关于linkedmap中的字典处理问题

[leidi0129]

删除节点的代码中_dic似乎是想要持有所有的Node，在队列中释放。

Node节点也注释说不持有前后节点，交给字典管理。

但是Map中的字典在赋值的时候用的却是__bridge，不转交对象管辖权，那么字典中的value应该无法持有Node节点才对？

@interface _YYLinkedMapNode : NSObject {
    @package
    __unsafe_unretained _YYLinkedMapNode *_prev; // retained by dic
    __unsafe_unretained _YYLinkedMapNode *_next; // retained by dic
...
}
@end
...
- (void)insertNodeAtHead:(_YYLinkedMapNode *)node {
    CFDictionarySetValue(_dic, (__bridge const void *)(node->_key), (__bridge const void *)(node));
   ...
}
- (void)removeAll {
     ...
    if (CFDictionaryGetCount(_dic) > 0) {
        CFMutableDictionaryRef holder = _dic;
        _dic = CFDictionaryCreateMutable(CFAllocatorGetDefault(), 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
        
        if (_releaseAsynchronously) {
            dispatch_queue_t queue = _releaseOnMainThread ? dispatch_get_main_queue() : YYMemoryCacheGetReleaseQueue();
            dispatch_async(queue, ^{
                CFRelease(holder); // hold and release in specified queue
            });
        }
       ...
    }
}