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comparison OrthancFramework/Sources/HttpServer/HttpContentNegociation.cpp @ 4044:d25f4c0fa160 framework

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splitting code into OrthancFramework and OrthancServer
author Sebastien Jodogne <s.jodogne@gmail.com>
date Wed, 10 Jun 2020 20:30:34 +0200
parents Core/HttpServer/HttpContentNegociation.cpp@2a170a8f1faf
children bf7b9edf6b81
comparison
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4043:6c6239aec462 4044:d25f4c0fa160
1 /**
2 * Orthanc - A Lightweight, RESTful DICOM Store
3 * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
4 * Department, University Hospital of Liege, Belgium
5 * Copyright (C) 2017-2020 Osimis S.A., Belgium
6 *
7 * This program is free software: you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation, either version 3 of the
10 * License, or (at your option) any later version.
11 *
12 * In addition, as a special exception, the copyright holders of this
13 * program give permission to link the code of its release with the
14 * OpenSSL project's "OpenSSL" library (or with modified versions of it
15 * that use the same license as the "OpenSSL" library), and distribute
16 * the linked executables. You must obey the GNU General Public License
17 * in all respects for all of the code used other than "OpenSSL". If you
18 * modify file(s) with this exception, you may extend this exception to
19 * your version of the file(s), but you are not obligated to do so. If
20 * you do not wish to do so, delete this exception statement from your
21 * version. If you delete this exception statement from all source files
22 * in the program, then also delete it here.
23 *
24 * This program is distributed in the hope that it will be useful, but
25 * WITHOUT ANY WARRANTY; without even the implied warranty of
26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
27 * General Public License for more details.
28 *
29 * You should have received a copy of the GNU General Public License
30 * along with this program. If not, see <http://www.gnu.org/licenses/>.
31 **/
32
33
34 #include "../PrecompiledHeaders.h"
35 #include "HttpContentNegociation.h"
36
37 #include "../Logging.h"
38 #include "../OrthancException.h"
39 #include "../Toolbox.h"
40
41 #include <boost/lexical_cast.hpp>
42
43 namespace Orthanc
44 {
45 HttpContentNegociation::Handler::Handler(const std::string& type,
46 const std::string& subtype,
47 IHandler& handler) :
48 type_(type),
49 subtype_(subtype),
50 handler_(handler)
51 {
52 }
53
54
55 bool HttpContentNegociation::Handler::IsMatch(const std::string& type,
56 const std::string& subtype) const
57 {
58 if (type == "*" && subtype == "*")
59 {
60 return true;
61 }
62
63 if (subtype == "*" && type == type_)
64 {
65 return true;
66 }
67
68 return type == type_ && subtype == subtype_;
69 }
70
71
72 struct HttpContentNegociation::Reference : public boost::noncopyable
73 {
74 const Handler& handler_;
75 uint8_t level_;
76 float quality_;
77
78 Reference(const Handler& handler,
79 const std::string& type,
80 const std::string& subtype,
81 float quality) :
82 handler_(handler),
83 quality_(quality)
84 {
85 if (type == "*" && subtype == "*")
86 {
87 level_ = 0;
88 }
89 else if (subtype == "*")
90 {
91 level_ = 1;
92 }
93 else
94 {
95 level_ = 2;
96 }
97 }
98
99 bool operator< (const Reference& other) const
100 {
101 if (level_ < other.level_)
102 {
103 return true;
104 }
105
106 if (level_ > other.level_)
107 {
108 return false;
109 }
110
111 return quality_ < other.quality_;
112 }
113 };
114
115
116 bool HttpContentNegociation::SplitPair(std::string& first /* out */,
117 std::string& second /* out */,
118 const std::string& source,
119 char separator)
120 {
121 size_t pos = source.find(separator);
122
123 if (pos == std::string::npos)
124 {
125 return false;
126 }
127 else
128 {
129 first = Toolbox::StripSpaces(source.substr(0, pos));
130 second = Toolbox::StripSpaces(source.substr(pos + 1));
131 return true;
132 }
133 }
134
135
136 float HttpContentNegociation::GetQuality(const Tokens& parameters)
137 {
138 for (size_t i = 1; i < parameters.size(); i++)
139 {
140 std::string key, value;
141 if (SplitPair(key, value, parameters[i], '=') &&
142 key == "q")
143 {
144 float quality;
145 bool ok = false;
146
147 try
148 {
149 quality = boost::lexical_cast<float>(value);
150 ok = (quality >= 0.0f && quality <= 1.0f);
151 }
152 catch (boost::bad_lexical_cast&)
153 {
154 }
155
156 if (ok)
157 {
158 return quality;
159 }
160 else
161 {
162 throw OrthancException(
163 ErrorCode_BadRequest,
164 "Quality parameter out of range in a HTTP request (must be between 0 and 1): " + value);
165 }
166 }
167 }
168
169 return 1.0f; // Default quality
170 }
171
172
173 void HttpContentNegociation::SelectBestMatch(std::unique_ptr<Reference>& best,
174 const Handler& handler,
175 const std::string& type,
176 const std::string& subtype,
177 float quality)
178 {
179 std::unique_ptr<Reference> match(new Reference(handler, type, subtype, quality));
180
181 if (best.get() == NULL ||
182 *best < *match)
183 {
184 #if __cplusplus < 201103L
185 best.reset(match.release());
186 #else
187 best = std::move(match);
188 #endif
189 }
190 }
191
192
193 void HttpContentNegociation::Register(const std::string& mime,
194 IHandler& handler)
195 {
196 std::string type, subtype;
197
198 if (SplitPair(type, subtype, mime, '/') &&
199 type != "*" &&
200 subtype != "*")
201 {
202 handlers_.push_back(Handler(type, subtype, handler));
203 }
204 else
205 {
206 throw OrthancException(ErrorCode_ParameterOutOfRange);
207 }
208 }
209
210
211 bool HttpContentNegociation::Apply(const HttpHeaders& headers)
212 {
213 HttpHeaders::const_iterator accept = headers.find("accept");
214 if (accept != headers.end())
215 {
216 return Apply(accept->second);
217 }
218 else
219 {
220 return Apply("*/*");
221 }
222 }
223
224
225 bool HttpContentNegociation::Apply(const std::string& accept)
226 {
227 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1
228 // https://en.wikipedia.org/wiki/Content_negotiation
229 // http://www.newmediacampaigns.com/blog/browser-rest-http-accept-headers
230
231 Tokens mediaRanges;
232 Toolbox::TokenizeString(mediaRanges, accept, ',');
233
234 std::unique_ptr<Reference> bestMatch;
235
236 for (Tokens::const_iterator it = mediaRanges.begin();
237 it != mediaRanges.end(); ++it)
238 {
239 Tokens parameters;
240 Toolbox::TokenizeString(parameters, *it, ';');
241
242 if (parameters.size() > 0)
243 {
244 float quality = GetQuality(parameters);
245
246 std::string type, subtype;
247 if (SplitPair(type, subtype, parameters[0], '/'))
248 {
249 for (Handlers::const_iterator it2 = handlers_.begin();
250 it2 != handlers_.end(); ++it2)
251 {
252 if (it2->IsMatch(type, subtype))
253 {
254 SelectBestMatch(bestMatch, *it2, type, subtype, quality);
255 }
256 }
257 }
258 }
259 }
260
261 if (bestMatch.get() == NULL) // No match was found
262 {
263 return false;
264 }
265 else
266 {
267 bestMatch->handler_.Call();
268 return true;
269 }
270 }
271 }