gzz.mediaserver
Class MultiplexingMediaserver

java.lang.Object
  |
  +--gzz.mediaserver.MultiplexingMediaserver

All Implemented Interfaces:

Mediaserver

public class MultiplexingMediaserver

extends java.lang.Object

implements Mediaserver

A mediaserver channeling all requests through to other mediaservers. One of the servers is a fallback, others are either read-only or read-write. Fallback is used to write all data that isn't written elsewhere, eg. new slices and pointers to nonexistent blocks. Otherwise data is written to all the servers that contain an associated block.

Nested Class Summary

Nested classes inherited from class gzz.mediaserver.Mediaserver

Mediaserver.Id, Mediaserver.InvalidID

Constructor Summary

MultiplexingMediaserver(Mediaserver fb, Mediaserver ro)

MultiplexingMediaserver(Mediaserver fb, Mediaserver[] ro, Mediaserver[] rw)

Method Summary

Mediaserver.Id	addDatum(byte[] data, java.util.Collection headerLines, Mediaserver.Id assocId, boolean addDefaultHeaders) Add a new datum, explicitly giving a collection of header lines.
Mediaserver.Id	addDatum(byte[] data, java.lang.String contentType) Creates a new block (to the fallback pool)
Mediaserver.Id	addDatum(byte[] data, java.lang.String contentType, Mediaserver.Id assocId) Creates a new block associated with some previous block.
void	cache(MediaserverBlock b) Cache a mediaserver block.
void	expungeDatum(Mediaserver.Id id) Permanently remove a block.
MediaserverBlock	getDatum(Mediaserver.Id id) Get the datum corresponding to the given id.
java.util.Set	getDiffsFrom(Mediaserver.Id id)
java.util.Set	getDiffsTo(Mediaserver.Id id)
java.util.Set	getIDs() Get a set of the IDs of all entries in the Mediaserver database.
Mediaserver.Id	getPointer(java.lang.String s) (Kludge) Get a String-identified pointer local to this mediaserver.
java.util.Set	getPointers() (Kludge) Get the names of all String-identified pointers local to this mediaserver.
PointerSet	getPointerSet(java.lang.String s)
java.lang.String	getPoolName() Get the name of the pool this mediaserver stores.
void	setPointer(java.lang.String s, Mediaserver.Id id) (Kludge) Set a String-identified pointer local to this mediaserver.
void	setPointer(java.lang.String s, Mediaserver.Id id, Mediaserver.Id obsolete)
void	setPointer(java.lang.String s, Mediaserver.Id id, java.util.Set obsoletes)
void	setPoolName(java.lang.String s) Set the name of the pool this mediaserver stores.
void	storeDatum(Mediaserver.Id id, byte[] data) Store an existing datum under a given ID.
void	uncache(MediaserverBlock b) Uncache a mediaserver block.

Methods inherited from class java.lang.Object

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

Constructor Detail

MultiplexingMediaserver

public MultiplexingMediaserver(Mediaserver fb,
                               Mediaserver[] ro,
                               Mediaserver[] rw)

Parameters:

fb - fallback storage pool, read-write, fallback for writes

ro - read-only storage pools

rw - read-write storage pools

MultiplexingMediaserver

public MultiplexingMediaserver(Mediaserver fb,
                               Mediaserver ro)

Method Detail

getPoolName

public java.lang.String getPoolName()
                             throws java.io.IOException

Get the name of the pool this mediaserver stores.

Specified by:

getPoolName in interface Mediaserver

java.io.IOException

setPoolName

public void setPoolName(java.lang.String s)
                 throws java.io.IOException

Set the name of the pool this mediaserver stores.

Specified by:

setPoolName in interface Mediaserver

java.io.IOException

getIDs

public java.util.Set getIDs()
                     throws java.io.IOException

Description copied from interface: Mediaserver

Get a set of the IDs of all entries in the Mediaserver database. Used in synchronization and pointer tracking.

Specified by:

getIDs in interface Mediaserver

java.io.IOException

getDatum

public MediaserverBlock getDatum(Mediaserver.Id id)
                          throws java.io.IOException

Description copied from interface: Mediaserver

Get the datum corresponding to the given id.

Specified by:

getDatum in interface Mediaserver

java.io.IOException

addDatum

public Mediaserver.Id addDatum(byte[] data,
                               java.lang.String contentType)
                        throws java.io.IOException

Creates a new block (to the fallback pool)

Specified by:

addDatum in interface Mediaserver

Returns:

The key of the new datum.

java.io.IOException

addDatum

public Mediaserver.Id addDatum(byte[] data,
                               java.lang.String contentType,
                               Mediaserver.Id assocId)
                        throws java.io.IOException

Creates a new block associated with some previous block. Association is used to determine which pools the block is saved to.

Specified by:

addDatum in interface Mediaserver

Returns:

The key of the new datum.

java.io.IOException

addDatum

public Mediaserver.Id addDatum(byte[] data,
                               java.util.Collection headerLines,
                               Mediaserver.Id assocId,
                               boolean addDefaultHeaders)
                        throws java.io.IOException

Description copied from interface: Mediaserver

Add a new datum, explicitly giving a collection of header lines.

Specified by:

addDatum in interface Mediaserver

Parameters:

assocId - May be null.

addDefaultHeaders - Whether to also add the default header lines: "Content-Transfer-Encoding: binary", "X-Injector: ...", and "Date: ...".

java.io.IOException

storeDatum

public void storeDatum(Mediaserver.Id id,
                       byte[] data)
                throws java.io.IOException

Description copied from interface: Mediaserver

Store an existing datum under a given ID.

Specified by:

storeDatum in interface Mediaserver

Parameters:

data - the pure data block obtained from another mediaserver, containing all header information etc.

java.io.IOException

expungeDatum

public void expungeDatum(Mediaserver.Id id)
                  throws java.io.IOException

Description copied from interface: Mediaserver

Permanently remove a block.

Specified by:

expungeDatum in interface Mediaserver

java.io.IOException

cache

public void cache(MediaserverBlock b)

Description copied from interface: Mediaserver

Cache a mediaserver block. The block must be from this mediaserver. This operation doesn't need to do anything, if this mediaserver does not support caching.

Specified by:

cache in interface Mediaserver

uncache

public void uncache(MediaserverBlock b)

Description copied from interface: Mediaserver

Uncache a mediaserver block. The block must be from this mediaserver. This operation doesn't need to do anything, if this mediaserver does not support caching. If the block wasn't in the cache, this should not issue an error message.

Specified by:

uncache in interface Mediaserver

getPointer

public Mediaserver.Id getPointer(java.lang.String s)
                          throws java.io.IOException

Description copied from interface: Mediaserver

(Kludge) Get a String-identified pointer local to this mediaserver. null if the pointer is not yet set.

Specified by:

getPointer in interface Mediaserver

java.io.IOException

See Also:

setPointer

getPointers

public java.util.Set getPointers()
                          throws java.io.IOException

Description copied from interface: Mediaserver

(Kludge) Get the names of all String-identified pointers local to this mediaserver. Needed for synching.

Specified by:

getPointers in interface Mediaserver

java.io.IOException

See Also:

getPointerSet

public PointerSet getPointerSet(java.lang.String s)
                         throws java.io.IOException

Specified by:

getPointerSet in interface Mediaserver

java.io.IOException

setPointer

public void setPointer(java.lang.String s,
                       Mediaserver.Id id)
                throws java.io.IOException

Description copied from interface: Mediaserver

(Kludge) Set a String-identified pointer local to this mediaserver. A pointer points to an ID. That way, the mediaserver can be used somewhat like a file system, in that there are references that can be updated. The system isn't very powerful, though, and needs to be rethought sometime soon.

XXX THIS EXPLANATION IS OUTDATED! Explain the new pointer system!

Specified by:

setPointer in interface Mediaserver

java.io.IOException

setPointer

public void setPointer(java.lang.String s,
                       Mediaserver.Id id,
                       Mediaserver.Id obsolete)
                throws java.io.IOException

Specified by:

setPointer in interface Mediaserver

java.io.IOException

setPointer

public void setPointer(java.lang.String s,
                       Mediaserver.Id id,
                       java.util.Set obsoletes)
                throws java.io.IOException

java.io.IOException

getDiffsFrom

public java.util.Set getDiffsFrom(Mediaserver.Id id)
                           throws java.io.IOException

Specified by:

getDiffsFrom in interface Mediaserver

java.io.IOException

getDiffsTo

public java.util.Set getDiffsTo(Mediaserver.Id id)
                         throws java.io.IOException

Specified by:

getDiffsTo in interface Mediaserver

java.io.IOException