org.modeshape.jcr.query.QueryContext Maven / Gradle / Ivy
/*
* ModeShape (http://www.modeshape.org)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.modeshape.jcr.query;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicLong;
import org.infinispan.schematic.internal.HashCode;
import org.modeshape.common.annotation.ThreadSafe;
import org.modeshape.common.collection.Problems;
import org.modeshape.common.collection.SimpleProblems;
import org.modeshape.common.util.CheckArg;
import org.modeshape.jcr.ExecutionContext;
import org.modeshape.jcr.NodeTypes;
import org.modeshape.jcr.RepositoryIndexes;
import org.modeshape.jcr.cache.NodeCache;
import org.modeshape.jcr.cache.RepositoryCache;
import org.modeshape.jcr.cache.WorkspaceNotFoundException;
import org.modeshape.jcr.query.model.BindVariableName;
import org.modeshape.jcr.query.model.TypeSystem;
import org.modeshape.jcr.query.plan.PlanHints;
import org.modeshape.jcr.query.validate.Schemata;
import org.modeshape.jcr.value.NamespaceRegistry;
/**
* An immutable context in which queries are to be executed. Each query context defines the information that is available during
* query execution.
*
* The only mutable state on this context is whether the query has been {@link #cancel() cancelled}.
*
*/
@ThreadSafe
public class QueryContext {
protected static final AtomicLong QUERY_COUNTER = new AtomicLong();
protected final ExecutionContext context;
protected final RepositoryCache repositoryCache;
protected final TypeSystem typeSystem;
protected final PlanHints hints;
protected final NodeTypes nodeTypes;
protected final Schemata schemata;
protected final RepositoryIndexes indexDefns;
protected final Problems problems;
protected final Map variables;
protected final Set workspaceNames;
protected final Map overriddenNodeCachesByWorkspaceName;
protected final BufferManager bufferManager;
private final long id;
private final AtomicBoolean cancelled = new AtomicBoolean(false);
/**
* Create a new context for query execution.
*
* @param context the context in which the query is being executed; may not be null
* @param repositoryCache the repository cache that should be used to load results; may be null if no results are to be loaded
* @param workspaceNames the name of each workspace to be queried, or an empty set if all the workspaces should be queried;
* may not be null
* @param overriddenNodeCachesByWorkspaceName the NodeCache instances that should be used to load results, which will be used
* instead of the RepositoryCache's NodeCache for a given workspace name; may be null or empty
* @param schemata the schemata
* @param indexDefns the definitions for the currently-defined indexes; never null
* @param nodeTypes the snapshot of the node types; may not be null
* @param bufferManager the buffer manager; may not be null
* @param hints the hints, or null if there are no hints
* @param problems the problems container, or null if a new problems container should be created
* @param variables the mapping of variables and values, or null if there are no such variables
* @param id the identifier for this query context
* @throws IllegalArgumentException if the context, workspace name, or schemata are null
*/
protected QueryContext( ExecutionContext context,
RepositoryCache repositoryCache,
Set workspaceNames,
Map overriddenNodeCachesByWorkspaceName,
Schemata schemata,
RepositoryIndexes indexDefns,
NodeTypes nodeTypes,
BufferManager bufferManager,
PlanHints hints,
Problems problems,
Map variables,
long id ) {
CheckArg.isNotNull(context, "context");
CheckArg.isNotNull(workspaceNames, "workspaceNames");
CheckArg.isNotNull(schemata, "schemata");
CheckArg.isNotNull(indexDefns, "indexDefns");
CheckArg.isNotNull(nodeTypes, "nodeTypes");
CheckArg.isNotNull(bufferManager, "bufferManager");
this.context = context;
this.repositoryCache = repositoryCache;
this.workspaceNames = workspaceNames;
this.typeSystem = context.getValueFactories().getTypeSystem();
this.hints = hints != null ? hints : new PlanHints();
this.indexDefns = indexDefns;
this.schemata = schemata;
this.nodeTypes = nodeTypes;
this.problems = problems != null ? problems : new SimpleProblems();
this.variables = variables != null ? new HashMap(variables) : new HashMap();
this.overriddenNodeCachesByWorkspaceName = overriddenNodeCachesByWorkspaceName != null ? overriddenNodeCachesByWorkspaceName : Collections.emptyMap();
this.bufferManager = bufferManager;
this.id = id;
assert this.typeSystem != null;
assert this.hints != null;
assert this.schemata != null;
assert this.problems != null;
assert this.variables != null;
assert this.workspaceNames != null;
}
/**
* Create a new context for query execution.
*
* @param context the context in which the query is being executed; may not be null
* @param repositoryCache the repository cache that should be used to load results; may be null if no results are to be loaded
* @param workspaceNames the name of each workspace to be queried, or an empty set if all the workspaces should be queried;
* may not be null
* @param overriddenNodeCachesByWorkspaceName the NodeCache instances that should be used to load results, which will be used
* instead of the RepositoryCache's NodeCache for a given workspace name; may be null or empty
* @param schemata the schemata
* @param indexDefns the definitions for the currently-defined indexes; never null
* @param nodeTypes the snapshot of the node types; may not be null
* @param bufferManager the buffer manager; may not be null
* @param hints the hints, or null if there are no hints
* @param problems the problems container, or null if a new problems container should be created
* @param variables the mapping of variables and values, or null if there are no such variables
* @throws IllegalArgumentException if the context, workspace name, or schemata are null
*/
public QueryContext( ExecutionContext context,
RepositoryCache repositoryCache,
Set workspaceNames,
Map overriddenNodeCachesByWorkspaceName,
Schemata schemata,
RepositoryIndexes indexDefns,
NodeTypes nodeTypes,
BufferManager bufferManager,
PlanHints hints,
Problems problems,
Map variables ) {
this(context, repositoryCache, workspaceNames, overriddenNodeCachesByWorkspaceName, schemata, indexDefns, nodeTypes,
bufferManager, hints, problems, variables, QUERY_COUNTER.incrementAndGet());
}
/**
* Create a new context for query execution.
*
* @param context the context in which the query is being executed; may not be null
* @param repositoryCache the repository cache that should be used to load results; may not be null
* @param workspaceNames the name of each workspace to be queried, or an empty set if all the workspaces should be queried;
* may not be null
* @param schemata the schemata
* @param indexDefns the definitions for the currently-defined indexes; never null
* @param nodeTypes the snapshot of the node types; may not be null
* @param bufferManager the buffer manager; may not be null
* @param hints the hints, or null if there are no hints
* @param problems the problems container, or null if a new problems container should be created
* @throws IllegalArgumentException if the context, workspace name, or schemata are null
*/
public QueryContext( ExecutionContext context,
RepositoryCache repositoryCache,
Set workspaceNames,
Schemata schemata,
RepositoryIndexes indexDefns,
NodeTypes nodeTypes,
BufferManager bufferManager,
PlanHints hints,
Problems problems ) {
this(context, repositoryCache, workspaceNames, null, schemata, indexDefns, nodeTypes, bufferManager, hints, problems,
null);
}
/**
* Create a new context for query execution.
*
* @param context the context in which the query is being executed; may not be null
* @param repositoryCache the repository cache that should be used to load results; may not be null
* @param workspaceNames the name of each workspace to be queried, or an empty set if all the workspaces should be queried;
* may not be null
* @param schemata the schemata
* @param indexDefns the definitions for the currently-defined indexes; never null
* @param nodeTypes the snapshot of the node types; may not be null
* @param bufferManager the buffer manager; may not be null
* @throws IllegalArgumentException if the context, workspace name, or schemata are null
*/
public QueryContext( ExecutionContext context,
RepositoryCache repositoryCache,
Set workspaceNames,
Schemata schemata,
RepositoryIndexes indexDefns,
NodeTypes nodeTypes,
BufferManager bufferManager ) {
this(context, repositoryCache, workspaceNames, null, schemata, indexDefns, nodeTypes, bufferManager, null, null, null);
}
/**
* Create a new context that is a copy of the supplied context. This constructor is useful for subclasses that wish to add
* store additional fields in a QueryContext.
*
* @param original the original context
* @throws IllegalArgumentException if the original is null
*/
protected QueryContext( QueryContext original ) {
this(original.context, original.repositoryCache, original.workspaceNames, original.overriddenNodeCachesByWorkspaceName,
original.schemata, original.indexDefns, original.nodeTypes, original.bufferManager, original.hints,
original.problems, original.variables, original.id);
}
/**
* Cancel the query if it is currently running. Note that this method does not block until the query is cancelled; it merely
* marks the query as being cancelled, and the query will terminate at its next available opportunity.
*
* @return true if the query was executing and will be cancelled, or false if the query was no longer running (because it had
* finished successfully or had already been cancelled) and could not be cancelled.
*/
public final boolean cancel() {
return this.cancelled.compareAndSet(false, true);
}
public final boolean isCancelled() {
return this.cancelled.get();
}
/**
* Get the local identifier used within the query engine to identify a query context. These identifiers are neither durable
* nor guaranteed to be unique over extended periods of time.
*
* @return the identifier
*/
public final long id() {
return id;
}
/**
* Get the NodeCache for the given workspace name. The result will either be the overridden value supplied in the constructor
* or the workspace cache from the referenced RepositoryCache.
*
* @param workspaceName the name of the workspace
* @return the node cache; never null
* @throws WorkspaceNotFoundException if there is no workspace with the supplied name
*/
public NodeCache getNodeCache( String workspaceName ) throws WorkspaceNotFoundException {
NodeCache cache = overriddenNodeCachesByWorkspaceName.get(workspaceName);
if (cache == null) {
cache = repositoryCache.getWorkspaceCache(workspaceName);
}
return cache;
}
/**
* Get the namespace registry with durable prefixes as used by the query indexes.
*
* @return the durable namespace registry; never null
*/
public NamespaceRegistry getNamespaceRegistry() {
// TODO: Durable namespace registry
return context.getNamespaceRegistry();
}
/**
* Get the RepositoryCache instance that should be used to load the result tuple values.
*
* @return the node cache
*/
public RepositoryCache getRepositoryCache() {
return repositoryCache;
}
/**
* Get the current index definitions.
*
* @return the immutable index definitions; never null
*/
public RepositoryIndexes getIndexDefinitions() {
return indexDefns;
}
/**
* Get the execution context in which the query is to be evaluated
*
* @return the execution context; never null
*/
public ExecutionContext getExecutionContext() {
return context;
}
/**
* Get the names of each workspace that is to be queried.
*
* @return the workspace name; never null
*/
public Set getWorkspaceNames() {
return workspaceNames;
}
/**
* Get the interface for working with literal values and types.
*
* @return the type system; never null
*/
public TypeSystem getTypeSystem() {
return typeSystem;
}
/**
* Get the plan hints.
*
* @return the plan hints; never null
*/
public final PlanHints getHints() {
return hints;
}
/**
* Get the problem container used by this query context. Any problems that have been encountered will be accumlated in this
* container.
*
* @return the problem container; never null
*/
public final Problems getProblems() {
return problems;
}
/**
* Get the definition of the tables available within this query context.
*
* @return the schemata; never null
*/
public Schemata getSchemata() {
return schemata;
}
/**
* Get an immutable snapshot of the node types.
*
* @return the node types; never null
*/
public NodeTypes getNodeTypes() {
return nodeTypes;
}
public BufferManager getBufferManager() {
return bufferManager;
}
/**
* Get the variables that are to be substituted into the {@link BindVariableName} used in the query.
*
* @return immutable map of variable values keyed by their name; never null but possibly empty
*/
public Map getVariables() {
return variables;
}
@Override
public int hashCode() {
return HashCode.compute(this.typeSystem, this.schemata, this.variables);
}
/**
* {@inheritDoc}
*
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals( Object obj ) {
if (obj == this) return true;
if (obj instanceof QueryContext) {
QueryContext that = (QueryContext)obj;
if (!this.typeSystem.equals(that.getTypeSystem())) return false;
if (!this.schemata.equals(that.getSchemata())) return false;
if (!this.variables.equals(that.getVariables())) return false;
return true;
}
return false;
}
/**
* Obtain a copy of this context, except that the copy uses the supplied schemata.
*
* @param schemata the schemata that should be used in the new context
* @return the new context; never null
* @throws IllegalArgumentException if the schemata reference is null
*/
public QueryContext with( Schemata schemata ) {
CheckArg.isNotNull(schemata, "schemata");
return new QueryContext(context, repositoryCache, workspaceNames, overriddenNodeCachesByWorkspaceName, schemata,
indexDefns, nodeTypes, bufferManager, hints, problems, variables);
}
/**
* Obtain a copy of this context, except that the copy uses the supplied hints.
*
* @param hints the hints that should be used in the new context
* @return the new context; never null
* @throws IllegalArgumentException if the hints reference is null
*/
public QueryContext with( PlanHints hints ) {
CheckArg.isNotNull(hints, "hints");
return new QueryContext(context, repositoryCache, workspaceNames, overriddenNodeCachesByWorkspaceName, schemata,
indexDefns, nodeTypes, bufferManager, hints, problems, variables);
}
/**
* Obtain a copy of this context, except that the copy uses the supplied problem container.
*
* @param problems the problems that should be used in the new context; may be null if a new problem container should be used
* @return the new context; never null
*/
public QueryContext with( Problems problems ) {
return new QueryContext(context, repositoryCache, workspaceNames, overriddenNodeCachesByWorkspaceName, schemata,
indexDefns, nodeTypes, bufferManager, hints, problems, variables);
}
/**
* Obtain a copy of this context, except that the copy uses the supplied variables.
*
* @param variables the variables that should be used in the new context; may be null if there are no such variables
* @return the new context; never null
*/
public QueryContext with( Map variables ) {
return new QueryContext(context, repositoryCache, workspaceNames, overriddenNodeCachesByWorkspaceName, schemata,
indexDefns, nodeTypes, bufferManager, hints, problems, variables);
}
}
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