|
|||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Objectorg.objectweb.medor.eval.lib.AbstractQueryEvaluator
org.objectweb.medor.eval.lib.SelectEvaluator
This class is a simple evaluator of query tree for data fetching. Its supports the data prefetching (loading additional data for next needs).
Field Summary | |
protected long |
cacheSize
The cache size for each node evaluator |
protected NodeEvaluatorFactory |
nodeEvaluatorFactory
The factory of node evaluator (QueryNode evaluator) |
protected java.util.Stack |
queryTreeStack
The query tree to evalued, stored as a stack |
Fields inherited from class org.objectweb.medor.eval.lib.AbstractQueryEvaluator |
query, wrapperFactory |
Constructor Summary | |
SelectEvaluator(QueryTree query,
long cacheSize)
|
Method Summary | |
TupleCollection |
evaluate(ParameterOperand[] parameters,
ConnectionResources resources,
java.util.Map evaluationMDMap)
First, it allocates a tree of Evaluator (Wrapper or NodeEvaluator) for the query tree associated to this evaluator. |
TupleCollection |
evaluate(ParameterOperand[] parameters,
ConnectionResources resources,
PrefetchBuffer prefetchBuffer,
java.util.Map evalMDMap)
Launch the evaluation of a query. |
long |
getCacheSize()
|
ConnectionResources |
getRequiredConnectionResources()
|
protected void |
toStack(QueryTree qt,
java.util.Stack pile)
|
Methods inherited from class org.objectweb.medor.eval.lib.AbstractQueryEvaluator |
getMemoryTupleCollection, getQueryTree, getWrapperFactory |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
protected NodeEvaluatorFactory nodeEvaluatorFactory
protected java.util.Stack queryTreeStack
protected long cacheSize
Constructor Detail |
public SelectEvaluator(QueryTree query, long cacheSize) throws EvaluationException
Method Detail |
protected void toStack(QueryTree qt, java.util.Stack pile) throws EvaluationException
EvaluationException
public ConnectionResources getRequiredConnectionResources()
public long getCacheSize()
public TupleCollection evaluate(ParameterOperand[] parameters, ConnectionResources resources, java.util.Map evaluationMDMap) throws EvaluationException
parameters
- is the array of parametersresources
- is the holder of connection used by the wrapper to
access the data support.evaluationMDMap
- contains a map associating an EvaluationMetaData object
to each of the query nodes of the query tree currently associated to the
QueryEvaluator.
EvaluationException
public TupleCollection evaluate(ParameterOperand[] parameters, ConnectionResources resources, PrefetchBuffer prefetchBuffer, java.util.Map evalMDMap) throws EvaluationException
QueryEvaluator
parameters
- is a ConnectionResources containing associations between the
DataStore names used in the QueryTree and the connection
objects to use for the evaluation.prefetchBuffer
- is the prefetchBuffer instance where buffer data must be put.
If this field is null, then no data prefetching mus be done.resources
- is a ConnectionResources containing associations between
the DataStore names used in the QueryTree and the connection objects to
use for the evaluation.It can be null.
EvaluationException
|
|||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |