michael@0: /*
michael@0:  * Copyright (C) 2013 Square, Inc.
michael@0:  *
michael@0:  * Licensed under the Apache License, Version 2.0 (the "License");
michael@0:  * you may not use this file except in compliance with the License.
michael@0:  * You may obtain a copy of the License at
michael@0:  *
michael@0:  *      http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing, software
michael@0:  * distributed under the License is distributed on an "AS IS" BASIS,
michael@0:  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
michael@0:  * See the License for the specific language governing permissions and
michael@0:  * limitations under the License.
michael@0:  */
michael@0: package com.squareup.picasso;
michael@0: 
michael@0: import android.graphics.Bitmap;
michael@0: 
michael@0: /**
michael@0:  * A memory cache for storing the most recently used images.
michael@0:  * <p/>
michael@0:  * <em>Note:</em> The {@link Cache} is accessed by multiple threads. You must ensure
michael@0:  * your {@link Cache} implementation is thread safe when {@link Cache#get(String)} or {@link
michael@0:  * Cache#set(String, android.graphics.Bitmap)} is called.
michael@0:  */
michael@0: public interface Cache {
michael@0:   /** Retrieve an image for the specified {@code key} or {@code null}. */
michael@0:   Bitmap get(String key);
michael@0: 
michael@0:   /** Store an image in the cache for the specified {@code key}. */
michael@0:   void set(String key, Bitmap bitmap);
michael@0: 
michael@0:   /** Returns the current size of the cache in bytes. */
michael@0:   int size();
michael@0: 
michael@0:   /** Returns the maximum size in bytes that the cache can hold. */
michael@0:   int maxSize();
michael@0: 
michael@0:   /** Clears the cache. */
michael@0:   void clear();
michael@0: 
michael@0:   /** A cache which does not store any values. */
michael@0:   Cache NONE = new Cache() {
michael@0:     @Override public Bitmap get(String key) {
michael@0:       return null;
michael@0:     }
michael@0: 
michael@0:     @Override public void set(String key, Bitmap bitmap) {
michael@0:       // Ignore.
michael@0:     }
michael@0: 
michael@0:     @Override public int size() {
michael@0:       return 0;
michael@0:     }
michael@0: 
michael@0:     @Override public int maxSize() {
michael@0:       return 0;
michael@0:     }
michael@0: 
michael@0:     @Override public void clear() {
michael@0:     }
michael@0:   };
michael@0: }