Revert Resulting.

Oops.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@6702 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/main/java/com/threerings/util/Resulting.java

@@ -0,0 +1,289 @@
+//
+// $Id$
+
+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
+    {
+    }
+}