/*
* 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.client.subsystem.sftp;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.MappedByteBuffer;
import java.nio.channels.AsynchronousCloseException;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;
import java.nio.channels.OverlappingFileLockException;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.EnumSet;
import java.util.List;
import java.util.Objects;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.sshd.common.subsystem.sftp.SftpConstants;
import org.apache.sshd.common.subsystem.sftp.SftpException;
import org.apache.sshd.common.util.GenericUtils;
import org.apache.sshd.common.util.ValidateUtils;
import org.apache.sshd.common.util.io.IoUtils;
/**
* @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
*/
public class SftpRemotePathChannel extends FileChannel {
public static final String COPY_BUFSIZE_PROP = "sftp-channel-copy-buf-size";
public static final int DEFAULT_TRANSFER_BUFFER_SIZE = IoUtils.DEFAULT_COPY_SIZE;
public static final Set<SftpClient.OpenMode> READ_MODES =
Collections.unmodifiableSet(EnumSet.of(SftpClient.OpenMode.Read));
public static final Set<SftpClient.OpenMode> WRITE_MODES =
Collections.unmodifiableSet(
EnumSet.of(SftpClient.OpenMode.Write, SftpClient.OpenMode.Append, SftpClient.OpenMode.Create, SftpClient.OpenMode.Truncate));
private final String path;
private final Collection<SftpClient.OpenMode> modes;
private final boolean closeOnExit;
private final SftpClient sftp;
private final SftpClient.CloseableHandle handle;
private final Object lock = new Object();
private final AtomicLong posTracker = new AtomicLong(0L);
private final AtomicReference<Thread> blockingThreadHolder = new AtomicReference<>(null);
public SftpRemotePathChannel(String path, SftpClient sftp, boolean closeOnExit, Collection<SftpClient.OpenMode> modes) throws IOException {
this.path = ValidateUtils.checkNotNullAndNotEmpty(path, "No remote file path specified");
this.modes = Objects.requireNonNull(modes, "No channel modes specified");
this.sftp = Objects.requireNonNull(sftp, "No SFTP client instance");
this.closeOnExit = closeOnExit;
this.handle = sftp.open(path, modes);
}
public String getRemotePath() {
return path;
}
@Override
public int read(ByteBuffer dst) throws IOException {
return (int) doRead(Collections.singletonList(dst), -1);
}
@Override
public int read(ByteBuffer dst, long position) throws IOException {
if (position < 0) {
throw new IllegalArgumentException("read(" + getRemotePath() + ") illegal position to read from: " + position);
}
return (int) doRead(Collections.singletonList(dst), position);
}
@Override
public long read(ByteBuffer[] dsts, int offset, int length) throws IOException {
List<ByteBuffer> buffers = Arrays.asList(dsts).subList(offset, offset + length);
return doRead(buffers, -1);
}
protected long doRead(List<ByteBuffer> buffers, long position) throws IOException {
ensureOpen(READ_MODES);
synchronized (lock) {
boolean completed = false;
boolean eof = false;
long curPos = (position >= 0L) ? position : posTracker.get();
try {
long totalRead = 0;
beginBlocking();
loop:
for (ByteBuffer buffer : buffers) {
while (buffer.remaining() > 0) {
ByteBuffer wrap = buffer;
if (!buffer.hasArray()) {
wrap = ByteBuffer.allocate(Math.min(IoUtils.DEFAULT_COPY_SIZE, buffer.remaining()));
}
int read = sftp.read(handle, curPos, wrap.array(), wrap.arrayOffset() + wrap.position(), wrap.remaining());
if (read > 0) {
if (wrap == buffer) {
wrap.position(wrap.position() + read);
} else {
buffer.put(wrap.array(), wrap.arrayOffset(), read);
}
curPos += read;
totalRead += read;
} else {
eof = read == -1;
break loop;
}
}
}
completed = true;
if (totalRead > 0) {
return totalRead;
}
if (eof) {
return -1;
} else {
return 0;
}
} finally {
if (position < 0L) {
posTracker.set(curPos);
}
endBlocking(completed);
}
}
}
@Override
public int write(ByteBuffer src) throws IOException {
return (int) doWrite(Collections.singletonList(src), -1);
}
@Override
public int write(ByteBuffer src, long position) throws IOException {
if (position < 0L) {
throw new IllegalArgumentException("write(" + getRemotePath() + ") illegal position to write to: " + position);
}
return (int) doWrite(Collections.singletonList(src), position);
}
@Override
public long write(ByteBuffer[] srcs, int offset, int length) throws IOException {
List<ByteBuffer> buffers = Arrays.asList(srcs).subList(offset, offset + length);
return doWrite(buffers, -1);
}
protected long doWrite(List<ByteBuffer> buffers, long position) throws IOException {
ensureOpen(WRITE_MODES);
synchronized (lock) {
boolean completed = false;
long curPos = (position >= 0L) ? position : posTracker.get();
try {
long totalWritten = 0L;
beginBlocking();
for (ByteBuffer buffer : buffers) {
while (buffer.remaining() > 0) {
ByteBuffer wrap = buffer;
if (!buffer.hasArray()) {
wrap = ByteBuffer.allocate(Math.min(IoUtils.DEFAULT_COPY_SIZE, buffer.remaining()));
buffer.get(wrap.array(), wrap.arrayOffset(), wrap.remaining());
}
int written = wrap.remaining();
sftp.write(handle, curPos, wrap.array(), wrap.arrayOffset() + wrap.position(), written);
if (wrap == buffer) {
wrap.position(wrap.position() + written);
}
curPos += written;
totalWritten += written;
}
}
completed = true;
return totalWritten;
} finally {
if (position < 0L) {
posTracker.set(curPos);
}
endBlocking(completed);
}
}
}
@Override
public long position() throws IOException {
ensureOpen(Collections.emptySet());
return posTracker.get();
}
@Override
public FileChannel position(long newPosition) throws IOException {
if (newPosition < 0L) {
throw new IllegalArgumentException("position(" + getRemotePath() + ") illegal file channel position: " + newPosition);
}
ensureOpen(Collections.emptySet());
posTracker.set(newPosition);
return this;
}
@Override
public long size() throws IOException {
ensureOpen(Collections.emptySet());
return sftp.stat(handle).getSize();
}
@Override
public FileChannel truncate(long size) throws IOException {
ensureOpen(Collections.emptySet());
sftp.setStat(handle, new SftpClient.Attributes().size(size));
return this;
}
@Override
public void force(boolean metaData) throws IOException {
ensureOpen(Collections.emptySet());
}
@Override
public long transferTo(long position, long count, WritableByteChannel target) throws IOException {
if ((position < 0) || (count < 0)) {
throw new IllegalArgumentException("transferTo(" + getRemotePath() + ") illegal position (" + position + ") or count (" + count + ")");
}
ensureOpen(READ_MODES);
synchronized (lock) {
boolean completed = false;
boolean eof = false;
long curPos = position;
try {
beginBlocking();
int bufSize = (int) Math.min(count, Short.MAX_VALUE + 1);
byte[] buffer = new byte[bufSize];
long totalRead = 0L;
while (totalRead < count) {
int read = sftp.read(handle, curPos, buffer, 0, buffer.length);
if (read > 0) {
ByteBuffer wrap = ByteBuffer.wrap(buffer);
while (wrap.remaining() > 0) {
target.write(wrap);
}
curPos += read;
totalRead += read;
} else {
eof = read == -1;
}
}
completed = true;
return totalRead > 0 ? totalRead : eof ? -1 : 0;
} finally {
endBlocking(completed);
}
}
}
@Override
public long transferFrom(ReadableByteChannel src, long position, long count) throws IOException {
if ((position < 0) || (count < 0)) {
throw new IllegalArgumentException("transferFrom(" + getRemotePath() + ") illegal position (" + position + ") or count (" + count + ")");
}
ensureOpen(WRITE_MODES);
int copySize = sftp.getClientSession().getIntProperty(COPY_BUFSIZE_PROP, DEFAULT_TRANSFER_BUFFER_SIZE);
boolean completed = false;
long curPos = (position >= 0L) ? position : posTracker.get();
long totalRead = 0L;
byte[] buffer = new byte[(int) Math.min(copySize, count)];
synchronized (lock) {
try {
beginBlocking();
while (totalRead < count) {
ByteBuffer wrap = ByteBuffer.wrap(buffer, 0, (int) Math.min(buffer.length, count - totalRead));
int read = src.read(wrap);
if (read > 0) {
sftp.write(handle, curPos, buffer, 0, read);
curPos += read;
totalRead += read;
} else {
break;
}
}
completed = true;
return totalRead;
} finally {
endBlocking(completed);
}
}
}
@Override
public MappedByteBuffer map(MapMode mode, long position, long size) throws IOException {
throw new UnsupportedOperationException("map(" + getRemotePath() + ")[" + mode + "," + position + "," + size + "] N/A");
}
@Override
public FileLock lock(long position, long size, boolean shared) throws IOException {
return tryLock(position, size, shared);
}
@Override
public FileLock tryLock(final long position, final long size, boolean shared) throws IOException {
ensureOpen(Collections.emptySet());
try {
sftp.lock(handle, position, size, 0);
} catch (SftpException e) {
if (e.getStatus() == SftpConstants.SSH_FX_LOCK_CONFLICT) {
throw new OverlappingFileLockException();
}
throw e;
}
return new FileLock(this, position, size, shared) {
private final AtomicBoolean valid = new AtomicBoolean(true);
@Override
public boolean isValid() {
return acquiredBy().isOpen() && valid.get();
}
@SuppressWarnings("synthetic-access")
@Override
public void release() throws IOException {
if (valid.compareAndSet(true, false)) {
sftp.unlock(handle, position, size);
}
}
};
}
@Override
protected void implCloseChannel() throws IOException {
try {
final Thread thread = blockingThreadHolder.get();
if (thread != null) {
thread.interrupt();
}
} finally {
try {
handle.close();
} finally {
if (closeOnExit) {
sftp.close();
}
}
}
}
private void beginBlocking() {
begin();
blockingThreadHolder.set(Thread.currentThread());
}
private void endBlocking(boolean completed) throws AsynchronousCloseException {
blockingThreadHolder.set(null);
end(completed);
}
/**
* Checks that the channel is open and that its current mode contains
* at least one of the required ones
*
* @param reqModes The required modes - ignored if {@code null}/empty
* @throws IOException If channel not open or the required modes are not
* satisfied
*/
private void ensureOpen(Collection<SftpClient.OpenMode> reqModes) throws IOException {
if (!isOpen()) {
throw new ClosedChannelException();
}
if (GenericUtils.size(reqModes) > 0) {
for (SftpClient.OpenMode m : reqModes) {
if (this.modes.contains(m)) {
return;
}
}
throw new IOException("ensureOpen(" + getRemotePath() + ") current channel modes (" + this.modes + ") do contain any of the required: " + reqModes);
}
}
@Override
public String toString() {
return getRemotePath();
}
}