/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * particular file as subject to the "Classpath" exception as provided

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 */

package sun.rmi.transport;

import java.io.DataInputStream;

import java.io.DataOutputStream;

import java.io.IOException;

import java.io.ObjectInput;

import java.io.ObjectOutput;

import java.io.StreamCorruptedException;

import java.rmi.RemoteException;

import java.rmi.MarshalException;

import java.rmi.UnmarshalException;

import java.rmi.server.ObjID;

import java.rmi.server.RemoteCall;

import sun.rmi.runtime.Log;

import sun.rmi.server.UnicastRef;

import sun.rmi.transport.tcp.TCPEndpoint;

/**

 * Stream-based implementation of the RemoteCall interface.

 *

 * @author Ann Wollrath

 */

public class StreamRemoteCall implements RemoteCall {

    private ConnectionInputStream in = null;

    private ConnectionOutputStream out = null;

    private Connection conn;

    private boolean resultStarted = false;

    private Exception serverException = null;

    public StreamRemoteCall(Connection c) {

        conn = c;

    }

    public StreamRemoteCall(Connection c, ObjID id, int op, long hash)

        throws RemoteException

    {

        try {

            conn = c;

            Transport.transportLog.log(Log.VERBOSE,

                "write remote call header...");

            // write out remote call header info...

            // call header, part 1 (read by Transport)

            conn.getOutputStream().write(TransportConstants.Call);

            getOutputStream();           // creates a MarshalOutputStream

            id.write(out);               // object id (target of call)

            // call header, part 2 (read by Dispatcher)

            out.writeInt(op);            // method number (operation index)

            out.writeLong(hash);         // stub/skeleton hash

        } catch (IOException e) {

            throw new MarshalException("Error marshaling call header", e);

        }

    }

    /**

     * Return the connection associated with this call.

     */

    public Connection getConnection() {

        return conn;

    }

    /**

     * Return the output stream the stub/skeleton should put arguments/results

     * into.

     */

    public ObjectOutput getOutputStream() throws IOException {

        return getOutputStream(false);

    }

    private ObjectOutput getOutputStream(boolean resultStream)

        throws IOException

    {

        if (out == null) {

            Transport.transportLog.log(Log.VERBOSE, "getting output stream");

            out = new ConnectionOutputStream(conn, resultStream);

        }

        return out;

    }

    /**

     * Release the outputStream  Currently, will not complain if the

     * output stream is released more than once.

     */

    public void releaseOutputStream() throws IOException {

        try {

            if (out != null) {

                try {

                    out.flush();

                } finally {

                    out.done();         // always start DGC ack timer

                }

            }

            conn.releaseOutputStream();

        } finally {

            out = null;

        }

    }

    /**

     * Get the InputStream the stub/skeleton should get results/arguments

     * from.

     */

    public ObjectInput getInputStream() throws IOException {

        if (in == null) {

            Transport.transportLog.log(Log.VERBOSE, "getting input stream");

            in = new ConnectionInputStream(conn.getInputStream());

        }

        return in;

    }

    /**

     * Release the input stream, this would allow some transports to release

     * the channel early.

     */

    public void releaseInputStream() throws IOException {

        /* WARNING: Currently, the UnicastRef.java invoke methods rely

         * upon this method not throwing an IOException.

         */

        try {

            if (in != null) {

                // execute MarshalInputStream "done" callbacks

                try {

                    in.done();

                } catch (RuntimeException e) {

                }

                // add saved references to DGC table

                in.registerRefs();

                /* WARNING: The connection being passed to done may have

                 * already been freed.

                 */

                in.done(conn);

            }

            conn.releaseInputStream();

        } finally {

            in = null;

        }

    }

    /**

     * Returns an output stream (may put out header information

     * relating to the success of the call).

     * @param success If true, indicates normal return, else indicates

     * exceptional return.

     * @exception StreamCorruptedException If result stream previously

     * acquired

     * @exception IOException For any other problem with I/O.

     */

    public ObjectOutput getResultStream(boolean success) throws IOException {

        /* make sure result code only marshaled once. */

        if (resultStarted)

            throw new StreamCorruptedException("result already in progress");

        else

            resultStarted = true;

        // write out return header

        // return header, part 1 (read by Transport)

        DataOutputStream wr = new DataOutputStream(conn.getOutputStream());

        wr.writeByte(TransportConstants.Return);// transport op

        getOutputStream(true);  // creates a MarshalOutputStream

        // return header, part 2 (read by client-side RemoteCall)

        if (success)            //

            out.writeByte(TransportConstants.NormalReturn);

        else

            out.writeByte(TransportConstants.ExceptionalReturn);

        out.writeID();          // write id for gcAck

        return out;

    }

    /**

     * Do whatever it takes to execute the call.

     */

    public void executeCall() throws Exception {

        byte returnType;

        // read result header

        DGCAckHandler ackHandler = null;

        try {

            if (out != null) {

                ackHandler = out.getDGCAckHandler();

            }

            releaseOutputStream();

            DataInputStream rd = new DataInputStream(conn.getInputStream());

            byte op = rd.readByte();

            if (op != TransportConstants.Return) {

                if (Transport.transportLog.isLoggable(Log.BRIEF)) {

                    Transport.transportLog.log(Log.BRIEF,

                        "transport return code invalid: " + op);

                }

                throw new UnmarshalException("Transport return code invalid");

            }

            getInputStream();

            returnType = in.readByte();

            in.readID();        // id for DGC acknowledgement

        } catch (UnmarshalException e) {

            throw e;

        } catch (IOException e) {

            throw new UnmarshalException("Error unmarshaling return header",

                                         e);

        } finally {

            if (ackHandler != null) {

                ackHandler.release();

            }

        }

        // read return value

        switch (returnType) {

        case TransportConstants.NormalReturn:

            break;

        case TransportConstants.ExceptionalReturn:

            Object ex;

            try {

                ex = in.readObject();

            } catch (Exception e) {

                throw new UnmarshalException("Error unmarshaling return", e);

            }

            // An exception should have been received,

            // if so throw it, else flag error

            if (ex instanceof Exception) {

                exceptionReceivedFromServer((Exception) ex);

            } else {

                throw new UnmarshalException("Return type not Exception");

            }

        default:

            if (Transport.transportLog.isLoggable(Log.BRIEF)) {

                Transport.transportLog.log(Log.BRIEF,

                    "return code invalid: " + returnType);

            }

            throw new UnmarshalException("Return code invalid");

        }

    }

    /**

     * Routine that causes the stack traces of remote exceptions to be

     * filled in with the current stack trace on the client.  Detail

     * exceptions are filled in iteratively.

     */

    protected void exceptionReceivedFromServer(Exception ex) throws Exception {

        serverException = ex;

        StackTraceElement[] serverTrace = ex.getStackTrace();

        StackTraceElement[] clientTrace = (new Throwable()).getStackTrace();

        StackTraceElement[] combinedTrace =

            new StackTraceElement[serverTrace.length + clientTrace.length];

        System.arraycopy(serverTrace, 0, combinedTrace, 0,

                         serverTrace.length);

        System.arraycopy(clientTrace, 0, combinedTrace, serverTrace.length,

                         clientTrace.length);

        ex.setStackTrace(combinedTrace);

        /*

         * Log the details of a server exception thrown as a result of a

         * remote method invocation.

         */

        if (UnicastRef.clientCallLog.isLoggable(Log.BRIEF)) {

            /* log call exception returned from server before it is rethrown */

            TCPEndpoint ep = (TCPEndpoint) conn.getChannel().getEndpoint();

            UnicastRef.clientCallLog.log(Log.BRIEF, "outbound call " +

                "received exception: [" + ep.getHost() + ":" +

                ep.getPort() + "] exception: ", ex);

        }

        throw ex;

    }

    /*

     * method to retrieve possible server side exceptions (which will

     * be throw from exceptionReceivedFromServer(...) )

     */

    public Exception getServerException() {

        return serverException;

    }

    public void done() throws IOException {

        /* WARNING: Currently, the UnicastRef.java invoke methods rely

         * upon this method not throwing an IOException.

         */

        releaseInputStream();

    }

}