在git push的时候，有时候我们会想办法撤销git commit的内容 
1、找到之前提交的git commit的id 
git log 
找到想要撤销的id 
2、git reset –hard id 
完成撤销,同时将代码恢复到前一commit_id 对应的版本 
3、git reset id 
完成Commit命令的撤销，但是不对代码修改进行撤销，可以直接通过git commit 重新提交对本地代码的修改

$ git reset HEAD^         			回退到上个版本，代码还在

注意：如果加上使用--hard会导致这里虽然回到了上个版本，但是commit上去，未push出去的就没法找回了
$ git reset --hard HEAD^         回退到上个版本
$ git reset --hard HEAD~3        回退到前3次提交之前，以此类推，回退到n次提交之前
$ git reset --hard commit_id     退到/进到 指定commit的sha码

方案1>  使用 Git 提交代码
进入到要提交的代码的目录，里面包含 .git 文件夹，输入指令 git config http.postBuffer 524288000

方案2> 使用 SourceTreee 提交代码
如图按照顺序依次点击在最后一步增加
[http] 
    postBuffer = 524288000

+ (NetworkManager *)sharedInstance
{
    static NetworkManager *sharedManager;

    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        sharedManager = [[NetworkManager alloc] init];
    });

    return sharedManager;
}

/*
 @method
 @brief 注册一个监听对象到监听列表中
 @discussion 把监听对象添加到监听列表中准备接收相应的事件
 @param delegate 需要注册的监听对象
 @param queue 通知监听对象时的线程
 @result
 */
- (void)addDelegate:(id<EMChatManagerDelegate>)delegate delegateQueue:(dispatch_queue_t)queue;

// 发通知一方
NSString *const kUserNameChangedNotification = @"UserNameChangedNotification";

NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
[notificationCenter postNotificationName:UserNameChangedNotification object:nil 	
 																userInfo:@{@"oldName":@"zhangsan","newName":"lisi"}];

// 接收通知的一方可以是
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(UserNameChanged1:) 
 																						 name:kUserNameChangedNotification object:nil];
// 也可以是
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(UserNameChanged2:) 
 																						 name:kUserNameChangedNotification object:nil];

DelegateReceivedViewModel1 *delegateReceiver1 = [[DelegateReceivedViewModel1 alloc] init];
DelegateReceivedViewModel2 *delegateReceiver2 = [[DelegateReceivedViewModel2 alloc] init];
self.delegateReceiver1 = delegateReceiver1;
self.delegateReceiver2 = delegateReceiver2;

// OneToManyDelegateNormalViewController1.h
#import "CJUIKitBaseHomeViewController.h"
#import "TSDelegate.h"

@interface OneToManyDelegateNormalViewController1 : CJUIKitBaseHomeViewController {
    
}
@property (nonatomic, weak) id<TSDelegate> delegate1;	// 提供给外部设置
@property (nonatomic, weak) id<TSDelegate> delegate2;	// 提供给外部设置

@end
  

// OneToManyDelegateNormalViewController1.m
loginModule.actionBlock = ^{
  [self.delegate1 delegate_didUpdateLoginState:YES];
  [self.delegate2 delegate_didUpdateLoginState:YES];
}

OneToManyDelegateNormalViewController1 *viewController = [[OneToManyDelegateNormalViewController1 alloc] init];
viewController.delegate1 = delegateReceiver1;
viewController.delegate2 = delegateReceiver2;
[self.navigationController pushViewController:viewController animated:YES];

OneToManyDelegateNormalMediator21 *delegateMediator
  
// 方法1：构造器注入
- (instancetype)initWithDelegate1:(Delegate1 *)delegate1 
                        delegate2:(Delegate2 *)delegate2;
@property (nonatomic, weak, readonly) Delegate1 *delegate1;
@property (nonatomic, weak, readonly) Delegate2 *delegate2;

// 方法2：Setter 注入
@property (nonatomic, weak) id<Delegate1> delegate1;
@property (nonatomic, weak) id<Delegate2> delegate2;

OneToManyDelegateNormalMediator21 *delegateMediator = [[OneToManyDelegateNormalMediator21 alloc] init];
delegateMediator.delegate1 = self.delegateReceiver1;
delegateMediator.delegate2 = self.delegateReceiver2;

OneToManyDelegateNormalViewController21 *viewController = [[OneToManyDelegateNormalViewController21 alloc] init];
viewController.delegateMediator = delegateMediator;
[self.navigationController pushViewController:viewController animated:YES];

// OneToManyDelegateNormalViewController21.m
loginModule.actionBlock = ^{
  //[self.delegate1 delegate_didUpdateLoginState:YES];
  //[self.delegate2 delegate_didUpdateLoginState:YES];
  [self.delegateMediator delegate_didUpdateLoginState:YES];
};

#pragma mark - TSDelegate
- (void)delegate_didUpdateLoginState:(BOOL)loginState {
    if (self.delegate1 && [self.delegate1 respondsToSelector:@selector(delegate_didUpdateLoginState:)]) {
        [self.delegate1 delegate_didUpdateLoginState:YES];
    }
    
    if (self.delegate2 && [self.delegate2 respondsToSelector:@selector(delegate_didUpdateLoginState:)]) {
        [self.delegate2 delegate_didUpdateLoginState:YES];
    }
}

OneToManyDelegateArrayMediator31 *delegateMediator = [[OneToManyDelegateArrayMediator31 alloc] init];
[delegateMediator addDelegate:self.delegateReceiver1];
[delegateMediator addDelegate:self.delegateReceiver2];

OneToManyDelegateArrayViewController31 *viewController = [[OneToManyDelegateArrayViewController31 alloc] init];
viewController.delegateMediator = delegateMediator;
[self.navigationController pushViewController:viewController animated:YES];

//  OneToManyDelegateArrayMediator31.m
_delegates = [NSPointerArray weakObjectsPointerArray];

- (void)addDelegate:(id)delegate {
    [_delegates addPointer:(__bridge void*)delegate];
}

#pragma mark - TSDelegate
- (void)delegate_didUpdateLoginState:(BOOL)loginState {
    for (NSUInteger i = 0; i < self.delegates.count; i++) {
        id delegate = (__bridge id)[self.delegates pointerAtIndex:i];
        if (delegate && [delegate respondsToSelector:@selector(delegate_didUpdateLoginState:)]) {
            [delegate delegate_didUpdateLoginState:YES];
        }
    }
}

// vc.m
loginModule.actionBlock = ^{
  if (self.delegateMediator && [self.delegateMediator respondsToSelector:@selector(delegate_didUpdateLoginState:)]) {
      [self.delegateMediator delegate_didUpdateLoginState:YES];
  }
};

// Mediator.m
#pragma mark - TSDelegate
- (void)delegate_didUpdateLoginState:(BOOL)loginState {
    for (NSUInteger i = 0; i < self.delegates.count; i++) {
        id delegate = (__bridge id)[self.delegates pointerAtIndex:i];
        if (delegate && [delegate respondsToSelector:@selector(delegate_didUpdateLoginState:)]) {
            [delegate delegate_didUpdateLoginState:YES];
        }
    }
}

// vc.m
loginModule.actionBlock = ^{
  [self.delegateMediator broadcastProtocol:@protocol(TSDelegate)
   																selector:@selector(delegate_didUpdateLoginState:)
   															 responder:^(id<TSDelegate> delegateReceiver) {
     [delegateReceiver delegate_didUpdateLoginState:YES];
   }];
};

// Mediator.m
- (void)broadcastProtocol:(Protocol * _Nonnull)protocol selector:(SEL _Nullable)selector responder:(void (^_Nonnull)(id _Nonnull delegateReceiver))block {
    NSAssert(protocol, @"Protocol is nil.");
    NSAssert(block, @"Block is nil.");
    
    for (NSUInteger i = 0; i < self.delegates.count; i++) {
        id delegateReceiver = (__bridge id)[self.delegates pointerAtIndex:i];
        if (!selector || [delegateReceiver respondsToSelector:selector]) {
            block(delegateReceiver);
        }
    }
}

// vc.m
loginModule.actionBlock = ^{
  if (self.delegateMediator && [self.delegateMediator respondsToSelector:@selector(delegate_didUpdateLoginState:)]) {
      [self.delegateMediator delegate_didUpdateLoginState:YES];
  }
};

// Mediator.m
- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector {
    NSMethodSignature *signature = [super methodSignatureForSelector:aSelector];
    if (signature) {
        return signature;
    }
  	[_delegates addPointer:nil]; //不加上这句的话，直接调用compact，并不能清除 _delegates 数组中的 nil 对象。
    [_delegates compact];   //注意 [_delegates compact]，这个方法可以帮助你去掉数组里面的野指针，避免你在快速遍历的时候拿到一个指向不存在对象的地址

    for (id delegate in _delegates) {
        if (!delegate) {
          continue;
        }
        signature = [delegate methodSignatureForSelector:aSelector];
        if (signature) {
          break;
        }
    }
    return signature;
}

- (void)forwardInvocation:(NSInvocation *)anInvocation {
    SEL selector = [anInvocation selector];
    BOOL responded = NO;
    for (id delegate in _delegates) {
        if (delegate && [delegate respondsToSelector:selector]) {
            [anInvocation invokeWithTarget:delegate];
            responded = YES;
        }
    }
    if (!responded) {
        [self doesNotRecognizeSelector:selector];
    }
}

// viewModel.m
#pragma mark - TSUserDelegate
- (void)userDelegate_didUpdateLoginState:(BOOL)loginState {
    NSLog(@"vm收到userDelegate:登录状态发生变化，您已%@", loginState ? @"登录" : @"登出");
}

#pragma mark - TSMessageDelegate
- (void)messageDelegate_didUpdateMessageState:(BOOL)messageState {
    NSLog(@"vm收到messageDelegate:信息状态发生变化");
}

// vc.m
loginModule.actionBlock = ^{
  [self.delegateMediator broadcastProtocol:@protocol(TSDelegate)
   																selector:@selector(delegate_didUpdateLoginState:)
   															 responder:^(id<TSDelegate> delegateReceiver) {
     [delegateReceiver delegate_didUpdateLoginState:YES];
   }];
};

// Mediator.m
- (void)broadcastProtocol:(Protocol * _Nonnull)protocol selector:(SEL _Nullable)selector responder:(void (^_Nonnull)(id _Nonnull delegateReceiver))block {
    NSAssert(protocol, @"Protocol is nil.");
    NSAssert(block, @"Block is nil.");
    
    for (NSUInteger i = 0; i < self.delegates.count; i++) {
        id delegateReceiver = (__bridge id)[self.delegates pointerAtIndex:i];
      
      	if (![delegateReceiver conformsToProtocol:protocol]) {  // 处理多个protocal中有同名方法,通过传进来的protocol参数，我们在判断接收者有我们想要的方法前，先找到有实现我们想要协议的那个接收者
            continue;
        }
      
        if (!selector || [delegateReceiver respondsToSelector:selector]) {
            block(delegateReceiver);
        }
    }
}

if (![delegateReceiver conformsToProtocol:protocol]) {  // 处理多个protocal中有同名方法,通过传进来的protocol参数，我们在判断接收者有我们想要的方法前，先找到有实现我们想要协议的那个接收者
        // continue or return or ...;
    }

for (NSUInteger i = 0; i < self.delegates.count; i++) {
       id delegateReceiver = (__bridge id)[self.delegates pointerAtIndex:i];
     
     	if (![delegateReceiver conformsToProtocol:protocol]) {  // 处理多个protocal中有同名方法,通过传进来的protocol参数，我们在判断接收者有我们想要的方法前，先找到有实现我们想要协议的那个接收者
           continue;
       }
     
       if (!selector || [delegateReceiver respondsToSelector:selector]) {
           block(delegateReceiver);
       }
   }

@synchronized(xxx) {
      
  }

// vc.m
loginModule.actionBlock = ^{
  [[TSNotificationCenter defaultCenter] broadcastProtocol:@protocol(TSDelegate)
   																	 selector:@selector(delegate_didUpdateLoginState:)
                            				responder:^(id<TSDelegate> delegateReceiver) {
  	[delegateReceiver delegate_didUpdateLoginState:YES];
  }];
};


// 该发送方法在`TSNotificationCenter.m`中的代码如下
- (void)broadcastProtocol:(Protocol * _Nonnull)protocol selector:(SEL _Nullable)selector responder:(void (^_Nonnull)(id _Nonnull delegateReceiver))block {
    NSAssert(protocol, @"Protocol is nil.");
    NSAssert(block, @"Block is nil.");
    
    for (NSUInteger i = 0; i < self.delegates.count; i++) {
        id delegateReceiver = (__bridge id)[self.delegates pointerAtIndex:i];
      
      	if (![delegateReceiver conformsToProtocol:protocol]) {  // 处理多个protocal中有同名方法,通过传进来的protocol参数，我们在判断接收者有我们想要的方法前，先找到有实现我们想要协议的那个接收者
            continue;
        }
      
        if (!selector || [delegateReceiver respondsToSelector:selector]) {
            block(delegateReceiver);
        }
    }
}

// receiver.m
[[TSNotificationCenter defaultCenter] addDelegate:self.diffDelegateReceiver
                                      forProtocol:@protocol(TSUserDelegate)];
[[TSNotificationCenter defaultCenter] addDelegate:self.diffDelegateReceiver
 																			forProtocol:@protocol(TSMessageDelegate)];

// 该添加方法在`TSNotificationCenter.m`中的代码如下
- (void)addDelegate:(id __nonnull)listener forProtocol:(Protocol * _Nonnull )protocol {
    NSAssert(listener, @"listener is nil");
    NSAssert(protocol, @"Protocol is nil");
#ifdef DEBUG
    NSAssert([listener conformsToProtocol:protocol], @"This listener does not conform to the protocol");
#endif
    
    @synchronized(protocol) {
        [self.hashTable addObject:listener];
    }
}