IN PROGRESS - issue BATCH-7: Remove transaction synchronization and state management from input/output sources (formerly buffering)

http://jira.springframework.org/browse/BATCH-7

Take some steps to make stream context keys unique in the StreamManager

spring-batch-execution/src/main/java/org/springframework/batch/execution/scope/SimpleStepContext.java

@@ -81,11 +81,8 @@ public class SimpleStepContext extends SynchronizedAttributeAccessor implements
 		super.setAttribute(name, value);
 		if (streamManager != null && (value instanceof ItemStream)) {
 			ItemStream stream = (ItemStream) value;
-			streamManager.register(this, stream);
 			stream.open();
-			if (streamContext != null) {
-				stream.restoreFrom(streamContext);
-			}
+			streamManager.register(this, stream, streamContext);
 		}
 	}
 
@@ -203,11 +200,10 @@ public class SimpleStepContext extends SynchronizedAttributeAccessor implements
 		return streamManager.getStreamContext(this);
 	}
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.batch.execution.scope.StepContext#setInitialStreamContext(org.springframework.batch.item.StreamContext)
+	/* (non-Javadoc)
+	 * @see org.springframework.batch.execution.scope.StepContext#restoreFrom(org.springframework.batch.item.StreamContext)
 	 */
-	public void setInitialStreamContext(StreamContext streamContext) {
+	public void restoreFrom(StreamContext streamContext) {
 		this.streamContext = streamContext;
 	}
 

spring-batch-execution/src/main/java/org/springframework/batch/execution/scope/StepContext.java

@@ -55,12 +55,13 @@ public interface StepContext extends AttributeAccessor, StreamContextProvider {
 	void close();
 
 	/**
-	 * Provide the stream context that will be needed to restore
-	 * {@link ItemStream} instances. If this is not set the streams will simply
-	 * not be initialised and repositioned for restart (which is sometimes
-	 * desirable).
+	 * Provide the stream context needed to restore {@link ItemStream}
+	 * instances. Implementations are free to use this as necessary (e.g. lazily
+	 * if all the streams are not available at once). If this is not set the
+	 * streams will simply not be initialised and repositioned for restart
+	 * (which is sometimes desirable).
 	 * 
 	 * @param streamContext
 	 */
-	void setInitialStreamContext(StreamContext streamContext);
+	void restoreFrom(StreamContext streamContext);
 }

spring-batch-execution/src/main/java/org/springframework/batch/execution/step/simple/SimpleStepExecutor.java

@@ -190,7 +190,7 @@ public class SimpleStepExecutor {
 		final boolean saveStreamContext = step.isSaveStreamContext();
 
 		if (saveStreamContext && isRestart) {
-			stepContext.setInitialStreamContext(stepInstance.getStreamContext());
+			stepContext.restoreFrom(stepInstance.getStreamContext());
 		}
 
 		try {

spring-batch-execution/src/test/java/org/springframework/batch/execution/scope/SimpleStepContextTests.java

@@ -171,7 +171,7 @@ public class SimpleStepContextTests extends TestCase {
 		public void open(Object key) {
 		}
 
-		public void register(Object key, ItemStream stream) {
+		public void register(Object key, ItemStream stream, StreamContext streamContext) {
 			map.put(key, stream);
 		}
 

spring-batch-execution/src/test/java/org/springframework/batch/execution/step/simple/SimpleStepExecutorTests.java

@@ -98,10 +98,13 @@ public class SimpleStepExecutorTests extends TestCase {
 	 */
 	protected void setUp() throws Exception {
 		super.setUp();
+		ResourcelessTransactionManager transactionManager = new ResourcelessTransactionManager();
+
 		stepConfiguration = new SimpleStep();
 		stepConfiguration.setTasklet(getTasklet(new String[] { "foo", "bar", "spam" }));
 		stepConfiguration.setJobRepository(new JobRepositorySupport());
-		stepConfiguration.setTransactionManager(new ResourcelessTransactionManager());
+		stepConfiguration.setTransactionManager(transactionManager);
+
 		stepExecutor = (SimpleStepExecutor) stepConfiguration.createStepExecutor();
 		template = new RepeatTemplate();
 		template.setCompletionPolicy(new SimpleCompletionPolicy(1));
@@ -113,6 +116,11 @@ public class SimpleStepExecutorTests extends TestCase {
 
 		jobInstance = new JobInstance(new Long(0), new JobParameters());
 		jobInstance.setJob(new JobSupport("FOO"));
+		
+		SimpleStreamManager streamManager = new SimpleStreamManager(transactionManager);
+		streamManager.setUseClassNameAsPrefix(false);
+		stepExecutor.setStreamManager(streamManager);
+
 	}
 
 	public void testStepExecutor() throws Exception {
@@ -304,6 +312,7 @@ public class SimpleStepExecutorTests extends TestCase {
 		stepConfiguration.setSaveStreamContext(true);
 		JobExecution jobExecutionContext = new JobExecution(jobInstance);
 		StepExecution stepExecution = new StepExecution(step, jobExecutionContext);
+		
 		stepExecution.getStep().setStreamContext(
 				new StreamContext(PropertiesConverter.stringToProperties("foo=bar")));