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

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.

Author:

Marek Potociar (marek.potociar at oracle.com)

Field Summary

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

NOTHING

Constructor Summary

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

Method Summary

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.
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.
boolean	put(ByteBuffer src) Put the ByteBuffer to the internal queue to be available for reading from the stream.
int	read()
int	tryRead() Behaves mostly like InputStream.read().
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).

Methods inherited from class java.io.InputStream

mark, markSupported, read, read, reset, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

ByteBufferInputStream

public ByteBufferInputStream()

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

Method Detail

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

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 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.