Author: chirino
Date: Thu Mar 19 16:50:51 2009
New Revision: 756084
URL: http://svn.apache.org/viewvc?rev=756084&view=rev
Log:
Prototyping a new better store interface
Added:
activemq/sandbox/activemq-flow/src/main/java/org/apache/activemq/broker/store/Store.java
Added:
activemq/sandbox/activemq-flow/src/main/java/org/apache/activemq/broker/store/Store.java
URL:
http://svn.apache.org/viewvc/activemq/sandbox/activemq-flow/src/main/java/org/apache/activemq/broker/store/Store.java?rev=756084&view=auto
==============================================================================
---
activemq/sandbox/activemq-flow/src/main/java/org/apache/activemq/broker/store/Store.java
(added)
+++
activemq/sandbox/activemq-flow/src/main/java/org/apache/activemq/broker/store/Store.java
Thu Mar 19 16:50:51 2009
@@ -0,0 +1,115 @@
+package org.apache.activemq.broker.store;
+
+import java.util.Iterator;
+
+import org.apache.activemq.protobuf.AsciiBuffer;
+import org.apache.activemq.protobuf.Buffer;
+
+/**
+ * Interface to persistently store and access data needed by the messaging
system.
+ *
+ */
+public interface Store {
+
+ public interface RecordKey {
+ }
+
+ /**
+ * This interface allows you to query and update the Store.
+ *
+ * This interface should only be called within the context of a
transaction
+ * controlled by the {...@link Store#execute(Callback)} mehtod.
+ *
+ */
+ public interface Session {
+
+ // Message related methods.
+ public RecordKey messageAdd(AsciiBuffer messageId, Buffer message);
+ public RecordKey messageGetKey(AsciiBuffer messageId);
+ public Buffer messageGet(RecordKey key);
+
+ // Message Chunking related methods.
+ public RecordKey messageChunkOpen(AsciiBuffer messageId, Buffer txid,
Buffer message);
+ public void messageChunkAdd(RecordKey key, Buffer message);
+ public void messageChunkClose(RecordKey key);
+ public Buffer messageChunkGet(RecordKey key, int offset, int max);
+
+ /// Queue related methods.
+ public Iterator<AsciiBuffer> queueList(AsciiBuffer first, int max);
+ public void queueAdd(AsciiBuffer queue);
+ public boolean queueRemove(AsciiBuffer queue);
+
+ public void queueAddMessage(AsciiBuffer queue, RecordKey key);
+ public void queueRemoveMessage(AsciiBuffer queue, RecordKey key);
+ public Iterator<RecordKey> queueListMessagesQueue(AsciiBuffer queue,
RecordKey firstRecord, int max);
+
+ // We could use this to associate additional data to a message on a
queue like
+ // which consumer a message has been dispatched to.
+ public void queueSetMessageAttachment(AsciiBuffer queue, RecordKey
key, Buffer attachment);
+ public Buffer queueGetMessageAttachment(AsciiBuffer queue, RecordKey
key);
+
+ /// Simple Key Value related methods could come in hand to store misc
data.
+ public Iterator<AsciiBuffer> mapList(AsciiBuffer first, int max);
+ public Buffer mapSet(AsciiBuffer map, Buffer key, Buffer value);
+ public Buffer mapGet(AsciiBuffer map, Buffer key);
+ public Buffer mapRemove(AsciiBuffer map, Buffer key);
+ public Iterator<Buffer> mapListKeys(AsciiBuffer map, Buffer first, int
max);
+
+ }
+
+ /**
+ *
+ * This interface is used to execute transacted code which returns a
result.
+ *
+ * It is used by the {...@link Store#execute(Callback)} method,
+ * often as anonymous class.
+ *
+ * @param <R> The type of result that the CallableCallback produces.
+ * @param <T> The type of exceptions that CallableCallback will throw.
+ */
+ public interface Callback<R, T extends Throwable> {
+
+ /**
+ * Gets called by the {...@link Store#execute(Callback)} method within
a transactional context.
+ * If any exception is thrown including Runtime exception, the
transaction is rolled back.
+ *
+ * @param session provides you access to read and update the
persistent data.
+ * @return the result of the CallableCallback
+ * @throws T if an error occurs and the transaction should get rolled
back
+ */
+ public R execute(Session session) throws T;
+ }
+
+ /**
+ * Convenience class which allows you to implement {...@link Callback}
classes which do not return a value.
+ */
+ public abstract class VoidCallback <T extends Throwable> implements
Callback<Object, T> {
+
+ /**
+ * Gets called by the {...@link Store#execute(VoidCallback)} method
within a transactional context.
+ * If any exception is thrown including Runtime exception, the
transaction is rolled back.
+ *
+ * @param session provides you access to read and update the
persistent data.
+ * @throws T if an error occurs and the transaction should get rolled
back
+ */
+ abstract public void run(Session session) throws T;
+
+ final public Object execute(Session session) throws T {
+ run(session);
+ return null;
+ }
+ }
+
+ /**
+ * Executes user supplied {...@link Callback}. If the {...@link Callback}
does not throw
+ * any Exceptions, all updates to the store are committed, otherwise they
+ * are rolled back. Any exceptions thrown by the {...@link Callback} are
propagated by
+ * this method.
+ *
+ * @param <T>
+ * @param closure
+ */
+ public <R, T extends Throwable> R execute(Callback<R,T> closure);
+
+
+}
