Package org.glassfish.jersey.internal.util.collection

Class ByteBufferInputStream

java.lang.Object

java.io.InputStream

org.glassfish.jersey.internal.util.collection.NonBlockingInputStream

org.glassfish.jersey.internal.util.collection.ByteBufferInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public final class ByteBufferInputStream
extends NonBlockingInputStream

An InputStream backed by a queue of byte buffers to be read.

This input stream serves as a bridging inbound I/O component between a blocking upper I/O layer and an underlying non-blocking I/O layer. In addition to the blocking InputStream.read operations, this input stream provides the non-blocking tryRead counterparts.

Field Summary

Fields

Modifier and Type	Field	Description
private final BlockingQueue<ByteBuffer>	buffers	Queue of byte buffers to be read.
private final AtomicBoolean	closed	Closed flag.
private ByteBuffer	current	Currently read byte buffer.
private boolean	eof	Read-side EOF flag.
private static final ByteBuffer	EOF	Constant buffer indicating EOF.
private final AtomicReference<Object>	queueStatus	Content represents the buffer queue status.

Fields inherited from class org.glassfish.jersey.internal.util.collection.NonBlockingInputStream

NOTHING

Constructor Summary

Constructors

Constructor	Description
ByteBufferInputStream()	Create a new input stream that is backed by a a queue of byte buffers to be read.

Method Summary

Modifier and Type	Method	Description
int	available()	Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream.
private void	checkNotClosed()
private void	checkThrowable()
void	close()
void	closeQueue()	Closes the byte buffer sink of this input stream to indicate that writing to the stream has been finished.
void	closeQueue(Throwable throwable)	Closes the byte buffer sink of this input stream to indicate that writing to the stream has been finished due to a throwable.
private boolean	fetchChunk(boolean block)
boolean	put(ByteBuffer src)	Put the ByteBuffer to the internal queue to be available for reading from the stream.
int	read()
int	read(byte[] b, int off, int len)
int	tryRead()	Behaves mostly like InputStream.read().
private int	tryRead(boolean block)
int	tryRead(byte[] b)	Behaves mostly like InputStream.read(byte[]).
int	tryRead(byte[] b, int off, int len)	Behaves mostly like InputStream.read(byte[], int, int).
private int	tryRead(byte[] b, int off, int len, boolean block)

Methods inherited from class java.io.InputStream

mark, markSupported, nullInputStream, read, readAllBytes, readNBytes, readNBytes, reset, skip, skipNBytes, transferTo

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

EOF

private static final ByteBuffer EOF

Constant buffer indicating EOF.

eof

private boolean eof

Read-side EOF flag. Does not have to be volatile, it is transient and only accessed from the reader thread.

current

private ByteBuffer current

Currently read byte buffer.

buffers

private final BlockingQueue<ByteBuffer> buffers

Queue of byte buffers to be read.

queueStatus

private final AtomicReference<Object> queueStatus

Content represents the buffer queue status. null = open, POISON_PILL = closed, Throwable = closed with error

closed

private final AtomicBoolean closed

Closed flag.

Constructor Details

ByteBufferInputStream

public ByteBufferInputStream()

Create a new input stream that is backed by a a queue of byte buffers to be read.

Method Details

fetchChunk

private boolean fetchChunk(boolean block)
                    throws InterruptedException

Throws:

InterruptedException

checkNotClosed

private void checkNotClosed()
                     throws IOException

Throws:

IOException

checkThrowable

private void checkThrowable()
                     throws IOException

Throws:

IOException

available

public int available()
              throws IOException

Description copied from class: NonBlockingInputStream

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream. The next invocation might be the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.

Note that while some implementations of InputStream will return the total number of bytes in the stream, many will not. It is never correct to use the return value of this method to allocate a buffer intended to hold all data in this stream.

A subclass' implementation of this method may choose to throw an IOException if this input stream has been closed by invoking the InputStream.close() method.

The default implementation of this method in NonBlockingInputStream throws an UnsupportedOperationException. This method must be overridden by subclasses. The overriding implementations must guarantee non-blocking behavior of the method. The overriding implementation must also guarantee that a non-empty stream does not return zero from the method. IOW, it must be possible to use the method for empty check: stream.available() == 0

Overrides:

available in class NonBlockingInputStream

Returns:

an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking or 0 when it reaches the end of the input stream or the stream is empty.

Throws:

IOException - if an I/O error occurs.

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

read

public int read(byte[] b,
 int off,
 int len)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

tryRead

public int tryRead()
            throws IOException

Description copied from class: NonBlockingInputStream

Behaves mostly like InputStream.read(). The main difference is that this method is non-blocking. In case there are no data available to be read, the method returns NonBlockingInputStream.NOTHING immediately.

Specified by:

tryRead in class NonBlockingInputStream

Returns:

next byte of data, -1 if end of the stream has been reached or NonBlockingInputStream.NOTHING in case no data are available to be read at the moment.

Throws:

IOException - if an I/O error occurs.

tryRead

public int tryRead(byte[] b)
            throws IOException

Description copied from class: NonBlockingInputStream

Behaves mostly like InputStream.read(byte[]). The main difference is that this method is non-blocking. In case there are no data available to be read, the method returns zero immediately.

Specified by:

tryRead in class NonBlockingInputStream

Parameters:

b - the buffer into which the data is read.

Returns:

the total number of bytes read into the buffer or -1 if end of the stream has been reached or 0 in case no data are available to be read at the moment.

Throws:

IOException - if an I/O error occurs.

tryRead

public int tryRead(byte[] b,
 int off,
 int len)
            throws IOException

Description copied from class: NonBlockingInputStream

Behaves mostly like InputStream.read(byte[], int, int). The main difference is that this method is non-blocking. In case there are no data available to be read, the method returns zero immediately.

Specified by:

tryRead in class NonBlockingInputStream

Parameters:

b - the buffer into which the data is read.

off - the start offset in array b at which the data is written.

len - the maximum number of bytes to read.

Returns:

the total number of bytes read into the buffer or -1 if end of the stream has been reached or 0 in case no data are available to be read at the moment.

Throws:

IOException - if an I/O error occurs.

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException

put

public boolean put(ByteBuffer src)
            throws InterruptedException

Put the ByteBuffer to the internal queue to be available for reading from the stream.

If the sink is open, the method puts the buffer into an internal byte buffer read queue , waiting if necessary for space to become available. Then the method returns true to indicate the buffer has been successfully queued. In case the internal read queue has been closed already, the method simply returns false without registering the buffer in the closed queue.

Parameters:

src - the source buffer to be registered in the byte buffer read queue.

Returns:

true if the byte buffer has been successfully put in the read queue, false if the read queue has been closed.

Throws:

InterruptedException - in case the put operation has been interrupted.

closeQueue

public void closeQueue()

Closes the byte buffer sink of this input stream to indicate that writing to the stream has been finished.

If the sink has already been closed then this method returns immediately. Otherwise the sink is marked as closed and no more data can be written to it.

closeQueue

public void closeQueue(Throwable throwable)

Closes the byte buffer sink of this input stream to indicate that writing to the stream has been finished due to a throwable. The throwable set by this method will be propagated to the reader thread when a new attempt to read bytes is made.

If the sink has already been closed then this method only sets the throwable in the stream and then returns immediately. Otherwise the sink is also marked as closed and no more data can be written to it.

Parameters:

throwable - throwable that is set in the stream. It will be thrown by the stream in case an attempt to read more data or check available bytes is made.

tryRead

private int tryRead(byte[] b,
 int off,
 int len,
 boolean block)
             throws IOException

Throws:

IOException

tryRead

private int tryRead(boolean block)
             throws IOException

Throws:

IOException