package com.cloudbees.groovy.cps.impl;
import com.cloudbees.groovy.cps.Block;
import com.cloudbees.groovy.cps.Continuation;
import com.cloudbees.groovy.cps.Env;
import com.cloudbees.groovy.cps.Next;
import javax.annotation.Nullable;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
/**
* Environment for evaluating the body of a try/catch block.
*
* @author Kohsuke Kawaguchi
*/
// TODO: should be package local once all the impls move into this class
public class TryBlockEnv extends ProxyEnv {
private final Map<Class,Continuation> handlers = new LinkedHashMap<Class, Continuation>();
@Nullable
private final Block finally_;
public TryBlockEnv(Env parent, Block finally_) {
super(parent);
this.finally_ = finally_;
}
/**
* Handlers can be only added immediately after instantiation.
*/
public void addHandler(Class<? extends Throwable> type, Continuation k) {
handlers.put(type,k);
}
@Override
public Continuation getExceptionHandler(Class<? extends Throwable> type) {
for (Entry<Class, Continuation> e : handlers.entrySet()) {
if (e.getKey().isAssignableFrom(type))
return e.getValue();
}
return withFinally(super.getExceptionHandler(type));
}
/**
* If the finally block exists, return a {@link Continuation} that evaluates the finally block then
* proceed to the given continuation.
*/
Continuation withFinally(Continuation k) {
if (finally_==null) return k;
else return new Finally(k);
}
@Override
public Continuation getReturnAddress() {
return withFinally(super.getReturnAddress());
}
@Override
public Continuation getBreakAddress(String label) {
return withFinally(super.getBreakAddress(label));
}
@Override
public Continuation getContinueAddress(String label) {
return withFinally(super.getContinueAddress(label));
}
/**
* Executes the finally clause, then go back to where it's supposed to be.
*/
private class Finally implements Continuation {
private final Continuation k;
public Finally(Continuation k) {
this.k = k;
}
public Next receive(final Object v) {
// finally block should be evaluated with 'parent', not 'TryBlockEnv.this' because
// exceptions thrown in here will not get caught by handlers we have.
// similarly, k should receive v, not the result of the evaluation of the finally block
return new Next(finally_, parent, new ValueBoundContinuation(k, v));
}
private static final long serialVersionUID = 1L;
}
private static final long serialVersionUID = 1L;
}