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
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
|
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef PPAPI_UTILITY_COMPLETION_CALLBACK_FACTORY_H_
#define PPAPI_UTILITY_COMPLETION_CALLBACK_FACTORY_H_
#include "ppapi/cpp/completion_callback.h"
#include "ppapi/utility/non_thread_safe_ref_count.h"
/// @file
/// This file defines the API to create CompletionCallback objects that are
/// bound to member functions.
namespace pp {
// TypeUnwrapper --------------------------------------------------------------
namespace internal {
// The TypeUnwrapper converts references and const references to the
// underlying type used for storage and passing as an argument. It is for
// internal use only.
template <typename T> struct TypeUnwrapper {
typedef T StorageType;
};
template <typename T> struct TypeUnwrapper<T&> {
typedef T StorageType;
};
template <typename T> struct TypeUnwrapper<const T&> {
typedef T StorageType;
};
} // namespace internal
// ----------------------------------------------------------------------------
/// CompletionCallbackFactory<T> may be used to create CompletionCallback
/// objects that are bound to member functions.
///
/// If a factory is destroyed, then any pending callbacks will be cancelled
/// preventing any bound member functions from being called. The CancelAll()
/// method allows pending callbacks to be cancelled without destroying the
/// factory.
///
/// <strong>Note: </strong><code>CompletionCallbackFactory<T></code> isn't
/// thread safe, but you can make it more thread-friendly by passing a
/// thread-safe refcounting class as the second template element. However, it
/// only guarantees safety for creating a callback from another thread, the
/// callback itself needs to execute on the same thread as the thread that
/// creates/destroys the factory. With this restriction, it is safe to create
/// the <code>CompletionCallbackFactory</code> on the main thread, create
/// callbacks from any thread and pass them to CallOnMainThread().
///
/// <strong>Example: </strong>
///
/// @code
/// class MyClass {
/// public:
/// // If an compiler warns on following using |this| in the initializer
/// // list, use PP_ALLOW_THIS_IN_INITIALIZER_LIST macro.
/// MyClass() : factory_(this) {
/// }
///
/// void OpenFile(const pp::FileRef& file) {
/// pp::CompletionCallback cc = factory_.NewCallback(&MyClass::DidOpen);
/// int32_t rv = file_io_.Open(file, PP_FileOpenFlag_Read, cc);
/// CHECK(rv == PP_OK_COMPLETIONPENDING);
/// }
///
/// private:
/// void DidOpen(int32_t result) {
/// if (result == PP_OK) {
/// // The file is open, and we can begin reading.
/// // ...
/// } else {
/// // Failed to open the file with error given by 'result'.
/// }
/// }
///
/// pp::CompletionCallbackFactory<MyClass> factory_;
/// };
/// @endcode
///
/// <strong>Passing additional parameters to your callback</strong>
///
/// As a convenience, the <code>CompletionCallbackFactory</code> can optionally
/// create a closure with up to three bound parameters that it will pass to
/// your callback function. This can be useful for passing information about
/// the request to your callback function, which is especially useful if your
/// class has multiple asynchronous callbacks pending.
///
/// For the above example, of opening a file, let's say you want to keep some
/// description associated with your request, you might implement your OpenFile
/// and DidOpen callback as follows:
///
/// @code
/// void OpenFile(const pp::FileRef& file) {
/// std::string message = "Opening file!";
/// pp::CompletionCallback cc = factory_.NewCallback(&MyClass::DidOpen,
/// message);
/// int32_t rv = file_io_.Open(file, PP_FileOpenFlag_Read, cc);
/// CHECK(rv == PP_OK_COMPLETIONPENDING);
/// }
/// void DidOpen(int32_t result, const std::string& message) {
/// // "message" will be "Opening file!".
/// ...
/// }
/// @endcode
///
/// <strong>Optional versus required callbacks</strong>
///
/// When you create an "optional" callback, the browser may return the results
/// synchronously if they are available. This can allow for higher performance
/// in some cases if data is available quickly (for example, for network loads
/// where there may be a lot of data coming quickly). In this case, the
/// callback will never be run.
///
/// When creating a new callback with the factory, there will be data allocated
/// on the heap that tracks the callback information and any bound arguments.
/// This data is freed when the callback executes. In the case of optional
/// callbacks, since the browser will never issue the callback, the internal
/// tracking data will be leaked.
///
/// Therefore, if you use optional callbacks, it's important to manually
/// issue the callback to free up this data. The typical pattern is:
///
/// @code
/// pp::CompletionCallback callback = callback_factory.NewOptionalCallback(
/// &MyClass::OnDataReady);
/// int32_t result = interface->GetData(callback);
/// if (result != PP_OK_COMPLETIONPENDING)
/// callback.Run(result);
/// @endcode
///
/// Because of this additional complexity, it's generally recommended that
/// you not use optional callbacks except when performance is more important
/// (such as loading large resources from the network). In most other cases,
/// the performance difference will not be worth the additional complexity,
/// and most functions may never actually have the ability to complete
/// synchronously.
///
/// <strong>Completion callbacks with output</strong>
///
/// For some API calls, the browser returns data to the caller via an output
/// parameter. These can be difficult to manage since the output parameter
/// must remain valid for as long as the callback is pending. Note also that
/// CancelAll (or destroying the callback factory) does <i>not</i> cancel the
/// callback from the browser's perspective, only the execution of the callback
/// in the plugin code, and the output parameter will still be written to!
/// This means that you can't use class members as output parameters without
/// risking crashes.
///
/// To make this case easier, the CompletionCallbackFactory can allocate and
/// manage the output data for you and pass it to your callback function. This
/// makes such calls more natural and less error-prone.
///
/// To create such a callback, use NewCallbackWithOutput and specify a callback
/// function that takes the output parameter as its second argument. Let's say
/// you're calling a function GetFile which asynchronously returns a
/// pp::FileRef. GetFile's signature will be <code>int32_t GetFile(const
/// CompletionCallbackWithOutput<pp::FileRef>& callback);</code> and your
/// calling code would look like this:
///
/// @code
/// void RequestFile() {
/// file_interface->GetFile(callback_factory_.NewCallbackWithOutput(
/// &MyClass::GotFile));
/// }
/// void GotFile(int32_t result, const pp::FileRef& file) {
/// if (result == PP_OK) {
/// ...use file...
/// } else {
/// ...handle error...
/// }
/// }
/// @endcode
///
/// As with regular completion callbacks, you can optionally add up to three
/// bound arguments. These are passed following the output argument.
///
/// Your callback may take the output argument as a copy (common for small
/// types like integers, a const reference (common for structures and
/// resources to avoid an extra copy), or as a non-const reference. One
/// optimization you can do if your callback function may take large arrays
/// is to accept your output argument as a non-const reference and to swap()
/// the argument with a vector of your own to store it. This means you don't
/// have to copy the buffer to consume it.
template <typename T, typename RefCount = NonThreadSafeRefCount>
class CompletionCallbackFactory {
public:
/// This constructor creates a <code>CompletionCallbackFactory</code>
/// bound to an object. If the constructor is called without an argument,
/// the default value of <code>NULL</code> is used. The user then must call
/// Initialize() to initialize the object.
///
/// param[in] object Optional parameter. An object whose member functions
/// are to be bound to CompletionCallbacks created by this
/// <code>CompletionCallbackFactory</code>. The default value of this
/// parameter is <code>NULL</code>.
explicit CompletionCallbackFactory(T* object = NULL)
: object_(object) {
InitBackPointer();
}
/// Destructor.
~CompletionCallbackFactory() {
ResetBackPointer();
}
/// CancelAll() cancels all <code>CompletionCallbacks</code> allocated from
/// this factory.
void CancelAll() {
ResetBackPointer();
InitBackPointer();
}
/// Initialize() binds the <code>CallbackFactory</code> to a particular
/// object. Use this when the object is not available at
/// <code>CallbackFactory</code> creation, and the <code>NULL</code> default
/// is passed to the constructor. The object may only be initialized once,
/// either by the constructor, or by a call to Initialize().
///
/// @param[in] object The object whose member functions are to be bound to
/// the <code>CompletionCallback</code> created by this
/// <code>CompletionCallbackFactory</code>.
void Initialize(T* object) {
PP_DCHECK(object);
PP_DCHECK(!object_); // May only initialize once!
object_ = object;
}
/// GetObject() returns the object that was passed at initialization to
/// Intialize().
///
/// @return the object passed to the constructor or Intialize().
T* GetObject() {
return object_;
}
/// NewCallback allocates a new, single-use <code>CompletionCallback</code>.
/// The <code>CompletionCallback</code> must be run in order for the memory
/// allocated by the methods to be freed.
///
/// @param[in] method The method to be invoked upon completion of the
/// operation.
///
/// @return A <code>CompletionCallback</code>.
template <typename Method>
CompletionCallback NewCallback(Method method) {
PP_DCHECK(object_);
return NewCallbackHelper(new Dispatcher0<Method>(method));
}
/// NewOptionalCallback() allocates a new, single-use
/// <code>CompletionCallback</code> that might not run if the method
/// taking it can complete synchronously. Thus, if after passing the
/// CompletionCallback to a Pepper method, the method does not return
/// PP_OK_COMPLETIONPENDING, then you should manually call the
/// CompletionCallback's Run method, or memory will be leaked.
///
/// @param[in] method The method to be invoked upon completion of the
/// operation.
///
/// @return A <code>CompletionCallback</code>.
template <typename Method>
CompletionCallback NewOptionalCallback(Method method) {
CompletionCallback cc = NewCallback(method);
cc.set_flags(cc.flags() | PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
return cc;
}
/// NewCallbackWithOutput() allocates a new, single-use
/// <code>CompletionCallback</code> where the browser will pass an additional
/// parameter comtaining the result of the request. The
/// <code>CompletionCallback</code> must be run in order for the memory
/// allocated by the methods to be freed.
///
/// @param[in] method The method to be invoked upon completion of the
/// operation.
///
/// @return A <code>CompletionCallback</code>.
template <typename Output>
CompletionCallbackWithOutput<
typename internal::TypeUnwrapper<Output>::StorageType>
NewCallbackWithOutput(void (T::*method)(int32_t, Output)) {
return NewCallbackWithOutputHelper(new DispatcherWithOutput0<
typename internal::TypeUnwrapper<Output>::StorageType,
void (T::*)(int32_t, Output)>(method));
}
/// NewCallback() allocates a new, single-use <code>CompletionCallback</code>.
/// The <code>CompletionCallback</code> must be run in order for the memory
/// allocated by the methods to be freed.
///
/// @param[in] method The method to be invoked upon completion of the
/// operation. Method should be of type:
/// <code>void (T::*)(int32_t result, const A& a)</code>
///
/// @param[in] a Passed to <code>method</code> when the completion callback
/// runs.
///
/// @return A <code>CompletionCallback</code>.
template <typename Method, typename A>
CompletionCallback NewCallback(Method method, const A& a) {
PP_DCHECK(object_);
return NewCallbackHelper(new Dispatcher1<Method, A>(method, a));
}
/// NewOptionalCallback() allocates a new, single-use
/// <code>CompletionCallback</code> that might not run if the method
/// taking it can complete synchronously. Thus, if after passing the
/// CompletionCallback to a Pepper method, the method does not return
/// PP_OK_COMPLETIONPENDING, then you should manually call the
/// CompletionCallback's Run method, or memory will be leaked.
///
/// @param[in] method The method to be invoked upon completion of the
/// operation. Method should be of type:
/// <code>void (T::*)(int32_t result, const A& a)</code>
///
/// @param[in] a Passed to <code>method</code> when the completion callback
/// runs.
///
/// @return A <code>CompletionCallback</code>.
template <typename Method, typename A>
CompletionCallback NewOptionalCallback(Method method, const A& a) {
CompletionCallback cc = NewCallback(method, a);
cc.set_flags(cc.flags() | PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
return cc;
}
/// NewCallbackWithOutput() allocates a new, single-use
/// <code>CompletionCallback</code> where the browser will pass an additional
/// parameter comtaining the result of the request. The
/// <code>CompletionCallback</code> must be run in order for the memory
/// allocated by the methods to be freed.
///
/// @param[in] method The method to be invoked upon completion of the
/// operation.
///
/// @param[in] a Passed to <code>method</code> when the completion callback
/// runs.
///
/// @return A <code>CompletionCallback</code>.
template <typename Output, typename A>
CompletionCallbackWithOutput<
typename internal::TypeUnwrapper<Output>::StorageType>
NewCallbackWithOutput(void (T::*method)(int32_t, Output, A),
const A& a) {
return NewCallbackWithOutputHelper(new DispatcherWithOutput1<
typename internal::TypeUnwrapper<Output>::StorageType,
void (T::*)(int32_t, Output, A),
typename internal::TypeUnwrapper<A>::StorageType>(method, a));
}
/// NewCallback() allocates a new, single-use
/// <code>CompletionCallback</code>.
/// The <code>CompletionCallback</code> must be run in order for the memory
/// allocated by the methods to be freed.
///
/// @param method The method taking the callback. Method should be of type:
/// <code>void (T::*)(int32_t result, const A& a, const B& b)</code>
///
/// @param[in] a Passed to <code>method</code> when the completion callback
/// runs.
///
/// @param[in] b Passed to <code>method</code> when the completion callback
/// runs.
///
/// @return A <code>CompletionCallback</code>.
template <typename Method, typename A, typename B>
CompletionCallback NewCallback(Method method, const A& a, const B& b) {
PP_DCHECK(object_);
return NewCallbackHelper(new Dispatcher2<Method, A, B>(method, a, b));
}
/// NewOptionalCallback() allocates a new, single-use
/// <code>CompletionCallback</code> that might not run if the method
/// taking it can complete synchronously. Thus, if after passing the
/// CompletionCallback to a Pepper method, the method does not return
/// PP_OK_COMPLETIONPENDING, then you should manually call the
/// CompletionCallback's Run method, or memory will be leaked.
///
/// @param[in] method The method taking the callback. Method should be of
/// type:
/// <code>void (T::*)(int32_t result, const A& a, const B& b)</code>
///
/// @param[in] a Passed to <code>method</code> when the completion callback
/// runs.
///
/// @param[in] b Passed to <code>method</code> when the completion callback
/// runs.
///
/// @return A <code>CompletionCallback</code>.
template <typename Method, typename A, typename B>
CompletionCallback NewOptionalCallback(Method method, const A& a,
const B& b) {
CompletionCallback cc = NewCallback(method, a, b);
cc.set_flags(cc.flags() | PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
return cc;
}
/// NewCallbackWithOutput() allocates a new, single-use
/// <code>CompletionCallback</code> where the browser will pass an additional
/// parameter comtaining the result of the request. The
/// <code>CompletionCallback</code> must be run in order for the memory
/// allocated by the methods to be freed.
///
/// @param[in] method The method to be invoked upon completion of the
/// operation.
///
/// @param[in] a Passed to <code>method</code> when the completion callback
/// runs.
///
/// @param[in] b Passed to <code>method</code> when the completion callback
/// runs.
///
/// @return A <code>CompletionCallback</code>.
template <typename Output, typename A, typename B>
CompletionCallbackWithOutput<
typename internal::TypeUnwrapper<Output>::StorageType>
NewCallbackWithOutput(void (T::*method)(int32_t, Output, A, B),
const A& a,
const B& b) {
return NewCallbackWithOutputHelper(new DispatcherWithOutput2<
typename internal::TypeUnwrapper<Output>::StorageType,
void (T::*)(int32_t, Output, A, B),
typename internal::TypeUnwrapper<A>::StorageType,
typename internal::TypeUnwrapper<B>::StorageType>(method, a, b));
}
/// NewCallback() allocates a new, single-use
/// <code>CompletionCallback</code>.
/// The <code>CompletionCallback</code> must be run in order for the memory
/// allocated by the methods to be freed.
///
/// @param method The method taking the callback. Method should be of type:
/// <code>
/// void (T::*)(int32_t result, const A& a, const B& b, const C& c)
/// </code>
///
/// @param[in] a Passed to <code>method</code> when the completion callback
/// runs.
///
/// @param[in] b Passed to <code>method</code> when the completion callback
/// runs.
///
/// @param[in] c Passed to <code>method</code> when the completion callback
/// runs.
///
/// @return A <code>CompletionCallback</code>.
template <typename Method, typename A, typename B, typename C>
CompletionCallback NewCallback(Method method, const A& a, const B& b,
const C& c) {
PP_DCHECK(object_);
return NewCallbackHelper(new Dispatcher3<Method, A, B, C>(method, a, b, c));
}
/// NewOptionalCallback() allocates a new, single-use
/// <code>CompletionCallback</code> that might not run if the method
/// taking it can complete synchronously. Thus, if after passing the
/// CompletionCallback to a Pepper method, the method does not return
/// PP_OK_COMPLETIONPENDING, then you should manually call the
/// CompletionCallback's Run method, or memory will be leaked.
///
/// @param[in] method The method taking the callback. Method should be of
/// type:
/// <code>
/// void (T::*)(int32_t result, const A& a, const B& b, const C& c)
/// </code>
///
/// @param[in] a Passed to <code>method</code> when the completion callback
/// runs.
///
/// @param[in] b Passed to <code>method</code> when the completion callback
/// runs.
///
/// @param[in] c Passed to <code>method</code> when the completion callback
/// runs.
///
/// @return A <code>CompletionCallback</code>.
template <typename Method, typename A, typename B, typename C>
CompletionCallback NewOptionalCallback(Method method, const A& a,
const B& b, const C& c) {
CompletionCallback cc = NewCallback(method, a, b, c);
cc.set_flags(cc.flags() | PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
return cc;
}
/// NewCallbackWithOutput() allocates a new, single-use
/// <code>CompletionCallback</code> where the browser will pass an additional
/// parameter comtaining the result of the request. The
/// <code>CompletionCallback</code> must be run in order for the memory
/// allocated by the methods to be freed.
///
/// @param method The method to be run.
///
/// @param[in] a Passed to <code>method</code> when the completion callback
/// runs.
///
/// @param[in] b Passed to <code>method</code> when the completion callback
/// runs.
///
/// @param[in] c Passed to <code>method</code> when the completion callback
/// runs.
///
/// @return A <code>CompletionCallback</code>.
template <typename Output, typename A, typename B, typename C>
CompletionCallbackWithOutput<
typename internal::TypeUnwrapper<Output>::StorageType>
NewCallbackWithOutput(void (T::*method)(int32_t, Output, A, B, C),
const A& a,
const B& b,
const C& c) {
return NewCallbackWithOutputHelper(new DispatcherWithOutput3<
typename internal::TypeUnwrapper<Output>::StorageType,
void (T::*)(int32_t, Output, A, B, C),
typename internal::TypeUnwrapper<A>::StorageType,
typename internal::TypeUnwrapper<B>::StorageType,
typename internal::TypeUnwrapper<C>::StorageType>(method, a, b, c));
}
private:
class BackPointer {
public:
typedef CompletionCallbackFactory<T, RefCount> FactoryType;
explicit BackPointer(FactoryType* factory)
: factory_(factory) {
}
void AddRef() {
ref_.AddRef();
}
void Release() {
if (ref_.Release() == 0)
delete this;
}
void DropFactory() {
factory_ = NULL;
}
T* GetObject() {
return factory_ ? factory_->GetObject() : NULL;
}
private:
RefCount ref_;
FactoryType* factory_;
};
template <typename Dispatcher>
class CallbackData {
public:
// Takes ownership of the given dispatcher pointer.
CallbackData(BackPointer* back_pointer, Dispatcher* dispatcher)
: back_pointer_(back_pointer),
dispatcher_(dispatcher) {
back_pointer_->AddRef();
}
~CallbackData() {
back_pointer_->Release();
delete dispatcher_;
}
Dispatcher* dispatcher() { return dispatcher_; }
static void Thunk(void* user_data, int32_t result) {
Self* self = static_cast<Self*>(user_data);
T* object = self->back_pointer_->GetObject();
// Please note that |object| may be NULL at this point. But we still need
// to call into Dispatcher::operator() in that case, so that it can do
// necessary cleanup.
(*self->dispatcher_)(object, result);
delete self;
}
private:
typedef CallbackData<Dispatcher> Self;
BackPointer* back_pointer_; // We own a ref to this refcounted object.
Dispatcher* dispatcher_; // We own this pointer.
// Disallow copying & assignment.
CallbackData(const CallbackData<Dispatcher>&);
CallbackData<Dispatcher>& operator=(const CallbackData<Dispatcher>&);
};
template <typename Method>
class Dispatcher0 {
public:
Dispatcher0() : method_(NULL) {}
explicit Dispatcher0(Method method) : method_(method) {
}
void operator()(T* object, int32_t result) {
if (object)
(object->*method_)(result);
}
private:
Method method_;
};
template <typename Output, typename Method>
class DispatcherWithOutput0 {
public:
typedef Output OutputType;
typedef internal::CallbackOutputTraits<Output> Traits;
DispatcherWithOutput0()
: method_(NULL),
output_() {
}
DispatcherWithOutput0(Method method)
: method_(method),
output_() {
}
void operator()(T* object, int32_t result) {
// We must call Traits::StorageToPluginArg() even if we don't need to call
// the callback anymore, otherwise we may leak resource or var references.
if (object)
(object->*method_)(result, Traits::StorageToPluginArg(output_));
else
Traits::StorageToPluginArg(output_);
}
typename Traits::StorageType* output() {
return &output_;
}
private:
Method method_;
typename Traits::StorageType output_;
};
template <typename Method, typename A>
class Dispatcher1 {
public:
Dispatcher1()
: method_(NULL),
a_() {
}
Dispatcher1(Method method, const A& a)
: method_(method),
a_(a) {
}
void operator()(T* object, int32_t result) {
if (object)
(object->*method_)(result, a_);
}
private:
Method method_;
A a_;
};
template <typename Output, typename Method, typename A>
class DispatcherWithOutput1 {
public:
typedef Output OutputType;
typedef internal::CallbackOutputTraits<Output> Traits;
DispatcherWithOutput1()
: method_(NULL),
a_(),
output_() {
}
DispatcherWithOutput1(Method method, const A& a)
: method_(method),
a_(a),
output_() {
}
void operator()(T* object, int32_t result) {
// We must call Traits::StorageToPluginArg() even if we don't need to call
// the callback anymore, otherwise we may leak resource or var references.
if (object)
(object->*method_)(result, Traits::StorageToPluginArg(output_), a_);
else
Traits::StorageToPluginArg(output_);
}
typename Traits::StorageType* output() {
return &output_;
}
private:
Method method_;
A a_;
typename Traits::StorageType output_;
};
template <typename Method, typename A, typename B>
class Dispatcher2 {
public:
Dispatcher2()
: method_(NULL),
a_(),
b_() {
}
Dispatcher2(Method method, const A& a, const B& b)
: method_(method),
a_(a),
b_(b) {
}
void operator()(T* object, int32_t result) {
if (object)
(object->*method_)(result, a_, b_);
}
private:
Method method_;
A a_;
B b_;
};
template <typename Output, typename Method, typename A, typename B>
class DispatcherWithOutput2 {
public:
typedef Output OutputType;
typedef internal::CallbackOutputTraits<Output> Traits;
DispatcherWithOutput2()
: method_(NULL),
a_(),
b_(),
output_() {
}
DispatcherWithOutput2(Method method, const A& a, const B& b)
: method_(method),
a_(a),
b_(b),
output_() {
}
void operator()(T* object, int32_t result) {
// We must call Traits::StorageToPluginArg() even if we don't need to call
// the callback anymore, otherwise we may leak resource or var references.
if (object)
(object->*method_)(result, Traits::StorageToPluginArg(output_), a_, b_);
else
Traits::StorageToPluginArg(output_);
}
typename Traits::StorageType* output() {
return &output_;
}
private:
Method method_;
A a_;
B b_;
typename Traits::StorageType output_;
};
template <typename Method, typename A, typename B, typename C>
class Dispatcher3 {
public:
Dispatcher3()
: method_(NULL),
a_(),
b_(),
c_() {
}
Dispatcher3(Method method, const A& a, const B& b, const C& c)
: method_(method),
a_(a),
b_(b),
c_(c) {
}
void operator()(T* object, int32_t result) {
if (object)
(object->*method_)(result, a_, b_, c_);
}
private:
Method method_;
A a_;
B b_;
C c_;
};
template <typename Output, typename Method, typename A, typename B,
typename C>
class DispatcherWithOutput3 {
public:
typedef Output OutputType;
typedef internal::CallbackOutputTraits<Output> Traits;
DispatcherWithOutput3()
: method_(NULL),
a_(),
b_(),
c_(),
output_() {
}
DispatcherWithOutput3(Method method, const A& a, const B& b, const C& c)
: method_(method),
a_(a),
b_(b),
c_(c),
output_() {
}
void operator()(T* object, int32_t result) {
// We must call Traits::StorageToPluginArg() even if we don't need to call
// the callback anymore, otherwise we may leak resource or var references.
if (object) {
(object->*method_)(result, Traits::StorageToPluginArg(output_),
a_, b_, c_);
} else {
Traits::StorageToPluginArg(output_);
}
}
typename Traits::StorageType* output() {
return &output_;
}
private:
Method method_;
A a_;
B b_;
C c_;
typename Traits::StorageType output_;
};
void InitBackPointer() {
back_pointer_ = new BackPointer(this);
back_pointer_->AddRef();
}
void ResetBackPointer() {
back_pointer_->DropFactory();
back_pointer_->Release();
}
// Takes ownership of the dispatcher pointer, which should be heap allocated.
template <typename Dispatcher>
CompletionCallback NewCallbackHelper(Dispatcher* dispatcher) {
PP_DCHECK(object_); // Expects a non-null object!
return CompletionCallback(
&CallbackData<Dispatcher>::Thunk,
new CallbackData<Dispatcher>(back_pointer_, dispatcher));
}
// Takes ownership of the dispatcher pointer, which should be heap allocated.
template <typename Dispatcher> CompletionCallbackWithOutput<
typename internal::TypeUnwrapper<
typename Dispatcher::OutputType>::StorageType>
NewCallbackWithOutputHelper(Dispatcher* dispatcher) {
PP_DCHECK(object_); // Expects a non-null object!
CallbackData<Dispatcher>* data =
new CallbackData<Dispatcher>(back_pointer_, dispatcher);
return CompletionCallbackWithOutput<typename Dispatcher::OutputType>(
&CallbackData<Dispatcher>::Thunk,
data,
data->dispatcher()->output());
}
// Disallowed:
CompletionCallbackFactory(const CompletionCallbackFactory&);
CompletionCallbackFactory& operator=(const CompletionCallbackFactory&);
T* object_;
BackPointer* back_pointer_;
};
} // namespace pp
#endif // PPAPI_UTILITY_COMPLETION_CALLBACK_FACTORY_H_
|