YYDiskCache缓存是通过file文件，splits进行数据存储与读取操作，直接放代码
初始化方法：
- (nullable instancetype)initWithPath:(NSString *)path;
- (nullable instancetype)initWithPath:(NSString *)path
inlineThreshold:(NSUInteger)threshold
我们看两个方法的实现：
- (instancetype)initWithPath:(NSString *)path {
return [self initWithPath:path inlineThreshold:1024 * 20]; // 20KB
}
- (instancetype)initWithPath:(NSString *)path
inlineThreshold:(NSUInteger)threshold {
self = [super init];
if (!self) return nil;
YYDiskCache *globalCache = _YYDiskCacheGetGlobal(path);
if (globalCache) return globalCache;
YYKVStorageType type;
if (threshold == 0) {
type = YYKVStorageTypeFile;
} else if (threshold == NSUIntegerMax) {
type = YYKVStorageTypeSQLite;
} else {
type = YYKVStorageTypeMixed;
}
YYKVStorage *kv = [[YYKVStorage alloc] initWithPath:path type:type];
if (!kv) return nil;
_kv = kv;
_path = path;
_lock = dispatch_semaphore_create(1);
_queue = dispatch_queue_create("com.ibireme.cache.disk", DISPATCH_QUEUE_CONCURRENT);
_inlineThreshold = threshold;
_countLimit = NSUIntegerMax;
_costLimit = NSUIntegerMax;
_ageLimit = DBL_MAX;
_freeDiskSpaceLimit = 0;
_autoTrimInterval = 60;
[self _trimRecursively];
_YYDiskCacheSetGlobal(self);
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(_appWillBeTerminated) name:UIApplicationWillTerminateNotification object:nil];
return self;
}
由上可见 initWithPath:方法是调用initWithPath:inlineThreshold:方法创建的disk缓存，disk缓存存在三种缓存策略YYKVStorageTypeFile文件缓存、YYKVStorageTypeSQLite数据库缓存、YYKVStorageTypeMixed混合缓存
- (instancetype)initWithPath:(NSString *)path创建的是默认20KB的混合缓存策略。缓存策略下一个小节去讲述概括
常用的属性：
@property (nullable, copy) NSString *name; // 缓存的名字
@property (readonly) NSString *path;//缓存的位置
@property (readonly) NSUInteger inlineThreshold; //缓存的临界数值用于缓存类型
@property (nullable, copy) NSData *(^customArchiveBlock)(id object); // 块方法归档数据
@property (nullable, copy) id (^customUnarchiveBlock)(NSData *data);// 块方法解归档数据
@property (nullable, copy) NSString *(^customFileNameBlock)(NSString *key); // 自定义文件设置文件名
/*disk缓存操作方法*/
/*是否含有缓存*/
- (BOOL)containsObjectForKey:(NSString *)key;
- (void)containsObjectForKey:(NSString *)key withBlock:(void(^)(NSString *key, BOOL contains))block;
/*获取缓存*/
- (nullable id<NSCoding>)objectForKey:(NSString *)key;
- (void)objectForKey:(NSString *)key withBlock:(void(^)(NSString *key, id<NSCoding> _Nullable object))block;
/*设置缓存*/
- (void)setObject:(nullable id<NSCoding>)object forKey:(NSString *)key;
- (void)setObject:(nullable id<NSCoding>)object forKey:(NSString *)key withBlock:(void(^)(void))block;
/*移除缓存*/
- (void)removeObjectForKey:(NSString *)key;
- (void)removeObjectForKey:(NSString *)key withBlock:(void(^)(NSString *key))block;
- (void)removeAllObjectsWithBlock:(void(^)(void))block;
- (void)removeAllObjectsWithProgressBlock:(nullable void(^)(int removedCount, int totalCount))progress
endBlock:(nullable void(^)(BOOL error))end;
- (void)removeAllObjects;
/*缓存数量*/
- (NSInteger)totalCount;
- (void)totalCountWithBlock:(void(^)(NSInteger totalCount))block;
/*缓存大小*/
- (NSInteger)totalCost;
- (void)totalCostWithBlock:(void(^)(NSInteger totalCost))block;
/*LRU缓存清除*/后期介绍
- (void)trimToCount:(NSUInteger)count;
- (void)trimToCount:(NSUInteger)count withBlock:(void(^)(void))block;
- (void)trimToCost:(NSUInteger)cost;
- (void)trimToCost:(NSUInteger)cost withBlock:(void(^)(void))block;
- (void)trimToAge:(NSTimeInterval)age;
- (void)trimToAge:(NSTimeInterval)age withBlock:(void(^)(void))block;
/*存取对象的扩展数据*/
+ (nullable NSData *)getExtendedDataFromObject:(id)object;
+ (void)setExtendedData:(nullable NSData *)extendedData toObject:(id)object;
使用方法：
func userDiskCache() -> Void {
var diskPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first!
diskPath += "/DiskCache"
// 创建默认为20KB的缓存，创建缓存的策略是file于SQlit混合使用
let diskCache:YYDiskCache = YYDiskCache.init(path: diskPath)!
diskCache.name = "DiskCacheName"
/*进行数据缓存*/
diskCache.setObject("你好" as NSCoding, forKey: "DiskCacheKey")
/*判断数据缓存*/
let isContent:Bool = diskCache.containsObject(forKey: "DiskCacheKey")
print("isContent:\(isContent)")
/*读取缓存数据*/
let data:String = diskCache.object(forKey: "DiskCacheKey") as! String
print("data:\(data)")
/*获取缓存的数量*/
let cacheCount:Int = diskCache.totalCount()
print("cacheCount:\(cacheCount)")
/*获取缓存的大小*/
let cacheSize:Int = diskCache.totalCost()
print("缓存的总体成本cacheSize:\(cacheSize)B")
}