gistfile1.java

package dependencies;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintStream;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

import org.eclipse.core.runtime.Platform;
import org.eclipse.equinox.app.IApplication;
import org.eclipse.equinox.app.IApplicationContext;
import org.osgi.framework.Bundle;
import org.osgi.framework.wiring.BundleWire;
import org.osgi.framework.wiring.BundleWiring;

public class Application implements IApplication {

	
	
	public Object start(IApplicationContext context) throws Exception {
		Bundle bundle = Platform.getBundle("org.eclipse.osgi");
		Bundle[] bundles = bundle.getBundleContext().getBundles();
		Map<String,Set<String>> nodes = new HashMap<String,Set<String>>();
		Map<String,Integer> sizes = new HashMap<String,Integer>();
		for (Bundle b : bundles) {
			BundleWiring wiring = b.adapt(BundleWiring.class);
			Set<String> dependencies = new HashSet<>();
			for (BundleWire r : wiring.getRequiredWires(null)) {
				dependencies.add(r.getProvider().getSymbolicName());
			}
			dependencies.remove(b.getSymbolicName());
			nodes.put(b.getSymbolicName(), dependencies);
			sizes.put(b.getSymbolicName(), wiring.listResources("/", "*.class", BundleWiring.LISTRESOURCES_RECURSE).size());
		}
		optimize(nodes);
		dump(nodes,sizes);

		
		return IApplication.EXIT_OK;
	}

	private void travel(Map<String, Set<String>> nodes, Set<String> visited, String p) {
		for(String next : nodes.get(p) ){
			if(visited.add(next)) {
				travel(nodes,visited,next);
			}
		}
	}
	
	private boolean dependsOn(Map<String, Set<String>> nodes, String from, String to) {
		HashSet<String> visited = new HashSet<>();
		travel(nodes,visited, from);
		return visited.contains(to);
	}
	
	private void optimize(Map<String, Set<String>> nodes) {
		for(String n : nodes.keySet() ){
			Set<String> directions = nodes.get(n);
			for(Iterator<String> iterator = directions.iterator();iterator.hasNext();) {
				String k = iterator.next();
				Set<String> visited = new HashSet<String>();
				
				for(String p : directions) {
					if(k!=p) {
						travel(nodes, visited, p);
					}
				}
				
				if(visited.contains(k)) {
					iterator.remove();
				}
			}
		}
	}
	
	private void dump(Map<String, Set<String>> nodes, Map<String, Integer> sizes) throws FileNotFoundException {
		PrintStream out = new PrintStream(new File("/tmp/dependencies/dependencies.dot"));
		out.println("digraph dependencies {");
		out.println("node [style = filled, shape = circle, fixedsize=true] ");
		
		for(String n : nodes.keySet()) {
			Set<String> flags = new HashSet<>();
			if(dependsOn(nodes,n,"org.eclipse.swt")) {
				flags.add("color=red");
			} else {
				flags.add("color=green");
			}
			flags.add("width="+0.1*Math.sqrt(sizes.get(n)));
			out.println("\""+n+"\" "+flags+";");
		}

		for(Entry<String, Set<String>> e : nodes.entrySet()) {
			for(String n : e.getValue()) {
				out.println("\t\""+e.getKey()+"\"->\""+n+"\";");
			}
		}
		out.println("}");
		out.close();
	}

	public void stop() {
	}

}