// MessageItemView.mm, CP是CrashProtected的简称 @implementation MessageItemView – (void)initContentLabel { m_label = [[MMCPLabel alloc] init]; m_label.cpKey = [MMCPUtil generateKeyWithObject:self.messageModel]; if ([MMCPUtil isUnsafeWithKey:m_label.cpKey]) { // 检验出messageModel最新消息文本有难题，过滤表明 m_label.text = @”该文本难以表明”; } else { m_label.text = self.messageModel.content; } } @end // MMCPLabel.mm @implementation MMCPLabel @synthesize cpKey = m_cpKey; // 对常见的排印/绘出USB做检查 – (void)layoutSublayersOfLayer:(CALayer *)layer { CScopedCrashCounter crashCounter(m_cpKey); [super layoutSublayersOfLayer:layer]; } – (void)drawLayer:(CALayer *)layer inContext:(CGContextRef)ctx { CScopedCrashCounter crashCounter(m_cpKey); [super drawLayer:layer inContext:ctx]; } – (CGSize)sizeThatFits:(CGSize)size { CScopedCrashCounter crashCounter(m_cpKey); return [super sizeThatFits:size]; } @end // MMCPUtil.mm // 利用C++特性，在声明C++类临时变量时，会自动执行构造函数，离开作用域会执行析构函数 // 因此构造函数做crashCount+1，析构函数做crashCount-1 class CScopedCrashCounter { public: CScopedCrashCounter(NSString *cpKey) { m_cpKey = cpKey; [MMCPUtil increaseCrashCountWithKey:m_cpKey]; } ~CScopedCrashCounter() { [MMCPUtil decreaseCrashCountWithKey:m_cpKey]; } private: NSString *m_cpKey; }; @implementation MMCPUtil @synthesize crashKeyMemoryMappedKV = m_crashKeyMemoryMappedKV; // 被判定为蓄意信息对应的key @synthesize crashCountMemoryMappedKV = m_crashCountMemoryMappedKV; // 每个key crash次数 – (BOOL)isUnsafeWithKey:(NSString *)key { return [m_crashKeyMemoryMappedKV getBoolForKey:key] == YES; } – (void)increaseCrashCountWithKey:(NSString *)key { // 这里记录key所在缓存 … int32_t count = [m_crashCountMemoryMappedKV getInt32ForKey:key]; [m_crashCountMemoryMappedKV setInt32:count + 1 forKey:key] } – (void)decreaseCrashCountWithKey:(NSString *)key { int32_t count = [m_crashCountMemoryMappedKV getInt32ForKey:key]; [m_crashCountMemoryMappedKV setInt32:MAX(0, count – 1) forKey:key]; } // crash回调函数 – (void)onSignalCrash:(siginfo_t *)info { // 先找到跟crash缓存相同的key NSString *key = [self lastCPKey:info->si_pid]; if (key == nil) return; if (m_isLastTimeCrashedBySpecialCharacter == NO) { // 增设当前是转义引发的维托县，如果crash次数大于1，则过滤这数组表明 [self setLastTimeCrashedBySpecialCharacter:YES]; if ([m_crashCountMemoryMappedKV getInt32ForKey:key] > 1) { [m_crashKeyMemoryMappedKV setBool:YES forKey:key]; } } else { // 已连续转义维托县，间接过滤 [m_crashKeyMemoryMappedKV setBool:YES forKey:key]; } } @end