type) buffer_;
m_zip_stream.avail_out =
static_cast<uInt>(buffer_size_ * sizeof(char_type));
size_t count = m_zip_stream.avail_in;
do {
if (m_zip_stream.avail_in == 0)
count = fill_input_buffer();
if (m_zip_stream.avail_in) {
m_err = inflate(&m_zip_stream, Z_SYNC_FLUSH);
}
} while (m_err == Z_OK && m_zip_stream.avail_out != 0 && count != 0);
// updating crc
m_crc = crc32(m_crc, (byte_buffer_type) buffer_,
buffer_size_ - m_zip_stream.avail_out / sizeof(char_type));
std::streamsize n_read = buffer_size_
- m_zip_stream.avail_out / sizeof(char_type);
// check if it is the end
if (m_err == Z_STREAM_END)
put_back_from_zip_stream();
return n_read;
}
template<typename Elem, typename Tr, typename ElemA, typename ByteT,
typename ByteAT>
void basic_unzip_streambuf<Elem, Tr, ElemA, ByteT, ByteAT>::put_back_from_zip_stream() {
if (m_zip_stream.avail_in == 0)
return;
m_istream.clear(std::ios::goodbit);
m_istream.seekg(-static_cast<int>(m_zip_stream.avail_in),
std::ios_base::cur);
m_zip_stream.avail_in = 0;
}
template<typename Elem, typename Tr, typename ElemA, typename ByteT,
typename ByteAT>
int basic_gzip_istream<Elem, Tr, ElemA, ByteT, ByteAT>::check_header() {
int method; /* method byte */
int flags; /* flags byte */
uInt len;
int c;
int err = 0;
z_stream& zip_stream = this->rdbuf()->get_zip_stream();
/* Check the gzip magic header */
for (len = 0; len < 2; len++) {
c = (int) this->rdbuf()->get_istream().get();
if (c != detail::gz_magic[len]) {
if (len != 0)
this->rdbuf()->get_istream().unget();
if (c != EOF) {
this->rdbuf()->get_istream().unget();
}
err = zip_stream.avail_in != 0 ? Z_OK : Z_STREAM_END;
return err;
}
}
method = (int) this->rdbuf()->get_istream().get();
flags = (int) this->rdbuf()->get_istream().get();
if (method != Z_DEFLATED || (flags & detail::gz_reserved) != 0) {
err = Z_DATA_ERROR;
return err;
}
/* Discard time, xflags and OS code: */
for (len = 0; len < 6; len++)
this->rdbuf()->get_istream().get();
if ((flags & detail::gz_extra_field) != 0) {
/* skip the extra field */
len = (uInt) this->rdbuf()->get_istream().get();
len += ((uInt) this->rdbuf()->get_istream().get()) << 8;
/* len is garbage if EOF but the loop below will quit anyway */
while (len-- != 0 && this->rdbuf()->get_istream().get() != EOF)
;
}
if ((flags & detail::gz_orig_name) != 0) {
/* skip the original file name */
while ((c = this->rdbuf()->get_istream().get()) != 0 && c != EOF)
;
}
if ((flags & detail::gz_comment) != 0) {
/* skip the .gz file comment */
while ((c = this->rdbuf()->get_istream().get()) != 0 && c != EOF)
;
}
if ((flags & detail::gz_head_crc) != 0) { /* skip the header crc */
for (len = 0; len < 2; len++)
this->rdbuf()->get_istream().get();
}
err = this->rdbuf()->get_istream().eof() ? Z_DATA_ERROR : Z_OK;
return err;
}
template<typename Elem, typename Tr, typename ElemA, typename ByteT,
typename ByteAT>
void basic_gzip_istream<Elem, Tr, ElemA, ByteT, ByteAT>::read_footer() {
read_long(this->rdbuf()->get_istream(), m_gzip_crc);
read_long(this->rdbuf()->get_istream(), m_gzip_data_size);
}
template<typename Elem, typename Tr, typename ElemA, typename ByteT,
typename ByteAT>
void basic_gzip_istream<Elem, Tr, ElemA, ByteT, ByteAT>::read_long(
istream_reference in_, unsigned int& x_) {
static const int size_ul = sizeof(unsigned int);
static const int size_c = sizeof(char_type);
static const int n_end = size_ul / size_c;
in_.read(reinterpret_cast<char*>(&x_), n_end);
}
} // zstream
#endif