/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.sshd.common.channel;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.io.OutputStream;
import org.apache.sshd.common.SshConstants;
import org.apache.sshd.common.SshException;
import org.apache.sshd.common.util.Buffer;
import org.slf4j.Logger;
/**
* TODO Add javadoc
*
* @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
*/
public class ChannelOutputStream extends OutputStream {
private final AbstractChannel channel;
private final Window remoteWindow;
private final Logger log;
private final SshConstants.Message cmd;
private final byte[] b = new byte[1];
private Buffer buffer;
private boolean closed;
private int bufferLength;
private int lastSize;
private boolean noDelay = false;
public ChannelOutputStream(AbstractChannel channel, Window remoteWindow, Logger log, SshConstants.Message cmd) {
this.channel = channel;
this.remoteWindow = remoteWindow;
this.log = log;
this.cmd = cmd;
newBuffer(0);
}
public void setNoDelay(boolean noDelay) {
this.noDelay = noDelay;
}
public boolean isNoDelay() {
return noDelay;
}
public synchronized void write(int w) throws IOException {
b[0] = (byte) w;
write(b, 0, 1);
}
public synchronized void write(byte[] buf, int s, int l) throws IOException {
if (closed) {
throw new SshException("Already closed");
}
while (l > 0) {
// The maximum amount we should admit without flushing again
// is enough to make up one full packet within our allowed
// window size. We give ourselves a credit equal to the last
// packet we sent to allow the producer to race ahead and fill
// out the next packet before we block and wait for space to
// become available again.
//
int _l = Math.min(l, Math.min(remoteWindow.getSize() + lastSize, remoteWindow.getPacketSize()) - bufferLength);
if (_l <= 0) {
if (bufferLength > 0) {
flush();
} else {
try {
remoteWindow.waitForSpace();
} catch (WindowClosedException e) {
closed = true;
throw e;
} catch (InterruptedException e) {
throw (IOException)new InterruptedIOException().initCause(e);
}
}
continue;
}
buffer.putRawBytes(buf, s, _l);
bufferLength += _l;
s += _l;
l -= _l;
}
if (noDelay) {
flush();
}
}
@Override
public synchronized void flush() throws IOException {
if (closed) {
throw new SshException("Already closed");
}
try {
while (bufferLength > 0) {
Buffer buf = buffer;
int total = bufferLength;
int length = Math.min(Math.min(remoteWindow.waitForSpace(), total), remoteWindow.getPacketSize());
int pos = buf.wpos();
buf.wpos(cmd == SshConstants.Message.SSH_MSG_CHANNEL_EXTENDED_DATA ? 14 : 10);
buf.putInt(length);
buf.wpos(buf.wpos() + length);
if (total == length) {
newBuffer(length);
} else {
int leftover = total - length;
newBuffer(Math.max(leftover, length));
buffer.putRawBytes(buf.array(), pos - leftover, leftover);
bufferLength = leftover;
}
lastSize = length;
remoteWindow.waitAndConsume(length);
log.debug("Send {} on channel {}", cmd, channel.getId());
channel.writePacket(buf);
}
} catch (WindowClosedException e) {
closed = true;
throw e;
} catch (SshException e) {
throw e;
} catch (Exception e) {
throw new SshException(e);
}
}
@Override
public synchronized void close() throws IOException {
flush();
closed = true;
}
private void newBuffer(int size) {
buffer = channel.getSession().createBuffer(cmd, size <= 0 ? 0 : 12 + size);
buffer.putInt(channel.getRecipient());
if (cmd == SshConstants.Message.SSH_MSG_CHANNEL_EXTENDED_DATA) {
buffer.putInt(1);
}
buffer.putInt(0);
bufferLength = 0;
}
}