freenet.support.io

Class NullRandomAccessBuffer

java.lang.Object

freenet.support.io.NullRandomAccessBuffer

All Implemented Interfaces:

LockableRandomAccessBuffer, RandomAccessBuffer, java.io.Closeable, java.lang.AutoCloseable

public class NullRandomAccessBuffer
extends java.lang.Object
implements LockableRandomAccessBuffer

Nested Class Summary

Nested classes/interfaces inherited from interface freenet.support.api.LockableRandomAccessBuffer

LockableRandomAccessBuffer.RAFLock

Constructor Summary

Constructors

Constructor and Description
NullRandomAccessBuffer(long length)

Method Summary

Modifier and Type	Method and Description
void	close()
boolean	equals(java.lang.Object o) Must reimplement equals().
void	free() Free the underlying resources.
int	hashCode() Must reimplement hashCode() if we change equals().
LockableRandomAccessBuffer.RAFLock	lockOpen() Keep the RAF open.
void	onResume(ClientContext context) Called on resuming, i.e.
void	pread(long fileOffset, byte[] buf, int bufOffset, int length) Read a block of data from a specific location in the file.
void	pwrite(long fileOffset, byte[] buf, int bufOffset, int length)
long	size()
void	storeTo(java.io.DataOutputStream dos) Write enough data to reconstruct the Bucket, or throw UnsupportedOperationException.

Methods inherited from class java.lang.Object

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

Constructor Detail

NullRandomAccessBuffer

public NullRandomAccessBuffer(long length)

Method Detail

size

public long size()

Specified by:

size in interface RandomAccessBuffer

pread

public void pread(long fileOffset,
                  byte[] buf,
                  int bufOffset,
                  int length)
           throws java.io.IOException

Description copied from interface: RandomAccessBuffer

Read a block of data from a specific location in the file. Guaranteed to read the whole range or to throw, like DataInputStream.readFully(). Must throw if the file is closed.

Specified by:

pread in interface RandomAccessBuffer

Parameters:

fileOffset - The offset within the file to read from.

buf - The buffer to write to.

bufOffset - The offset within the buffer to the first read byte.

length - The length of data to read.

Throws:

java.io.IOException - If we were unable to read the required number of bytes etc.

pwrite

public void pwrite(long fileOffset,
                   byte[] buf,
                   int bufOffset,
                   int length)
            throws java.io.IOException

Specified by:

pwrite in interface RandomAccessBuffer

Throws:

java.io.IOException

close

public void close()

Specified by:

close in interface RandomAccessBuffer

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

free

public void free()

Description copied from interface: RandomAccessBuffer

Free the underlying resources. May do nothing in some implementations. You should make sure the object can be GC'ed as well.

Specified by:

free in interface RandomAccessBuffer

lockOpen

public LockableRandomAccessBuffer.RAFLock lockOpen()
                                            throws java.io.IOException

Description copied from interface: LockableRandomAccessBuffer

Keep the RAF open. Does not prevent others from writing to it. Will block until a slot is available if necessary. Hence can deadlock.

Specified by:

lockOpen in interface LockableRandomAccessBuffer

Throws:

java.io.IOException

onResume

public void onResume(ClientContext context)
              throws ResumeFailedException

Description copied from interface: LockableRandomAccessBuffer

Called on resuming, i.e. after serialization. Use to e.g. register with the list of temporary files.

Specified by:

onResume in interface LockableRandomAccessBuffer

Throws:

ResumeFailedException

storeTo

public void storeTo(java.io.DataOutputStream dos)
             throws java.io.IOException

Description copied from interface: LockableRandomAccessBuffer

Write enough data to reconstruct the Bucket, or throw UnsupportedOperationException. Used for recovering in emergencies, should be versioned if necessary. To make this work, write a fixed, unique integer magic value for the class, and add a clause to BucketTools.restoreRAFFrom().

Specified by:

storeTo in interface LockableRandomAccessBuffer

Throws:

java.io.IOException

hashCode

public int hashCode()

Description copied from interface: LockableRandomAccessBuffer

Must reimplement hashCode() if we change equals().

Specified by:

hashCode in interface LockableRandomAccessBuffer

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object o)

Description copied from interface: LockableRandomAccessBuffer

Must reimplement equals(). Sometimes we will need to compare two RAFs to see if they represent the same stored object, notably during resuming a splitfile insert.

Specified by:

equals in interface LockableRandomAccessBuffer

Overrides:

equals in class java.lang.Object