[jboss-cvs] JBossAS SVN: r90216 - projects/vfs/trunk/src/main/java/org/jboss/virtual/plugins/context/jar.

[jboss-cvs-commits at lists.jboss.org]

Author: david.lloyd at jboss.com
Date: 2009-06-15 18:07:12 -0400 (Mon, 15 Jun 2009)
New Revision: 90216

Modified:
   projects/vfs/trunk/src/main/java/org/jboss/virtual/plugins/context/jar/JarUtils.java
Log:
Use HashSet which is typically O(1) rather than COWAS which is typically O(n)

Modified: projects/vfs/trunk/src/main/java/org/jboss/virtual/plugins/context/jar/JarUtils.java
===================================================================
--- projects/vfs/trunk/src/main/java/org/jboss/virtual/plugins/context/jar/JarUtils.java	2009-06-15 20:26:46 UTC (rev 90215)
+++ projects/vfs/trunk/src/main/java/org/jboss/virtual/plugins/context/jar/JarUtils.java	2009-06-15 22:07:12 UTC (rev 90216)
@@ -24,7 +24,8 @@
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.Set;
-import java.util.concurrent.CopyOnWriteArraySet;
+import java.util.HashSet;
+import java.util.Collections;
 
 /**
  * JarUtils.
@@ -34,20 +35,26 @@
  */
 public class JarUtils
 {
-   /** The jar suffixes */
-   private static Set<String> jarSuffixes = new CopyOnWriteArraySet<String>();
+   /** The jar suffixes (immutable, do not update unless updateLock is held) */
+   private static volatile Set<String> jarSuffixes;
+   /** The lock to hold in order to update jarSuffixes */
+   private static final Object updateLock = new Object();
 
    // Initialise known suffixes
    static
    {
-      jarSuffixes.add(".zip");
-      jarSuffixes.add(".ear");
-      jarSuffixes.add(".jar");
-      jarSuffixes.add(".rar");
-      jarSuffixes.add(".war");
-      jarSuffixes.add(".sar");
-      jarSuffixes.add(".har");
-      jarSuffixes.add(".aop");
+      final HashSet<String> set = new HashSet<String>();
+      set.add(".zip");
+      set.add(".ear");
+      set.add(".jar");
+      set.add(".rar");
+      set.add(".war");
+      set.add(".sar");
+      set.add(".har");
+      set.add(".aop");
+      synchronized (updateLock) {
+         jarSuffixes = set;
+      }
    }
 
    /**
@@ -60,7 +67,11 @@
    {
       if (suffixes == null)
          throw new IllegalArgumentException("Null suffix");
-      jarSuffixes = suffixes;
+
+      synchronized (updateLock)
+      {
+         jarSuffixes = new HashSet<String>(suffixes);
+      }
    }
 
    /**
@@ -74,7 +85,19 @@
    {
       if (suffix == null)
          throw new IllegalArgumentException("Null suffix");
-      return jarSuffixes.add(suffix);
+
+      synchronized (updateLock)
+      {
+         if (jarSuffixes.contains(suffix))
+            return false;
+         else
+         {
+            final HashSet<String> newSet = new HashSet<String>(jarSuffixes);
+            newSet.add(suffix);
+            jarSuffixes = Collections.unmodifiableSet(newSet);
+            return true;
+         }
+      }
    }
 
    /**
@@ -88,13 +111,28 @@
    {
       if (suffix == null)
          throw new IllegalArgumentException("Null suffix");
-      return jarSuffixes.remove(suffix);
+
+      synchronized (updateLock)
+      {
+         if (jarSuffixes.contains(suffix))
+         {
+            final HashSet<String> newSet = new HashSet<String>(jarSuffixes);
+            newSet.remove(suffix);
+            if (newSet.isEmpty())
+               jarSuffixes = Collections.emptySet();
+            else
+               jarSuffixes = Collections.unmodifiableSet(newSet);
+            return true;
+         }
+         else
+            return false;
+      }
    }
    
    /**
-    * Get the lis of jar suffixes
+    * Get the set of jar suffixes
     * 
-    * @return the list of suffixes
+    * @return the set of suffixes
     */
    public static Set<String> getSuffixes()
    {
@@ -102,12 +140,13 @@
    }
 
    /**
-    * Clear the list of suffixes
-    * 
+    * Clear the set of suffixes
     */
    public static void clearSuffixes()
    {
-      jarSuffixes.clear();
+      synchronized (updateLock) {
+         jarSuffixes = Collections.emptySet();
+      }
    }
 
    /**