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io.vertx.core.file.impl.AsyncFileImpl Maven / Gradle / Ivy
/*
* Copyright (c) 2011-2013 The original author or authors
* ------------------------------------------------------
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Apache License v2.0 which accompanies this distribution.
*
* The Eclipse Public License is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* The Apache License v2.0 is available at
* http://www.opensource.org/licenses/apache2.0.php
*
* You may elect to redistribute this code under either of these licenses.
*/
package io.vertx.core.file.impl;
import io.netty.buffer.ByteBuf;
import io.vertx.core.AsyncResult;
import io.vertx.core.Future;
import io.vertx.core.Handler;
import io.vertx.core.buffer.Buffer;
import io.vertx.core.file.AsyncFile;
import io.vertx.core.file.FileSystemException;
import io.vertx.core.file.OpenOptions;
import io.vertx.core.impl.Arguments;
import io.vertx.core.impl.ContextImpl;
import io.vertx.core.impl.VertxInternal;
import io.vertx.core.logging.Logger;
import io.vertx.core.logging.LoggerFactory;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousFileChannel;
import java.nio.file.OpenOption;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.nio.file.attribute.FileAttribute;
import java.nio.file.attribute.PosixFilePermissions;
import java.util.HashSet;
import java.util.Objects;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
/**
*
* This class is optimised for performance when used on the same event loop that is was passed to the handler with.
* However it can be used safely from other threads.
*
* The internal state is protected using the synchronized keyword. If always used on the same event loop, then
* we benefit from biased locking which makes the overhead of synchronized near zero.
*
* @author Tim Fox
*/
public class AsyncFileImpl implements AsyncFile {
private static final Logger log = LoggerFactory.getLogger(AsyncFile.class);
public static final int DEFAULT_READ_BUFFER_SIZE = 8192;
private final VertxInternal vertx;
private final AsynchronousFileChannel ch;
private final ContextImpl context;
private boolean closed;
private Runnable closedDeferred;
private long writesOutstanding;
private Handler exceptionHandler;
private Handler drainHandler;
private long writePos;
private int maxWrites = 128 * 1024; // TODO - we should tune this for best performance
private int lwm = maxWrites / 2;
private int readBufferSize = DEFAULT_READ_BUFFER_SIZE;
private boolean paused;
private Handler dataHandler;
private Handler endHandler;
private long readPos;
private boolean readInProgress;
AsyncFileImpl(VertxInternal vertx, String path, OpenOptions options, ContextImpl context) {
if (!options.isRead() && !options.isWrite()) {
throw new FileSystemException("Cannot open file for neither reading nor writing");
}
this.vertx = vertx;
Path file = Paths.get(path);
HashSet opts = new HashSet<>();
if (options.isRead()) opts.add(StandardOpenOption.READ);
if (options.isWrite()) opts.add(StandardOpenOption.WRITE);
if (options.isCreate()) opts.add(StandardOpenOption.CREATE);
if (options.isCreateNew()) opts.add(StandardOpenOption.CREATE_NEW);
if (options.isSync()) opts.add(StandardOpenOption.SYNC);
if (options.isDsync()) opts.add(StandardOpenOption.DSYNC);
if (options.isDeleteOnClose()) opts.add(StandardOpenOption.DELETE_ON_CLOSE);
if (options.isSparse()) opts.add(StandardOpenOption.SPARSE);
if (options.isTruncateExisting()) opts.add(StandardOpenOption.TRUNCATE_EXISTING);
try {
if (options.getPerms() != null) {
FileAttribute attrs = PosixFilePermissions.asFileAttribute(PosixFilePermissions.fromString(options.getPerms()));
ch = AsynchronousFileChannel.open(file, opts, vertx.getWorkerPool(), attrs);
} else {
ch = AsynchronousFileChannel.open(file, opts, vertx.getWorkerPool());
}
} catch (IOException e) {
throw new FileSystemException(e);
}
this.context = context;
}
@Override
public void close() {
closeInternal(null);
}
@Override
public void close(Handler> handler) {
closeInternal(handler);
}
@Override
public void end() {
close();
}
@Override
public synchronized AsyncFile read(Buffer buffer, int offset, long position, int length, Handler> handler) {
Objects.requireNonNull(buffer, "buffer");
Objects.requireNonNull(handler, "handler");
Arguments.require(offset >= 0, "offset must be >= 0");
Arguments.require(position >= 0, "position must be >= 0");
Arguments.require(length >= 0, "length must be >= 0");
check();
ByteBuffer bb = ByteBuffer.allocate(length);
doRead(buffer, offset, bb, position, handler);
return this;
}
@Override
public AsyncFile write(Buffer buffer, long position, Handler> handler) {
Objects.requireNonNull(handler, "handler");
return doWrite(buffer, position, handler);
}
private synchronized AsyncFile doWrite(Buffer buffer, long position, Handler> handler) {
Objects.requireNonNull(buffer, "buffer");
Arguments.require(position >= 0, "position must be >= 0");
check();
Handler> wrapped = ar -> {
if (ar.succeeded()) {
checkContext();
checkDrained();
if (writesOutstanding == 0 && closedDeferred != null) {
closedDeferred.run();
}
if (handler != null) {
handler.handle(ar);
}
} else {
if (handler != null) {
handler.handle(ar);
} else {
handleException(ar.cause());
}
}
};
ByteBuf buf = buffer.getByteBuf();
if (buf.nioBufferCount() > 1) {
doWrite(buf.nioBuffers(), position, wrapped);
} else {
ByteBuffer bb = buf.nioBuffer();
doWrite(bb, position, bb.limit(), wrapped);
}
return this;
}
@Override
public synchronized AsyncFile write(Buffer buffer) {
int length = buffer.length();
doWrite(buffer, writePos, null);
writePos += length;
return this;
}
@Override
public synchronized AsyncFile setWriteQueueMaxSize(int maxSize) {
Arguments.require(maxSize >= 2, "maxSize must be >= 2");
check();
this.maxWrites = maxSize;
this.lwm = maxWrites / 2;
return this;
}
@Override
public synchronized AsyncFile setReadBufferSize(int readBufferSize) {
this.readBufferSize = readBufferSize;
return this;
}
@Override
public synchronized boolean writeQueueFull() {
check();
return writesOutstanding >= maxWrites;
}
@Override
public synchronized AsyncFile drainHandler(Handler handler) {
check();
this.drainHandler = handler;
checkDrained();
return this;
}
@Override
public synchronized AsyncFile exceptionHandler(Handler handler) {
check();
this.exceptionHandler = handler;
return this;
}
@Override
public synchronized AsyncFile handler(Handler handler) {
check();
this.dataHandler = handler;
if (dataHandler != null && !paused && !closed) {
doRead();
}
return this;
}
@Override
public synchronized AsyncFile endHandler(Handler handler) {
check();
this.endHandler = handler;
return this;
}
@Override
public synchronized AsyncFile pause() {
check();
paused = true;
return this;
}
@Override
public synchronized AsyncFile resume() {
check();
if (paused && !closed) {
paused = false;
if (dataHandler != null) {
doRead();
}
}
return this;
}
@Override
public AsyncFile flush() {
doFlush(null);
return this;
}
@Override
public AsyncFile flush(Handler> handler) {
doFlush(handler);
return this;
}
@Override
public synchronized AsyncFile setReadPos(long readPos) {
this.readPos = readPos;
return this;
}
@Override
public synchronized AsyncFile setWritePos(long writePos) {
this.writePos = writePos;
return this;
}
private synchronized void checkDrained() {
if (drainHandler != null && writesOutstanding <= lwm) {
Handler handler = drainHandler;
drainHandler = null;
handler.handle(null);
}
}
private void handleException(Throwable t) {
if (exceptionHandler != null && t instanceof Exception) {
exceptionHandler.handle(t);
} else {
log.error("Unhandled exception", t);
}
}
private synchronized void doWrite(ByteBuffer[] buffers, long position, Handler> handler) {
AtomicInteger cnt = new AtomicInteger();
AtomicBoolean sentFailure = new AtomicBoolean();
for (ByteBuffer b: buffers) {
int limit = b.limit();
doWrite(b, position, limit, ar -> {
if (ar.succeeded()) {
if (cnt.incrementAndGet() == buffers.length) {
handler.handle(ar);
}
} else {
if (sentFailure.compareAndSet(false, true)) {
handler.handle(ar);
}
}
});
position += limit;
}
}
private synchronized void doRead() {
if (!readInProgress) {
readInProgress = true;
Buffer buff = Buffer.buffer(readBufferSize);
read(buff, 0, readPos, readBufferSize, ar -> {
if (ar.succeeded()) {
readInProgress = false;
Buffer buffer = ar.result();
if (buffer.length() == 0) {
// Empty buffer represents end of file
handleEnd();
} else {
readPos += buffer.length();
handleData(buffer);
if (!paused && dataHandler != null) {
doRead();
}
}
} else {
handleException(ar.cause());
}
});
}
}
private synchronized void handleData(Buffer buffer) {
if (dataHandler != null) {
checkContext();
dataHandler.handle(buffer);
}
}
private synchronized void handleEnd() {
if (endHandler != null) {
checkContext();
endHandler.handle(null);
}
}
private synchronized void doFlush(Handler> handler) {
checkClosed();
context.executeBlocking(() -> {
try {
ch.force(false);
return null;
} catch (IOException e) {
throw new FileSystemException(e);
}
}, handler);
}
private void doWrite(ByteBuffer buff, long position, long toWrite, Handler> handler) {
if (toWrite == 0) {
throw new IllegalStateException("Cannot save zero bytes");
}
writesOutstanding += toWrite;
writeInternal(buff, position, handler);
}
private void writeInternal(ByteBuffer buff, long position, Handler> handler) {
ch.write(buff, position, null, new java.nio.channels.CompletionHandler() {
public void completed(Integer bytesWritten, Object attachment) {
long pos = position;
if (buff.hasRemaining()) {
// partial write
pos += bytesWritten;
// resubmit
writeInternal(buff, pos, handler);
} else {
// It's been fully written
context.runOnContext((v) -> {
writesOutstanding -= buff.limit();
handler.handle(Future.succeededFuture());
});
}
}
public void failed(Throwable exc, Object attachment) {
if (exc instanceof Exception) {
context.runOnContext((v) -> handler.handle(Future.succeededFuture()));
} else {
log.error("Error occurred", exc);
}
}
});
}
private void doRead(Buffer writeBuff, int offset, ByteBuffer buff, long position, Handler> handler) {
ch.read(buff, position, null, new java.nio.channels.CompletionHandler() {
long pos = position;
private void done() {
context.runOnContext((v) -> {
buff.flip();
writeBuff.setBytes(offset, buff);
handler.handle(Future.succeededFuture(writeBuff));
});
}
public void completed(Integer bytesRead, Object attachment) {
if (bytesRead == -1) {
//End of file
done();
} else if (buff.hasRemaining()) {
// partial read
pos += bytesRead;
// resubmit
doRead(writeBuff, offset, buff, pos, handler);
} else {
// It's been fully written
done();
}
}
public void failed(Throwable t, Object attachment) {
context.runOnContext((v) -> handler.handle(Future.failedFuture(t)));
}
});
}
private void check() {
checkClosed();
}
private void checkClosed() {
if (closed) {
throw new IllegalStateException("File handle is closed");
}
}
private void checkContext() {
if (!vertx.getContext().equals(context)) {
throw new IllegalStateException("AsyncFile must only be used in the context that created it, expected: "
+ context + " actual " + vertx.getContext());
}
}
private void doClose(Handler> handler) {
Future res = Future.future();
try {
ch.close();
res.complete(null);
} catch (IOException e) {
res.fail(e);
}
if (handler != null) {
vertx.runOnContext(v -> handler.handle(res));
}
}
private synchronized void closeInternal(Handler> handler) {
check();
closed = true;
if (writesOutstanding == 0) {
doClose(handler);
} else {
closedDeferred = () -> doClose(handler);
}
}
}
