org.eclipse.jetty.spdy.api.DataInfo Maven / Gradle / Ivy
//
// ========================================================================
// Copyright (c) 1995-2018 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// 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.
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//
package org.eclipse.jetty.spdy.api;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
/**
* A container for DATA frames metadata and content bytes.
* Specialized subclasses (like {@link StringDataInfo}) may be used by applications
* to send specific types of content.
* Applications may send multiple instances of {@link DataInfo}, usually of the same
* type, via {@link Stream#data(DataInfo)}. The last instance must have the
* {@link #isClose() close flag} set, so that the client knows that no more content is
* expected.
* Receivers of {@link DataInfo} via {@link StreamFrameListener#onData(Stream, DataInfo)}
* have two different APIs to read the data content bytes: a {@link #readInto(ByteBuffer) read}
* API that does not interact with flow control, and a {@link #consumeInto(ByteBuffer) drain}
* API that interacts with flow control.
* Flow control is defined so that when the sender wants to sends a number of bytes larger
* than the {@link Settings.ID#INITIAL_WINDOW_SIZE} value, it will stop sending as soon as it
* has sent a number of bytes equal to the window size. The receiver has to consume
* the data bytes that it received in order to tell the sender to send more bytes.
* Consuming the data bytes can be done only via {@link #consumeInto(ByteBuffer)} or by a combination
* of {@link #readInto(ByteBuffer)} and {@link #consume(int)} (possibly at different times).
*/
public abstract class DataInfo extends Info
{
/**
* Flag that indicates that this {@link DataInfo} is the last frame in the stream.
*
* @see #isClose()
* @see #getFlags()
*/
public final static byte FLAG_CLOSE = 1;
private final AtomicInteger consumed = new AtomicInteger();
private boolean close;
/**
* Creates a new {@link DataInfo} with the given close flag and no compression flag.
*
* @param close the value of the close flag
*/
public DataInfo(boolean close)
{
setClose(close);
}
/**
* Creates a new {@link DataInfo} with the given close flag and no compression flag.
*
* @param timeout
* @param unit
* @param close the value of the close flag
*/
protected DataInfo(long timeout, TimeUnit unit, boolean close)
{
super(timeout, unit);
this.close = close;
}
/**
* @return the value of the close flag
* @see #setClose(boolean)
*/
public boolean isClose()
{
return close;
}
/**
* @param close the value of the close flag
* @see #isClose()
*/
public void setClose(boolean close)
{
this.close = close;
}
/**
* @return the close and compress flags as integer
* @see #FLAG_CLOSE
*/
public byte getFlags()
{
return isClose() ? FLAG_CLOSE : 0;
}
/**
* @return the total number of content bytes
* @see #available()
*/
public abstract int length();
/**
* Returns the available content bytes that can be read via {@link #readInto(ByteBuffer)}.
* Each invocation to {@link #readInto(ByteBuffer)} modifies the value returned by this method,
* until no more content bytes are available.
*
* @return the available content bytes
* @see #readInto(ByteBuffer)
*/
public abstract int available();
/**
* Copies the content bytes of this {@link DataInfo} into the given {@link ByteBuffer}.
* If the given {@link ByteBuffer} cannot contain the whole content of this {@link DataInfo}
* then after the read {@link #available()} will return a positive value, and further content
* may be retrieved by invoking again this method with a new output buffer.
*
* @param output the {@link ByteBuffer} to copy the bytes into
* @return the number of bytes copied
* @see #available()
* @see #consumeInto(ByteBuffer)
*/
public abstract int readInto(ByteBuffer output);
/**
* Copies the content bytes of this {@link DataInfo} into the given byte array.
* If the given byte array cannot contain the whole content of this {@link DataInfo}
* then after the read {@link #available()} will return a positive value, and further content
* may be retrieved by invoking again this method with a new byte array.
*
* @param bytes the byte array to copy the bytes into
* @param offset the index of the byte array to start copying
* @param length the number of bytes to copy
* @return the number of bytes copied
*/
public abstract int readInto(byte[] bytes, int offset, int length);
/**
* Reads and consumes the content bytes of this {@link DataInfo} into the given {@link ByteBuffer}.
*
* @param output the {@link ByteBuffer} to copy the bytes into
* @return the number of bytes copied
* @see #consume(int)
*/
public int consumeInto(ByteBuffer output)
{
int read = readInto(output);
consume(read);
return read;
}
/**
* Reads and consumes the content bytes of this {@link DataInfo} into the given byte array,
* starting from index {@code offset} for {@code length} bytes.
*
* @param bytes the byte array to copy the bytes into
* @param offset the offset of the byte array to start copying
* @param length the number of bytes to copy
* @return the number of bytes copied
*/
public int consumeInto(byte[] bytes, int offset, int length)
{
int read = readInto(bytes, offset, length);
consume(read);
return read;
}
/**
* Consumes the given number of bytes from this {@link DataInfo}.
*
* @param delta the number of bytes consumed
*/
public void consume(int delta)
{
if (delta < 0)
throw new IllegalArgumentException();
int read = length() - available();
int newConsumed = consumed() + delta;
// if (newConsumed > read)
// throw new IllegalStateException("Consuming without reading: consumed " + newConsumed + " but only read " + read);
consumed.addAndGet(delta);
}
/**
* @return the number of bytes consumed
*/
public int consumed()
{
return consumed.get();
}
/**
*
* @param charset the charset used to convert the bytes
* @param consume whether to consume the content
* @return a String with the content of this {@link DataInfo}
*/
public String asString(String charset, boolean consume)
{
return asString(Charset.forName(charset), consume);
}
/**
*
* @param charset the charset used to convert the bytes
* @param consume whether to consume the content
* @return a String with the content of this {@link DataInfo}
*/
public String asString(Charset charset, boolean consume)
{
ByteBuffer buffer = asByteBuffer(consume);
return charset.decode(buffer).toString();
}
/**
* @return a byte array with the content of this {@link DataInfo}
* @param consume whether to consume the content
*/
public byte[] asBytes(boolean consume)
{
ByteBuffer buffer = asByteBuffer(consume);
byte[] result = new byte[buffer.remaining()];
buffer.get(result);
return result;
}
/**
* @return a {@link ByteBuffer} with the content of this {@link DataInfo}
* @param consume whether to consume the content
*/
public ByteBuffer asByteBuffer(boolean consume)
{
ByteBuffer buffer = allocate(available());
if (consume)
consumeInto(buffer);
else
readInto(buffer);
buffer.flip();
return buffer;
}
protected ByteBuffer allocate(int size)
{
return ByteBuffer.allocate(size);
}
@Override
public String toString()
{
return String.format("DATA @%x available=%d consumed=%d close=%b", hashCode(), available(), consumed(), isClose());
}
}