freenet.support.io

Class DiskSpaceCheckingRandomAccessBufferFactory

java.lang.Object

freenet.support.io.DiskSpaceCheckingRandomAccessBufferFactory

All Implemented Interfaces:

LockableRandomAccessBufferFactory, DiskSpaceChecker, FileRandomAccessBufferFactory

public class DiskSpaceCheckingRandomAccessBufferFactory
extends java.lang.Object
implements LockableRandomAccessBufferFactory, DiskSpaceChecker, FileRandomAccessBufferFactory

Constructor Summary

Constructors

Constructor and Description
DiskSpaceCheckingRandomAccessBufferFactory(LockableRandomAccessBufferFactory underlying, java.io.File dir, long minDiskSpace)

Method Summary

Modifier and Type	Method and Description
boolean	checkDiskSpace(java.io.File file, int toWrite, int bufferSize) Is there enough space to extend the file?
PooledFileRandomAccessBuffer	createNewRAF(java.io.File file, long size, java.util.Random random) Create a new RAF for a specified file, which must exist but be 0 bytes long.
LockableRandomAccessBuffer	makeRAF(byte[] initialContents, int offset, int size, boolean readOnly) Create a bucket with specified initial contents.
LockableRandomAccessBuffer	makeRAF(long size) Create a bucket.
void	setMinDiskSpace(long min)
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

DiskSpaceCheckingRandomAccessBufferFactory

public DiskSpaceCheckingRandomAccessBufferFactory(LockableRandomAccessBufferFactory underlying,
                                                  java.io.File dir,
                                                  long minDiskSpace)

Method Detail

setMinDiskSpace

public void setMinDiskSpace(long min)

makeRAF

public LockableRandomAccessBuffer makeRAF(long size)
                                   throws java.io.IOException

Description copied from interface: LockableRandomAccessBufferFactory

Create a bucket.

Specified by:

makeRAF in interface LockableRandomAccessBufferFactory

Parameters:

size - The maximum size of the data. Most factories will pre-allocate this space, and it may not be exceeded. However we do not guarantee that any I/O operation will complete; even if we have pre-allocated the disk space, we may be unable to write to it because of e.g. a hardware error.

Returns:

A LockableRandomAccessBuffer of the requested size.

Throws:

java.io.IOException - If an I/O error prevented the operation.

makeRAF

public LockableRandomAccessBuffer makeRAF(byte[] initialContents,
                                          int offset,
                                          int size,
                                          boolean readOnly)
                                   throws java.io.IOException

Description copied from interface: LockableRandomAccessBufferFactory

Create a bucket with specified initial contents.

Specified by:

makeRAF in interface LockableRandomAccessBufferFactory

Parameters:

initialContents - Byte array from which to copy data. Data will be copied even if the underlying implementation is a byte array, for reasons of consistency.

offset - Offset within the array to start copying data from.

size - Number of bytes to copy i.e. length of the new RandomAccessBuffer.

Returns:

Throws:

java.io.IOException - If an I/O error prevented the operation.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

createNewRAF

public PooledFileRandomAccessBuffer createNewRAF(java.io.File file,
                                                 long size,
                                                 java.util.Random random)
                                          throws java.io.IOException

Create a new RAF for a specified file, which must exist but be 0 bytes long. Will delete the file if an RAF cannot be created.

Specified by:

createNewRAF in interface FileRandomAccessBufferFactory

Throws:

InsufficientDiskSpaceException - If there is not enough disk space.

java.io.IOException - If some other disk I/O error occurs.

checkDiskSpace

public boolean checkDiskSpace(java.io.File file,
                              int toWrite,
                              int bufferSize)

Description copied from interface: DiskSpaceChecker

Is there enough space to extend the file?

Specified by:

checkDiskSpace in interface DiskSpaceChecker

Parameters:

file - The current filename

toWrite - Length of the proposed write

bufferSize - The caller only checks disk space when the number of bytes written since the last check exceeds this value.

Returns:

True if there is sufficient disk space