Module org.xbib.rpm

Package org.xbib.rpm.io

Class ChannelWrapper

java.lang.Object

org.xbib.rpm.io.ChannelWrapper

Direct Known Subclasses:

ReadableChannelWrapper, WritableChannelWrapper

public abstract class ChannelWrapper
extends Object

Wraps an IO channel so that bytes may be observed during transmission. Wrappers around IO channels are used for a variety of purposes, including counting byte output for use in generating headers, calculating a signature across output bytes, and digesting output bytes using a one-way secure hash.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	ChannelWrapper.Consumer<T>	Interface describing an object that consumes data from a byte buffer.
static class	ChannelWrapper.Key<T>

Constructor Summary

Constructors

Constructor	Description
ChannelWrapper()

Method Summary

Modifier and Type	Method	Description
void	close()
static void	empty(WritableByteChannel out, ByteBuffer buffer)	Empties the contents of the given buffer into the writable channel provided.
static ByteBuffer	fill(ReadableByteChannel in, int size)	Creates a new buffer and fills it with bytes from the provided channel.
static ByteBuffer	fill(ReadableByteChannel in, ByteBuffer buffer)	Fills the provided buffer it with bytes from the provided channel.
<T> T	finish(ChannelWrapper.Key<T> object)
ChannelWrapper.Key<Integer>	startCount()	Initializes a byte counter on this channel.
ChannelWrapper.Key<byte[]>	startCount(ChannelWrapper.Consumer<byte[]> consumer)	Add a new consumer to this channel.

Methods inherited from class java.lang.Object

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

Constructor Details

ChannelWrapper

public ChannelWrapper()

Method Details

startCount

public ChannelWrapper.Key<Integer> startCount()

Initializes a byte counter on this channel.

Returns:

reference to the new key added to the consumers

startCount

public ChannelWrapper.Key<byte[]> startCount(ChannelWrapper.Consumer<byte[]> consumer)

Add a new consumer to this channel.

Parameters:

consumer - the channel consumer

Returns:

reference to the new key added to the consumers

finish

public <T> T finish(ChannelWrapper.Key<T> object)

close

public void close()
           throws IOException

Throws:

IOException

fill

public static ByteBuffer fill(ReadableByteChannel in,
 int size)
                       throws IOException

Creates a new buffer and fills it with bytes from the provided channel. The amount of data to read is specified in the arguments.

Parameters:

in - the channel to read from

size - the number of bytes to read into a new buffer

Returns:

a new buffer containing the bytes read

Throws:

IOException - if an IO error occurs

fill

public static ByteBuffer fill(ReadableByteChannel in,
 ByteBuffer buffer)
                       throws IOException

Fills the provided buffer it with bytes from the provided channel. The amount of data to read is dependant on the available space in the provided buffer.

Parameters:

in - the channel to read from

buffer - the buffer to read into

Returns:

the provided buffer

Throws:

IOException - if an IO error occurs

empty

public static void empty(WritableByteChannel out,
 ByteBuffer buffer)
                  throws IOException

Empties the contents of the given buffer into the writable channel provided. The buffer will be copied to the channel in it's entirety.

Parameters:

out - the channel to write to

buffer - the buffer to write out to the channel

Throws:

IOException - if an IO error occurs