You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@jackrabbit.apache.org by ju...@apache.org on 2010/09/28 12:26:01 UTC
svn commit: r1002101 -
/jackrabbit/trunk/jackrabbit-core/src/main/java/org/apache/jackrabbit/core/persistence/util/BundleCache.java
Author: jukka
Date: Tue Sep 28 10:26:01 2010
New Revision: 1002101
URL: http://svn.apache.org/viewvc?rev=1002101&view=rev
Log:
JCR-2699: Improve read/write concurrency
Make BundleCache synchronized and use the LinkedHashMap class instead of the LinkedMap from Commons Collections (LinkedHashMap supports access-ordering, which makes it better for a LRU map)
Modified:
jackrabbit/trunk/jackrabbit-core/src/main/java/org/apache/jackrabbit/core/persistence/util/BundleCache.java
Modified: jackrabbit/trunk/jackrabbit-core/src/main/java/org/apache/jackrabbit/core/persistence/util/BundleCache.java
URL: http://svn.apache.org/viewvc/jackrabbit/trunk/jackrabbit-core/src/main/java/org/apache/jackrabbit/core/persistence/util/BundleCache.java?rev=1002101&r1=1002100&r2=1002101&view=diff
==============================================================================
--- jackrabbit/trunk/jackrabbit-core/src/main/java/org/apache/jackrabbit/core/persistence/util/BundleCache.java (original)
+++ jackrabbit/trunk/jackrabbit-core/src/main/java/org/apache/jackrabbit/core/persistence/util/BundleCache.java Tue Sep 28 10:26:01 2010
@@ -16,7 +16,9 @@
*/
package org.apache.jackrabbit.core.persistence.util;
-import org.apache.commons.collections.map.LinkedMap;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
import org.apache.jackrabbit.core.id.NodeId;
import org.slf4j.LoggerFactory;
import org.slf4j.Logger;
@@ -54,15 +56,29 @@ public class BundleCache {
/**
* a map of the cache entries
*/
- private LinkedMap bundles = new LinkedMap();
+ private final LinkedHashMap<NodeId, NodePropBundle> bundles;
/**
* Creates a new BundleCache
*
* @param maxSize the maximum size of this cache in bytes.
*/
+ @SuppressWarnings("serial")
public BundleCache(long maxSize) {
this.maxSize = maxSize;
+ this.bundles = new LinkedHashMap<NodeId, NodePropBundle>(
+ (int) maxSize / 1024, 0.75f, true /* access-ordered */) {
+ @Override
+ protected boolean removeEldestEntry(
+ Map.Entry<NodeId, NodePropBundle> e) {
+ if (curSize > BundleCache.this.maxSize) {
+ curSize -= e.getValue().getSize();
+ return true;
+ } else {
+ return false;
+ }
+ }
+ };
}
/**
@@ -90,11 +106,9 @@ public class BundleCache {
* @param id the id of the bundle
* @return the cached bundle or <code>null</code>
*/
- public NodePropBundle get(NodeId id) {
- Entry entry = (Entry) bundles.remove(id);
- if (entry != null) {
- // at end
- bundles.put(id, entry);
+ public synchronized NodePropBundle get(NodeId id) {
+ NodePropBundle bundle = bundles.get(id);
+ if (bundle != null) {
hits++;
} else {
misses++;
@@ -106,32 +120,21 @@ public class BundleCache {
log.info("num=" + bundles.size() + " mem=" + c + "k max=" + m + "k avg=" + a
+ " hits=" + hits + " miss=" + misses);
}
- return entry == null ? null : entry.bundle;
+ return bundle;
}
/**
- * Puts a bunlde to the cache. If the new size of the cache exceeds the
- * {@link #getMaxSize() max size} of the cache it will remove bundles from
- * this cache until the limit is satisfied.
+ * Puts a bundle to the cache.
*
* @param bundle the bunlde to put to the cache
*/
- public void put(NodePropBundle bundle) {
- Entry entry = (Entry) bundles.remove(bundle.getId());
- if (entry == null) {
- entry = new Entry(bundle, bundle.getSize());
- } else {
- curSize -= entry.size;
- entry.bundle = bundle;
- entry.size = bundle.getSize();
- }
- bundles.put(bundle.getId(), entry);
- curSize += entry.size;
- // now limit size of cache
- while (curSize > maxSize) {
- entry = (Entry) bundles.remove(0);
- curSize -= entry.size;
+ public synchronized void put(NodePropBundle bundle) {
+ NodePropBundle previous = bundles.get(bundle.getId());
+ if (previous != null) {
+ curSize -= previous.getSize();
}
+ bundles.put(bundle.getId(), bundle);
+ curSize += bundle.getSize();
}
/**
@@ -141,7 +144,7 @@ public class BundleCache {
* @return <code>true</code> if the bundle is cached;
* <code>false</code> otherwise.
*/
- public boolean contains(NodeId id) {
+ public synchronized boolean contains(NodeId id) {
return bundles.containsKey(id);
}
@@ -152,51 +155,22 @@ public class BundleCache {
* @return the previously cached bunlde or <code>null</code> of the bundle
* was not cached.
*/
- public NodePropBundle remove(NodeId id) {
- Entry entry = (Entry) bundles.remove(id);
- if (entry != null) {
- curSize -= entry.size;
- return entry.bundle;
- } else {
- return null;
+ public synchronized NodePropBundle remove(NodeId id) {
+ NodePropBundle bundle = bundles.remove(id);
+ if (bundle != null) {
+ curSize -= bundle.getSize();
}
+ return bundle;
}
/**
* Clears this cache and removes all bundles.
*/
- public void clear() {
+ public synchronized void clear() {
bundles.clear();
curSize = 0;
hits = 0;
misses = 0;
}
- /**
- * Internal class that holds the bundles.
- */
- private static final class Entry {
-
- /**
- * the cached bundle
- */
- private NodePropBundle bundle;
-
- /**
- * the memory usage of the bundle in bytes
- */
- private long size;
-
- /**
- * Creates a new entry.
- *
- * @param bundle the bundle to cache
- * @param size the size of the bundle
- */
- public Entry(NodePropBundle bundle, long size) {
- this.bundle = bundle;
- this.size = size;
- }
- }
-
}