MemoryAnalyzer/Extending Memory Analyzer

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Introduction

The Memory Analyzer tool offers several possibilities to extend it. This page contains an overview of the different extension points and what can be achieved with them.

Within the extensions one will usually extract certain pieces of information from the objects in the heap dump. See TODO for more details on how to read data from a heap dump.

IClassSpecificNameResolver

The name resolver extension point provides a mechanism to give a readable description of an object, similar to what a toString() method will do. Some extensions which MAT provides are for example for to show the content of objects representing String, to show the bundle symbolic name for Equinox classloaders, to show the name for Thread objects, etc…

The extension should implement the IClassSpecificNameResolver interface which defines a single method.

public String resolve(IObject object) throws SnapshotException;

The method takes an IObject as an argument and should return a string representation.

To specify the class for which the resolver should be used one can use the @Subject( annotation.

The method getClassSpecificName of IObject will look for extensions which match the class of the object and execute the resolve() method to return the proper String. Thus it is relatively easy to return a description based on one or more String fields, as strings are already resolved.

Here is a sample implementation that will return the name of an Eclipse Job:

@Subject("org.eclipse.core.runtime.jobs.Job")
public class JobNameResolver implements IClassSpecificNameResolver
{

	@Override
	public String resolve(IObject object) throws SnapshotException
	{
		IObject name = (IObject) object.resolveValue("name");
		if (name != null) return name.getClassSpecificName();
		return null;
	}

}