|
1513
|
1 /**
|
|
|
2 * Orthanc - A Lightweight, RESTful DICOM Store
|
|
|
3 * Copyright (C) 2012-2015 Sebastien Jodogne, Medical Physics
|
|
|
4 * Department, University Hospital of Liege, Belgium
|
|
|
5 *
|
|
|
6 * This program is free software: you can redistribute it and/or
|
|
|
7 * modify it under the terms of the GNU General Public License as
|
|
|
8 * published by the Free Software Foundation, either version 3 of the
|
|
|
9 * License, or (at your option) any later version.
|
|
|
10 *
|
|
|
11 * In addition, as a special exception, the copyright holders of this
|
|
|
12 * program give permission to link the code of its release with the
|
|
|
13 * OpenSSL project's "OpenSSL" library (or with modified versions of it
|
|
|
14 * that use the same license as the "OpenSSL" library), and distribute
|
|
|
15 * the linked executables. You must obey the GNU General Public License
|
|
|
16 * in all respects for all of the code used other than "OpenSSL". If you
|
|
|
17 * modify file(s) with this exception, you may extend this exception to
|
|
|
18 * your version of the file(s), but you are not obligated to do so. If
|
|
|
19 * you do not wish to do so, delete this exception statement from your
|
|
|
20 * version. If you delete this exception statement from all source files
|
|
|
21 * in the program, then also delete it here.
|
|
|
22 *
|
|
|
23 * This program is distributed in the hope that it will be useful, but
|
|
|
24 * WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
25 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
|
26 * General Public License for more details.
|
|
|
27 *
|
|
|
28 * You should have received a copy of the GNU General Public License
|
|
|
29 * along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
30 **/
|
|
|
31
|
|
|
32
|
|
|
33 #include "../PrecompiledHeaders.h"
|
|
|
34 #include "GzipCompressor.h"
|
|
|
35
|
|
|
36 #include <stdio.h>
|
|
|
37 #include <string.h>
|
|
|
38 #include <zlib.h>
|
|
|
39
|
|
|
40 #include "../OrthancException.h"
|
|
|
41 #include "../Logging.h"
|
|
|
42
|
|
|
43 namespace Orthanc
|
|
|
44 {
|
|
|
45 uint64_t GzipCompressor::GuessUncompressedSize(const void* compressed,
|
|
|
46 size_t compressedSize)
|
|
|
47 {
|
|
|
48 /**
|
|
|
49 * "Is there a way to find out the size of the original file which
|
|
|
50 * is inside a GZIP file? [...] There is no truly reliable way,
|
|
|
51 * other than gunzipping the stream. You do not need to save the
|
|
|
52 * result of the decompression, so you can determine the size by
|
|
|
53 * simply reading and decoding the entire file without taking up
|
|
|
54 * space with the decompressed result.
|
|
|
55 *
|
|
|
56 * There is an unreliable way to determine the uncompressed size,
|
|
|
57 * which is to look at the last four bytes of the gzip file, which
|
|
|
58 * is the uncompressed length of that entry modulo 232 in little
|
|
|
59 * endian order.
|
|
|
60 *
|
|
|
61 * It is unreliable because a) the uncompressed data may be longer
|
|
|
62 * than 2^32 bytes, and b) the gzip file may consist of multiple
|
|
|
63 * gzip streams, in which case you would find the length of only
|
|
|
64 * the last of those streams.
|
|
|
65 *
|
|
|
66 * If you are in control of the source of the gzip files, you know
|
|
|
67 * that they consist of single gzip streams, and you know that
|
|
|
68 * they are less than 2^32 bytes uncompressed, then and only then
|
|
|
69 * can you use those last four bytes with confidence."
|
|
|
70 *
|
|
|
71 * http://stackoverflow.com/a/9727599/881731
|
|
|
72 **/
|
|
|
73
|
|
|
74 if (compressedSize < 4)
|
|
|
75 {
|
|
|
76 throw OrthancException(ErrorCode_BadFileFormat);
|
|
|
77 }
|
|
|
78
|
|
|
79 const uint8_t* p = reinterpret_cast<const uint8_t*>(compressed) + compressedSize - 4;
|
|
|
80
|
|
|
81 return ((static_cast<uint32_t>(p[0]) << 0) +
|
|
|
82 (static_cast<uint32_t>(p[1]) << 8) +
|
|
|
83 (static_cast<uint32_t>(p[2]) << 16) +
|
|
|
84 (static_cast<uint32_t>(p[3]) << 24));
|
|
|
85 }
|
|
|
86
|
|
|
87
|
|
|
88
|
|
|
89 void GzipCompressor::Compress(std::string& compressed,
|
|
|
90 const void* uncompressed,
|
|
|
91 size_t uncompressedSize)
|
|
|
92 {
|
|
|
93 uLongf compressedSize = compressBound(uncompressedSize) + 1024 /* security margin */;
|
|
|
94 if (compressedSize == 0)
|
|
|
95 {
|
|
|
96 compressedSize = 1;
|
|
|
97 }
|
|
|
98
|
|
|
99 uint8_t* target;
|
|
|
100 if (HasPrefixWithUncompressedSize())
|
|
|
101 {
|
|
|
102 compressed.resize(compressedSize + sizeof(uint64_t));
|
|
|
103 target = reinterpret_cast<uint8_t*>(&compressed[0]) + sizeof(uint64_t);
|
|
|
104 }
|
|
|
105 else
|
|
|
106 {
|
|
|
107 compressed.resize(compressedSize);
|
|
|
108 target = reinterpret_cast<uint8_t*>(&compressed[0]);
|
|
|
109 }
|
|
|
110
|
|
|
111 z_stream stream;
|
|
|
112 memset(&stream, 0, sizeof(stream));
|
|
|
113
|
|
|
114 stream.next_in = const_cast<Bytef*>(reinterpret_cast<const Bytef*>(uncompressed));
|
|
|
115 stream.next_out = reinterpret_cast<Bytef*>(target);
|
|
|
116
|
|
|
117 stream.avail_in = static_cast<uInt>(uncompressedSize);
|
|
|
118 stream.avail_out = static_cast<uInt>(compressedSize);
|
|
|
119
|
|
|
120 // Ensure no overflow (if the buffer is too large for the current archicture)
|
|
|
121 if (static_cast<size_t>(stream.avail_in) != uncompressedSize ||
|
|
|
122 static_cast<size_t>(stream.avail_out) != compressedSize)
|
|
|
123 {
|
|
|
124 throw OrthancException(ErrorCode_NotEnoughMemory);
|
|
|
125 }
|
|
|
126
|
|
|
127 // Initialize the compression engine
|
|
|
128 int error = deflateInit2(&stream,
|
|
|
129 GetCompressionLevel(),
|
|
|
130 Z_DEFLATED,
|
|
|
131 MAX_WBITS + 16, // ask for gzip output
|
|
|
132 8, // default memory level
|
|
|
133 Z_DEFAULT_STRATEGY);
|
|
|
134
|
|
|
135 if (error != Z_OK)
|
|
|
136 {
|
|
|
137 // Cannot initialize zlib
|
|
|
138 compressed.clear();
|
|
|
139 throw OrthancException(ErrorCode_InternalError);
|
|
|
140 }
|
|
|
141
|
|
|
142 // Compress the input buffer
|
|
|
143 error = deflate(&stream, Z_FINISH);
|
|
|
144
|
|
|
145 if (error != Z_STREAM_END)
|
|
|
146 {
|
|
|
147 deflateEnd(&stream);
|
|
|
148 compressed.clear();
|
|
|
149
|
|
|
150 switch (error)
|
|
|
151 {
|
|
|
152 case Z_MEM_ERROR:
|
|
|
153 throw OrthancException(ErrorCode_NotEnoughMemory);
|
|
|
154
|
|
|
155 default:
|
|
|
156 throw OrthancException(ErrorCode_InternalError);
|
|
|
157 }
|
|
|
158 }
|
|
|
159
|
|
|
160 size_t size = stream.total_out;
|
|
|
161
|
|
|
162 if (deflateEnd(&stream) != Z_OK)
|
|
|
163 {
|
|
|
164 throw OrthancException(ErrorCode_InternalError);
|
|
|
165 }
|
|
|
166
|
|
|
167 // The compression was successful
|
|
|
168 if (HasPrefixWithUncompressedSize())
|
|
|
169 {
|
|
|
170 uint64_t s = static_cast<uint64_t>(uncompressedSize);
|
|
|
171 memcpy(&compressed[0], &s, sizeof(uint64_t));
|
|
|
172 compressed.resize(size + sizeof(uint64_t));
|
|
|
173 }
|
|
|
174 else
|
|
|
175 {
|
|
|
176 compressed.resize(size);
|
|
|
177 }
|
|
|
178 }
|
|
|
179
|
|
|
180
|
|
|
181 void GzipCompressor::Uncompress(std::string& uncompressed,
|
|
|
182 const void* compressed,
|
|
|
183 size_t compressedSize)
|
|
|
184 {
|
|
|
185 uint64_t uncompressedSize;
|
|
|
186 const uint8_t* source = reinterpret_cast<const uint8_t*>(compressed);
|
|
|
187
|
|
|
188 if (HasPrefixWithUncompressedSize())
|
|
|
189 {
|
|
|
190 uncompressedSize = ReadUncompressedSizePrefix(compressed, compressedSize);
|
|
|
191 source += sizeof(uint64_t);
|
|
|
192 compressedSize -= sizeof(uint64_t);
|
|
|
193 }
|
|
|
194 else
|
|
|
195 {
|
|
|
196 uncompressedSize = GuessUncompressedSize(compressed, compressedSize);
|
|
|
197 }
|
|
|
198
|
|
|
199 try
|
|
|
200 {
|
|
|
201 uncompressed.resize(uncompressedSize);
|
|
|
202 }
|
|
|
203 catch (...)
|
|
|
204 {
|
|
|
205 throw OrthancException(ErrorCode_NotEnoughMemory);
|
|
|
206 }
|
|
|
207
|
|
|
208 z_stream stream;
|
|
|
209 memset(&stream, 0, sizeof(stream));
|
|
|
210
|
|
|
211 char dummy = '\0'; // zlib does not like NULL output buffers (even if the uncompressed data is empty)
|
|
|
212 stream.next_in = const_cast<Bytef*>(source);
|
|
|
213 stream.next_out = reinterpret_cast<Bytef*>(uncompressedSize == 0 ? &dummy : &uncompressed[0]);
|
|
|
214
|
|
|
215 stream.avail_in = static_cast<uInt>(compressedSize);
|
|
|
216 stream.avail_out = static_cast<uInt>(uncompressedSize);
|
|
|
217
|
|
|
218 // Ensure no overflow (if the buffer is too large for the current archicture)
|
|
|
219 if (static_cast<size_t>(stream.avail_in) != compressedSize ||
|
|
|
220 static_cast<size_t>(stream.avail_out) != uncompressedSize)
|
|
|
221 {
|
|
|
222 throw OrthancException(ErrorCode_NotEnoughMemory);
|
|
|
223 }
|
|
|
224
|
|
|
225 // Initialize the compression engine
|
|
|
226 int error = inflateInit2(&stream,
|
|
|
227 MAX_WBITS + 16); // this is a gzip input
|
|
|
228
|
|
|
229 if (error != Z_OK)
|
|
|
230 {
|
|
|
231 // Cannot initialize zlib
|
|
|
232 uncompressed.clear();
|
|
|
233 throw OrthancException(ErrorCode_InternalError);
|
|
|
234 }
|
|
|
235
|
|
|
236 // Uncompress the input buffer
|
|
|
237 error = inflate(&stream, Z_FINISH);
|
|
|
238
|
|
|
239 if (error != Z_STREAM_END)
|
|
|
240 {
|
|
|
241 inflateEnd(&stream);
|
|
|
242 uncompressed.clear();
|
|
|
243
|
|
|
244 switch (error)
|
|
|
245 {
|
|
|
246 case Z_MEM_ERROR:
|
|
|
247 throw OrthancException(ErrorCode_NotEnoughMemory);
|
|
|
248
|
|
|
249 case Z_BUF_ERROR:
|
|
|
250 case Z_NEED_DICT:
|
|
|
251 throw OrthancException(ErrorCode_BadFileFormat);
|
|
|
252
|
|
|
253 default:
|
|
|
254 throw OrthancException(ErrorCode_InternalError);
|
|
|
255 }
|
|
|
256 }
|
|
|
257
|
|
|
258 size_t size = stream.total_out;
|
|
|
259
|
|
|
260 if (inflateEnd(&stream) != Z_OK)
|
|
|
261 {
|
|
|
262 uncompressed.clear();
|
|
|
263 throw OrthancException(ErrorCode_InternalError);
|
|
|
264 }
|
|
|
265
|
|
|
266 if (size != uncompressedSize)
|
|
|
267 {
|
|
|
268 uncompressed.clear();
|
|
|
269
|
|
|
270 // The uncompressed size was not that properly guess, presumably
|
|
|
271 // because of a file size over 4GB. Should fallback to
|
|
|
272 // stream-based decompression.
|
|
|
273 LOG(ERROR) << "The uncompressed size of a gzip-encoded buffer was not properly guessed";
|
|
|
274 throw OrthancException(ErrorCode_NotImplemented);
|
|
|
275 }
|
|
|
276 }
|
|
|
277 }
|
