just before adding authorization service.

[photos] / src / main / java / org / wamblee / photos / concurrent / ConcurrentAlbum.java

diff --git a/src/main/java/org/wamblee/photos/concurrent/ConcurrentAlbum.java b/src/main/java/org/wamblee/photos/concurrent/ConcurrentAlbum.java
new file mode 100644 (file)
index 0000000..47520a2
--- /dev/null
+++ b/src/main/java/org/wamblee/photos/concurrent/ConcurrentAlbum.java
@@ -0,0 +1,159 @@
+/*
+ * Copyright 2005 the original author or authors.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */ 
+package org.wamblee.photos.concurrent;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.wamblee.photos.model.Album;
+import org.wamblee.photos.model.Path;
+import org.wamblee.photos.model.Photo;
+import org.wamblee.photos.model.PhotoEntry;
+
+/**
+ * Decorator for an album providing defined behavior when used in a concurrent setting. 
+ */
+public class ConcurrentAlbum extends ConcurrentPhotoEntry implements Album {
+    
+    /**
+     * Constructs concurrent album as a decorator for an album implementation. 
+     * @param aAlbum Album to decorate. 
+     */
+    public ConcurrentAlbum(Album aAlbum) {
+        super(aAlbum); 
+    }
+    
+    private Album decorated() {
+        return (Album)getEntry(); 
+    }
+    
+    /**
+     * Creates a decorate for the photo entry to make it safe for concurrent access.  
+     * @param aEntry Entry to decorate
+     * @return Decorated photo. 
+     */
+    private <T extends PhotoEntry> T decorate(T aEntry) {
+        if ( aEntry == null ) {
+            return null;    
+        }
+        else if ( aEntry instanceof Photo) {
+            return (T) new ConcurrentPhoto((Photo)aEntry); 
+        } else if ( aEntry instanceof Album) {
+            return (T) new ConcurrentAlbum((Album)aEntry); 
+        } else {
+            throw new IllegalArgumentException("Entry is neither a photo nor an album: " + aEntry); 
+        }
+    }
+
+    /* (non-Javadoc)
+     * @see org.wamblee.photos.model.Album#getEntry(java.lang.String)
+     */
+    public PhotoEntry getEntry(String aPath) {
+        lock().acquireRead(); 
+        try {
+            return decorate(decorated().getEntry(aPath));    
+        } finally {
+            lock().releaseRead(); 
+        }
+    }
+    
+    public PhotoEntry getEntry(Path aPath) {
+        lock().acquireRead(); 
+         try {
+             return decorate(decorated().getEntry(aPath));    
+         } finally {
+             lock().releaseRead(); 
+         }
+    }
+
+    /* (non-Javadoc)
+     * @see org.wamblee.photos.model.Album#getEntry(int)
+     */
+    public PhotoEntry getEntry(int aIndex) {
+        lock().acquireRead(); 
+        try {
+            return decorate(decorated().getEntry(aIndex)); 
+        } finally {
+            lock().releaseRead(); 
+        }
+    }
+
+    /* (non-Javadoc)
+     * @see org.wamblee.photos.model.Album#size()
+     */
+    public int size() {
+        lock().acquireRead(); 
+        try {
+            return decorated().size(); 
+        } finally {
+            lock().releaseRead(); 
+        }
+    }
+
+    /* (non-Javadoc)
+     * @see org.wamblee.photos.model.Album#addImage(java.lang.String, java.io.InputStream)
+     */
+    public void addImage(String aId, InputStream aImage) throws IOException {
+        lock().acquireWrite();
+        try {
+            decorated().addImage(aId, aImage); 
+        } finally {
+            lock().releaseWrite(); 
+        }
+    }
+
+    /* (non-Javadoc)
+     * @see org.wamblee.photos.model.Album#addAlbum(java.lang.String)
+     */
+    public void addAlbum(String aId) throws IOException {
+        lock().acquireWrite();
+        try {
+            decorated().addAlbum(aId);  
+        } finally {
+            lock().releaseWrite(); 
+        }
+    }
+
+    /* (non-Javadoc)
+     * @see org.wamblee.photos.model.Album#removeEntry(java.lang.String)
+     */
+    public void removeEntry(String aId) throws IOException {
+        lock().acquireWrite();
+        try {
+            decorated().removeEntry(aId);  
+        } finally {
+            lock().releaseWrite(); 
+        }
+    }
+    
+    public Photo findPhotoBefore(String aId) {
+        lock().acquireWrite();
+         try {
+             return decorate(decorated().findPhotoBefore(aId));  
+         } finally {
+             lock().releaseWrite(); 
+         }
+    }
+    
+    public Photo findPhotoAfter(String aId) {
+        lock().acquireWrite();
+         try {
+             return decorate(decorated().findPhotoAfter(aId));  
+         } finally {
+             lock().releaseWrite(); 
+         }
+    }
+}