org.objectweb.cjdbc.controller.cache
Class QueryCacheEntry

java.lang.Object
  org.objectweb.cjdbc.controller.cache.QueryCacheEntry

public class QueryCacheEntry

extends java.lang.Object

A CacheEntry represents a SQL select request with its reponse. The cache entry can have 3 states:

• CACHE_VALID when it is valid
• CACHE_DIRTY when the result has been marked dirty (may be invalid)
• CACHE_INVALID when there is no result (request has to be re-issued to the database)

Version:

1.0

Author:

Emmanuel Cecchet

Field Summary

private static int	CACHE_DIRTY
private static int	CACHE_INVALID
private static int	CACHE_VALID
private QueryCacheEntry	next
private QueryCacheEntry	prev
private SelectRequest	request
private java.sql.ResultSet	result
private int	state

Constructor Summary

QueryCacheEntry(SelectRequest request, java.sql.ResultSet result)
Creates a new CacheEntry instance.

Method Summary

QueryCacheEntry	getNext() Gets the value of next QueryCacheEntry in LRU.
QueryCacheEntry	getPrev() Gets the value of previous QueryCacheEntry in LRU.
SelectRequest	getRequest() Returns the SELECT request of this cache entry.
java.sql.ResultSet	getResult() Returns the ResultSet of the cached select request
void	invalidate() Invalidates this cache entry (removes the ResultSet and turn state to CACHE_INVALID).
boolean	isDirty() Returns true if cache entry state is marked dirty (state is CACHE_DIRTY).
boolean	isValid() Return true if cache entry state is valid (state is CACHE_VALID).
void	markDirty() Marks this entry dirty (state becomes CACHE_DIRTY).
void	setNext(QueryCacheEntry next) Sets the value of next QueryCacheEntry in LRU.
void	setPrev(QueryCacheEntry prev) Sets the value of previous QueryCacheEntry in LRU.
void	setResult(java.sql.ResultSet result) Set a new ResultSet of the cached select request (cache update).
void	setValid() Marks this entry valid (state becomes CACHE_VALID).

Methods inherited from class java.lang.Object

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

Field Detail

request

private SelectRequest request

result

private java.sql.ResultSet result

state

private int state

next

private QueryCacheEntry next

prev

private QueryCacheEntry prev

CACHE_VALID

private static final int CACHE_VALID

See Also:

Constant Field Values

CACHE_DIRTY

private static final int CACHE_DIRTY

See Also:

Constant Field Values

CACHE_INVALID

private static final int CACHE_INVALID

See Also:

Constant Field Values

Constructor Detail

QueryCacheEntry

public QueryCacheEntry(SelectRequest request,
                       java.sql.ResultSet result)

Creates a new CacheEntry instance.

Parameters:

request - a SelectRequest value

result - a ResultSet value

Method Detail

isValid

public boolean isValid()

Return true if cache entry state is valid (state is CACHE_VALID).

Returns:

a boolean value

isDirty

public boolean isDirty()

Returns true if cache entry state is marked dirty (state is CACHE_DIRTY).

Returns:

a boolean value

getRequest

public SelectRequest getRequest()

Returns the SELECT request of this cache entry.

Returns:

a SelectRequest value

getResult

public java.sql.ResultSet getResult()

Returns the ResultSet of the cached select request

Returns:

a ResultSet value

setResult

public void setResult(java.sql.ResultSet result)

Set a new ResultSet of the cached select request (cache update).

The cache state is automatically set to valid (CACHE_VALID).

Parameters:

result - a ResultSet value

invalidate

public void invalidate()

Invalidates this cache entry (removes the ResultSet and turn state to CACHE_INVALID).

markDirty

public void markDirty()

Marks this entry dirty (state becomes CACHE_DIRTY).

The ResultSet if not affected by this method.

setValid

public void setValid()

Marks this entry valid (state becomes CACHE_VALID).

getNext

public QueryCacheEntry getNext()

Gets the value of next QueryCacheEntry in LRU.

Returns:

value of next.

setNext

public void setNext(QueryCacheEntry next)

Sets the value of next QueryCacheEntry in LRU.

Parameters:

next - value to assign to next.

getPrev

public QueryCacheEntry getPrev()

Gets the value of previous QueryCacheEntry in LRU.

Returns:

value of previous.

setPrev

public void setPrev(QueryCacheEntry prev)

Sets the value of previous QueryCacheEntry in LRU.

Parameters:

prev - value to assign to prev.