/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.synapse.endpoints.algorithms;
import org.apache.axis2.context.ConfigurationContext;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.synapse.util.Replicator;
import java.util.HashMap;
import java.util.Map;
/**
* Keeps the runtime state of the algorithm
*/
public class AlgorithmContext {
private static final Log log = LogFactory.getLog(AlgorithmContext.class);
private static final String KEY_PREFIX = "synapse.endpoint.lb.algorithm.";
private static final String CURRENT_EPR = ".current_epr";
/* The axis2 configuration context - this hold state in a clustered environment. */
private ConfigurationContext cfgCtx;
/* Are we supporting clustering ? */
private boolean isClusteringEnabled = false;
/* The key for 'currentEPR' attribute when replicated in a cluster */
private String CURRENT_EPR_PROP_KEY;
/* Prefix for uniquely identify properties of a particular endpoint */
private String PROPERTY_KEY_PREFIX;
/* The pointer to current epr - The position of the current EPR */
private int currentEPR = 0;
/* The map of properties stored locally */
private Map<String, Object> localProperties;
public AlgorithmContext(boolean clusteringEnabled, ConfigurationContext cfgCtx, String endpointName) {
this.cfgCtx = cfgCtx;
this.isClusteringEnabled = clusteringEnabled;
if (!clusteringEnabled) {
localProperties = new HashMap<String, Object>();
} else {
PROPERTY_KEY_PREFIX = KEY_PREFIX + endpointName;
CURRENT_EPR_PROP_KEY = PROPERTY_KEY_PREFIX + CURRENT_EPR;
}
}
/**
* To get the position of the current EPR for use. Default to 0 - i.e. first endpoint
*
* @return The position of the current EPR
*/
public int getCurrentEndpointIndex() {
if (isClusteringEnabled) {
Object value = cfgCtx.getPropertyNonReplicable(this.CURRENT_EPR_PROP_KEY);
if (value == null) {
return 0;
} else if (value instanceof Integer) {
return ((Integer) value);
}
} else {
return currentEPR;
}
return 0;
}
/**
* The position of the current EPR
*
* @param currentEPR The current position
*/
public void setCurrentEndpointIndex(int currentEPR) {
this.currentEPR = currentEPR;
cfgCtx.setNonReplicableProperty(CURRENT_EPR_PROP_KEY, currentEPR);
}
/**
* Get the configuration context instance . This is only available for cluster env.
*
* @return Returns the ConfigurationContext instance
*/
public ConfigurationContext getConfigurationContext() {
return cfgCtx;
}
/**
* Get the property value corresponding to a specified key
*
* @param key The key of the property
* @return The value of the property or null if the key does not exist
*/
public Object getProperty(String key) {
if (isClusteringEnabled) {
return cfgCtx.getPropertyNonReplicable(PROPERTY_KEY_PREFIX + key);
} else {
return localProperties.get(key);
}
}
/**
* Store a property in the algorithm context. In a clustered environment
* properties will be saved in the configuration context and replicated.
* In non-clustered environments properties will be stored in a local property
* map.
*
* @param key The key of the property
* @param value The value of the property
*/
public void setProperty(String key, Object value) {
if (key != null && value != null) {
if (isClusteringEnabled) {
Replicator.setAndReplicateState(PROPERTY_KEY_PREFIX + key, value, cfgCtx);
} else {
localProperties.put(key, value);
}
}
}
}