/*
* The MIT License
*
* Copyright (c) 2004-2009, Sun Microsystems, Inc., Kohsuke Kawaguchi
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package hudson.remoting;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.io.OutputStream;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* {@link OutputStream} that sends bits to an exported
* {@link OutputStream} on a remote machine.
*/
final class ProxyOutputStream extends OutputStream {
private static final Logger LOGGER = Logger.getLogger(ProxyOutputStream.class.getName());
private Channel channel;
private int oid;
private PipeWindow window;
/**
* If bytes are written to this stream before it's connected
* to a remote object, bytes will be stored in this buffer.
*/
private ByteArrayOutputStream tmp;
/**
* Set to true if the stream is closed.
*/
private boolean closed;
/**
* Creates unconnected {@link ProxyOutputStream}.
* The returned stream accepts data right away, and
* when it's {@link #connect(Channel, int) connected} later,
* the data will be sent at once to the remote stream.
*/
public ProxyOutputStream() {
}
/**
* Creates an already connected {@link ProxyOutputStream}.
*
* @param oid The object id of the exported {@link OutputStream}.
*/
public ProxyOutputStream(Channel channel, int oid) throws IOException {
connect(channel, oid);
}
/**
* Connects this stream to the specified remote object.
*/
synchronized void connect(Channel channel, int oid) throws IOException {
if (this.channel != null) {
throw new IllegalStateException("Cannot connect twice");
}
if (oid == 0) {
throw new IllegalArgumentException("oid=0");
}
this.channel = channel;
this.oid = oid;
window = channel.getPipeWindow(oid);
// if we already have bytes to write, do so now.
if (tmp != null) {
byte[] b = tmp.toByteArray();
tmp = null;
_write(b, 0, b.length);
}
if (closed) // already marked closed?
{
doClose();
}
}
public void write(int b) throws IOException {
write(new byte[]{(byte) b}, 0, 1);
}
public void write(byte b[], int off, int len) throws IOException {
if (closed) {
throw new IOException("stream is already closed");
}
_write(b, off, len);
}
/**
* {@link #write(byte[])} without the close check.
*/
private synchronized void _write(byte[] b, int off, int len) throws IOException {
if (channel == null) {
if (tmp == null) {
tmp = new ByteArrayOutputStream();
}
tmp.write(b, off, len);
} else {
while (len > 0) {
int sendable;
try {
sendable = Math.min(window.get(), len);
} catch (InterruptedException e) {
throw (IOException) new InterruptedIOException().initCause(e);
}
channel.send(new Chunk(oid, b, off, sendable));
window.decrease(sendable);
off += sendable;
len -= sendable;
}
}
}
public synchronized void flush() throws IOException {
if (channel != null) {
channel.send(new Flush(oid));
}
}
public synchronized void close() throws IOException {
closed = true;
if (channel != null) {
doClose();
}
}
@Override
protected void finalize() throws Throwable {
super.finalize();
// if we haven't done so, release the exported object on the remote side.
if (channel != null) {
channel.send(new Unexport(oid));
channel = null;
oid = -1;
}
}
/**
* I/O operations in remoting gets executed by a separate pipe thread asynchronously.
* So if a closure performs some I/O (such as writing to the RemoteOutputStream) then returns,
* it is possible that the calling thread unblocks before the I/O actually completes.
* <p/>
* So the goal of this code is to automatically ensure the proper ordering of the return from
* the {@link Request#call(Channel)} and the I/O operations done during the call. We do this
* by attributing I/O call to a {@link Request}, then keeping track of the last I/O operation
* performed.
*/
private static void markForIoSync(Channel channel, int requestId, java.util.concurrent.Future<?> ioOp) {
Request<?, ?> call = channel.pendingCalls.get(requestId);
// call==null if:
// 1) the remote peer uses old version that doesn't set the requestId field
// 2) a bug in the code, but in that case we are being defensive
if (call != null) {
call.lastIo = ioOp;
}
}
private void doClose() throws IOException {
channel.send(new EOF(oid));
channel = null;
oid = -1;
}
/**
* {@link Command} for sending bytes.
*/
private static final class Chunk extends Command {
private final int oid;
private final byte[] buf;
private final int requestId = Request.getCurrentRequestId();
public Chunk(int oid, byte[] buf, int start, int len) {
// to improve the performance when a channel is used purely as a pipe,
// don't record the stack trace. On FilePath.writeToTar case, the stack trace and the OOS header
// takes up about 1.5K.
super(false);
this.oid = oid;
if (start == 0 && len == buf.length) {
this.buf = buf;
} else {
this.buf = new byte[len];
System.arraycopy(buf, start, this.buf, 0, len);
}
}
protected void execute(final Channel channel) {
final OutputStream os = (OutputStream) channel.getExportedObject(oid);
markForIoSync(channel, requestId, channel.pipeWriter.submit(new Runnable() {
public void run() {
try {
os.write(buf);
} catch (IOException e) {
try {
channel.send(new NotifyDeadWriter(e, oid));
} catch (ChannelClosedException x) {
// the other direction can be already closed if the connection
// shut down is initiated from this side. In that case, remain silent.
} catch (IOException x) {
LOGGER.log(Level.WARNING, "Failed to notify the sender that the write end is dead", x);
LOGGER.log(Level.WARNING, "... the failed write was:", e);
}
} finally {
if (channel.remoteCapability.supportsPipeThrottling()) {
try {
channel.send(new Ack(oid, buf.length));
} catch (ChannelClosedException x) {
// the other direction can be already closed if the connection
// shut down is initiated from this side. In that case, remain silent.
} catch (IOException e) {
// ignore errors
LOGGER.log(Level.WARNING, "Failed to ack the stream", e);
}
}
}
}
}));
}
public String toString() {
return "Pipe.Chunk(" + oid + "," + buf.length + ")";
}
private static final long serialVersionUID = 1L;
}
/**
* {@link Command} for flushing.
*/
private static final class Flush extends Command {
private final int oid;
public Flush(int oid) {
super(false);
this.oid = oid;
}
protected void execute(Channel channel) {
final OutputStream os = (OutputStream) channel.getExportedObject(oid);
channel.pipeWriter.submit(new Runnable() {
public void run() {
try {
os.flush();
} catch (IOException e) {
// ignore errors
}
}
});
}
public String toString() {
return "Pipe.Flush(" + oid + ")";
}
private static final long serialVersionUID = 1L;
}
/**
* {@link Command} for releasing an export table.
* <p/>
* Unlike {@link EOF}, this just unexports but not closes the stream.
*/
private static class Unexport extends Command {
private final int oid;
public Unexport(int oid) {
this.oid = oid;
}
protected void execute(final Channel channel) {
channel.pipeWriter.submit(new Runnable() {
public void run() {
channel.unexport(oid);
}
});
}
public String toString() {
return "Pipe.Unexport(" + oid + ")";
}
private static final long serialVersionUID = 1L;
}
/**
* {@link Command} for sending EOF.
*/
private static final class EOF extends Command {
private final int oid;
public EOF(int oid) {
this.oid = oid;
}
protected void execute(final Channel channel) {
final OutputStream os = (OutputStream) channel.getExportedObject(oid);
channel.pipeWriter.submit(new Runnable() {
public void run() {
channel.unexport(oid);
try {
os.close();
} catch (IOException e) {
// ignore errors
}
}
});
}
public String toString() {
return "Pipe.EOF(" + oid + ")";
}
private static final long serialVersionUID = 1L;
}
/**
* {@link Command} to notify the sender that it can send some more data.
*/
private static class Ack extends Command {
/**
* The oid of the {@link OutputStream} on the receiver side of the data.
*/
private final int oid;
/**
* The number of bytes that were freed up.
*/
private final int size;
private Ack(int oid, int size) {
super(false); // performance optimization
this.oid = oid;
this.size = size;
}
protected void execute(Channel channel) {
PipeWindow w = channel.getPipeWindow(oid);
w.increase(size);
}
public String toString() {
return "Pipe.Ack(" + oid + ',' + size + ")";
}
private static final long serialVersionUID = 1L;
}
/**
* {@link Command} to notify the sender that the receiver is dead.
*/
private static final class NotifyDeadWriter extends Command {
private final int oid;
private NotifyDeadWriter(Throwable cause, int oid) {
super(cause);
this.oid = oid;
}
@Override
protected void execute(Channel channel) {
PipeWindow w = channel.getPipeWindow(oid);
w.dead(createdAt.getCause());
}
public String toString() {
return "Pipe.Dead(" + oid + ")";
}
private static final long serialVersionUID = 1L;
}
}