1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7 #include "nsTArray.h"
8 #include "nsCharSeparatedTokenizer.h"
9 #include "nsEscape.h"
10 #include "nsIURI.h"
11 #include <utility>
12
13 #include "nsMediaFragmentURIParser.h"
14
15 using std::make_pair;
16 using std::pair;
17
18 namespace mozilla {
19 namespace net {
20
nsMediaFragmentURIParser(nsIURI * aURI)21 nsMediaFragmentURIParser::nsMediaFragmentURIParser(nsIURI* aURI)
22 : mClipUnit(eClipUnit_Pixel) {
23 nsAutoCString ref;
24 aURI->GetRef(ref);
25 Parse(ref);
26 }
27
nsMediaFragmentURIParser(nsCString & aRef)28 nsMediaFragmentURIParser::nsMediaFragmentURIParser(nsCString& aRef)
29 : mClipUnit(eClipUnit_Pixel) {
30 Parse(aRef);
31 }
32
ParseNPT(nsDependentSubstring aString)33 bool nsMediaFragmentURIParser::ParseNPT(nsDependentSubstring aString) {
34 nsDependentSubstring original(aString);
35 if (aString.Length() > 4 && aString[0] == 'n' && aString[1] == 'p' &&
36 aString[2] == 't' && aString[3] == ':') {
37 aString.Rebind(aString, 4);
38 }
39
40 if (aString.Length() == 0) {
41 return false;
42 }
43
44 double start = -1.0;
45 double end = -1.0;
46
47 ParseNPTTime(aString, start);
48
49 if (aString.Length() == 0) {
50 mStart.emplace(start);
51 return true;
52 }
53
54 if (aString[0] != ',') {
55 aString.Rebind(original, 0);
56 return false;
57 }
58
59 aString.Rebind(aString, 1);
60
61 if (aString.Length() == 0) {
62 aString.Rebind(original, 0);
63 return false;
64 }
65
66 ParseNPTTime(aString, end);
67
68 if (end <= start || aString.Length() != 0) {
69 aString.Rebind(original, 0);
70 return false;
71 }
72
73 mStart.emplace(start);
74 mEnd.emplace(end);
75 return true;
76 }
77
ParseNPTTime(nsDependentSubstring & aString,double & aTime)78 bool nsMediaFragmentURIParser::ParseNPTTime(nsDependentSubstring& aString,
79 double& aTime) {
80 if (aString.Length() == 0) {
81 return false;
82 }
83
84 return ParseNPTHHMMSS(aString, aTime) || ParseNPTMMSS(aString, aTime) ||
85 ParseNPTSec(aString, aTime);
86 }
87
88 // Return true if the given character is a numeric character
IsDigit(nsDependentSubstring::char_type aChar)89 static bool IsDigit(nsDependentSubstring::char_type aChar) {
90 return (aChar >= '0' && aChar <= '9');
91 }
92
93 // Return the index of the first character in the string that is not
94 // a numerical digit, starting from 'aStart'.
FirstNonDigit(nsDependentSubstring & aString,uint32_t aStart)95 static uint32_t FirstNonDigit(nsDependentSubstring& aString, uint32_t aStart) {
96 while (aStart < aString.Length() && IsDigit(aString[aStart])) {
97 ++aStart;
98 }
99 return aStart;
100 }
101
ParseNPTSec(nsDependentSubstring & aString,double & aSec)102 bool nsMediaFragmentURIParser::ParseNPTSec(nsDependentSubstring& aString,
103 double& aSec) {
104 nsDependentSubstring original(aString);
105 if (aString.Length() == 0) {
106 return false;
107 }
108
109 uint32_t index = FirstNonDigit(aString, 0);
110 if (index == 0) {
111 return false;
112 }
113
114 nsDependentSubstring n(aString, 0, index);
115 nsresult ec;
116 int32_t s = PromiseFlatString(n).ToInteger(&ec);
117 if (NS_FAILED(ec)) {
118 return false;
119 }
120
121 aString.Rebind(aString, index);
122 double fraction = 0.0;
123 if (!ParseNPTFraction(aString, fraction)) {
124 aString.Rebind(original, 0);
125 return false;
126 }
127
128 aSec = s + fraction;
129 return true;
130 }
131
ParseNPTMMSS(nsDependentSubstring & aString,double & aTime)132 bool nsMediaFragmentURIParser::ParseNPTMMSS(nsDependentSubstring& aString,
133 double& aTime) {
134 nsDependentSubstring original(aString);
135 uint32_t mm = 0;
136 uint32_t ss = 0;
137 double fraction = 0.0;
138 if (!ParseNPTMM(aString, mm)) {
139 aString.Rebind(original, 0);
140 return false;
141 }
142
143 if (aString.Length() < 2 || aString[0] != ':') {
144 aString.Rebind(original, 0);
145 return false;
146 }
147
148 aString.Rebind(aString, 1);
149 if (!ParseNPTSS(aString, ss)) {
150 aString.Rebind(original, 0);
151 return false;
152 }
153
154 if (!ParseNPTFraction(aString, fraction)) {
155 aString.Rebind(original, 0);
156 return false;
157 }
158 aTime = mm * 60 + ss + fraction;
159 return true;
160 }
161
ParseNPTFraction(nsDependentSubstring & aString,double & aFraction)162 bool nsMediaFragmentURIParser::ParseNPTFraction(nsDependentSubstring& aString,
163 double& aFraction) {
164 double fraction = 0.0;
165
166 if (aString.Length() > 0 && aString[0] == '.') {
167 uint32_t index = FirstNonDigit(aString, 1);
168
169 if (index > 1) {
170 nsDependentSubstring number(aString, 0, index);
171 nsresult ec;
172 fraction = PromiseFlatString(number).ToDouble(&ec);
173 if (NS_FAILED(ec)) {
174 return false;
175 }
176 }
177 aString.Rebind(aString, index);
178 }
179
180 aFraction = fraction;
181 return true;
182 }
183
ParseNPTHHMMSS(nsDependentSubstring & aString,double & aTime)184 bool nsMediaFragmentURIParser::ParseNPTHHMMSS(nsDependentSubstring& aString,
185 double& aTime) {
186 nsDependentSubstring original(aString);
187 uint32_t hh = 0;
188 double seconds = 0.0;
189 if (!ParseNPTHH(aString, hh)) {
190 return false;
191 }
192
193 if (aString.Length() < 2 || aString[0] != ':') {
194 aString.Rebind(original, 0);
195 return false;
196 }
197
198 aString.Rebind(aString, 1);
199 if (!ParseNPTMMSS(aString, seconds)) {
200 aString.Rebind(original, 0);
201 return false;
202 }
203
204 aTime = hh * 3600 + seconds;
205 return true;
206 }
207
ParseNPTHH(nsDependentSubstring & aString,uint32_t & aHour)208 bool nsMediaFragmentURIParser::ParseNPTHH(nsDependentSubstring& aString,
209 uint32_t& aHour) {
210 if (aString.Length() == 0) {
211 return false;
212 }
213
214 uint32_t index = FirstNonDigit(aString, 0);
215 if (index == 0) {
216 return false;
217 }
218
219 nsDependentSubstring n(aString, 0, index);
220 nsresult ec;
221 int32_t u = PromiseFlatString(n).ToInteger(&ec);
222 if (NS_FAILED(ec)) {
223 return false;
224 }
225
226 aString.Rebind(aString, index);
227 aHour = u;
228 return true;
229 }
230
ParseNPTMM(nsDependentSubstring & aString,uint32_t & aMinute)231 bool nsMediaFragmentURIParser::ParseNPTMM(nsDependentSubstring& aString,
232 uint32_t& aMinute) {
233 return ParseNPTSS(aString, aMinute);
234 }
235
ParseNPTSS(nsDependentSubstring & aString,uint32_t & aSecond)236 bool nsMediaFragmentURIParser::ParseNPTSS(nsDependentSubstring& aString,
237 uint32_t& aSecond) {
238 if (aString.Length() < 2) {
239 return false;
240 }
241
242 if (IsDigit(aString[0]) && IsDigit(aString[1])) {
243 nsDependentSubstring n(aString, 0, 2);
244 nsresult ec;
245 int32_t u = PromiseFlatString(n).ToInteger(&ec);
246 if (NS_FAILED(ec)) {
247 return false;
248 }
249
250 aString.Rebind(aString, 2);
251 if (u >= 60) return false;
252
253 aSecond = u;
254 return true;
255 }
256
257 return false;
258 }
259
ParseInteger(nsDependentSubstring & aString,int32_t & aResult)260 static bool ParseInteger(nsDependentSubstring& aString, int32_t& aResult) {
261 uint32_t index = FirstNonDigit(aString, 0);
262 if (index == 0) {
263 return false;
264 }
265
266 nsDependentSubstring n(aString, 0, index);
267 nsresult ec;
268 int32_t s = PromiseFlatString(n).ToInteger(&ec);
269 if (NS_FAILED(ec)) {
270 return false;
271 }
272
273 aString.Rebind(aString, index);
274 aResult = s;
275 return true;
276 }
277
ParseCommaSeparator(nsDependentSubstring & aString)278 static bool ParseCommaSeparator(nsDependentSubstring& aString) {
279 if (aString.Length() > 1 && aString[0] == ',') {
280 aString.Rebind(aString, 1);
281 return true;
282 }
283
284 return false;
285 }
286
ParseXYWH(nsDependentSubstring aString)287 bool nsMediaFragmentURIParser::ParseXYWH(nsDependentSubstring aString) {
288 int32_t x, y, w, h;
289 ClipUnit clipUnit;
290
291 // Determine units.
292 if (StringBeginsWith(aString, NS_LITERAL_STRING("pixel:"))) {
293 clipUnit = eClipUnit_Pixel;
294 aString.Rebind(aString, 6);
295 } else if (StringBeginsWith(aString, NS_LITERAL_STRING("percent:"))) {
296 clipUnit = eClipUnit_Percent;
297 aString.Rebind(aString, 8);
298 } else {
299 clipUnit = eClipUnit_Pixel;
300 }
301
302 // Read and validate coordinates.
303 if (ParseInteger(aString, x) && x >= 0 && ParseCommaSeparator(aString) &&
304 ParseInteger(aString, y) && y >= 0 && ParseCommaSeparator(aString) &&
305 ParseInteger(aString, w) && w > 0 && ParseCommaSeparator(aString) &&
306 ParseInteger(aString, h) && h > 0 && aString.Length() == 0) {
307 // Reject invalid percentage coordinates.
308 if (clipUnit == eClipUnit_Percent && (x + w > 100 || y + h > 100)) {
309 return false;
310 }
311
312 mClip.emplace(x, y, w, h);
313 mClipUnit = clipUnit;
314 return true;
315 }
316
317 return false;
318 }
319
Parse(nsACString & aRef)320 void nsMediaFragmentURIParser::Parse(nsACString& aRef) {
321 // Create an array of possibly-invalid media fragments.
322 nsTArray<std::pair<nsCString, nsCString> > fragments;
323 nsCCharSeparatedTokenizer tokenizer(aRef, '&');
324
325 while (tokenizer.hasMoreTokens()) {
326 const nsACString& nv = tokenizer.nextToken();
327 int32_t index = nv.FindChar('=');
328 if (index >= 0) {
329 nsAutoCString name;
330 nsAutoCString value;
331 NS_UnescapeURL(StringHead(nv, index), esc_Ref | esc_AlwaysCopy, name);
332 NS_UnescapeURL(Substring(nv, index + 1, nv.Length()),
333 esc_Ref | esc_AlwaysCopy, value);
334 fragments.AppendElement(make_pair(name, value));
335 }
336 }
337
338 // Parse the media fragment values.
339 bool gotTemporal = false, gotSpatial = false;
340 for (int i = fragments.Length() - 1; i >= 0; --i) {
341 if (gotTemporal && gotSpatial) {
342 // We've got one of each possible type. No need to look at the rest.
343 break;
344 } else if (!gotTemporal && fragments[i].first.EqualsLiteral("t")) {
345 nsAutoString value = NS_ConvertUTF8toUTF16(fragments[i].second);
346 gotTemporal = ParseNPT(nsDependentSubstring(value, 0));
347 } else if (!gotSpatial && fragments[i].first.EqualsLiteral("xywh")) {
348 nsAutoString value = NS_ConvertUTF8toUTF16(fragments[i].second);
349 gotSpatial = ParseXYWH(nsDependentSubstring(value, 0));
350 }
351 }
352 }
353
354 } // namespace net
355 } // namespace mozilla
356