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
|
//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2018
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include "td/utils/Gzip.h"
char disable_linker_warning_about_empty_file_gzip_cpp TD_UNUSED;
#if TD_HAVE_ZLIB
#include "td/utils/logging.h"
#include <cstring>
#include <limits>
#include <zlib.h>
namespace td {
class Gzip::Impl {
public:
z_stream stream_;
// z_stream is not copyable nor movable
Impl() = default;
Impl(const Impl &other) = delete;
Impl &operator=(const Impl &other) = delete;
Impl(Impl &&other) = delete;
Impl &operator=(Impl &&other) = delete;
~Impl() = default;
};
Status Gzip::init_encode() {
CHECK(mode_ == Empty);
init_common();
mode_ = Encode;
int ret = deflateInit2(&impl_->stream_, 6, Z_DEFLATED, 15, MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
if (ret != Z_OK) {
return Status::Error("zlib deflate init failed");
}
return Status::OK();
}
Status Gzip::init_decode() {
CHECK(mode_ == Empty);
init_common();
mode_ = Decode;
int ret = inflateInit2(&impl_->stream_, MAX_WBITS + 32);
if (ret != Z_OK) {
return Status::Error("zlib inflate init failed");
}
return Status::OK();
}
void Gzip::set_input(Slice input) {
CHECK(input_size_ == 0);
CHECK(!close_input_flag_);
CHECK(input.size() <= std::numeric_limits<uInt>::max());
CHECK(impl_->stream_.avail_in == 0);
input_size_ = input.size();
impl_->stream_.avail_in = static_cast<uInt>(input.size());
impl_->stream_.next_in = reinterpret_cast<Bytef *>(const_cast<char *>(input.data()));
}
void Gzip::set_output(MutableSlice output) {
CHECK(output_size_ == 0);
CHECK(output.size() <= std::numeric_limits<uInt>::max());
CHECK(impl_->stream_.avail_out == 0);
output_size_ = output.size();
impl_->stream_.avail_out = static_cast<uInt>(output.size());
impl_->stream_.next_out = reinterpret_cast<Bytef *>(output.data());
}
Result<Gzip::State> Gzip::run() {
while (true) {
int ret;
if (mode_ == Decode) {
ret = inflate(&impl_->stream_, Z_NO_FLUSH);
} else {
ret = deflate(&impl_->stream_, close_input_flag_ ? Z_FINISH : Z_NO_FLUSH);
}
if (ret == Z_OK) {
return Running;
}
if (ret == Z_STREAM_END) {
// TODO(now): fail if input is not empty;
clear();
return Done;
}
clear();
return Status::Error(PSLICE() << "zlib error " << ret);
}
}
size_t Gzip::left_input() const {
return impl_->stream_.avail_in;
}
size_t Gzip::left_output() const {
return impl_->stream_.avail_out;
}
void Gzip::init_common() {
std::memset(&impl_->stream_, 0, sizeof(impl_->stream_));
impl_->stream_.zalloc = Z_NULL;
impl_->stream_.zfree = Z_NULL;
impl_->stream_.opaque = Z_NULL;
impl_->stream_.avail_in = 0;
impl_->stream_.next_in = nullptr;
impl_->stream_.avail_out = 0;
impl_->stream_.next_out = nullptr;
input_size_ = 0;
output_size_ = 0;
close_input_flag_ = false;
}
void Gzip::clear() {
if (mode_ == Decode) {
inflateEnd(&impl_->stream_);
} else if (mode_ == Encode) {
deflateEnd(&impl_->stream_);
}
mode_ = Empty;
}
Gzip::Gzip() : impl_(make_unique<Impl>()) {
}
Gzip::Gzip(Gzip &&other) = default;
Gzip &Gzip::operator=(Gzip &&other) = default;
Gzip::~Gzip() {
clear();
}
BufferSlice gzdecode(Slice s) {
Gzip gzip;
gzip.init_decode().ensure();
auto message = ChainBufferWriter::create_empty();
gzip.set_input(s);
gzip.close_input();
double k = 2;
gzip.set_output(message.prepare_append(static_cast<size_t>(static_cast<double>(s.size()) * k)));
while (true) {
auto r_state = gzip.run();
if (r_state.is_error()) {
return BufferSlice();
}
auto state = r_state.ok();
if (state == Gzip::Done) {
message.confirm_append(gzip.flush_output());
break;
}
if (gzip.need_input()) {
return BufferSlice();
}
if (gzip.need_output()) {
message.confirm_append(gzip.flush_output());
k *= 1.5;
gzip.set_output(message.prepare_append(static_cast<size_t>(static_cast<double>(gzip.left_input()) * k)));
}
}
return message.extract_reader().move_as_buffer_slice();
}
BufferSlice gzencode(Slice s, double k) {
Gzip gzip;
gzip.init_encode().ensure();
gzip.set_input(s);
gzip.close_input();
size_t max_size = static_cast<size_t>(static_cast<double>(s.size()) * k);
BufferWriter message{max_size};
gzip.set_output(message.prepare_append());
auto r_state = gzip.run();
if (r_state.is_error()) {
return BufferSlice();
}
auto state = r_state.ok();
if (state != Gzip::Done) {
return BufferSlice();
}
message.confirm_append(gzip.flush_output());
return message.as_buffer_slice();
}
} // namespace td
#endif
|
