Improve Entity Capabilities code

Most importantly, rename reload() method of persistent cache to
"DiscoverInfo lookup(String nodeVer)" and lazily load the data from the
persistent cache to the memory cache.

smack-extensions/src/main/java/org/jivesoftware/smackx/caps/EntityCapsManager.java

@@ -62,7 +62,6 @@ import java.util.WeakHashMap;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import java.io.IOException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 
@@ -97,7 +96,7 @@ public class EntityCapsManager extends Manager {
     /**
      * Map of (node + '#" + hash algorithm) to DiscoverInfo data
      */
-    protected static Map<String, DiscoverInfo> caps = new Cache<String, DiscoverInfo>(1000, -1);
+    private static final Cache<String, DiscoverInfo> CAPS_CACHE = new Cache<String, DiscoverInfo>(1000, -1);
 
     /**
      * Map of Full JID -&gt; DiscoverInfo/null. In case of c2s connection the
@@ -105,7 +104,7 @@ public class EntityCapsManager extends Manager {
      * link-local connection the key is formed as user@host (no resource) In
      * case of a server or component the key is formed as domain
      */
-    protected static Map<String, NodeVerHash> jidCaps = new Cache<String, NodeVerHash>(10000, -1);
+    private static final Cache<String, NodeVerHash> JID_TO_NODEVER_CACHE = new Cache<String, NodeVerHash>(10000, -1);
 
     static {
         XMPPConnection.addConnectionCreationListener(new ConnectionCreationListener() {
@@ -141,7 +140,7 @@ public class EntityCapsManager extends Manager {
      *            DiscoverInfo for the specified node.
      */
     public static void addDiscoverInfoByNode(String nodeVer, DiscoverInfo info) {
-        caps.put(nodeVer, info);
+        CAPS_CACHE.put(nodeVer, info);
 
         if (persistentCache != null)
             persistentCache.addDiscoverInfoByNodePersistent(nodeVer, info);
@@ -156,7 +155,7 @@ public class EntityCapsManager extends Manager {
      * @return the node version (node#ver) or null
      */
     public static String getNodeVersionByJid(String jid) {
-        NodeVerHash nvh = jidCaps.get(jid);
+        NodeVerHash nvh = JID_TO_NODEVER_CACHE.get(jid);
         if (nvh != null) {
             return nvh.nodeVer;
         } else {
@@ -165,7 +164,7 @@ public class EntityCapsManager extends Manager {
     }
 
     public static NodeVerHash getNodeVerHashByJid(String jid) {
-        return jidCaps.get(jid);
+        return JID_TO_NODEVER_CACHE.get(jid);
     }
 
     /**
@@ -178,7 +177,7 @@ public class EntityCapsManager extends Manager {
      * @return the discovered info
      */
     public static DiscoverInfo getDiscoverInfoByUser(String user) {
-        NodeVerHash nvh = jidCaps.get(user);
+        NodeVerHash nvh = JID_TO_NODEVER_CACHE.get(user);
         if (nvh == null)
             return null;
 
@@ -194,7 +193,18 @@ public class EntityCapsManager extends Manager {
      * @return The corresponding DiscoverInfo or null if none is known.
      */
     public static DiscoverInfo getDiscoveryInfoByNodeVer(String nodeVer) {
-        DiscoverInfo info = caps.get(nodeVer);
+        DiscoverInfo info = CAPS_CACHE.get(nodeVer);
+
+        // If it was not in CAPS_CACHE, try to retrieve the information from persistentCache
+        if (info == null) {
+            info = persistentCache.lookup(nodeVer);
+            // Promote the information to CAPS_CACHE if one was found
+            if (info != null) {
+                CAPS_CACHE.put(nodeVer, info);
+            }
+        }
+
+        // If we were able to retrieve information from one of the caches, copy it before returning
         if (info != null)
             info = new DiscoverInfo(info);
 
@@ -205,40 +215,37 @@ public class EntityCapsManager extends Manager {
      * Set the persistent cache implementation
      * 
      * @param cache
-     * @throws IOException
      */
-    public static void setPersistentCache(EntityCapsPersistentCache cache) throws IOException {
+    public static void setPersistentCache(EntityCapsPersistentCache cache) {
-        if (persistentCache != null)
-            throw new IllegalStateException("Entity Caps Persistent Cache was already set");
         persistentCache = cache;
-        persistentCache.replay();
     }
 
     /**
-     * Sets the maximum Cache size for the JID to nodeVer Cache
+     * Sets the maximum cache sizes
      *
-     * @param maxCacheSize
+     * @param maxJidToNodeVerSize
+     * @param maxCapsCacheSize
      */
-    @SuppressWarnings("rawtypes")
+    public static void setMaxsCacheSizes(int maxJidToNodeVerSize, int maxCapsCacheSize) {
-    public static void setJidCapsMaxCacheSize(int maxCacheSize) {
+        JID_TO_NODEVER_CACHE.setMaxCacheSize(maxJidToNodeVerSize);
-        ((Cache) jidCaps).setMaxCacheSize(maxCacheSize);
+        CAPS_CACHE.setMaxCacheSize(maxCapsCacheSize);
     }
 
     /**
-     * Sets the maximum Cache size for the nodeVer to DiscoverInfo Cache
+     * Clears the memory cache.
-     * 
-     * @param maxCacheSize
      */
-    @SuppressWarnings("rawtypes")
+    public static void clearMemoryCache() {
-    public static void setCapsMaxCacheSize(int maxCacheSize) {
+        JID_TO_NODEVER_CACHE.clear();
-        ((Cache) caps).setMaxCacheSize(maxCacheSize);
+        CAPS_CACHE.clear();
     }
 
-    private ServiceDiscoveryManager sdm;
+    private final Queue<String> lastLocalCapsVersions = new ConcurrentLinkedQueue<String>();
+
+    private final ServiceDiscoveryManager sdm;
+
     private boolean entityCapsEnabled;
     private String currentCapsVersion;
     private boolean presenceSend = false;
-    private Queue<String> lastLocalCapsVersions = new ConcurrentLinkedQueue<String>();
 
     /**
      * The entity node String used by this EntityCapsManager instance.
@@ -286,7 +293,7 @@ public class EntityCapsManager extends Manager {
                 String node = ext.getNode();
                 String ver = ext.getVer();
 
-                jidCaps.put(from, new NodeVerHash(node, ver, hash));
+                JID_TO_NODEVER_CACHE.put(from, new NodeVerHash(node, ver, hash));
             }
 
         }, PRESENCES_WITH_CAPS);
@@ -297,7 +304,7 @@ public class EntityCapsManager extends Manager {
                 // always remove the JID from the map, even if entityCaps are
                 // disabled
                 String from = packet.getFrom();
-                jidCaps.remove(from);
+                JID_TO_NODEVER_CACHE.remove(from);
             }
         }, PRESENCES_WITHOUT_CAPS);
 
@@ -367,7 +374,7 @@ public class EntityCapsManager extends Manager {
      *            the user (Full JID)
      */
     public void removeUserCapsNode(String user) {
-        jidCaps.remove(user);
+        JID_TO_NODEVER_CACHE.remove(user);
     }
 
     /**
@@ -441,9 +448,9 @@ public class EntityCapsManager extends Manager {
         }
         lastLocalCapsVersions.add(currentCapsVersion);
 
-        caps.put(currentCapsVersion, discoverInfo);
+        CAPS_CACHE.put(currentCapsVersion, discoverInfo);
         if (connection != null)
-            jidCaps.put(connection.getUser(), new NodeVerHash(entityNode, currentCapsVersion, "sha-1"));
+            JID_TO_NODEVER_CACHE.put(connection.getUser(), new NodeVerHash(entityNode, currentCapsVersion, "sha-1"));
 
         final List<Identity> identities = new LinkedList<Identity>(ServiceDiscoveryManager.getInstanceFor(connection).getIdentities());
         sdm.setNodeInformationProvider(entityNode + '#' + currentCapsVersion, new NodeInformationProvider() {

smack-extensions/src/main/java/org/jivesoftware/smackx/caps/cache/EntityCapsPersistentCache.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright © 2011-2013 Florian Schmaus
+ * Copyright © 2011-2014 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,23 +16,21 @@
  */
 package org.jivesoftware.smackx.caps.cache;
 
-import java.io.IOException;
-
 import org.jivesoftware.smackx.disco.packet.DiscoverInfo;
 
 public interface EntityCapsPersistentCache {
     /**
      * Add an DiscoverInfo to the persistent Cache
      * 
-     * @param node
+     * @param nodeVer
      * @param info
      */
-    void addDiscoverInfoByNodePersistent(String node, DiscoverInfo info);
+    void addDiscoverInfoByNodePersistent(String nodeVer, DiscoverInfo info);
 
     /**
-     * Replay the Caches data into EntityCapsManager
+     * Lookup DiscoverInfo by a Node string
      */
-    void replay() throws IOException;
+    DiscoverInfo lookup(String nodeVer);
 
     /**
      * Empty the Cache

smack-extensions/src/main/java/org/jivesoftware/smackx/caps/cache/SimpleDirectoryPersistentCache.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright © 2011 Florian Schmaus
+ * Copyright © 2011-2014 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,7 +31,6 @@ import org.jivesoftware.smack.packet.IQ;
 import org.jivesoftware.smack.provider.IQProvider;
 import org.jivesoftware.smack.util.Base32Encoder;
 import org.jivesoftware.smack.util.StringEncoder;
-import org.jivesoftware.smackx.caps.EntityCapsManager;
 import org.jivesoftware.smackx.disco.packet.DiscoverInfo;
 import org.jivesoftware.smackx.disco.provider.DiscoverInfoProvider;
 import org.xmlpull.v1.XmlPullParserFactory;
@@ -87,9 +86,8 @@ public class SimpleDirectoryPersistentCache implements EntityCapsPersistentCache
     }
 
     @Override
-    public void addDiscoverInfoByNodePersistent(String node, DiscoverInfo info) {
+    public void addDiscoverInfoByNodePersistent(String nodeVer, DiscoverInfo info) {
-        String filename = filenameEncoder.encode(node);
+        File nodeFile = getFileFor(nodeVer);
-        File nodeFile = new File(cacheDir, filename);
         try {
             if (nodeFile.createNewFile())
                 writeInfoToFile(nodeFile, info);
@@ -99,18 +97,28 @@ public class SimpleDirectoryPersistentCache implements EntityCapsPersistentCache
     }
 
     @Override
-    public void replay() throws IOException {
+    public DiscoverInfo lookup(String nodeVer) {
-        File[] files = cacheDir.listFiles();
+        File nodeFile = getFileFor(nodeVer);
-        for (File f : files) {
+        if (!nodeFile.isFile()) {
-            String node = filenameEncoder.decode(f.getName());
+            return null;
-            DiscoverInfo info = restoreInfoFromFile(f);
-            if (info == null)
-                continue;
-
-            EntityCapsManager.addDiscoverInfoByNode(node, info);
         }
+        DiscoverInfo info = null;
+        try {
+            info = restoreInfoFromFile(nodeFile);
+        }
+        catch (IOException e) {
+            LOGGER.log(Level.WARNING, "Coud not restore info from file", e);
+        }
+        return info;
     }
 
+    private File getFileFor(String nodeVer) {
+        String filename = filenameEncoder.encode(nodeVer);
+        File nodeFile = new File(cacheDir, filename);
+        return nodeFile;
+    }
+
+    @Override
     public void emptyCache() {
         File[] files = cacheDir.listFiles();
         for (File f : files) {

smack-extensions/src/test/java/org/jivesoftware/smackx/caps/EntityCapsManagerTest.java

@@ -94,10 +94,7 @@ public class EntityCapsManagerTest {
         EntityCapsManager.addDiscoverInfoByNode(nodeVer, di);
 
         // Lose all the data
-        EntityCapsManager.caps.clear();
+        EntityCapsManager.clearMemoryCache();
-
-        // Restore the data from the persistent Cache
-        cache.replay();
 
         DiscoverInfo restored_di = EntityCapsManager.getDiscoveryInfoByNodeVer(nodeVer);
         assertNotNull(restored_di);