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1 // Copyright 2014 The Chromium Authors. All rights reserved. | 1 // Copyright 2014 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #import "base/ios/crb_protocol_observers.h" | 5 #import "base/ios/crb_protocol_observers.h" |
6 | 6 |
7 #include <objc/runtime.h> | 7 #include <objc/runtime.h> |
| 8 #include <algorithm> |
| 9 #include <vector> |
8 | 10 |
9 #include "base/logging.h" | 11 #include "base/logging.h" |
10 #include "base/mac/scoped_nsobject.h" | 12 #include "base/mac/scoped_nsobject.h" |
11 | 13 |
| 14 @interface CRBProtocolObservers () { |
| 15 base::scoped_nsobject<Protocol> _protocol; |
| 16 // ivars declared here are private to the implementation but must be |
| 17 // public for allowing the C++ |Iterator| class access to those ivars. |
| 18 @public |
| 19 // vector of weak pointers to observers. |
| 20 std::vector<__unsafe_unretained id> _observers; |
| 21 // The nested level of observer iteration. |
| 22 // A depth of 0 means nobody is currently iterating on the list of observers. |
| 23 int _invocationDepth; |
| 24 } |
| 25 |
| 26 // Removes nil observers from the list and is called when the |
| 27 // |_invocationDepth| reaches 0. |
| 28 - (void)compact; |
| 29 |
| 30 @end |
| 31 |
| 32 namespace { |
| 33 |
| 34 class Iterator { |
| 35 public: |
| 36 explicit Iterator(CRBProtocolObservers* protocol_observers); |
| 37 ~Iterator(); |
| 38 id GetNext(); |
| 39 |
| 40 private: |
| 41 CRBProtocolObservers* protocol_observers_; |
| 42 size_t index_; |
| 43 size_t max_index_; |
| 44 }; |
| 45 |
| 46 Iterator::Iterator(CRBProtocolObservers* protocol_observers) |
| 47 : protocol_observers_(protocol_observers), |
| 48 index_(0), |
| 49 max_index_(protocol_observers->_observers.size()) { |
| 50 DCHECK(protocol_observers_); |
| 51 ++protocol_observers->_invocationDepth; |
| 52 } |
| 53 |
| 54 Iterator::~Iterator() { |
| 55 if (protocol_observers_ && --protocol_observers_->_invocationDepth == 0) |
| 56 [protocol_observers_ compact]; |
| 57 } |
| 58 |
| 59 id Iterator::GetNext() { |
| 60 if (!protocol_observers_) |
| 61 return nil; |
| 62 auto& observers = protocol_observers_->_observers; |
| 63 // Skip nil elements. |
| 64 size_t max_index = std::min(max_index_, observers.size()); |
| 65 while (index_ < max_index && !observers[index_]) |
| 66 ++index_; |
| 67 return index_ < max_index ? observers[index_++] : nil; |
| 68 } |
| 69 } |
| 70 |
12 @interface CRBProtocolObservers () | 71 @interface CRBProtocolObservers () |
13 | 72 |
14 // Designated initializer. | 73 // Designated initializer. |
15 - (id)initWithProtocol:(Protocol*)protocol; | 74 - (id)initWithProtocol:(Protocol*)protocol; |
16 | 75 |
17 @end | 76 @end |
18 | 77 |
19 @implementation CRBProtocolObservers { | 78 @implementation CRBProtocolObservers |
20 base::scoped_nsobject<Protocol> _protocol; | |
21 base::scoped_nsobject<NSHashTable> _observers; | |
22 } | |
23 | 79 |
24 + (CRBProtocolObservers*)observersWithProtocol:(Protocol*)protocol { | 80 + (instancetype)observersWithProtocol:(Protocol*)protocol { |
25 return [[[self alloc] initWithProtocol:protocol] autorelease]; | 81 return [[[self alloc] initWithProtocol:protocol] autorelease]; |
26 } | 82 } |
27 | 83 |
28 - (id)init { | 84 - (id)init { |
29 NOTREACHED(); | 85 NOTREACHED(); |
30 return nil; | 86 return nil; |
31 } | 87 } |
32 | 88 |
33 - (id)initWithProtocol:(Protocol*)protocol { | 89 - (id)initWithProtocol:(Protocol*)protocol { |
34 self = [super init]; | 90 self = [super init]; |
35 if (self) { | 91 if (self) { |
36 _protocol.reset([protocol retain]); | 92 _protocol.reset([protocol retain]); |
37 _observers.reset([[NSHashTable weakObjectsHashTable] retain]); | |
38 } | 93 } |
39 return self; | 94 return self; |
40 } | 95 } |
41 | 96 |
42 - (Protocol*)protocol { | 97 - (Protocol*)protocol { |
43 return _protocol.get(); | 98 return _protocol.get(); |
44 } | 99 } |
45 | 100 |
46 - (void)addObserver:(id)observer { | 101 - (void)addObserver:(id)observer { |
| 102 DCHECK(observer); |
47 DCHECK([observer conformsToProtocol:self.protocol]); | 103 DCHECK([observer conformsToProtocol:self.protocol]); |
48 [_observers addObject:observer]; | 104 |
| 105 if (std::find(_observers.begin(), _observers.end(), observer) != |
| 106 _observers.end()) |
| 107 return; |
| 108 |
| 109 _observers.push_back(observer); |
49 } | 110 } |
50 | 111 |
51 - (void)removeObserver:(id)observer { | 112 - (void)removeObserver:(id)observer { |
52 [_observers removeObject:observer]; | 113 DCHECK(observer); |
| 114 auto it = std::find(_observers.begin(), _observers.end(), observer); |
| 115 if (it != _observers.end()) { |
| 116 if (_invocationDepth) |
| 117 *it = nil; |
| 118 else |
| 119 _observers.erase(it); |
| 120 } |
| 121 } |
| 122 |
| 123 - (BOOL)empty { |
| 124 int count = 0; |
| 125 for (id observer : _observers) { |
| 126 if (observer != nil) |
| 127 ++count; |
| 128 } |
| 129 return count == 0; |
53 } | 130 } |
54 | 131 |
55 #pragma mark - NSObject | 132 #pragma mark - NSObject |
56 | 133 |
57 - (NSMethodSignature*)methodSignatureForSelector:(SEL)selector { | 134 - (NSMethodSignature*)methodSignatureForSelector:(SEL)selector { |
58 NSMethodSignature* signature = [super methodSignatureForSelector:selector]; | 135 NSMethodSignature* signature = [super methodSignatureForSelector:selector]; |
59 if (signature) | 136 if (signature) |
60 return signature; | 137 return signature; |
61 | 138 |
62 // Look for a required method in the protocol. protocol_getMethodDescription | 139 // Look for a required method in the protocol. protocol_getMethodDescription |
(...skipping 10 matching lines...) Expand all Loading... |
73 return [NSMethodSignature signatureWithObjCTypes:description.types]; | 150 return [NSMethodSignature signatureWithObjCTypes:description.types]; |
74 | 151 |
75 // There is neither a required nor optional method with this selector in the | 152 // There is neither a required nor optional method with this selector in the |
76 // protocol, so invoke -[NSObject doesNotRecognizeSelector:] to raise | 153 // protocol, so invoke -[NSObject doesNotRecognizeSelector:] to raise |
77 // NSInvalidArgumentException. | 154 // NSInvalidArgumentException. |
78 [self doesNotRecognizeSelector:selector]; | 155 [self doesNotRecognizeSelector:selector]; |
79 return nil; | 156 return nil; |
80 } | 157 } |
81 | 158 |
82 - (void)forwardInvocation:(NSInvocation*)invocation { | 159 - (void)forwardInvocation:(NSInvocation*)invocation { |
| 160 DCHECK(invocation); |
| 161 if (_observers.empty()) |
| 162 return; |
83 SEL selector = [invocation selector]; | 163 SEL selector = [invocation selector]; |
84 base::scoped_nsobject<NSArray> observers([[_observers allObjects] retain]); | 164 Iterator it(self); |
85 for (id observer in observers.get()) { | 165 id observer; |
| 166 while ((observer = it.GetNext()) != nil) { |
86 if ([observer respondsToSelector:selector]) | 167 if ([observer respondsToSelector:selector]) |
87 [invocation invokeWithTarget:observer]; | 168 [invocation invokeWithTarget:observer]; |
88 } | 169 } |
89 } | 170 } |
90 | 171 |
91 - (void)executeOnObservers:(ExecutionWithObserverBlock)callback { | 172 - (void)executeOnObservers:(ExecutionWithObserverBlock)callback { |
92 DCHECK(callback); | 173 DCHECK(callback); |
93 base::scoped_nsobject<NSArray> observers([[_observers allObjects] retain]); | 174 if (_observers.empty()) |
94 for (id observer in observers.get()) { | 175 return; |
| 176 Iterator it(self); |
| 177 id observer; |
| 178 while ((observer = it.GetNext()) != nil) |
95 callback(observer); | 179 callback(observer); |
96 } | 180 } |
| 181 |
| 182 #pragma mark - Private |
| 183 |
| 184 - (void)compact { |
| 185 DCHECK(!_invocationDepth); |
| 186 _observers.erase(std::remove(_observers.begin(), _observers.end(), nil), |
| 187 _observers.end()); |
97 } | 188 } |
98 | 189 |
99 @end | 190 @end |
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