wt.epm.util
Class EPMCache.VersionCache

java.lang.Object
  wt.epm.util.EPMCache.VersionCache

Enclosing class:

EPMCache

public static class EPMCache.VersionCache

extends Object

A Version Cache holds Iterated objects and indexes them using version keys. Given a version key it returns the object with the same branch identifier. If an object is not in its cache, the Version Cache will query it from the database and add it to its cache.

Field Summary

private HashMap

cache

Constructor Summary

EPMCache.VersionCache()
Constructs a VersionCache.

EPMCache.VersionCache(Collection objects)
Constructs a VersionCache adding the collection of Iterated objects to its cache.

Method Summary

void	add(Collection objects) Adds a collection of Iterated objects to the Version Cache.
void	add(Iterated object) Adds an Iterated object to the Version Cache.
boolean	contains(Iterated object) Returns true if the cache contains the given Iterated object.
boolean	contains(VersionForeignKey versionKey) Returns true if the cache contains the Iterated object with the given version key.
List	find(Collection versionKeys) Given a collection of version keys, returns the Iterated objects with the same branch identifiers.
private List	findObjects(Collection versionKeys) Given a collection of version keys, retrieves the Iterated objects with the same branch identifiers from the database.
Iterated	get(VersionForeignKey versionKey) Given an version key, returns the object with the same branch identifier provided the object is in the cache.
boolean	isEmpty() Returns true if this cache contains no objects.
Collection	objects() Returns an unmodifiable collection view of the objects in this cache.

Methods inherited from class java.lang.Object

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

Field Detail

cache

private HashMap cache

Constructor Detail

EPMCache.VersionCache

public EPMCache.VersionCache()

Constructs a VersionCache.

EPMCache.VersionCache

public EPMCache.VersionCache(Collection objects)
                      throws WTException

Constructs a VersionCache adding the collection of Iterated objects to its cache.

Method Detail

get

public Iterated get(VersionForeignKey versionKey)

Given an version key, returns the object with the same branch identifier provided the object is in the cache. If it is not, this method returns null.

add

public void add(Iterated object)
         throws WTException

Adds an Iterated object to the Version Cache.

Throws:

WTException

add

public void add(Collection objects)
         throws WTException

Adds a collection of Iterated objects to the Version Cache.

Throws:

WTException

find

public List find(Collection versionKeys)
          throws WTException

Given a collection of version keys, returns the Iterated objects with the same branch identifiers. If an object is not in its cache, the Version Cache will query it from the database and add it to its cache.

Throws:

WTException

objects

public Collection objects()

Returns an unmodifiable collection view of the objects in this cache.

isEmpty

public boolean isEmpty()

Returns true if this cache contains no objects.

contains

public boolean contains(Iterated object)
                 throws WTException

Returns true if the cache contains the given Iterated object.

Throws:

WTException

contains

public boolean contains(VersionForeignKey versionKey)

Returns true if the cache contains the Iterated object with the given version key.

findObjects

private List findObjects(Collection versionKeys)
                  throws WTException

Given a collection of version keys, retrieves the Iterated objects with the same branch identifiers from the database.

Throws:

WTException