freenet.support.io

Class PersistentTempBucketFactory

java.lang.Object

freenet.support.io.PersistentTempBucketFactory

All Implemented Interfaces:

BucketFactory, DiskSpaceChecker, PersistentFileTracker

public class PersistentTempBucketFactory
extends java.lang.Object
implements BucketFactory, PersistentFileTracker

Handles persistent temp files. These are used for e.g. persistent downloads. These are temporary files in the directory specified for the PersistentFileTracker (which supports changing the directory, i.e. moving the files). These temporary files are encrypted using an ephemeral key (unless the node is configured not to encrypt temporary files as happens with physical security level LOW). FIXME NO CRYPTO AT THE MOMENT. Note that the files are only deleted *after* the transaction containing their deletion reaches disk - so we should not leak temporary files, or forget that we deleted a bucket and try to reuse it, if there is an unclean shutdown. PERSISTENCE: This class is involved in persistence but is not itself Serializable; it is recreated on every startup, and persistent Bucket's register themselves with it.

Field Summary

Fields

Modifier and Type	Field and Description
FilenameGenerator	fg Filename generator.

Constructor Summary

Constructors

Constructor and Description
PersistentTempBucketFactory(java.io.File dir, java.lang.String prefix, RandomSource strongPRNG, java.util.Random weakPRNG, boolean encrypt) Create a temporary bucket factory.

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?
long	commitID() A positive number incremented on every transaction.
void	completedInit() Called when boot-up is complete.
void	delayedFree(DelayedFree b, long createdCommitID) Free an allocated bucket, but only after the change has been written to disk.
void	finishDelayedFree(DelayedFree[] buckets) Delete the buckets.
java.io.File	getDir() Get the directory we are creating temporary files in
FilenameGenerator	getGenerator() Get the FilenameGenerator
DelayedFree[]	grabBucketsToFree() Returns a list of buckets to free.
boolean	isEncrypting() Are we encrypting temporary files?
RandomAccessBucket	makeBucket(long size) Create a persistent temporary bucket.
void	register(java.io.File file) Notify the bucket factory that a file is a temporary file, and not to be deleted.
void	setDiskSpaceChecker(DiskSpaceChecker checker)
void	setEncryption(boolean encrypt) Set whether to encrypt new persistent temp buckets.
void	setMasterSecret(MasterSecret secret)

Methods inherited from class java.lang.Object

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

Field Detail

fg

public final FilenameGenerator fg

Filename generator. Tracks the directory and the prefix for temp files, can move them if these change, generates filenames.

Constructor Detail

PersistentTempBucketFactory

public PersistentTempBucketFactory(java.io.File dir,
                                   java.lang.String prefix,
                                   RandomSource strongPRNG,
                                   java.util.Random weakPRNG,
                                   boolean encrypt)
                            throws java.io.IOException

Create a temporary bucket factory.

Parameters:

dir - Where to put it.

prefix - Prefix for temporary file names.

strongPRNG - Cryptographically strong random number generator, for making keys etc.

weakPRNG - Weak but fast random number generator.

encrypt - Whether to encrypt temporary files.

Throws:

java.io.IOException - If we are unable to read the directory, etc.

Method Detail

setDiskSpaceChecker

public void setDiskSpaceChecker(DiskSpaceChecker checker)

setMasterSecret

public void setMasterSecret(MasterSecret secret)

register

public void register(java.io.File file)

Notify the bucket factory that a file is a temporary file, and not to be deleted. FIXME this is not currently used. @see #completedInit()

Specified by:

register in interface PersistentFileTracker

completedInit

public void completedInit()

Called when boot-up is complete. Deletes any old temp files still unclaimed.

makeBucket

public RandomAccessBucket makeBucket(long size)
                              throws java.io.IOException

Create a persistent temporary bucket. Encrypted if appropriate. Wrapped in a DelayedFreeBucket so that they will not be deleted until after the transaction deleting them in the database commits.

Specified by:

makeBucket in interface BucketFactory

Parameters:

size - The maximum size of the data, or -1 or Long.MAX_VALUE if we don't know. Some buckets will throw IOException if you go over this length.

Returns:

Throws:

java.io.IOException

delayedFree

public void delayedFree(DelayedFree b,
                        long createdCommitID)

Free an allocated bucket, but only after the change has been written to disk.

Specified by:

delayedFree in interface PersistentFileTracker

Parameters:

b - The bucket to free.

createdCommitID - 0 if the bucket was created before the last node restart, otherwise the return value of commitID() when it was created. If there hasn't been a commit, we can free the bucket immediately...

grabBucketsToFree

public DelayedFree[] grabBucketsToFree()

Returns a list of buckets to free. The caller should write the buckets to the checkpoint, and free them after the checkpoint has written successfully, by calling postCommit().

commitID

public long commitID()

Description copied from interface: PersistentFileTracker

A positive number incremented on every transaction.

Specified by:

commitID in interface PersistentFileTracker

getDir

public java.io.File getDir()

Get the directory we are creating temporary files in

Specified by:

getDir in interface PersistentFileTracker

getGenerator

public FilenameGenerator getGenerator()

Get the FilenameGenerator

Specified by:

getGenerator in interface PersistentFileTracker

isEncrypting

public boolean isEncrypting()

Are we encrypting temporary files?

setEncryption

public void setEncryption(boolean encrypt)

Set whether to encrypt new persistent temp buckets. Note that we do not encrypt/decrypt old ones when this changes.

finishDelayedFree

public void finishDelayedFree(DelayedFree[] buckets)

Delete the buckets.

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