Fixes #159. Remove external cache locking.

Author: emacarron

src/main/java/org/apache/ibatis/cache/Cache.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2012 the original author or authors.
+ *    Copyright 2009-2014 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.
@@ -17,20 +17,71 @@
 
 import java.util.concurrent.locks.ReadWriteLock;
 
+/**
+ * Interface to be implemented by cache providers.
+ * 
+ * One instance of cache will be created for each namespace.
+ * 
+ * The cache implementation must have a constructor that receives the cache id as an String parameter.
+ * 
+ * <pre>
+ * public MyCache(final String id) {
+ *  if (id == null) {
+ *    throw new IllegalArgumentException("Cache instances require an ID");
+ *  }
+ *  this.id = id;
+ *  initialize();
+ * }
+ * </pre>
+ *
+ */
+
 public interface Cache {
 
+  /**
+   * @return The identifier of this cache
+   */
   String getId();
 
+  /**
+   * Optional. It is not called by the core.
+   * 
+   * @return The cache size.
+   */
   int getSize();
 
+  /**
+   * @param key Can be any object but usually it is a {@link CacheKey}
+   * @param value The result of a select.
+   */
   void putObject(Object key, Object value);
 
+  /**
+   * @param key The key
+   * @return The object stored in the cache.
+   */
   Object getObject(Object key);
 
+  /**
+   * Optional. It is not called by the core.
+   * 
+   * @param key The key
+   * @return The object that was removed
+   */
   Object removeObject(Object key);
 
+  /**
+   * Clears this cache instance
+   */  
   void clear();
 
+  /** 
+   * As of 3.2.6 this method is no longer called by the core. 
+   * Any locking needed by the cache must be provided internally by the cache provider.
+   * 
+   * @return A ReadWriteLock 
+   * @deprecated 
+   */
   ReadWriteLock getReadWriteLock();
 
 }

src/main/java/org/apache/ibatis/cache/decorators/FifoCache.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2012 the original author or authors.
+ *    Copyright 2009-2014 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.
@@ -35,10 +35,12 @@ public FifoCache(Cache delegate) {
     this.size = 1024;
   }
 
+  @Override
   public String getId() {
     return delegate.getId();
   }
 
+  @Override
   public int getSize() {
     return delegate.getSize();
   }
@@ -47,26 +49,31 @@ public void setSize(int size) {
     this.size = size;
   }
 
+  @Override
   public void putObject(Object key, Object value) {
     cycleKeyList(key);
     delegate.putObject(key, value);
   }
 
+  @Override
   public Object getObject(Object key) {
     return delegate.getObject(key);
   }
 
+  @Override
   public Object removeObject(Object key) {
     return delegate.removeObject(key);
   }
 
+  @Override
   public void clear() {
     delegate.clear();
-    keyList = new LinkedList<Object>(); // see #138
+    keyList.clear();
   }
 
+  @Override
   public ReadWriteLock getReadWriteLock() {
-    return delegate.getReadWriteLock();
+    return null;
   }
 
   private void cycleKeyList(Object key) {

src/main/java/org/apache/ibatis/cache/decorators/LoggingCache.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2012 the original author or authors.
+ *    Copyright 2009-2014 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.
@@ -23,7 +23,7 @@
 
 public class LoggingCache implements Cache {
 
-  private static final Log log = LogFactory.getLog(LoggingCache.class);
+  private static final Log log = LogFactory.getLog(LoggingCache.class); 
 
   private Cache delegate;
   protected int requests = 0;
@@ -33,18 +33,22 @@ public LoggingCache(Cache delegate) {
     this.delegate = delegate;
   }
 
+  @Override
   public String getId() {
     return delegate.getId();
   }
 
+  @Override
   public int getSize() {
     return delegate.getSize();
   }
 
+  @Override
   public void putObject(Object key, Object object) {
     delegate.putObject(key, object);
   }
 
+  @Override
   public Object getObject(Object key) {
     requests++;
     final Object value = delegate.getObject(key);
@@ -57,22 +61,27 @@ public Object getObject(Object key) {
     return value;
   }
 
+  @Override
   public Object removeObject(Object key) {
     return delegate.removeObject(key);
   }
 
+  @Override
   public void clear() {
     delegate.clear();
   }
 
+  @Override
   public ReadWriteLock getReadWriteLock() {
-    return delegate.getReadWriteLock();
+    return null;
   }
 
+  @Override
   public int hashCode() {
     return delegate.hashCode();
   }
 
+  @Override
   public boolean equals(Object obj) {
     return delegate.equals(obj);
   }

src/main/java/org/apache/ibatis/cache/decorators/LruCache.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2012 the original author or authors.
+ *    Copyright 2009-2014 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.
@@ -15,7 +15,6 @@
  */
 package org.apache.ibatis.cache.decorators;
 
-import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.concurrent.locks.ReadWriteLock;
@@ -36,17 +35,18 @@ public LruCache(Cache delegate) {
     setSize(1024);
   }
 
+  @Override
   public String getId() {
     return delegate.getId();
   }
 
+  @Override
   public int getSize() {
     return delegate.getSize();
   }
 
   public void setSize(final int size) {
-    // TODO look for a better solution to this, see issue #335
-    keyMap = Collections.synchronizedMap(new LinkedHashMap<Object, Object>(size, .75F, true) {
+    keyMap = new LinkedHashMap<Object, Object>(size, .75F, true) {
       private static final long serialVersionUID = 4267176411845948333L;
 
       protected boolean removeEldestEntry(Map.Entry<Object, Object> eldest) {
@@ -56,31 +56,34 @@ protected boolean removeEldestEntry(Map.Entry<Object, Object> eldest) {
         }
         return tooBig;
       }
-    });
+    };
   }
 
+  @Override
   public void putObject(Object key, Object value) {
     delegate.putObject(key, value);
     cycleKeyList(key);
   }
 
+  @Override
   public Object getObject(Object key) {
     keyMap.get(key); //touch
     return delegate.getObject(key);
-
   }
 
+  @Override
   public Object removeObject(Object key) {
     return delegate.removeObject(key);
   }
 
+  @Override
   public void clear() {
     delegate.clear();
     keyMap.clear();
   }
 
   public ReadWriteLock getReadWriteLock() {
-    return delegate.getReadWriteLock();
+    return null;
   }
 
   private void cycleKeyList(Object key) {
@@ -92,4 +95,3 @@ private void cycleKeyList(Object key) {
   }
 
 }
-

src/main/java/org/apache/ibatis/cache/decorators/ScheduledCache.java

@@ -1,5 +1,5 @@
 /*
- *    Copyright 2009-2012 the original author or authors.
+ *    Copyright 2009-2014 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.
@@ -35,20 +35,24 @@ public void setClearInterval(long clearInterval) {
     this.clearInterval = clearInterval;
   }
 
+  @Override
   public String getId() {
     return delegate.getId();
   }
 
+  @Override
   public int getSize() {
     clearWhenStale();
     return delegate.getSize();
   }
 
+  @Override
   public void putObject(Object key, Object object) {
     clearWhenStale();
     delegate.putObject(key, object);
   }
 
+  @Override
   public Object getObject(Object key) {
     if (clearWhenStale()) {
       return null;
@@ -57,24 +61,29 @@ public Object getObject(Object key) {
     }
   }
 
+  @Override
   public Object removeObject(Object key) {
     clearWhenStale();
     return delegate.removeObject(key);
   }
 
+  @Override
   public void clear() {
     lastClear = System.currentTimeMillis();
     delegate.clear();
   }
 
+  @Override
   public ReadWriteLock getReadWriteLock() {
-    return delegate.getReadWriteLock();
+    return null;
   }
 
+  @Override
   public int hashCode() {
     return delegate.hashCode();
   }
 
+  @Override
   public boolean equals(Object obj) {
     return delegate.equals(obj);
   }