org.semanticdesktop.aperture.accessor.base
Class FilterAccessData

java.lang.Object
  org.semanticdesktop.aperture.accessor.base.FilterAccessData

All Implemented Interfaces:

AccessData

public abstract class FilterAccessData
extends Object
implements AccessData

Abstract superclass for AccessData implementations that wrap other AccessData instances in order to filter certain information. The abstract class FilterAccessData itself provides default methods that pass requests to the contained AccessData. Subclasses of FilterAccessData should override some of these methods and may also provide additional methods and fields.

Field Summary

Fields inherited from interface org.semanticdesktop.aperture.accessor.AccessData

BYTE_SIZE_KEY, DATE_KEY, REDIRECTS_TO_KEY

Constructor Summary

FilterAccessData(AccessData accessData)

Method Summary

void	clear() Clears this AccessData.
String	get(String id, String key) Gets specific information about the specified id.
AccessData	getAccessData()
Set	getAggregatedIDs(String id) Returns a set of id's that are aggregated immediately below the given one.
ClosableIterator	getAggregatedIDsClosure(String id) Returns an iterator over all ids aggregated within the given one, both directly and indirectly.
Set	getReferredIDs(String id) Returns all referred resources of the specified resource.
int	getSize() Gets the number of resources for which information has been stored in this AccessData.
Set	getStoredIDs() Gets the IDs of all resources for which information has been stored in this AccessData.
ClosableIterator	getUntouchedIDsIterator() Returns an iterator over all ID's in this access data instance that have not been touched since the last call to AccessData.initialize()
void	initialize() Prepares the AccessData for operation.
boolean	isKnownId(String id) Returns whether this AccessData holds any information about the specified ID.
boolean	isTouched(String id) Returns true if this id is known and has been touched since the last call to AccessData.initialize(), false if the id is not known, or hasn't been touched since the last call to AccessData.initialize().
void	put(String id, String key, String value) Stores information (a key-value pair) for the specified id.
void	putAggregatedID(String id, String aggregatedID) Puts a link between the given id and the aggregated ID.
void	putReferredID(String id, String referredID) Stores a reference relation between two resources, modeling e.g. a link.
void	remove(String id) Removes all information about the resource with the specified ID.
void	remove(String id, String key) Removes the value for the specified id and key.
void	removeAggregatedID(String id, String aggregatedID) Removes the link between the given id and the aggregated ID.
void	removeReferredID(String id, String referredID) Removes a reference relationship between two resources.
void	removeReferredIDs(String id) Removes all referred IDs of a resource.
void	removeUntouchedIDs() Removes all untouched IDS
void	store() Informs the AccessData that processing has completed and, in case of a persistent storage, now is a good time to write or flush results.
void	touch(String id) Touches an id.
void	touchRecursively(String id) Recursively touches all ids within the aggregation subtree beginning with the given id

Methods inherited from class java.lang.Object

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

Constructor Detail

FilterAccessData

public FilterAccessData(AccessData accessData)

Method Detail

getAccessData

public AccessData getAccessData()

clear

public void clear()
           throws IOException

Description copied from interface: AccessData

Clears this AccessData. This may be invoked on initialized and unititialized AccessData's. Both in-memory information as any persistent storage will be cleared. Afterwards the AccessData may be in an unusable state until 'initialize' is invoked again.

Specified by:

clear in interface AccessData

Throws:

IOException

get

public String get(String id,
                  String key)

Description copied from interface: AccessData

Gets specific information about the specified id.

Specified by:

get in interface AccessData

Parameters:

id - The resource's ID.

key - The info key.

Returns:

The stored info value, or null if no info has been stored for the specified id and key.

getReferredIDs

public Set getReferredIDs(String id)

Description copied from interface: AccessData

Returns all referred resources of the specified resource.

Specified by:

getReferredIDs in interface AccessData

Returns:

A Set of Strings, or null when there are no referred resources registered for this resource.

getSize

public int getSize()

Description copied from interface: AccessData

Gets the number of resources for which information has been stored in this AccessData.

Specified by:

getSize in interface AccessData

Returns:

The number of registered resources.

getStoredIDs

public Set getStoredIDs()

Description copied from interface: AccessData

Gets the IDs of all resources for which information has been stored in this AccessData.

Specified by:

getStoredIDs in interface AccessData

Returns:

A Set of Strings.

initialize

public void initialize()
                throws IOException

Description copied from interface: AccessData

Prepares the AccessData for operation. This may for example mean reading files or opening repositories that hold the stored data.

Specified by:

initialize in interface AccessData

Throws:

IOException

isKnownId

public boolean isKnownId(String id)

Description copied from interface: AccessData

Returns whether this AccessData holds any information about the specified ID.

Specified by:

isKnownId in interface AccessData

Returns:

"true" when this AccessData has information about the specified ID, "false" otherwise.

put

public void put(String id,
                String key,
                String value)

Description copied from interface: AccessData

Stores information (a key-value pair) for the specified id.

Specified by:

put in interface AccessData

Parameters:

id - The resource's ID.

key - The info key.

value - The info value.

putReferredID

public void putReferredID(String id,
                          String referredID)

Description copied from interface: AccessData

Stores a reference relation between two resources, modeling e.g. a link.

Specified by:

putReferredID in interface AccessData

Parameters:

id - The referring resource's ID.

referredID - The referred resource's ID.

remove

public void remove(String id,
                   String key)

Description copied from interface: AccessData

Removes the value for the specified id and key.

Specified by:

remove in interface AccessData

Parameters:

id - A resource ID.

key - A key under which info is stored.

remove

public void remove(String id)

Description copied from interface: AccessData

Removes all information about the resource with the specified ID.

Specifically:

• Remove all keys and values pertaining to that ID
• Remove all links between this id and all id's it refers to
• Remove the aggregation link "upwards" to the parent id
• Remove recursively all aggregated id's

Note that this method does NOT remove ids this id is referred BY. I.e. it does remove "outgoing" referredID links but it does NOT remove "incomming" referred ID's. To be on the safe side - the crawler should take care about this by itself.

Specified by:

remove in interface AccessData

Parameters:

id - A resource ID.

removeReferredID

public void removeReferredID(String id,
                             String referredID)

Description copied from interface: AccessData

Removes a reference relationship between two resources.

Specified by:

removeReferredID in interface AccessData

Parameters:

id - The referring resource's ID.

referredID - The referred resource's ID.

removeReferredIDs

public void removeReferredIDs(String id)

Description copied from interface: AccessData

Removes all referred IDs of a resource.

Specified by:

removeReferredIDs in interface AccessData

Parameters:

id - The referring resource's ID.

store

public void store()
           throws IOException

Description copied from interface: AccessData

Informs the AccessData that processing has completed and, in case of a persistent storage, now is a good time to write or flush results. Afterwards the AccessData may be in an unusable state until 'initialize' is invoked again.

Specified by:

store in interface AccessData

Throws:

IOException

getAggregatedIDs

public Set getAggregatedIDs(String id)

Description copied from interface: AccessData

Returns a set of id's that are aggregated immediately below the given one.

Specified by:

getAggregatedIDs in interface AccessData

Returns:

a set of id's that are aggregated immediately below the given one.

See Also:

AccessData.getAggregatedIDs(java.lang.String)

getAggregatedIDsClosure

public ClosableIterator getAggregatedIDsClosure(String id)

Description copied from interface: AccessData

Returns an iterator over all ids aggregated within the given one, both directly and indirectly. The iterator will traverse the entire aggregation subtree beginning with the given id.

Specified by:

getAggregatedIDsClosure in interface AccessData

Parameters:

id - the id whose aggregation subtree is to be traversed

Returns:

an iterator over the aggregation subtree

See Also:

AccessData.getAggregatedIDsClosure(java.lang.String)

getUntouchedIDsIterator

public ClosableIterator getUntouchedIDsIterator()

Description copied from interface: AccessData

Returns an iterator over all ID's in this access data instance that have not been touched since the last call to AccessData.initialize()

Specified by:

getUntouchedIDsIterator in interface AccessData

Returns:

an iterator over all untouched IDs

See Also:

AccessData.getUntouchedIDsIterator()

putAggregatedID

public void putAggregatedID(String id,
                            String aggregatedID)

Description copied from interface: AccessData

Puts a link between the given id and the aggregated ID. The aggregated ID will appear in the aggregation closure (returned by AccessData.getAggregatedIDsClosure(String)), will be touched by the AccessData.touchRecursively(String) method, it will be removed if the id is removed (@link AccessData.remove(String)). Note that the aggregation graph must not contain cycles, each id can have at most one parent, the implementations are expected to enforce this. If the aggregatedID had a parent before, the previous link will be removed.

Specified by:

putAggregatedID in interface AccessData

Parameters:

id - the parent id

aggregatedID - the aggregated id

See Also:

AccessData.putAggregatedID(java.lang.String, java.lang.String)

removeAggregatedID

public void removeAggregatedID(String id,
                               String aggregatedID)

Description copied from interface: AccessData

Removes the link between the given id and the aggregated ID. After a call to this method, the aggregated ID will not appear in the aggregation closure (AccessData.getAggregatedIDsClosure(String) and will not be touched by the AccessData.touchRecursively(String) method. A call to remove the id will not remove the aggregated id.

Specified by:

removeAggregatedID in interface AccessData

See Also:

AccessData.removeAggregatedID(java.lang.String, java.lang.String)

removeUntouchedIDs

public void removeUntouchedIDs()

Description copied from interface: AccessData

Removes all untouched IDS

Specified by:

removeUntouchedIDs in interface AccessData

See Also:

AccessData.removeUntouchedIDs()

touchRecursively

public void touchRecursively(String id)

Description copied from interface: AccessData

Recursively touches all ids within the aggregation subtree beginning with the given id

Specified by:

touchRecursively in interface AccessData

See Also:

AccessData.touchRecursively(java.lang.String)

isTouched

public boolean isTouched(String id)

Description copied from interface: AccessData

Returns true if this id is known and has been touched since the last call to AccessData.initialize(), false if the id is not known, or hasn't been touched since the last call to AccessData.initialize().

Specified by:

isTouched in interface AccessData

Parameters:

id - the id to check

Returns:

true if the id has been touched, false if not

See Also:

AccessData.isTouched(java.lang.String)

touch

public void touch(String id)

Description copied from interface: AccessData

Touches an id. This id will not appear on the list returned by AccessData.getUntouchedIDsIterator() and will not be removed by AccessData.removeUntouchedIDs()

Specified by:

touch in interface AccessData

See Also:

AccessData.touch(java.lang.String)