Nobody's using this here, it's not very well documented, and I want to make

something better anyway. Let's get it out of the way. git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@6701 542714f4-19e9-0310-aa3c-eee0fc999fb1
2011-09-27 00:19:30 +00:00
parent bbcf3e9ada
commit 58f1db2a8d
1 changed files with 0 additions and 289 deletions
@@ -1,289 +0,0 @@
 //
 // $Id$
 package com.threerings.util;
 import com.google.common.base.Function;
 import com.google.common.base.Objects;
 import com.samskivert.util.ArrayUtil;
 import com.samskivert.util.IntResultListener;
 import com.samskivert.util.Invoker;
 import com.samskivert.util.Logger;
 import com.samskivert.util.ResultListener;
 import com.threerings.presents.client.InvocationService;
 import com.threerings.presents.data.InvocationCodes;
 import com.threerings.presents.server.InvocationException;
 import static com.threerings.NaryaLog.log;
 /**
 * A chainable ResultListener, InvocationListener, and Invoker.Unit all in one.
 *
 * TODO: add some examples of different usages.
 */
 public class Resulting<T> extends Invoker.Unit
    implements ResultListener<T>,
        InvocationService.ConfirmListener, InvocationService.ResultListener
 {
    /** A handy Object->Void function for when you wish to chain to a ResultListener<Void>. */
    public static final Function<Object, Void> TO_VOID =
        new Function<Object, Void>() {
            public Void apply (Object o) {
                return null;
            }
        };
    public Resulting (String name)
    {
        super(name);
    }
    public Resulting (String name, Resulting<T> chain)
    {
        this(name, (ResultListener<T>)chain);
    }
    public Resulting (Resulting<T> chain)
    {
        this(chain.toString(), chain);
    }
    public Resulting (String name, ResultListener<T> chain)
    {
        this(name);
        _chain = chain;
    }
    public Resulting (ResultListener<T> chain)
    {
        this(chain.toString(), chain);
    }
    public Resulting (String name, InvocationService.InvocationListener chain)
    {
        this(name);
        _invChain = chain;
    }
    public Resulting (InvocationService.InvocationListener chain)
    {
        this(chain.toString(), chain);
    }
    public <Q> Resulting (
        String name, final ResultListener<Q> chain, final Function<? super T, ? extends Q> xform)
    {
        this(name, new ResultListener<T>() {
            public void requestCompleted (T result) {
                chain.requestCompleted(xform.apply(result));
            }
            public void requestFailed (Exception cause) {
                chain.requestFailed(cause);
            }
        });
    }
    public <Q> Resulting (ResultListener<Q> chain, Function<? super T, ? extends Q> xform)
    {
        this(chain.toString(), chain, xform);
    }
    public Resulting (String name, Logger log, Object... logArgs)
    {
        this(name);
        _log = log;
        _logArgs = logArgs;
    }
    /**
     * Construct your Resulting<Integer>, overriding what you need to,
     * then call this to adapt it.
     */
    public final IntResultListener asIntResultListener ()
    {
        return new IntResultListener() {
            public void requestCompleted (int result) {
                // call the invocation method and it will do the unsafe cast for us.
                Resulting.this.requestProcessed((Object)result);
            }
            public void requestFailed (Exception cause) {
                Resulting.this.requestFailed(cause);
            }
        };
    }
 // TODO: Maybe we don't extend Invoker.Unit
 //    public Invoker.Unit asUnit (Callable<T> callable)
 //    {
 //    }
 //
 //    public Invoker.Unit asUnit ()
 //    {
 //    }
 //
    /**
     * Override this if you are using a Resulting as an Invoker unit.
     */
    public T invokePersist ()
        throws Exception
    {
        // please to be overriding
        return null;
    }
    @Override
    public final boolean invoke ()
    {
        try {
            _result = invokePersist();
        } catch (StopException se) {
            return false;
        } catch (Exception e) {
            _error = e;
        }
        return true;
    }
    /**
     * Call this from your invokePersist() to suppress returning to the dobj thread.
     * @throws StopException every time.
     */
    protected final T stop ()
        throws StopException
    {
        throw STOP.get();
    }
    @Override
    public final void handleResult ()
    {
        if (_error != null) {
            requestFailed(_error);
        } else {
            requestCompleted(_result);
        }
    }
    // from InvocationService.InvocationListener
    public final void requestFailed (String error)
    {
        requestFailed(INV_EX.get().setMessage(error));
    }
    // from InvocationService.ConfirmListener
    public final void requestProcessed ()
    {
        requestCompleted(null);
    }
    // from InvocationService.ResultListener
    public final void requestProcessed (Object result)
    {
        @SuppressWarnings("unchecked") T casted = (T)result;
        requestCompleted(casted);
    }
    /**
     * Override this to handle a request failed in your own way.
     */
    public void requestFailed (Exception cause)
    {
        if (_chain != null) {
            _chain.requestFailed(cause);
        } else if (_invChain != null) {
            _invChain.requestFailed((cause instanceof InvocationException)
                ? cause.getMessage()
                : InvocationCodes.INTERNAL_ERROR);
        } else {
            Object[] logArgs = Objects.firstNonNull(_logArgs, ArrayUtil.EMPTY_OBJECT);
            Object[] args;
            if (cause instanceof InvocationException) {
                args = new Object[logArgs.length + 4];
                args[args.length - 2] = "error";
                args[args.length - 1] = cause.getMessage();
            } else {
                args = new Object[logArgs.length + 3];
                args[args.length - 1] = cause;
            }
            args[0] = "Resulting";
            args[1] = this;
            System.arraycopy(logArgs, 0, args, 2, logArgs.length);
            Objects.firstNonNull(_log, log).warning("Request failed", args);
        }
    }
    /**
     * Override this to handle a request completion in your own way.
     */
    public void requestCompleted (T result)
    {
        if (_chain != null) {
            _chain.requestCompleted(result);
        } else if (_invChain instanceof InvocationService.ResultListener) {
            ((InvocationService.ResultListener)_invChain).requestProcessed(result);
        } else if (_invChain instanceof InvocationService.ConfirmListener) {
            ((InvocationService.ConfirmListener)_invChain).requestProcessed();
        }
    }
    /** Our invocation chain, if any. */
    protected InvocationService.InvocationListener _invChain;
    protected ResultListener<T> _chain;
    protected Logger _log;
    protected Object[] _logArgs;
    protected T _result;
    protected Exception _error;
    protected static final ThreadLocal<ReusableInvocationException> INV_EX =
        new ThreadLocal<ReusableInvocationException>() {
            @Override protected ReusableInvocationException initialValue () {
                return new ReusableInvocationException();
            }
        };
    protected static class ReusableInvocationException extends InvocationException
    {
        public ReusableInvocationException ()
        {
            super("");
        }
        public ReusableInvocationException setMessage (String msg)
        {
            _msg = msg;
            return this;
        }
        @Override public String getMessage ()
        {
            return _msg;
        }
        protected String _msg;
    }
    protected static final ThreadLocal<StopException> STOP =
        new ThreadLocal<StopException>() {
            @Override protected StopException initialValue () {
                return new StopException();
            }
        };
    protected static class StopException extends RuntimeException
    {
    }
 }