org.apache.derby.impl.sql.catalog
Class OIDTDCacheable

java.lang.Object
  extended by org.apache.derby.impl.sql.catalog.TDCacheable
      extended by org.apache.derby.impl.sql.catalog.OIDTDCacheable
All Implemented Interfaces:
Cacheable

 class OIDTDCacheable
extends TDCacheable

This class implements a Cacheable for a DataDictionary cache of table descriptors, with the lookup key being the UUID of the table.


Field Summary
private  UUID identity
           
 
Fields inherited from class org.apache.derby.impl.sql.catalog.TDCacheable
dd, td
 
Constructor Summary
OIDTDCacheable(DataDictionaryImpl dd)
           
 
Method Summary
 void clearIdentity()
          Put the object into the No Identity state.
 Cacheable createIdentity(java.lang.Object key, java.lang.Object createParameter)
          Create a new item.
 java.lang.Object getIdentity()
          Get the identity of this object.
 Cacheable setIdentity(java.lang.Object key)
          Set the identity of the object.
 
Methods inherited from class org.apache.derby.impl.sql.catalog.TDCacheable
checkConsistency, clean, getTableDescriptor, isDirty
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

identity

private UUID identity
Constructor Detail

OIDTDCacheable

OIDTDCacheable(DataDictionaryImpl dd)
Method Detail

clearIdentity

public void clearIdentity()
Description copied from interface: Cacheable
Put the object into the No Identity state.
MT - single thread required - Method must only be called be cache manager and the cache manager will guarantee only one thread can be calling it.

See Also:
Cacheable.clearIdentity()

getIdentity

public java.lang.Object getIdentity()
Description copied from interface: Cacheable
Get the identity of this object.
MT - thread safe.

See Also:
Cacheable.getIdentity()

createIdentity

public Cacheable createIdentity(java.lang.Object key,
                                java.lang.Object createParameter)
Description copied from interface: Cacheable
Create a new item.

Create a new item and set the identity of the object to represent it. The object will be in the No Identity state, ie. it will have just been created or clearIdentity() was just called.
The object must copy the information out of key, not just store a reference to key if the key is not immutable. After this call the expression getIdentity().equals(key) must return true.

If the class of the object needs to change (e.g. to support a different format) then the object should create a new object, call its initParameter() with the parameters the original object was called with, set its identity and return a reference to it. The cache manager will discard the reference to the old object.
If an exception is thrown the object must be left in the no-identity state.
MT - single thread required - Method must only be called be cache manager and the cache manager will guarantee only one thread can be calling it.

Returns:
an object reference if the object can take on the identity, null otherwise.
See Also:
Cacheable.createIdentity(java.lang.Object, java.lang.Object)

setIdentity

public Cacheable setIdentity(java.lang.Object key)
                      throws StandardException
Description copied from interface: Cacheable
Set the identity of the object.

Set the identity of the object to represent an item that already exists, e.g. an existing container. The object will be in the No Identity state, ie. it will have just been created or clearIdentity() was just called.
The object must copy the information out of key, not just store a reference to key. After this call the expression getIdentity().equals(key) must return true.
If the class of the object needs to change (e.g. to support a different format) then the object should create a new object, call its initParameter() with the parameters the original object was called with, set its identity and return a reference to it. The cache manager will discard the reference to the old object.
If an exception is thrown the object must be left in the no-identity state.
MT - single thread required - Method must only be called be cache manager and the cache manager will guarantee only one thread can be calling it.

Returns:
an object reference if the object can take on the identity, null otherwise.
Throws:
StandardException - Thrown on error
See Also:
Cacheable.setIdentity(java.lang.Object)

Built on Thu 2010-12-23 20:49:13+0000, from revision ???

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