Merge pull request #25 from sinnerschrader-mobile/feature_delegateDis…

…patch

Feature delegate dispatch

DelegateDispatch/S2MDelegateDispatcher.h

@@ -0,0 +1,47 @@
+//
+//  S2MDelegateDispatcher.h
+//  DelegateDispatch
+//
+//  Created by Nils Grabenhorst on 22/05/15.
+//  Copyright (c) 2015 SinnerSchrader-Mobile. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+@protocol S2MDelegateDispatcher
+@property (nonatomic, readonly) NSUInteger delegateCount;
+
+/**
+ Adds a delegate to an internal list of delegates.
+ @param delegate The delegate @b must conform to the protocol that was provided when initializing an instance of this RFMessageTrampoline.
+ */
+- (void)addDelegate:(id)delegate;
+
+
+/**
+ Removes a delegate from the internal list of delegates.
+ */
+- (void)removeDelegate:(id)delegate;
+
+- (BOOL)isRegisteredAsDelegate:(id)delegate;
+@end
+
+
+
+
+
+/**
+ Forwards messages to multiple delegates.
+ The messages must belong to a given protocol.
+ Works for instance methods only, not for class methods.
+ 
+ @note Each delegate can only be added once. Pointer equality is checked to determine whether a delegate can be added to the list. Two separate objects with the same hash and returning \c YES for \c isEqual can therefore be added to the list of delegates.
+ 
+ @warning The return value of a message is undefined. Only the return value of the last delegate is returned to the sender of a message. Since the order of delegates called is undefined, it is best to only specify methods that do not return anything in the given protocol.
+ */
+@interface S2MDelegateDispatcher : NSProxy <S2MDelegateDispatcher>
+- (instancetype)initWithDelegateProtocol:(Protocol *)protocol;
+@end
+
+
+
+

DelegateDispatch/S2MDelegateDispatcher.m

@@ -0,0 +1,136 @@
+//
+//  S2MDelegateDispatcher.m
+//  DelegateDispatch
+//
+//  Created by Nils Grabenhorst on 22/05/15.
+//  Copyright (c) 2015 SinnerSchrader-Mobile. All rights reserved.
+//
+
+#import "S2MDelegateDispatcher.h"
+#import "S2MProtocolIntrospector.h"
+#import <ObjC/runtime.h>
+
+@interface S2MDelegateDispatcher ()
+
+@property (nonatomic, strong) NSHashTable *delegates;
+@property (nonatomic, strong) S2MProtocolIntrospector *protocolIntrospector;
+@property (nonatomic) Protocol *delegateProtocol;
+
+/// This queue is used to assure serial access to the delegates hashTable.
+@property (nonatomic, strong) dispatch_queue_t serialQueue;
+@end
+
+@implementation S2MDelegateDispatcher
+
+- (instancetype)initWithDelegateProtocol:(Protocol *)protocol
+{
+	NSParameterAssert(protocol);
+	if (self) {
+		_serialQueue = dispatch_queue_create("com.sinnerschrader-mobile.delegateDispatcher.accessSerializationQueue", DISPATCH_QUEUE_SERIAL);
+
+		_delegateProtocol = protocol;
+		_protocolIntrospector = [[S2MProtocolIntrospector alloc] initWithProtocol:_delegateProtocol];
+		_delegates = [[NSHashTable alloc] initWithOptions:NSHashTableWeakMemory | NSHashTableObjectPointerPersonality
+												 capacity:1];
+	}
+	return self;
+}
+
+#pragma mark - Public
+
+- (void)addDelegate:(id)delegate
+{
+	NSAssert([delegate conformsToProtocol:self.delegateProtocol], @"You can only add delegates conforming to %@.", self.delegateProtocol);
+	if ([delegate conformsToProtocol:self.delegateProtocol]) {
+		dispatch_sync(self.serialQueue, ^{
+			[self.delegates addObject:delegate];
+		});
+	}
+}
+
+- (void)removeDelegate:(id)delegate
+{
+	dispatch_sync(self.serialQueue, ^{
+		[self.delegates removeObject:delegate];
+	});
+}
+
+- (BOOL)isRegisteredAsDelegate:(id)delegate
+{
+	__block BOOL isRegistered = NO;
+	dispatch_sync(self.serialQueue, ^{
+		isRegistered = [self.delegates containsObject:delegate];
+	});
+	return isRegistered;
+}
+
+- (NSString *)description
+{
+	NSString *__block description;
+	dispatch_sync(self.serialQueue, ^{
+		description = [NSString stringWithFormat:@"%@<%@> (current delegates: %@)", NSStringFromClass(self.class), NSStringFromProtocol(self.delegateProtocol), self.delegates];
+	});
+	return description;
+}
+
+
+
+#pragma mark - Accessors
+
+- (NSUInteger)delegateCount
+{
+	NSArray *__block allDelegates;
+	dispatch_sync(self.serialQueue, ^{
+		allDelegates = [self.delegates allObjects];
+	});
+	// the count of an NSHashTable does not update if a collection member has been deallocated and therefore zeroed out. Hence we need to count allObjects to get the correct number.
+	return [allDelegates count];
+}
+
+
+
+#pragma mark - HOM
+
+- (BOOL)conformsToProtocol:(Protocol *)aProtocol {
+	return protocol_isEqual(aProtocol, self.delegateProtocol);
+}
+
+- (BOOL)respondsToSelector:(SEL)aSelector
+{
+	if ([self.protocolIntrospector protocolDeclaresMethodForSelector:aSelector]) {
+		return YES;
+	}
+	return [super respondsToSelector:aSelector];
+}
+
+- (void)forwardInvocation:(NSInvocation *)anInvocation
+{
+	NSArray *__block allDelegates;
+	dispatch_sync(self.serialQueue, ^{
+		allDelegates = [self.delegates allObjects];
+	});
+
+	for (id delegate in allDelegates) {
+		if ([delegate respondsToSelector:anInvocation.selector]) {
+			[anInvocation invokeWithTarget:delegate];
+		}
+	}
+}
+
+- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector
+{
+	NSAssert(self.protocolIntrospector, @"There is no protocolIntrospector!");
+	NSMethodSignature *signature = [self.protocolIntrospector protocolMethodSignatureForSelector:aSelector];
+
+	if (!signature) {
+		signature = [super methodSignatureForSelector:aSelector];
+	}
+	NSAssert(signature, @"Could not get a method description for the selector '%@' from protocol '%@'.", NSStringFromSelector(aSelector), NSStringFromProtocol(self.delegateProtocol));
+
+	return signature;
+}
+
+
+
+
+@end

DelegateDispatch/S2MProtocolIntrospector.h

@@ -0,0 +1,18 @@
+//
+//  S2MProtocolIntrospector.h
+//  DelegateDispatch
+//
+//  Created by Nils Grabenhorst on 22/05/15.
+//  Copyright (c) 2015 SinnerSchrader-Mobile. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+@interface S2MProtocolIntrospector : NSObject
+
+- (BOOL)protocolDeclaresMethodForSelector:(SEL)aSelector;
+- (NSMethodSignature *)protocolMethodSignatureForSelector:(SEL)aSelector;
+
+- (instancetype)initWithProtocol:(Protocol *)protocol NS_DESIGNATED_INITIALIZER;
+
+@end

DelegateDispatch/S2MProtocolIntrospector.m

@@ -0,0 +1,98 @@
+//
+//  S2MProtocolIntrospector.m
+//  DelegateDispatch
+//
+//  Created by Nils Grabenhorst on 22/05/15.
+//  Copyright (c) 2015 SinnerSchrader-Mobile. All rights reserved.
+//
+
+#import "S2MProtocolIntrospector.h"
+#import <ObjC/runtime.h>
+#import <libkern/OSAtomic.h>
+
+@interface S2MProtocolIntrospector () {
+	CFDictionaryRef _signatures;
+}
+@property (nonatomic) Protocol *protocol;
+@property (nonatomic) CFDictionaryRef signatures;
+@end
+
+@implementation S2MProtocolIntrospector
+
+#pragma mark - Lifecycle
+
+- (instancetype)initWithProtocol:(Protocol *)protocol {
+	self = [super init];
+	if (self) {
+		_protocol = protocol;
+	}
+	return self;
+}
+
+#pragma mark - Public
+
+- (BOOL)protocolDeclaresMethodForSelector:(SEL)aSelector {
+	return [self protocolMethodSignatureForSelector:aSelector] != nil;
+}
+
+- (NSMethodSignature *)protocolMethodSignatureForSelector:(SEL)aSelector {
+	return CFDictionaryGetValue(self.signatures, aSelector);
+}
+
+
+#pragma mark - Accessors
+
+- (CFDictionaryRef)signatures {
+	if (!_signatures) {
+		_signatures = [self methodSignaturesForProtocol:self.protocol];
+	}
+	return _signatures;
+}
+
+#pragma mark - Private
+
+// See https://github.com/steipete/PSTDelegateProxy
+static CFMutableDictionaryRef _protocolCache = nil;
+static OSSpinLock _lock = OS_SPINLOCK_INIT;
+
+- (CFDictionaryRef)methodSignaturesForProtocol:(Protocol *)protocol {
+	OSSpinLockLock(&_lock);
+	// Cache lookup
+	if (!_protocolCache) _protocolCache = CFDictionaryCreateMutable(NULL, 0, NULL, &kCFTypeDictionaryValueCallBacks);
+	CFDictionaryRef signatureCache = CFDictionaryGetValue(_protocolCache, (__bridge const void *)(protocol));
+
+	if (!signatureCache) {
+		// Add protocol methods + derived protocol method definitions into protocolCache.
+		signatureCache = CFDictionaryCreateMutable(NULL, 0, NULL, &kCFTypeDictionaryValueCallBacks);
+		[self methodSignaturesForProtocol:protocol inDictionary:(CFMutableDictionaryRef)signatureCache];
+		CFDictionarySetValue(_protocolCache, (__bridge const void *)(protocol), signatureCache);
+		CFRelease(signatureCache);
+	}
+	OSSpinLockUnlock(&_lock);
+	return signatureCache;
+}
+
+- (void)methodSignaturesForProtocol:(Protocol *)protocol inDictionary:(CFMutableDictionaryRef)cache {
+	void (^enumerateRequiredMethods)(BOOL) = ^(BOOL isRequired) {
+		unsigned int methodCount;
+		struct objc_method_description *descr = protocol_copyMethodDescriptionList(protocol, isRequired, YES, &methodCount);
+		for (NSUInteger idx = 0; idx < methodCount; idx++) {
+			NSMethodSignature *signature = [NSMethodSignature signatureWithObjCTypes:descr[idx].types];
+			CFDictionarySetValue(cache, descr[idx].name, (__bridge const void *)(signature));
+		}
+		free(descr);
+	};
+	// We need to enumerate both required and optional protocol methods.
+	enumerateRequiredMethods(NO); enumerateRequiredMethods(YES);
+
+	// There might be sub-protocols we need to catch as well.
+	unsigned int inheritedProtocolCount;
+	Protocol *__unsafe_unretained* inheritedProtocols = protocol_copyProtocolList(protocol, &inheritedProtocolCount);
+	for (NSUInteger idx = 0; idx < inheritedProtocolCount; idx++) {
+		[self methodSignaturesForProtocol:inheritedProtocols[idx] inDictionary:cache];
+	}
+	free(inheritedProtocols);
+}
+
+
+@end

Example/Podfile

@@ -9,6 +9,7 @@ target "S2MToolbox" do
   pod 'S2MToolbox/ShopFinder', :path => "../"
   pod 'S2MToolbox/HockeyApp', :path => "../"
   pod 'S2MToolbox/LocalNotificationHelper', :path => "../"
+  pod 'S2MToolbox/DelegateDispatch', :path => "../"
 end
 
 target "S2MToolboxTests", :exclusive => true do

Example/Podfile.lock

@@ -1,21 +1,23 @@
 PODS:
-  - HockeySDK (3.6.2)
+  - HockeySDK (3.6.4)
   - Kiwi (2.3.1)
-  - S2MToolbox (0.2.0):
-    - S2MToolbox/Foundation (= 0.2.0)
-    - S2MToolbox/UIKit (= 0.2.0)
-  - S2MToolbox/Foundation (0.2.0)
-  - S2MToolbox/HockeyApp (0.2.0):
+  - S2MToolbox (0.2.2):
+    - S2MToolbox/Foundation (= 0.2.2)
+    - S2MToolbox/UIKit (= 0.2.2)
+  - S2MToolbox/DelegateDispatch (0.2.2)
+  - S2MToolbox/Foundation (0.2.2)
+  - S2MToolbox/HockeyApp (0.2.2):
     - HockeySDK
-  - S2MToolbox/Kiwi (0.2.0):
+  - S2MToolbox/Kiwi (0.2.2):
     - Kiwi (~> 2.3.0)
-  - S2MToolbox/LocalNotificationHelper (0.2.0)
-  - S2MToolbox/QRCode (0.2.0)
-  - S2MToolbox/ShopFinder (0.2.0)
-  - S2MToolbox/UIKit (0.2.0)
+  - S2MToolbox/LocalNotificationHelper (0.2.2)
+  - S2MToolbox/QRCode (0.2.2)
+  - S2MToolbox/ShopFinder (0.2.2)
+  - S2MToolbox/UIKit (0.2.2)
 
 DEPENDENCIES:
   - S2MToolbox (from `../`)
+  - S2MToolbox/DelegateDispatch (from `../`)
   - S2MToolbox/HockeyApp (from `../`)
   - S2MToolbox/Kiwi (from `../`)
   - S2MToolbox/LocalNotificationHelper (from `../`)
@@ -27,8 +29,8 @@ EXTERNAL SOURCES:
     :path: ../
 
 SPEC CHECKSUMS:
-  HockeySDK: bfd1f5ac75938b07499c4ac12932244b72a2e70b
-  Kiwi: 73e1400209055ee9c8ba78c6012b6b642d0fb9f7
-  S2MToolbox: d8460f4f9a8fa633283106f34b670bf19cfa834d
+  HockeySDK: c07cdd580296737edcd0963e292c19885a53f563
+  Kiwi: f038a6c61f7a9e4d7766bff5717aa3b3fdb75f55
+  S2MToolbox: 162cfcf46316ba952776fe8d16ff034e6e0bae51
 
-COCOAPODS: 0.35.0
+COCOAPODS: 0.37.1