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/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 2010-2014 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* http://glassfish.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
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* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
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*/
package org.glassfish.jersey.message.internal;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.glassfish.jersey.internal.LocalizationMessages;
import jersey.repackaged.com.google.common.base.Preconditions;
/**
* A committing output stream with optional serialized entity buffering functionality
* which allows measuring of the entity size.
*
* When buffering functionality is enabled the output stream buffers
* the written bytes into an internal buffer of a configurable size. After the last
* written byte the {@link #commit()} method is expected to be called to notify
* a {@link org.glassfish.jersey.message.internal.OutboundMessageContext.StreamProvider#getOutputStream(int) callback}
* with an actual measured entity size. If the entity is too large to
* fit into the internal buffer and the buffer exceeds before the {@link #commit()}
* is called then the stream is automatically committed and the callback is called
* with parameter {@code size} value of {@code -1}.
*
*
* Callback method also returns the output stream in which the output will be written. The committing output stream
* must be initialized with the callback using
* {@link #setStreamProvider(org.glassfish.jersey.message.internal.OutboundMessageContext.StreamProvider)}
* before first byte is written.
*
* The buffering is by default disabled and can be enabled by calling {@link #enableBuffering()}
* or {@link #enableBuffering(int)} before writing the first byte into this output stream. The former
* method enables buffering with the default size
* {@value CommittingOutputStream#DEFAULT_BUFFER_SIZE} bytes specified in {@link #DEFAULT_BUFFER_SIZE}.
*
*
* @author Paul Sandoz
* @author Marek Potociar (marek.potociar at oracle.com)
* @author Miroslav Fuksa (miroslav.fuksa at oracle.com)
*/
final class CommittingOutputStream extends OutputStream {
private static final Logger LOGGER = Logger.getLogger(CommittingOutputStream.class.getName());
/**
* Null stream provider.
*/
private static final OutboundMessageContext.StreamProvider NULL_STREAM_PROVIDER =
new OutboundMessageContext.StreamProvider() {
@Override
public OutputStream getOutputStream(int contentLength) throws IOException {
return new NullOutputStream();
}
};
/**
* Default size of the buffer which will be used if no user defined size is specified.
*/
static final int DEFAULT_BUFFER_SIZE = 8192;
/**
* Adapted output stream.
*/
private OutputStream adaptedOutput;
/**
* Buffering stream provider.
*/
private OutboundMessageContext.StreamProvider streamProvider;
/**
* Internal buffer size.
*/
private int bufferSize = 0;
/**
* Entity buffer.
*/
private ByteArrayOutputStream buffer;
/**
* When {@code true}, the data are written directly to output stream and not to the buffer.
*/
private boolean directWrite = true;
/**
* When {@code true}, the stream is already committed (redirected to adaptedOutput).
*/
private boolean isCommitted;
/**
* When {@code true}, the stream is already closed.
*/
private boolean isClosed;
private static final String STREAM_PROVIDER_NULL = LocalizationMessages.STREAM_PROVIDER_NULL();
private static final String COMMITTING_STREAM_BUFFERING_ILLEGAL_STATE = LocalizationMessages.COMMITTING_STREAM_BUFFERING_ILLEGAL_STATE();
/**
* Creates new committing output stream. The returned stream instance still needs to be initialized before
* writing first bytes.
*/
public CommittingOutputStream() {
}
/**
* Set the buffering output stream provider. If the committing output stream works in buffering mode
* this method must be called before first bytes are written into this stream.
*
* @param streamProvider non-null stream provider callback.
*/
public void setStreamProvider(OutboundMessageContext.StreamProvider streamProvider) {
if (isClosed) {
throw new IllegalStateException(LocalizationMessages.OUTPUT_STREAM_CLOSED());
}
Preconditions.checkNotNull(streamProvider);
if (this.streamProvider != null) {
LOGGER.log(Level.WARNING, LocalizationMessages.COMMITTING_STREAM_ALREADY_INITIALIZED());
}
this.streamProvider = streamProvider;
}
/**
* Enable buffering of the serialized entity.
*
* @param bufferSize size of the buffer. When the value is less or equal to zero then
* buffering will be disabled and -1 will be passed to the
* {@link org.glassfish.jersey.message.internal.OutboundMessageContext.StreamProvider#getOutputStream(int) callback}.
*/
public void enableBuffering(int bufferSize) {
Preconditions.checkState(!isCommitted && (this.buffer == null || this.buffer.size() == 0), COMMITTING_STREAM_BUFFERING_ILLEGAL_STATE);
this.bufferSize = bufferSize;
if (bufferSize <= 0) {
this.directWrite = true;
this.buffer = null;
} else {
directWrite = false;
buffer = new ByteArrayOutputStream(bufferSize);
}
}
/**
* Enable buffering of the serialized entity with the {@link #DEFAULT_BUFFER_SIZE default buffer size }.
*/
public void enableBuffering() {
enableBuffering(DEFAULT_BUFFER_SIZE);
}
/**
* Determine whether the stream was already committed or not.
*
* @return {@code true} if this stream was already committed, {@code false} otherwise.
*/
public boolean isCommitted() {
return isCommitted;
}
private void commitStream() throws IOException {
commitStream(-1);
}
private void commitStream(int currentSize) throws IOException {
if (!isCommitted) {
Preconditions.checkState(streamProvider != null, STREAM_PROVIDER_NULL);
adaptedOutput = streamProvider.getOutputStream(currentSize);
if (adaptedOutput == null) {
adaptedOutput = new NullOutputStream();
}
directWrite = true;
isCommitted = true;
}
}
@Override
public void write(byte b[]) throws IOException {
if (directWrite) {
commitStream();
adaptedOutput.write(b);
} else {
if (b.length + buffer.size() > bufferSize) {
flushBuffer(false);
adaptedOutput.write(b);
} else {
buffer.write(b);
}
}
}
@Override
public void write(byte b[], int off, int len) throws IOException {
if (directWrite) {
commitStream();
adaptedOutput.write(b, off, len);
} else {
if (len + buffer.size() > bufferSize) {
flushBuffer(false);
adaptedOutput.write(b, off, len);
} else {
buffer.write(b, off, len);
}
}
}
@Override
public void write(int b) throws IOException {
if (directWrite) {
commitStream();
adaptedOutput.write(b);
} else {
if (buffer.size() + 1 > bufferSize) {
flushBuffer(false);
adaptedOutput.write(b);
} else {
buffer.write(b);
}
}
}
/**
* Commit the output stream.
*
* @throws IOException when underlying stream returned from the callback method throws the io exception.
*/
void commit() throws IOException {
flushBuffer(true);
commitStream();
}
@Override
public void close() throws IOException {
if (isClosed) {
return;
}
isClosed = true;
if (streamProvider == null) {
streamProvider = NULL_STREAM_PROVIDER;
}
commit();
adaptedOutput.close();
}
/**
* Check if the committing output stream has been closed already.
*
* @return {@code true} if the stream has been closed, {@code false} otherwise.
*/
public boolean isClosed() {
return isClosed;
}
@Override
public void flush() throws IOException {
if (isCommitted()) {
adaptedOutput.flush();
}
}
private void flushBuffer(boolean endOfStream) throws IOException {
if (!directWrite) {
int currentSize;
if (endOfStream) {
currentSize = buffer == null ? 0 : buffer.size();
} else {
currentSize = -1;
}
commitStream(currentSize);
if (buffer != null) {
buffer.writeTo(adaptedOutput);
}
}
}
}