Author: nuttycom
Date: Thu Oct 19 08:54:20 2006
New Revision: 465667
URL: http://svn.apache.org/viewvc?view=rev&rev=465667
Log:
This stage driver factory is useful in cases where it
may be possible to overflow the memory available to the
system. It limits the size of the input queue to any
stage managed by the generated driver, blocking if this
limit is exceeded.
Added:
jakarta/commons/sandbox/pipeline/trunk/src/main/java/org/apache/commons/pipeline/driver/BoundedQueueDedicatedThreadSDF.java
(with props)
Added:
jakarta/commons/sandbox/pipeline/trunk/src/main/java/org/apache/commons/pipeline/driver/BoundedQueueDedicatedThreadSDF.java
URL:
http://svn.apache.org/viewvc/jakarta/commons/sandbox/pipeline/trunk/src/main/java/org/apache/commons/pipeline/driver/BoundedQueueDedicatedThreadSDF.java?view=auto&rev=465667
==============================================================================
---
jakarta/commons/sandbox/pipeline/trunk/src/main/java/org/apache/commons/pipeline/driver/BoundedQueueDedicatedThreadSDF.java
(added)
+++
jakarta/commons/sandbox/pipeline/trunk/src/main/java/org/apache/commons/pipeline/driver/BoundedQueueDedicatedThreadSDF.java
Thu Oct 19 08:54:20 2006
@@ -0,0 +1,147 @@
+/*
+ * Copyright 2005 The Apache Software Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.pipeline.driver;
+
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.commons.pipeline.Stage;
+import org.apache.commons.pipeline.StageContext;
+import org.apache.commons.pipeline.StageDriver;
+import org.apache.commons.pipeline.StageDriverFactory;
+
+/**
+ * This factory is used to create [EMAIL PROTECTED]
DedicatedThreadStageDriver} instances
+ * configured to run specific stages. The [EMAIL PROTECTED] BlockingQueue}
used to buffer
+ * input to the stage is created with a finite capacity, which can be
configured
+ * with the [EMAIL PROTECTED] #setQueueSize(int)} method.
+ */
+public class BoundedQueueDedicatedThreadSDF implements StageDriverFactory {
+ private final Log log =
LogFactory.getLog(BoundedQueueDedicatedThreadSDF.class);
+
+ /**
+ * Creates a new instance of FiniteDedicatedThreadStageDriverFactory
+ */
+ public BoundedQueueDedicatedThreadSDF() {
+ }
+
+ /**
+ * Creates the new [EMAIL PROTECTED] DedicatedThreadStageDriver} based
upon the
+ * configuration of this factory instance
+ *
+ * @param stage The stage to be run by the newly created driver
+ * @param context The context in which the stage will be run
+ * @return the newly created driver
+ */
+ public StageDriver createStageDriver(Stage stage, StageContext context) {
+ BlockingQueue queue = new LinkedBlockingQueue(this.queueSize);
+
+ log.info("Creating a StageDriver with queue size " + this.queueSize);
+ try {
+ return new DedicatedThreadStageDriver(stage, context, queue,
timeout, faultTolerance);
+ } catch (Exception e) {
+ throw new IllegalStateException("Instantiation of driver failed
due to illegal factory state.", e);
+ }
+ }
+
+ /**
+ * Holds value of property timeout.
+ */
+ private long timeout = 500;
+
+ /**
+ * Timeout for wait to ensure deadlock cannot occur on thread termination.
+ * Default is 500
+ *
+ * @return Value of property timeout.
+ */
+ public long getTimeout() {
+ return this.timeout;
+ }
+
+ /**
+ * Setter for property timeout.
+ * @param timeout New value of property timeout.
+ */
+ public void setTimeout(long timeout) {
+ this.timeout = timeout;
+ }
+
+ /**
+ * Holds value of property faultTolerance.
+ */
+ private FaultTolerance faultTolerance = FaultTolerance.NONE;
+
+ /**
+ * Getter for property faultTolerance. See [EMAIL PROTECTED]
FaultTolerance} for valid
+ * values.
+ * @return Value of property faultTolerance.
+ */
+ public FaultTolerance getFaultTolerance() {
+ return this.faultTolerance;
+ }
+
+ /**
+ * Setter for property faultTolerance.
+ *
+ * @param faultTolerance New value of property faultTolerance.
+ */
+ public void setFaultTolerance(FaultTolerance faultTolerance) {
+ this.faultTolerance = faultTolerance;
+ }
+
+ /**
+ * Convenience setter for property faultTolerance for use by Digester.
+ *
+ * @param level New value of property level ("ALL","CHECKED", or "NONE").
+ */
+ public void setFaultToleranceLevel(String level) {
+ this.faultTolerance = FaultTolerance.valueOf(level);
+ }
+
+ /**
+ * Holds value of property queueSize.
+ * The default capacity is 100 elements.
+ */
+ private int queueSize = 100;
+
+ /**
+ * Gets the queueSize, used to set the capacity of BlockingQueues that
buffer
+ * input to the stages. The default queue size is 100 objects.
+ * The queueSize is passed to the <CODE>LinkedBlockingQueue</CODE>
+ * constructor as a capacity argument. The no arg constructor has an
+ * unlimited capacity, so the fixed capacity constructor called by this
+ * factory avoids Java <CODE>OutOfMemoryError</CODE>s
+ * due to overflowing queues.
+ *
+ * @return Value of property queueSize.
+ */
+ public int getQueueSize() {
+ return this.queueSize;
+ }
+
+ /**
+ * Set the capacity of queues that buffer objects between the stages.
+ *
+ * @param capacity New value of property queueSize.
+ */
+ public void setQueueSize(int capacity) {
+ this.queueSize = capacity;
+ }
+
+}
Propchange:
jakarta/commons/sandbox/pipeline/trunk/src/main/java/org/apache/commons/pipeline/driver/BoundedQueueDedicatedThreadSDF.java
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