Added some synchronization to the KadBucket and DHT

src/kademlia/KademliaNode.java

@@ -318,7 +318,7 @@ public class KademliaNode
      * @throws java.io.IOException
      * @throws kademlia.exceptions.ContentNotFoundException
      */
-    public StorageEntry get(GetParameter param) throws NoSuchElementException, IOException, ContentNotFoundException
+    public synchronized StorageEntry get(GetParameter param) throws NoSuchElementException, IOException, ContentNotFoundException
     {
         if (this.dht.contains(param))
         {
@@ -340,7 +340,7 @@ public class KademliaNode
      *
      * @throws java.io.IOException
      */
-    public void refresh() throws IOException
+    public synchronized void refresh() throws IOException
     {
         new KadRefreshOperation(this.server, this, this.dht, this.config).execute();
     }
@@ -368,7 +368,7 @@ public class KademliaNode
      *
      * @throws java.io.FileNotFoundException
      */
-    public void shutdown(final boolean saveState) throws IOException
+    public synchronized void shutdown(final boolean saveState) throws IOException
     {
         /* Shut down the server */
         this.server.shutdown();
@@ -388,7 +388,7 @@ public class KademliaNode
      *
      * @throws java.io.FileNotFoundException
      */
-    private void saveKadState() throws IOException
+    private synchronized void saveKadState() throws IOException
     {
         DataOutputStream dout;
 
@@ -459,7 +459,7 @@ public class KademliaNode
      * @return The string representation of this Kad instance
      */
     @Override
-    public String toString()
+    public synchronized String toString()
     {
         StringBuilder sb = new StringBuilder("\n\nPrinting Kad State for instance with owner: ");
         sb.append(this.ownerId);

src/kademlia/core/DefaultConfiguration.java

@@ -10,7 +10,7 @@ import java.io.File;
 public class DefaultConfiguration implements KadConfiguration
 {
 
-    private final static long RESTORE_INTERVAL = 30 * 1000; // in milliseconds
+    private final static long RESTORE_INTERVAL = 60 * 1000; // in milliseconds
     private final static long RESPONSE_TIMEOUT = 1500;
     private final static long OPERATION_TIMEOUT = 3000;
     private final static int CONCURRENCY = 10;

src/kademlia/dht/DHT.java

@@ -25,7 +25,7 @@ import kademlia.util.serializer.KadSerializer;
 public class DHT
 {
 
-    private transient StoredContentManager entriesManager;
+    private transient StoredContentManager contentManager;
     private transient KadSerializer<StorageEntry> serializer = null;
     private transient KadConfiguration config;
 
@@ -43,7 +43,7 @@ public class DHT
      */
     public final void initialize()
     {
-        entriesManager = new StoredContentManager();
+        contentManager = new StoredContentManager();
     }
 
     /**
@@ -83,9 +83,9 @@ public class DHT
     public synchronized boolean store(StorageEntry content) throws IOException
     {
         /* Lets check if we have this content and it's the updated version */
-        if (this.entriesManager.contains(content.getContentMetadata()))
+        if (this.contentManager.contains(content.getContentMetadata()))
         {
-            StorageEntryMetadata current = this.entriesManager.get(content.getContentMetadata());
+            StorageEntryMetadata current = this.contentManager.get(content.getContentMetadata());
 
             /* update the last republished time */
             current.updateLastRepublished();
@@ -118,7 +118,7 @@ public class DHT
         {
             //System.out.println("Adding new content.");
             /* Keep track of this content in the entries manager */
-            StorageEntryMetadata sEntry = this.entriesManager.put(content.getContentMetadata());
+            StorageEntryMetadata sEntry = this.contentManager.put(content.getContentMetadata());
 
             /* Now we store the content locally in a file */
             String contentStorageFolder = this.getContentStorageFolderName(content.getContentMetadata().getKey());
@@ -155,7 +155,7 @@ public class DHT
      *
      * @return A KadContent object
      */
-    private StorageEntry retrieve(KademliaId key, int hashCode) throws FileNotFoundException, IOException, ClassNotFoundException
+    private synchronized StorageEntry retrieve(KademliaId key, int hashCode) throws FileNotFoundException, IOException, ClassNotFoundException
     {
         String folder = this.getContentStorageFolderName(key);
         DataInputStream din = new DataInputStream(new FileInputStream(folder + File.separator + hashCode + ".kct"));
@@ -169,9 +169,9 @@ public class DHT
      *
      * @return boolean Whether any content exist that satisfy the criteria
      */
-    public boolean contains(GetParameter param)
+    public synchronized boolean contains(GetParameter param)
     {
-        return this.entriesManager.contains(param);
+        return this.contentManager.contains(param);
     }
 
     /**
@@ -183,7 +183,7 @@ public class DHT
      *
      * @throws java.io.IOException
      */
-    public StorageEntry get(StorageEntryMetadata entry) throws IOException, NoSuchElementException
+    public synchronized StorageEntry get(StorageEntryMetadata entry) throws IOException, NoSuchElementException
     {
         try
         {
@@ -212,12 +212,12 @@ public class DHT
      *
      * @throws java.io.IOException
      */
-    public StorageEntry get(GetParameter param) throws NoSuchElementException, IOException
+    public synchronized StorageEntry get(GetParameter param) throws NoSuchElementException, IOException
     {
         /* Load a KadContent if any exist for the given criteria */
         try
         {
-            StorageEntryMetadata e = this.entriesManager.get(param);
+            StorageEntryMetadata e = this.contentManager.get(param);
             return this.retrieve(e.getKey(), e.hashCode());
         }
         catch (FileNotFoundException e)
@@ -241,17 +241,17 @@ public class DHT
      *
      * @throws kademlia.exceptions.ContentNotFoundException
      */
-    public void remove(KadContent content) throws ContentNotFoundException
+    public synchronized void remove(KadContent content) throws ContentNotFoundException
     {
         this.remove(new StorageEntryMetadata(content));
     }
 
-    public void remove(StorageEntryMetadata entry) throws ContentNotFoundException
+    public synchronized void remove(StorageEntryMetadata entry) throws ContentNotFoundException
     {
         String folder = this.getContentStorageFolderName(entry.getKey());
         File file = new File(folder + File.separator + entry.hashCode() + ".kct");
 
-        entriesManager.remove(entry);
+        contentManager.remove(entry);
 
         if (file.exists())
         {
@@ -270,7 +270,7 @@ public class DHT
      *
      * @return String The name of the folder
      */
-    private String getContentStorageFolderName(KademliaId key)
+    private synchronized String getContentStorageFolderName(KademliaId key)
     {
         /**
          * Each content is stored in a folder named after the first 10 characters of the NodeId
@@ -294,7 +294,7 @@ public class DHT
      */
     public synchronized List<StorageEntryMetadata> getStorageEntries()
     {
-        return entriesManager.getAllEntries();
+        return contentManager.getAllEntries();
     }
 
     /**
@@ -303,13 +303,13 @@ public class DHT
      *
      * @param ientries The entries to add
      */
-    public void putStorageEntries(List<StorageEntryMetadata> ientries)
+    public synchronized void putStorageEntries(List<StorageEntryMetadata> ientries)
     {
         for (StorageEntryMetadata e : ientries)
         {
             try
             {
-                this.entriesManager.put(e);
+                this.contentManager.put(e);
             }
             catch (ContentExistException ex)
             {
@@ -321,6 +321,6 @@ public class DHT
     @Override
     public synchronized String toString()
     {
-        return this.entriesManager.toString();
+        return this.contentManager.toString();
     }
 }

src/kademlia/routing/KadBucketImpl.java

@@ -44,7 +44,7 @@ public class KadBucketImpl implements KadBucket
     }
 
     @Override
-    public void insert(Contact c)
+    public synchronized void insert(Contact c)
     {
         if (this.contacts.contains(c))
         {
@@ -99,25 +99,25 @@ public class KadBucketImpl implements KadBucket
     }
 
     @Override
-    public void insert(Node n)
+    public synchronized void insert(Node n)
     {
         this.insert(new Contact(n));
     }
 
     @Override
-    public boolean containsContact(Contact c)
+    public synchronized boolean containsContact(Contact c)
     {
         return this.contacts.contains(c);
     }
 
     @Override
-    public boolean containsNode(Node n)
+    public synchronized boolean containsNode(Node n)
     {
         return this.containsContact(new Contact(n));
     }
 
     @Override
-    public boolean removeContact(Contact c)
+    public synchronized boolean removeContact(Contact c)
     {
         /* If the contact does not exist, then we failed to remove it */
         if (!this.contacts.contains(c))
@@ -142,7 +142,7 @@ public class KadBucketImpl implements KadBucket
         return true;
     }
 
-    public Contact getFromContacts(Node n)
+    public synchronized Contact getFromContacts(Node n)
     {
         for (Contact c : this.contacts)
         {
@@ -156,7 +156,7 @@ public class KadBucketImpl implements KadBucket
         throw new NoSuchElementException("The contact does not exist in the contacts list.");
     }
 
-    public Contact removeFromContacts(Node n)
+    public synchronized Contact removeFromContacts(Node n)
     {
         for (Contact c : this.contacts)
         {
@@ -172,19 +172,19 @@ public class KadBucketImpl implements KadBucket
     }
 
     @Override
-    public boolean removeNode(Node n)
+    public synchronized boolean removeNode(Node n)
     {
         return this.removeContact(new Contact(n));
     }
 
     @Override
-    public int numContacts()
+    public synchronized int numContacts()
     {
         return this.contacts.size();
     }
 
     @Override
-    public int getDepth()
+    public synchronized int getDepth()
     {
         return this.depth;
     }
@@ -198,7 +198,7 @@ public class KadBucketImpl implements KadBucket
     /**
      * When the bucket is filled, we keep extra contacts in the replacement cache.
      */
-    private void insertIntoReplacementCache(Contact c)
+    private synchronized void insertIntoReplacementCache(Contact c)
     {
         /* Just return if this contact is already in our replacement cache */
         if (this.replacementCache.contains(c))
@@ -223,7 +223,7 @@ public class KadBucketImpl implements KadBucket
         }
     }
 
-    public Contact removeFromReplacementCache(Node n)
+    public synchronized Contact removeFromReplacementCache(Node n)
     {
         for (Contact c : this.replacementCache)
         {
@@ -239,7 +239,7 @@ public class KadBucketImpl implements KadBucket
     }
 
     @Override
-    public String toString()
+    public synchronized String toString()
     {
         StringBuilder sb = new StringBuilder("Bucket at depth: ");
         sb.append(this.depth);