1 | /*************************************************************************** |
2 | * Copyright (C) 2005-2014 by the Quassel Project * |
3 | * devel@quassel-irc.org * |
4 | * * |
5 | * This program is free software; you can redistribute it and/or modify * |
6 | * it under the terms of the GNU General Public License as published by * |
7 | * the Free Software Foundation; either version 2 of the License, or * |
8 | * (at your option) version 3. * |
9 | * * |
10 | * This program is distributed in the hope that it will be useful, * |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of * |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * |
13 | * GNU General Public License for more details. * |
14 | * * |
15 | * You should have received a copy of the GNU General Public License * |
16 | * along with this program; if not, write to the * |
17 | * Free Software Foundation, Inc., * |
18 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * |
19 | ***************************************************************************/ |
20 | |
21 | #include "compressor.h" |
22 | |
23 | #include <QTcpSocket> |
24 | #include <QTimer> |
25 | |
26 | #ifdef HAVE_ZLIB |
27 | # include <zlib.h> |
28 | #else |
29 | # define MINIZ_HEADER_FILE_ONLY |
30 | # include "../../3rdparty/miniz/miniz.c" |
31 | #endif |
32 | |
33 | const int maxBufferSize = 64 * 1024 * 1024; // protect us from zip bombs |
34 | const int ioBufferSize = 64 * 1024; // chunk size for inflate/deflate; should not be too large as we preallocate that space! |
35 | |
36 | Compressor::Compressor(QTcpSocket *socket, Compressor::CompressionLevel level, QObject *parent) |
37 | : QObject(parent), |
38 | _socket(socket), |
39 | _level(level), |
40 | _inflater(0), |
41 | _deflater(0) |
42 | { |
43 | connect(socket, SIGNAL(readyRead()), SLOT(readData())); |
44 | |
45 | bool ok = true; |
46 | if (level != NoCompression) |
47 | ok = initStreams(); |
48 | |
49 | if (!ok) { |
50 | // something went wrong during initialization... but we can only emit an error after RemotePeer has connected its signal |
51 | QTimer::singleShot(0, this, SIGNAL(error())); |
52 | return; |
53 | } |
54 | |
55 | // It's possible that more data has already arrived during the handshake, so readyRead() wouldn't be triggered. |
56 | // However, we want to give RemotePeer a chance to connect to our signals, so trigger this asynchronously. |
57 | if (socket->bytesAvailable()) |
58 | QTimer::singleShot(0, this, SLOT(readData())); |
59 | } |
60 | |
61 | |
62 | Compressor::~Compressor() |
63 | { |
64 | // release resources allocated by zlib |
65 | if (_inflater) { |
66 | inflateEnd(_inflater); |
67 | delete _inflater; |
68 | } |
69 | if (_deflater) { |
70 | deflateEnd(_deflater); |
71 | delete _deflater; |
72 | } |
73 | } |
74 | |
75 | |
76 | bool Compressor::initStreams() |
77 | { |
78 | int zlevel; |
79 | switch(compressionLevel()) { |
80 | case BestCompression: |
81 | zlevel = 9; |
82 | break; |
83 | case BestSpeed: |
84 | zlevel = 1; |
85 | break; |
86 | default: |
87 | zlevel = Z_DEFAULT_COMPRESSION; |
88 | } |
89 | |
90 | _inflater = new z_stream; |
91 | memset(_inflater, 0, sizeof(z_stream)); |
92 | if (Z_OK != inflateInit(_inflater)) { |
93 | qWarning() << "Could not initialize the inflate stream!" ; |
94 | return false; |
95 | } |
96 | |
97 | _deflater = new z_stream; |
98 | memset(_deflater, 0, sizeof(z_stream)); |
99 | if (Z_OK != deflateInit(_deflater, zlevel)) { |
100 | qWarning() << "Could not intialize the deflate stream!" ; |
101 | return false; |
102 | } |
103 | |
104 | _inputBuffer.reserve(ioBufferSize); // pre-allocate space |
105 | _outputBuffer.resize(ioBufferSize); // not a typo; we never change the size of this buffer anyway (we *do* for _inputBuffer!) |
106 | |
107 | qDebug() << "Enabling compression..." ; |
108 | |
109 | return true; |
110 | } |
111 | |
112 | |
113 | |
114 | qint64 Compressor::bytesAvailable() const |
115 | { |
116 | return _readBuffer.size(); |
117 | } |
118 | |
119 | |
120 | qint64 Compressor::read(char *data, qint64 maxSize) |
121 | { |
122 | if (maxSize <= 0) |
123 | maxSize = _readBuffer.size(); |
124 | |
125 | qint64 n = qMin(maxSize, (qint64)_readBuffer.size()); |
126 | memcpy(data, _readBuffer.constData(), n); |
127 | |
128 | // TODO: don't copy for every read |
129 | if (n == _readBuffer.size()) |
130 | _readBuffer.clear(); |
131 | else |
132 | _readBuffer = _readBuffer.mid(n); |
133 | |
134 | // If there's still data left in the socket buffer, make sure to schedule a read |
135 | if (_socket->bytesAvailable()) |
136 | QTimer::singleShot(0, this, SLOT(readData())); |
137 | |
138 | return n; |
139 | } |
140 | |
141 | |
142 | // The usual usage pattern is to write a blocksize first, followed by the actual data. |
143 | // By setting NoFlush, one can indicate that the write buffer should not immediately be |
144 | // written, which should make things a bit more efficient. |
145 | qint64 Compressor::write(const char *data, qint64 count, WriteBufferHint flush) |
146 | { |
147 | int pos = _writeBuffer.size(); |
148 | _writeBuffer.resize(pos + count); |
149 | memcpy(_writeBuffer.data() + pos, data, count); |
150 | |
151 | if (flush != NoFlush) |
152 | writeData(); |
153 | |
154 | return count; |
155 | } |
156 | |
157 | |
158 | void Compressor::readData() |
159 | { |
160 | // don't try to read more data if we're already closing |
161 | if (_socket->state() != QAbstractSocket::ConnectedState) |
162 | return; |
163 | |
164 | if (!_socket->bytesAvailable() || _readBuffer.size() >= maxBufferSize) |
165 | return; |
166 | |
167 | if (compressionLevel() == NoCompression) { |
168 | _readBuffer.append(_socket->read(maxBufferSize - _readBuffer.size())); |
169 | emit readyRead(); |
170 | return; |
171 | } |
172 | |
173 | // We let zlib directly append to the readBuffer, which means we pre-allocate extra space for ioBufferSize. |
174 | // Afterwards, we'll shrink the buffer appropriately. Since shrinking should not reallocate, the readBuffer's |
175 | // capacity should over time adapt to the largest message sizes we encounter. However, this is not a bad thing |
176 | // considering that otherwise (using an intermediate buffer) we'd copy around data for every single message. |
177 | // TODO: Benchmark if it would still make sense to squeeze the buffer from time to time (e.g. after initial sync)! |
178 | |
179 | while (_socket->bytesAvailable() && _readBuffer.size() + ioBufferSize < maxBufferSize && _inputBuffer.size() < ioBufferSize) { |
180 | _readBuffer.resize(_readBuffer.size() + ioBufferSize); |
181 | _inputBuffer.append(_socket->read(ioBufferSize - _inputBuffer.size())); |
182 | |
183 | _inflater->next_in = reinterpret_cast<unsigned char *>(_inputBuffer.data()); |
184 | _inflater->avail_in = _inputBuffer.size(); |
185 | _inflater->next_out = reinterpret_cast<unsigned char *>(_readBuffer.data() + _readBuffer.size() - ioBufferSize); |
186 | _inflater->avail_out = ioBufferSize; |
187 | |
188 | const unsigned char *orig_out = _inflater->next_out; // so we see if we have actually produced any output |
189 | |
190 | int status = inflate(_inflater, Z_SYNC_FLUSH); // get as much data as possible |
191 | |
192 | // adjust input and output buffers |
193 | _readBuffer.resize(_inflater->next_out - reinterpret_cast<unsigned char *>(_readBuffer.data())); |
194 | if (_inflater->avail_in > 0) |
195 | memmove(_inputBuffer.data(), _inflater->next_in, _inflater->avail_in); |
196 | _inputBuffer.resize(_inflater->avail_in); |
197 | |
198 | if (_inflater->next_out != orig_out) |
199 | emit readyRead(); |
200 | |
201 | switch(status) { |
202 | case Z_NEED_DICT: |
203 | case Z_DATA_ERROR: |
204 | case Z_MEM_ERROR: |
205 | case Z_STREAM_ERROR: |
206 | qWarning() << "Error while decompressing stream:" << status; |
207 | emit error(StreamError); |
208 | return; |
209 | case Z_BUF_ERROR: |
210 | // means that we need more input to continue, so this is not an actual error |
211 | return; |
212 | case Z_STREAM_END: |
213 | qWarning() << "Reached end of zlib stream!" ; // this should really never happen |
214 | return; |
215 | default: |
216 | // just try to get more out of the stream |
217 | break; |
218 | } |
219 | } |
220 | //qDebug() << "inflate in:" << _inflater->total_in << "out:" << _inflater->total_out << "ratio:" << (double)_inflater->total_in/_inflater->total_out; |
221 | } |
222 | |
223 | |
224 | void Compressor::writeData() |
225 | { |
226 | if (compressionLevel() == NoCompression) { |
227 | _socket->write(_writeBuffer); |
228 | _writeBuffer.clear(); |
229 | return; |
230 | } |
231 | |
232 | _deflater->next_in = reinterpret_cast<unsigned char *>(_writeBuffer.data()); |
233 | _deflater->avail_in = _writeBuffer.size(); |
234 | |
235 | int status; |
236 | do { |
237 | _deflater->next_out = reinterpret_cast<unsigned char *>(_outputBuffer.data()); |
238 | _deflater->avail_out = ioBufferSize; |
239 | status = deflate(_deflater, Z_PARTIAL_FLUSH); |
240 | if (status != Z_OK && status != Z_BUF_ERROR) { |
241 | qWarning() << "Error while compressing stream:" << status; |
242 | emit error(StreamError); |
243 | return; |
244 | } |
245 | |
246 | if (_deflater->avail_out == static_cast<unsigned int>(ioBufferSize)) |
247 | continue; // nothing to write here |
248 | |
249 | if (!_socket->write(_outputBuffer.constData(), ioBufferSize - _deflater->avail_out)) { |
250 | qWarning() << "Error while writing to socket:" << _socket->errorString(); |
251 | emit error(DeviceError); |
252 | return; |
253 | } |
254 | } while (_deflater->avail_out == 0); // the output buffer being full is the only reason we should have to loop here! |
255 | |
256 | if (_deflater->avail_in > 0) { |
257 | qWarning() << "Oops, something weird happened: data still remaining in write buffer!" ; |
258 | emit error(StreamError); |
259 | } |
260 | |
261 | _writeBuffer.resize(0); |
262 | |
263 | //qDebug() << "deflate in:" << _deflater->total_in << "out:" << _deflater->total_out << "ratio:" << (double)_deflater->total_out/_deflater->total_in; |
264 | } |
265 | |
266 | |
267 | void Compressor::flush() |
268 | { |
269 | if (compressionLevel() == NoCompression && _socket->state() == QAbstractSocket::ConnectedState) |
270 | _socket->flush(); |
271 | |
272 | // FIXME: missing impl for enabled compression; but then we're not using this method yet |
273 | } |
274 | |