org.modeshape.graph.query
Class QueryEngine

java.lang.Object
  org.modeshape.graph.query.QueryEngine

All Implemented Interfaces:

Queryable

@ThreadSafe
public class QueryEngine
extends Object
implements Queryable

A query engine that is able to execute formal queries expressed in the Graph API's Abstract Query Model.

Constructor Summary

QueryEngine(Planner planner, Optimizer optimizer, Processor processor)
Create a new query engine given the planner, optimizer, processor, and schemata.

Method Summary

protected QueryResultColumns	determineQueryResultColumns(PlanNode optimizedPlan, PlanHints hints)
QueryResults	execute(QueryContext context, QueryCommand query) Execute the supplied query by planning, optimizing, and then processing it.

Methods inherited from class java.lang.Object

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

Constructor Detail

QueryEngine

public QueryEngine(Planner planner,
                   Optimizer optimizer,
                   Processor processor)

Create a new query engine given the planner, optimizer, processor, and schemata.

Parameters:

planner - the planner that should be used to generate canonical query plans for the queries; may be null if the CanonicalPlanner should be used

optimizer - the optimizer that should be used to optimize the canonical query plan; may be null if the RuleBasedOptimizer should be used

processor - the processor implementation that should be used to process the planned query and return the results

Throws:

IllegalArgumentException - if the processor reference is null

Method Detail

execute

public QueryResults execute(QueryContext context,
                            QueryCommand query)

Execute the supplied query by planning, optimizing, and then processing it.

Specified by:

execute in interface Queryable

Parameters:

context - the context in which the query should be executed

query - the query that is to be executed

Returns:

the query results; never null

See Also:

Queryable.execute(org.modeshape.graph.query.QueryContext, org.modeshape.graph.query.model.QueryCommand)

determineQueryResultColumns

protected QueryResultColumns determineQueryResultColumns(PlanNode optimizedPlan,
                                                         PlanHints hints)