Adding tx.DataStructureFactory which builds proxy objects

that use a TransactionalNodeStore to commit all writes
after a data structure operation.

This allows the user to wrap operations in locks they
are able to coordinate between all clients.

TODO

@@ -3,7 +3,4 @@
    o CouchDB
    o Other?
  - Implement other data structures / algorithms?
- - Transactions
-   o SubTransactions do not have visibility into parent transaction
-     operations. They should.
  - Implement Sorted Map Interface to BTree.

src/main/java/org/sdsai/dsds/PagedList.java

@@ -54,9 +54,9 @@ public class PagedList<STOREKEY, V>
      */
     private int pageSize;
 
-    public PagedList(final NodeStore<STOREKEY, STOREKEY, V> nodeStore,
-                     final STOREKEY headKey,
-                     final int pageSize )
+    public PagedList(final STOREKEY headKey,
+                     final NodeStore<STOREKEY, STOREKEY, V> nodeStore,
+                     final int pageSize)
     {
         this.pageSize = pageSize;
         this.nodeStore = nodeStore;
@@ -66,13 +66,12 @@ public PagedList(final NodeStore<STOREKEY, STOREKEY, V> nodeStore,
         getHead();
     }
 
-    public PagedList(final NodeStore<STOREKEY, STOREKEY, V> nodeStore,
-                     final STOREKEY headKey)
+    public PagedList(final STOREKEY headKey,
+                     final NodeStore<STOREKEY, STOREKEY, V> nodeStore)
     {
-        this(nodeStore, headKey, 100);
+        this(headKey, nodeStore, 100);
     }
 
-
     private Node<STOREKEY, STOREKEY> getHead()
     {
         Node<STOREKEY, STOREKEY> root;

src/main/java/org/sdsai/dsds/node/tx/DataStructureFactory.java

@@ -5,6 +5,9 @@
 import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.InvocationTargetException;
 
+import java.util.List;
+import java.util.Map;
+
 import org.sdsai.dsds.BTree;
 import org.sdsai.dsds.PagedList;
 import org.sdsai.dsds.node.NodeStore;
@@ -13,38 +16,42 @@
 /**
  * Build transactional datastructures using {@link Proxy}.
  */
-public class DataStructureFactory<USERKEY, STOREKEY, VALUE>
+public class DataStructureFactory
 {
-    private NodeStore<USERKEY, STOREKEY, VALUE> nodeStore;
-
     /**
      * Build a new DataStructureFactory.
      *
      * @throws RuntimeException If a TransactionalNodeStore is passed as the nodeStore parameter.
      */
-    public DataStructureFactory(final NodeStore<USERKEY, STOREKEY, VALUE> nodeStore)
+    private DataStructureFactory()
+    {
+    }
+
+    private static <USERKEY, STOREKEY, VALUE> TransactionalNodeStore<USERKEY, STOREKEY, VALUE> txNodeStore(
+        final NodeStore<USERKEY, STOREKEY, VALUE> nodeStore)
     {
         if ( nodeStore instanceof TransactionalNodeStore )
         {
             throw new RuntimeException("DataStructureFactory is incompatible with TransactionalNodeStore.");
         }
 
-        this.nodeStore = nodeStore;
+        return new TransactionalNodeStore<USERKEY, STOREKEY, VALUE>(nodeStore);
     }
 
-    private InvocationHandler buildTxCommittingInvocationHandler()
+    private static <USERKEY, STOREKEY, VALUE> InvocationHandler buildTxCommittingInvocationHandler(
+        final NodeStore<USERKEY, STOREKEY, VALUE> nodeStore,
+        final Object dispatchObject)
     {
-        final TransactionalNodeStore<USERKEY, STOREKEY, VALUE> transactionalNodeStore =
-            new TransactionalNodeStore<USERKEY, STOREKEY, VALUE>(nodeStore);
 
+        final TransactionalNodeStore<USERKEY, STOREKEY, VALUE> transactionalNodeStore = txNodeStore(nodeStore);
         final InvocationHandler ivh = new InvocationHandler()
         {
             @Override
-            public Object invoke(Object proxy, Method method, Object[] args)
+            public Object invoke(final Object proxy, final Method method, final Object[] args)
             {
                 try
                 {
-                    final Object returnObject = method.invoke(proxy, args);
+                    final Object returnObject = method.invoke(dispatchObject, args);
 
                     transactionalNodeStore.commit();
 
@@ -64,27 +71,69 @@ public Object invoke(Object proxy, Method method, Object[] args)
         return ivh;
     }
 
-    public PagedList<STOREKEY, VALUE> pagedList()
+    public static <STOREKEY, VALUE> List<VALUE> pagedList(
+        final STOREKEY root,
+        final NodeStore<STOREKEY, STOREKEY, VALUE> nodeStore,
+        final int size)
     {
+        final PagedList<STOREKEY, VALUE> pagedList = new PagedList<STOREKEY, VALUE>(root, nodeStore, size);
+
         @SuppressWarnings("unchecked")
-        final PagedList<STOREKEY, VALUE> pagedList = (PagedList<STOREKEY, VALUE>)
+        final List<VALUE> list = (List<VALUE>)
             Proxy.newProxyInstance(
                 PagedList.class.getClassLoader(),
-                new Class<?>[]{ PagedList.class },
-                buildTxCommittingInvocationHandler());
+                new Class<?>[]{ List.class },
+                buildTxCommittingInvocationHandler(nodeStore, pagedList));
 
-        return pagedList;
+        return list;
     }
 
-    public BTree<USERKEY, STOREKEY, VALUE> bTree()
+    public static <STOREKEY, VALUE> List<VALUE> pagedList(
+        final STOREKEY root,
+        final NodeStore<STOREKEY, STOREKEY, VALUE> nodeStore)
     {
+        final PagedList<STOREKEY, VALUE> pagedList = new PagedList<STOREKEY, VALUE>(root, nodeStore);
+
+        @SuppressWarnings("unchecked")
+        final List<VALUE> list = (List<VALUE>)
+            Proxy.newProxyInstance(
+                PagedList.class.getClassLoader(),
+                new Class<?>[]{ List.class },
+                buildTxCommittingInvocationHandler(nodeStore, pagedList));
+
+        return list;
+    }
+
+    public static <USERKEY, STOREKEY, VALUE> Map<USERKEY, VALUE> bTree(
+        final USERKEY root,
+        final NodeStore<USERKEY, STOREKEY, VALUE> nodeStore,
+        final int size)
+    {
+        final BTree<USERKEY, STOREKEY, VALUE> bTree = new BTree<USERKEY, STOREKEY, VALUE>(root, nodeStore, size);
+
+        @SuppressWarnings("unchecked")
+        final Map<USERKEY, VALUE> map = (Map<USERKEY, VALUE>)
+            Proxy.newProxyInstance(
+                BTree.class.getClassLoader(),
+                new Class<?>[]{ Map.class },
+                buildTxCommittingInvocationHandler(nodeStore, bTree));
+
+        return map;
+    }
+
+    public static <USERKEY, STOREKEY, VALUE> Map<USERKEY, VALUE> bTree(
+        final USERKEY root,
+        final NodeStore<USERKEY, STOREKEY, VALUE> nodeStore)
+    {
+        final BTree<USERKEY, STOREKEY, VALUE> bTree = new BTree<USERKEY, STOREKEY, VALUE>(root, nodeStore);
+
         @SuppressWarnings("unchecked")
-        final BTree<USERKEY, STOREKEY, VALUE> bTree = (BTree<USERKEY, STOREKEY, VALUE>)
+        final Map<USERKEY, VALUE> map = (Map<USERKEY, VALUE>)
             Proxy.newProxyInstance(
                 BTree.class.getClassLoader(),
-                new Class<?>[]{ BTree.class },
-                buildTxCommittingInvocationHandler());
+                new Class<?>[]{ Map.class },
+                buildTxCommittingInvocationHandler(nodeStore, bTree));
 
-        return bTree;
+        return map;
     }
 }

src/main/java/org/sdsai/dsds/node/tx/TransactionalNodeStore.java

@@ -32,23 +32,32 @@ public class TransactionalNodeStore<USERKEY, STOREKEY, VALUE>
 
     private Map<STOREKEY, Operation<STOREKEY, Node<USERKEY, STOREKEY>>> nodes;
 
+    private TransactionalNodeStore<USERKEY, STOREKEY, VALUE> parentTransaction;
+
+    public TransactionalNodeStore(final NodeStore<USERKEY, STOREKEY, VALUE> nodeStore)
+    {
+        this(nodeStore, null);
+    }
+
     /**
      * Create a new transaction that operates against the given {@link NodeStore}.
      */
-    public TransactionalNodeStore(final NodeStore<USERKEY, STOREKEY, VALUE> nodeStore)
+    public TransactionalNodeStore(final NodeStore<USERKEY, STOREKEY, VALUE> nodeStore, final TransactionalNodeStore<USERKEY, STOREKEY, VALUE> parentTransaction)
     {
         this.nodeStore = nodeStore;
         this.operations = new LinkedList<Operation<?,?>>();
         this.values = new HashMap<STOREKEY, Operation<STOREKEY, VALUE>>();
         this.nodes = new HashMap<STOREKEY, Operation<STOREKEY, Node<USERKEY, STOREKEY>>>();
+        this.parentTransaction = parentTransaction;
     }
 
     /**
      * Give the user a sub-transaction which is merged into this transaction when {@link SubTx#buildTx(TransactionalNodeStore)} returns.
      */
     public void subTransaction(final SubTx<USERKEY, STOREKEY, VALUE> subTx)
     {
-        final TransactionalNodeStore<USERKEY, STOREKEY, VALUE> tx = new TransactionalNodeStore<USERKEY, STOREKEY, VALUE>(nodeStore);
+        final TransactionalNodeStore<USERKEY, STOREKEY, VALUE> tx =
+            new TransactionalNodeStore<USERKEY, STOREKEY, VALUE>(nodeStore, this);
 
         subTx.buildTx(tx);
 
@@ -100,13 +109,28 @@ public STOREKEY generateKey(final Node<USERKEY,STOREKEY> node, final VALUE value
         return nodeStore.generateKey(node, value);
     }
 
+    /**
+     * Attempt to find a read operation in this transaction or any parent transaction.
+     */
+    private Operation<STOREKEY, VALUE> loadDataReadOperation(final STOREKEY key)
+    {
+        Operation<STOREKEY, VALUE> readOperation = values.get(key);
+
+        if (readOperation == null && parentTransaction != null)
+        {
+            readOperation = parentTransaction.loadDataReadOperation(key);
+        }
+
+        return readOperation;
+    }
+
     /**
      * {@inheritDoc}
      */
     @Override
     public VALUE loadData(final STOREKEY key)
     {
-        final Operation<STOREKEY, VALUE> readOperation = values.get(key);
+        final Operation<STOREKEY, VALUE> readOperation = loadDataReadOperation(key);
 
         if ( readOperation == null ) 
         {
@@ -122,13 +146,27 @@ public VALUE loadData(final STOREKEY key)
         }
     }
 
+    /**
+     * Attempt to find a read operation in this transaction or any parent transaction.
+     */
+    private Operation<STOREKEY, Node<USERKEY, STOREKEY>> loadNodeReadOperation(final STOREKEY key)
+    {
+        Operation<STOREKEY, Node<USERKEY, STOREKEY>> readOperation = nodes.get(key);
+
+        if (readOperation == null && parentTransaction != null)
+        {
+            readOperation = parentTransaction.loadNodeReadOperation(key);
+        }
+
+        return readOperation;
+    }
     /**
      * {@inheritDoc}
      */
     @Override
     public Node<USERKEY, STOREKEY> loadNode(final STOREKEY key)
     {
-        final Operation<STOREKEY, Node<USERKEY, STOREKEY>> readOperation = nodes.get(key);
+        final Operation<STOREKEY, Node<USERKEY, STOREKEY>> readOperation = loadNodeReadOperation(key);
 
         if ( readOperation == null ) 
         {

src/test/java/org/sdsai/dsds/BTreeIteratorTest.java

@@ -188,7 +188,7 @@ private void bkwdIteration(final BTree<UUID, File, String> bt)
     public void forwardsBackwardsTest()
     {
         final NodeStore<Integer, File, String> ns = 
-            new DirectoryNodeStore("target/forwadsBackwardsTest");
+            new DirectoryNodeStore<Integer, String>("target/forwadsBackwardsTest");
 
         final Integer btId = 0;
 

src/test/java/org/sdsai/dsds/PagedListTest.java

@@ -74,7 +74,7 @@ private void print(final PagedList<File, String> p)
     public void testAddRemove()
     {
         PagedList<File, String> pl = 
-            new PagedList<File, String>(nodeStore, nodeStore.generateKey(null, null), 3);
+            new PagedList<File, String>(nodeStore.generateKey(null, null), nodeStore, 3);
 
         try
         {
@@ -108,7 +108,7 @@ public void testAddRemove()
     public void testAddRandomRemove()
     {
         PagedList<File, String> pl = 
-            new PagedList<File, String>(nodeStore, nodeStore.generateKey(null, null), 3);
+            new PagedList<File, String>(nodeStore.generateKey(null, null), nodeStore, 3);
 
         try
         {
@@ -143,7 +143,7 @@ public void testAddRandomRemove()
     public void testAddRandom()
     {
         PagedList<File, String> pl = 
-            new PagedList<File, String>(nodeStore, nodeStore.generateKey(null, null), 3);
+            new PagedList<File, String>(nodeStore.generateKey(null, null), nodeStore, 3);
 
         try
         {

src/test/java/org/sdsai/dsds/node/tx/DataStructureFactoryTest.java

@@ -1,13 +1,62 @@
 package org.sdsai.dsds.node.tx;
 
 import java.util.UUID;
+import java.util.Map;
+import java.util.List;
 
 import org.sdsai.dsds.BaseTest;
+import org.sdsai.dsds.BTree;
+import org.sdsai.dsds.node.NodeStore;
+import org.sdsai.dsds.fs.DirectoryNodeStore;
+import java.io.File;
+import java.io.Serializable;
 
 import org.junit.Test;
+import org.junit.Before;
 import org.junit.Ignore;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
-public class DataStructureFactoryTest extends BaseTest<UUID>
+import static java.util.UUID.randomUUID;
+import static org.junit.Assert.assertEquals;
+
+public class DataStructureFactoryTest
 {
-    private final Logger logger = LoggerFactory.getLogger(BTreeTest.class);
+    private final Logger logger = LoggerFactory.getLogger(DataStructureFactoryTest.class);
+
+    private static <USERKEY extends Serializable> NodeStore<USERKEY, File, String> buildNodeStore(final Class<USERKEY> clazz)
+    {
+        final NodeStore<USERKEY, File, String> nodeStore =
+            new DirectoryNodeStore<USERKEY, String>("target/DirectoryNodeStore/"+DataStructureFactoryTest.class.getSimpleName());
+
+        return nodeStore;
+    }
+
+    @Test
+    public void testTxBTree()
+    {
+        final UUID btKey = randomUUID();
+        final Map<UUID, String> map = DataStructureFactory.bTree(btKey, buildNodeStore(UUID.class));
+    }
+
+    @Test
+    public void testTxPagedList()
+    {
+        final NodeStore<File, File, String> nodeStore = buildNodeStore(File.class);
+
+        final List<String> list = DataStructureFactory.pagedList(nodeStore.generateKey(null, null), nodeStore, 3);
+
+        for(int i = 0; i < 100; i++)
+        {
+            list.add("Hi "+i);
+        }
+
+        for(int i = 0; i < 100; i++)
+        {
+            final String s = "Hi "+i;
+            assertEquals(s, list.get(i));
+        }
+
+        list.clear();
+    }
 }

src/test/java/org/sdsai/dsds/riak/RiakNodeStoreTest.java

@@ -61,7 +61,7 @@ public void setup() throws UnknownHostException
         {
             final IRiakClient riakClient = RiakFactory.httpClient();
 
-            ns = new RiakNodeStore(riakClient, nodeBucket, dataBucket, String.class);
+            ns = new RiakNodeStore<String, String>(riakClient, nodeBucket, dataBucket, String.class);
 
             bt = new BTree<String, String, String>("btRoot", ns, 1);