Added NSCache (OS X 10.6) implementation.

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@28581 72102866-910b-0410-8b05-ffd578937521

Headers/Foundation/NSCache.h

@@ -0,0 +1,112 @@
+#if OS_API_VERSION(MAC_OS_X_VERSION_10_6, GS_API_LATEST)
+
+#import <Foundation/NSObjCRuntime.h>
+
+@class NSString;
+@class NSMutableDictionary;
+@class NSMutableArray;
+#ifndef __has_feature
+#define __has_feature(x) 0
+#endif
+@interface NSCache : NSObject
+{
+#if !__has_feature(objc_nonfragile_abi) || defined(EXPOSE_GSCACHE_IVARS)
+	@private
+	/** The maximum total cost of all cache objects. */
+	NSUInteger _costLimit;
+	/** Total cost of currently-stored objects. */
+	NSUInteger _totalCost;
+	/** The maximum number of objects in the cache. */
+	NSUInteger _countLimit;
+	/** The delegate object, notified when objects are about to be evicted. */
+	id _delegate;
+	/** Flag indicating whether discarded objects should be evicted */
+	BOOL _evictsObjectsWithDiscardedContent;
+	/** Name of this cache. */
+	NSString *_name;
+	/** The mapping from names to objects in this cache. */
+	NSMutableDictionary *_objects;
+	/** LRU ordering of all potentially-evictable objects in this cache. */
+	NSMutableArray *_accesses;
+	/** Total number of accesses to objects */
+	int64_t _totalAccesses;
+#endif
+}
+/** 
+ * Returns the maximum number of objects that are supported by this cache.
+ */
+- (NSUInteger)countLimit;
+/**
+ * Returns the cache's delegate.
+ */
+- (id)delegate;
+/**
+ * Returns whether objects stored in this cache which implement the
+ * NSDiscardableContent protocol are removed from the cache when their contents
+ * are evicted.
+ */
+- (BOOL)evictsObjectsWithDiscardedContent;
+/**
+ * Returns the name associated with this cache.
+ */
+- (NSString*)name;
+/**
+ * Returns an object associated with the specified key in this cache.
+ */
+- (id)objectForKey: (id)key;
+/**
+ * Removes all objects from this cache.
+ */
+- (void)removeAllObjects;
+/**
+ * Removes the object associated with the given key.
+ */
+- (void)removeObjectForKey: (id)key;
+/**
+ * Sets the maximum number of objects permitted in this cache.  This limit is
+ * advisory; caches may choose to disregard it temporarily or permanently.  A
+ * limit of 0 is used to indicate no limit; this is the default.
+ */
+- (void)setCountLimit: (NSUInteger)lim;;
+/**
+ * Sets the delegate for this cache.  The delegate will be notified when an
+ * object is being evicted or removed from the cache.
+ */
+- (void)setDelegate:(id)del;
+/**
+ * Sets whether this cache will evict objects that conform to the
+ * NSDiscardableContent protocol, or simply discard their contents.
+ */
+- (void)setEvictsObjectsWithDiscardedContent:(BOOL)b;
+/**
+ * Sets the name for this cache.
+ */
+- (void)setName: (NSString*)cacheName;
+/**
+ * Adds an object and its associated cost.  The cache will endeavor to keep the
+ * total cost below the value set with -setTotalCostLimit: by discarding the
+ * contents of objects which implement the NSDiscardableContent protocol.
+ */
+- (void)setObject: (id)obj forKey: (id)key cost: (NSUInteger)num;
+/**
+ * Adds an object to the cache without associating a cost with it.
+ */
+- (void)setObject: (id)obj forKey: (id)key;
+/**
+ * Sets the maximum total cost for objects stored in this cache.  This limit is
+ * advisory; caches may choose to disregard it temporarily or permanently.  A
+ * limit of 0 is used to indicate no limit; this is the default.
+ */
+- (void)setTotalCostLimit: (NSUInteger)lim;
+@end
+/**
+ * Protocol implemented by NSCache delegate objects.
+ */
+@protocol NSCacheDelegate
+/**
+ * Delegate method, called just before the cache removes an object, either as
+ * the result of user action or due to the cache becoming full.
+ */
+- (void)cache: (NSCache*)cache willEvictObject: (id)obj;
+@end
+#endif //OS_API_VERSION(MAC_OS_X_VERSION_10_6, GS_API_LATEST)