1 /*******************************************************************************
2 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
4 * All rights reserved. This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License v1.0
6 * which accompanies this distribution, and is available at
7 * http://www.eclipse.org/legal/epl-v10.html
10 * VTT Technical Research Centre of Finland - initial API and implementation
11 *******************************************************************************/
12 package org.simantics.db.service;
14 import java.util.Collection;
16 import org.simantics.db.AsyncReadGraph;
17 import org.simantics.db.ReadGraph;
18 import org.simantics.db.Resource;
19 import org.simantics.db.WriteGraph;
20 import org.simantics.db.procedure.AsyncContextMultiProcedure;
21 import org.simantics.db.procedure.AsyncMultiProcedure;
22 import org.simantics.db.request.ExternalRead;
26 * @author Antti Villberg
28 public interface QueryControl {
30 interface ControlProcedure {
31 void execute(AsyncReadGraph graph);
36 * @return current amount of queries
41 * @return The amount of fixed queries after best effort flush
44 int flush(ReadGraph graph);
48 * @param allowedTimeInMs The amount of allowed time use in ms.
50 void gc(ReadGraph graph, int allowedTimeInMs);
53 * Collects all external read requests and their parent queries that are no
54 * longer listened to. Needs to perform exclusive locking of the database
55 * client internally so do not invoke this from within a graph read or write
56 * request but use {@link #gc(WriteGraph, Collection)} instead.
60 void gc(Collection<ExternalRead<?>> reads);
63 * Collects all external read requests and their parent queries that are no
64 * longer listened to. The write graph argument is used to ensure that the
65 * invocation is performed from within a write request with exclusive
68 * @param graph write request handle
69 * @param reads the external read requests to attempt garbage collection for
71 void gc(WriteGraph graph, Collection<ExternalRead<?>> reads);
73 int getAmountOfQueryThreads();
75 int getGraphThread(AsyncReadGraph graph);
77 boolean resume(AsyncReadGraph graph);
79 void schedule(AsyncReadGraph graph, int targetThread, ControlProcedure procedure);
81 boolean scheduleByCluster(AsyncReadGraph graph, Resource resource, AsyncMultiProcedure<Resource> procedure);
82 <C> boolean scheduleByCluster(AsyncReadGraph graph, Resource resource, C context, AsyncContextMultiProcedure<C, Resource> procedure);
85 * Returns a new ReadGraph based on the specified ReadGraph. The returned
86 * ReadGraph does not accumulate query dependencies into the requests
87 * performed with the specified ReadGraph. DB listeners are therefore not
88 * triggered by anything that is performed with the returned ReadGraph.
90 * @param graph read transaction handle to clone for listener-independent
92 * @return read transaction handle that is independent of the requests
93 * performed with the parameter
95 ReadGraph getIndependentGraph(ReadGraph graph);
96 boolean hasParentRequest(ReadGraph graph);