//
//  RMTileCache.h
//
// Copyright (c) 2008-2009, Route-Me Contributors
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice, this
//   list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
//   this list of conditions and the following disclaimer in the documentation
//   and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

#import <Foundation/Foundation.h>
#import "RMTile.h"
#import "RMTileSource.h"
#import "RMCacheObject.h"

@class RMTileImage, RMMemoryCache;

typedef enum {
	RMCachePurgeStrategyLRU,
	RMCachePurgeStrategyFIFO,
} RMCachePurgeStrategy;

#pragma mark -

@protocol RMTileCache <NSObject>

// Returns the cached image if it exists. nil otherwise.
- (UIImage *)cachedImage:(RMTile)tile withCacheKey:(NSString *)cacheKey;

- (void)didReceiveMemoryWarning;

@optional

- (void)addImage:(UIImage *)image forTile:(RMTile)tile withCacheKey:(NSString *)cacheKey;

// removes all tile images from the memory and disk subcaches
- (void)removeAllCachedImages;

@end

#pragma mark -

@interface RMTileCache : NSObject <RMTileCache>
{
	NSMutableArray *caches;

    // The memory cache, if we have one
    // This one has its own variable because we want to propagate cache hits down in
    // the cache hierarchy up to the memory cache
    RMMemoryCache *memoryCache;    
}

+ (NSNumber *)tileHash:(RMTile)tile;

// Add another cache to the chain
- (void)addCache:(id <RMTileCache>)cache;

- (void)didReceiveMemoryWarning;

@end