DO NOT REPLY [Bug 19080] New: - Performance bottleneck in BaseDeserializerFactory.getDeserializerMethod()

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http://nagoya.apache.org/bugzilla/show_bug.cgi?id=19080

Performance bottleneck in BaseDeserializerFactory.getDeserializerMethod()

           Summary: Performance bottleneck in
                    BaseDeserializerFactory.getDeserializerMethod()
           Product: Axis
           Version: 1.1rc2
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: Enhancement
          Priority: Other
         Component: Serialization/Deserialization
        AssignedTo: axis-dev@ws.apache.org
        ReportedBy: joel.shellman@summit.fiserv.com


We ran axis under a profiler yesterday and found a serious bottleneck in 
BaseDeserializerFactory:

The problem is that that method is being called with int and String many 
(100's I think) times during our test. Calling it with int and string (maybe 
others, that's all I saw in our test) results in a ClassNotFoundException. 
Throwing exceptions is rather expensive so it's slowing it way down. I changed 
the code to use a static cache and there was a huge improvement: 5-10 times 
faster.

Here's the new code for that method and the declaration for the cache (it's 
currently not synchronized--if it needs to be, you can use synchronization or 
a HashTable if you like--given the nature of the cache, I'm not sure that's 
necessary, though):


    private transient static Map methodCache = new java.util.HashMap();

    /**
     * Returns the "getDeserializer" method if any.
     */
    private Method getDeserializerMethod(Class clazz) {
    	String className = clazz.getName();
        Method method = null;

    	if (!methodCache.containsKey(className)) {

	        try {
	            method = 
	                clazz.getMethod("getDeserializer",
	                                   new Class[] {String.class, 
	                                                Class.class, 
	                                                QName.class});
	        } catch (NoSuchMethodException e) {}
	        if (method == null) {
		            try {
		                Class helper = ClassUtils.forName(
		            		className + "_Helper");
		                method =
		                    helper.getMethod("getDeserializer", 
		                                     new Class[] 
{String.class, 
		                                                  Class.class, 
		                                                  
QName.class});
		            } catch (NoSuchMethodException e) {
		            } catch (ClassNotFoundException e) {
		            }
	        }
    		methodCache.put(className, method);
		} else {
			method = (Method)methodCache.get(className);
		}
	    
        return method;
    }

It seems to me that the real fix might be something else (I'm not familiar 
with Axis code in general), but this simple change made a huge difference all 
by itself. Running profiler afterwards didn't show any huge bottleneck like 
this one.

Joel Shellman