Support invalidating connections when related local entry changed

I introduced an enhancement to the way we handle connections
 in relation to local entries.A mechanism was established where the key
 associated with a localEntry is passed from the InvokeMediator
 to the TemplateMediator then further propagated to the TemplateContext,
 ensuring that the specific localEntry is accessible from connection handling code.

 With the availability of the localEntry key, each active connection(dynamic/static) has been
 bound to its respective localEntry in a map.

 So when a localEntry is undeployed or removed, this change is detected by
 the Synapse Observer, and the connections associated with that specific localEntry
 are invalidated.

 Fixes: wso2/product-micro-integrator#3002

modules/core/src/main/java/org/apache/synapse/SynapseConstants.java

@@ -155,6 +155,8 @@ public static final class Axis2Param {
 
     /** The name of the Parameter set on the Axis2Configuration to hold the Synapse Configuration */
     public static final String SYNAPSE_CONFIG = "synapse.config";
+    /** EIP pattern name */
+    public static final String INIT_EIP_PATTERN = "init";
     /** The name of the Parameter set on the Axis2Configuration to hold the Synapse Environment */
     public static final String SYNAPSE_ENV = "synapse.env";
     /** The name of the Parameter set on AxisConfiguration to hold the ServerContextInformation */

modules/core/src/main/java/org/apache/synapse/mediators/template/InvokeMediator.java

@@ -76,12 +76,15 @@ public class InvokeMediator extends AbstractMediator implements
 	private Map<String, Value> pName2ExpressionMap;
 
 	private boolean dynamicMediator = false;
-
-	/** The local registry key which is used to pick a sequence definition */
+
 	private Value key = null;
 
-    /** Reference to the synapse environment */
-    private SynapseEnvironment synapseEnv;
+	private String localEntryKey = null;
+
+	/**
+	 * Reference to the synapse environment
+	 */
+	private SynapseEnvironment synapseEnv;
 
 	public InvokeMediator() {
 		// LinkedHashMap is used to preserve tag order
@@ -129,6 +132,10 @@ private boolean mediate(MessageContext synCtx, boolean executePreFetchingSequenc
 		if (executePreFetchingSequence && key != null) {
 			String defaultConfiguration = key.evaluateValue(synCtx);
 			Mediator m = synCtx.getDefaultConfiguration(defaultConfiguration);
+			if (m instanceof InvokeMediator) {
+				InvokeMediator invokeMediator = (InvokeMediator) m;
+				invokeMediator.setLocalEntryKey(defaultConfiguration);
+			}
 			if (m == null) {
 				handleException("Sequence named " + key + " cannot be found", synCtx);
 
@@ -149,6 +156,9 @@ private boolean mediate(MessageContext synCtx, boolean executePreFetchingSequenc
 		}
 
 		if (mediator != null && mediator instanceof TemplateMediator) {
+			if (localEntryKey != null) {
+				((TemplateMediator) mediator).setLocalEntryKey(localEntryKey);
+			}
 			populateParameters(synCtx, ((TemplateMediator) mediator).getName());
 			if (executePreFetchingSequence) {
 				ContinuationStackManager.addReliantContinuationState(synCtx,
@@ -319,6 +329,12 @@ public Value getKey() {
 	public void setKey(Value key) {
 		this.key = key;
 	}
+	public void setLocalEntryKey(String localEntryKey) {
+		this.localEntryKey = localEntryKey;
+	}
+	public String getLocalEntryKey() {
+		return localEntryKey;
+	}
 
 	public String getPackageName() {
 		return packageName;

modules/core/src/main/java/org/apache/synapse/mediators/template/TemplateContext.java

@@ -51,10 +51,15 @@ public class TemplateContext {
      * refers to the parameters of the function
      */
     private Collection<TemplateParam> parameters;
+    private final String INIT_CONFIG_KEY = "INIT_CONFIG_KEY";
     /**
      * contains a map for parameterNames to evaluated values
      */
     private Map mappedValues;
+    /**
+     * The local entry key name
+     */
+    private String localEntryKey = null;
 
     public TemplateContext(String name, Collection<TemplateParam> parameters) {
         this.fName = name;
@@ -68,6 +73,9 @@ public TemplateContext(String name, Collection<TemplateParam> parameters) {
      * @param synCtxt Synapse MessageContext
      */
     public void setupParams(MessageContext synCtxt) {
+        if (SynapseConstants.INIT_EIP_PATTERN.equals(fName) && getLocalEntryKey() != null) {
+            mappedValues.put(INIT_CONFIG_KEY, getLocalEntryKey());
+        }
         Iterator<TemplateParam> paramNames = parameters.iterator();
         while (paramNames.hasNext()) {
             TemplateParam parameter = paramNames.next();
@@ -182,6 +190,14 @@ public Map getMappedValues() {
         return mappedValues;
     }
 
+    public String getLocalEntryKey() {
+        return localEntryKey;
+    }
+
+    public void setLocalEntryKey(String localEntryKey) {
+        this.localEntryKey = localEntryKey;
+    }
+
     public void setMappedValues(Map map) {
         this.mappedValues = map;
     }

modules/core/src/main/java/org/apache/synapse/mediators/template/TemplateMediator.java

@@ -55,6 +55,17 @@ public class TemplateMediator extends AbstractListMediator {
 
     private String errorHandler = null;
 
+    /** The local entry key name */
+    private String localEntryKey = null;
+
+    public String getLocalEntryKey() {
+        return localEntryKey;
+    }
+
+    public void setLocalEntryKey(String localEntryKey) {
+        this.localEntryKey = localEntryKey;
+    }
+
     public void setParameters(Collection<TemplateParam> paramNames) {
         this.templateParams = paramNames;
     }
@@ -161,6 +172,9 @@ public boolean mediate(MessageContext synCtx) {
      */
     private void pushFuncContextTo(MessageContext synCtx) {
         TemplateContext funcContext = new TemplateContext(eipPatternName, templateParams);
+        if (localEntryKey != null) {
+            funcContext.setLocalEntryKey(localEntryKey);
+        }
         //process the raw parameters parsed in
         funcContext.setupParams(synCtx);