org.jlf.dataMap
Class CachedObject

java.lang.Object
  |
  +--org.jlf.dataMap.DataObject
        |
        +--org.jlf.dataMap.DataMappedObject
              |
              +--org.jlf.dataMap.CachedObject

All Implemented Interfaces:

java.io.Serializable

public class CachedObject

extends DataMappedObject

This class is used to cache DataMappedObject instances read from the default data source.

See Also:

DataMappedObject, Serialized Form

Field Summary

protected static java.lang.String	READ_ALL_CACHE_NAME The "read all" cache is a vector which holds ALL instances of the object, so they are kept in the correct order.
protected static java.lang.String	READ_ONE_CACHE_NAME The "read one" cache is used to cache individual instances of objects.

Fields inherited from class org.jlf.dataMap.DataMappedObject

DATA_LOCATION_KEY_PROPERTY_SUFFIX, DEFAULT_DATA_LOCATION_KEY, deleteOnWrite, FIND_ALL_CRITERIA_KEY, FIND_BY_PRIMARY_KEY_CRITERIA_KEY, hasBeenReadFromDataSource, HIERARCHY_HASHTABLE_VARIABLE_NAME, HIERARCHY_TABLE_KEY_VECTOR_VARIABLE_NAME, INITIAL_HIERARCHY_HASHTABLE_SIZE, INITIAL_HIERARCHY_TABLE_KEY_VECTOR_SIZE, INITIAL_RELATIONSHIP_DESCRIPTOR_HASHTABLE_SIZE, INITIAL_RELATIONSHIPS_HASHTABLE_SIZE, key, RELATIONSHIP_DESCRIPTOR_VECTOR_VARIABLE_NAME

Fields inherited from class org.jlf.dataMap.DataObject

ATTRIBUTE_DESCRIPTOR_VECTOR_VARIABLE_NAME, attributes, INITIAL_ATTRIBUTE_DESCRIPTOR_HASHTABLE_SIZE, INITIAL_ATTRIBUTE_HASHTABLE_SIZE

Constructor Summary

CachedObject()

Method Summary

protected void	addObjectsToReadOneCache(java.util.Vector dmos) Adds all elements of the vector into the read one cache.
protected void	addObjectToReadOneCache(DataMappedObject dmo) Adds one entry to the read one cache
java.util.Vector	findAll() Quick accessor method to read all of this particular object's type from the default data location.
DataMappedObject	findByPrimaryKey() Quick accessor method to read one object of this particular object's type from the default data location, using its already populated primary key.
protected DataMappedObject	findByPrimaryKeyFromCache() Tries to find an entry in the read one cache which matches the primary key of this object.
protected int	getCacheSizeAllocation() This method is used to size the cache so it is not too large (wasted cache entries) or small (cache has to grow at a performance hit).
protected java.util.Vector	getReadAllCache() Get the "read all" cache.
protected java.util.Hashtable	getReadOneCache() Get the "read one" cache.
protected void	setReadAllCache(java.util.Vector dmos) Sets all elements of the read all cache vector to the objects passed in the input vector.

Methods inherited from class org.jlf.dataMap.DataMappedObject

addRelatedObject, addRelatedObjects, areAllKeyAttributesPresent, areAllRequiredAttributesPresent, basicGetHierarchyTable, basicGetHierarchyTableKeyAttributes, basicGetKey, basicGetRelationshipDescriptors, cleanupAfterWrite, deleteOnWrite, findAll, findByPrimaryKey, findByRelationship, findManyBySearchCriteria, findManyBySearchCriteria, findOneBySearchCriteria, findOneBySearchCriteria, getAllRelationshipNames, getDataMapper, getDefaultDataLocationKey, getDefaultDataMapper, getDeletedRelatedObjects, getHierachyTableKeyForDataArray, getHierarchyTable, getHierarchyTableKeyAttributes, getKey, getNewInstance, getNewInstance, getNewInstance, getRelatedObject, getRelatedObjects, getRelationship, getRelationshipDescriptor, getRelationshipDescriptors, getUndeletedRelatedObjects, hasBeenReadFromDataSource, hasHierarchyTable, hasKey, newInstanceForDataArray, populateFromDataArray, populateKeyFromParentRelationship, preWriteValidation, processRelationshipsFromDataArray, setHasBeenReadFromDataSource, shouldDeleteOnWrite, validateRequiredAttributesPresent, write

Methods inherited from class org.jlf.dataMap.DataObject

attributeEquals, basicGetAttributeDescriptors, equals, getAllAttributeNames, getAttribute, getAttributeDescriptor, getAttributeDescriptors, getAttributeValue, getDoubleAttribute, getLongAttribute, getStringAttribute, hasAttributeDefined, hashCode, setAttributeValue, setDoubleAttribute, setLongAttribute, setStringAttribute

Methods inherited from class java.lang.Object

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

Field Detail

READ_ONE_CACHE_NAME

protected static java.lang.String READ_ONE_CACHE_NAME

The "read one" cache is used to cache individual instances of objects. It is a hashtable, so you can retrieve instances by their primary key pretty fast. This cache is used to speed up reads for one object given its primary key.

READ_ALL_CACHE_NAME

protected static java.lang.String READ_ALL_CACHE_NAME

The "read all" cache is a vector which holds ALL instances of the object, so they are kept in the correct order. Objects read here are also put in the read one cache, just in case. This cache is used to speed up read all queries.

Constructor Detail

CachedObject

public CachedObject()

Method Detail

getCacheSizeAllocation

protected int getCacheSizeAllocation()

This method is used to size the cache so it is not too large (wasted cache entries) or small (cache has to grow at a performance hit). The default is 100 entries, the normal default for vectors/hashtables.

getReadOneCache

protected java.util.Hashtable getReadOneCache()

Get the "read one" cache. If it is not it allocates one of the size specified by getCacheSizeAllocation().

Returns:

returns a hash table to be used for read-one type caching.

getReadAllCache

protected java.util.Vector getReadAllCache()

Get the "read all" cache. If it is not it allocates one of the size specified by getCacheSizeAllocation().

Returns:

returns a vector to be used for read-all type caching.

findByPrimaryKeyFromCache

protected DataMappedObject findByPrimaryKeyFromCache()

Tries to find an entry in the read one cache which matches the primary key of this object.

addObjectToReadOneCache

protected void addObjectToReadOneCache(DataMappedObject dmo)

Adds one entry to the read one cache

addObjectsToReadOneCache

protected void addObjectsToReadOneCache(java.util.Vector dmos)

Adds all elements of the vector into the read one cache.

setReadAllCache

protected void setReadAllCache(java.util.Vector dmos)

Sets all elements of the read all cache vector to the objects passed in the input vector.

findByPrimaryKey

public DataMappedObject findByPrimaryKey()

Quick accessor method to read one object of this particular object's type from the default data location, using its already populated primary key.

This method is an override of the superclass to additionally try to find the object in the "read one" cache first instead of going directly to the data source.

Overrides:

findByPrimaryKey in class DataMappedObject

findAll

public java.util.Vector findAll()

Quick accessor method to read all of this particular object's type from the default data location.

This method overrides the superclass to try and see if the cache is populated. If it is, it returns the cache. if not, it tries to populate the cache.

Overrides:

findAll in class DataMappedObject