org.apache.derby.impl.sql.catalog
Class NameTDCacheable
java.lang.Object
org.apache.derby.impl.sql.catalog.TDCacheable
org.apache.derby.impl.sql.catalog.NameTDCacheable
- All Implemented Interfaces:
- Cacheable
- class NameTDCacheable
- extends TDCacheable
This class implements a Cacheable for a DataDictionary cache of
table descriptors, with the lookup key being the name of the table.
Assumes client passes in a string that includes the schema name.
Method Summary |
protected boolean |
checkConsistency(TableDescriptor uncachedTD,
java.lang.Object identity,
HeaderPrintWriter reportInconsistent)
Check the consistency of the table descriptor held by this TDCacheable
versus an uncached table descriptor. |
void |
clean(boolean forRemove)
Clean the object.
|
void |
clearIdentity()
Put the object into the No Identity state.
|
Cacheable |
createIdentity(java.lang.Object key,
java.lang.Object createParameter)
Create a new item and set the identity of the object to represent it.
|
java.lang.Object |
getIdentity()
Get the identity of this object.
|
TableDescriptor |
getTableDescriptor()
Get the table descriptor that is associated with this Cacheable |
boolean |
isDirty()
Returns true of the object is dirty.
|
Cacheable |
setIdentity(java.lang.Object key)
Set the identity of the object to represent an item that already exists,
e.g. an existing container.
|
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
identity
private TableKey identity
td
protected TableDescriptor td
dd
protected final DataDictionaryImpl dd
NameTDCacheable
NameTDCacheable(DataDictionaryImpl dd)
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 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 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)
clean
public void clean(boolean forRemove)
- Description copied from interface:
Cacheable
- Clean the object.
It is up to the object to ensure synchronization of the isDirty()
and clean() method calls.
If forRemove is true then the
object is being removed due to an explict remove request, in this case
the cache manager will have called this method regardless of the
state of the isDirty()
If an exception is thrown the object must be left in the clean state.
MT - thread safe - Can be called at any time by the cache manager, it is the
responsibility of the object implementing Cacheable to ensure any users of the
object do not conflict with the clean call.
- Specified by:
clean
in interface Cacheable
- See Also:
Cacheable.clean(boolean)
isDirty
public boolean isDirty()
- Description copied from interface:
Cacheable
- Returns true of the object is dirty.
May be called when the object is kept or unkept.
MT - thread safe
- Specified by:
isDirty
in interface Cacheable
- See Also:
Cacheable.isDirty()
getTableDescriptor
public TableDescriptor getTableDescriptor()
- Get the table descriptor that is associated with this Cacheable
checkConsistency
protected boolean checkConsistency(TableDescriptor uncachedTD,
java.lang.Object identity,
HeaderPrintWriter reportInconsistent)
throws StandardException
- Check the consistency of the table descriptor held by this TDCacheable
versus an uncached table descriptor.
- Parameters:
uncachedTD
- The uncached descriptor to compare toidentity
- The identity of the table descriptorreportInconsistent
- A HeaderPrintWriter to send complaints to
- Returns:
- true if the descriptors are the same, false if they're different
- Throws:
StandardException
- Thrown on error
Apache Derby V10.0 Engine Documentation - Copyright © 1997,2004 The Apache Software Foundation or its licensors, as applicable.