Virtual Graphs - Revision history

Tuukka Lehtonen: /* Examples */

2012-01-12T11:52:22Z

Examples

← Older revision		Revision as of 11:52, 12 January 2012
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			== Debugging ==

			The standard Simantics Graph Debugger view shows for every statement which virtual graph it belongs to. This information is visible on the ''Graph'' column of the statement table. The Graph column will show:
			;DB: when the statement is in the persistent graph
			;'name' (W): when the statement is in a named workspace-persistent virtual graph
			;'name' (M): when the statement is in a named memory-persistent (transient) virtual graph

			[[Image:GraphDebuggerVG.png\|frame\|center\|Graph debugger example with statements in virtual graphs.]]

	[[Category: Database Development]]		[[Category: Database Development]]

Tuukka Lehtonen: /* Specification */

2012-01-12T10:39:58Z

Specification

← Older revision		Revision as of 10:39, 12 January 2012
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	* Claim statements are added into the given virtual graph		* Claim statements are added into the given virtual graph
	* Value changes are applied into the given virtual graph		* Value changes are applied into the given virtual graph
	* For denied statements the location of the statement is determined and the statement is removed from that virtual graph. If the denied statement is not a part of any virtual graph, it is removed from the persistent graph.		* When the virtual graph provided to the WriteRequest is:
			** '''null''':
			*** For denied statements the location of the statement is determined and the statement is removed from that virtual graph. If the denied statement is not a part of any virtual graph, it is removed from the persistent graph.
			** '''non-null''':
			*** Statements are only removed from the virtual graph specified for the write request

	The user can perform modifications into multiple virtual graphs within a single transaction. This is accomplished by issuing a new synchronous modification (WriteGraph.sync) into a new virtual graph.		The user can perform modifications into multiple virtual graphs within a single transaction. This is accomplished by issuing a new synchronous modification (WriteGraph.sync) into a new virtual graph.

Tuukka Lehtonen: /* Specification */

2011-09-20T20:31:07Z

Specification

← Older revision		Revision as of 20:31, 20 September 2011
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	* Claim statements are added into the given virtual graph		* Claim statements are added into the given virtual graph
	* Value changes are applied into the given virtual graph		* Value changes are applied into the given virtual graph
	* For denied statements the location of the statement is determined and the statement is removed from that virtual graph.		* For denied statements the location of the statement is determined and the statement is removed from that virtual graph. If the denied statement is not a part of any virtual graph, it is removed from the persistent graph.

	The user can perform modifications into multiple virtual graphs within a single transaction. This is accomplished by issuing a new synchronous modification (WriteGraph.sync) into a new virtual graph.		The user can perform modifications into multiple virtual graphs within a single transaction. This is accomplished by issuing a new synchronous modification (WriteGraph.sync) into a new virtual graph.

Tuukka Lehtonen at 22:15, 3 September 2011

2011-09-03T22:15:38Z

← Older revision		Revision as of 22:15, 3 September 2011
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			[[Category: Database Development]]

Tuukka Lehtonen: /* Specification */

2011-09-03T22:04:53Z

Specification

← Older revision		Revision as of 22:04, 3 September 2011
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	== Specification ==		== Specification ==

	A write request has a single graph into which it writes. This is determined by WriteTraits and usually as a parameter to WriteRequest. If null is provided, the client applies modifications into the persistent graph. The following rules apply		A write request has a single graph into which it writes. This is determined by ''WriteTraits'' and usually as a parameter to ''WriteRequest''. If null is provided, the client applies modifications into the persistent graph. The following rules apply:

	* New resources are created into the given virtual graph		* New resources are created into the given virtual graph

Tuukka Lehtonen: /* Intro */

2011-09-03T22:04:08Z

Intro

← Older revision		Revision as of 22:04, 3 September 2011
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	Virtual graphs are manipulated via the following interfaces		Virtual graphs are manipulated via the following interfaces

	* org.simantics.db.service.VirtualGraphSupport, for management		* '''org.simantics.db.service.VirtualGraphSupport''', for management
	* org.simantics.db.request.WriteTraits, for identifying the graph to write into		* '''org.simantics.db.request.WriteTraits''', for identifying the graph to write into

	== Specification ==		== Specification ==

Tuukka Lehtonen: /* Examples */

2011-09-03T21:25:16Z

Examples

← Older revision		Revision as of 21:25, 3 September 2011
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	public class VirtualGraphExample {		public class VirtualGraphExample {

	public Resource createLibrary(RequestProcessor processor, VirtualGraph vg, final String libraryName) throws DatabaseException {		public Resource createLibrary(RequestProcessor processor, VirtualGraph vg, final String libraryName)
			throws DatabaseException {
	return processor.syncRequest(new WriteResultRequest<Resource>(vg) {		return processor.syncRequest(new WriteResultRequest<Resource>(vg) {
	@Override		@Override

Tuukka Lehtonen: /* Examples */

2011-09-03T21:22:29Z

Examples

← Older revision		Revision as of 21:22, 3 September 2011
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	import org.simantics.layer0.Layer0;		import org.simantics.layer0.Layer0;

	public class ~~VirtualGraphTests~~ {		public class VirtualGraphExample {

	public Resource createLibrary(RequestProcessor processor, VirtualGraph vg, final String libraryName) throws DatabaseException {		public Resource createLibrary(RequestProcessor processor, VirtualGraph vg, final String libraryName) throws DatabaseException {

Tuukka Lehtonen: /* Examples */

2011-09-03T21:19:02Z

Examples

← Older revision		Revision as of 21:19, 3 September 2011
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	<syntaxhighlight lang="java">		<syntaxhighlight lang="java">
	package org.~~example~~;		package org.simantics.db.tests.api.support.virtualGraphSupport;

	import org.simantics.db.ReadGraph;		import org.simantics.db.ReadGraph;

Tuukka Lehtonen at 21:14, 3 September 2011

2011-09-03T21:14:20Z

← Older revision		Revision as of 21:14, 3 September 2011
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	The user can perform modifications into multiple virtual graphs within a single transaction. This is accomplished by issuing a new synchronous modification (WriteGraph.sync) into a new virtual graph.		The user can perform modifications into multiple virtual graphs within a single transaction. This is accomplished by issuing a new synchronous modification (WriteGraph.sync) into a new virtual graph.

			== Examples ==

			The following code examples show in practice how to write into virtual graphs, both memory- and disk-based. Writing to several virtual graphs within the same write transaction is also demonstrated.

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			package org.example;

			import org.simantics.db.ReadGraph;
			import org.simantics.db.RequestProcessor;
			import org.simantics.db.Resource;
			import org.simantics.db.Session;
			import org.simantics.db.Statement;
			import org.simantics.db.VirtualGraph;
			import org.simantics.db.WriteGraph;
			import org.simantics.db.common.request.ReadRequest;
			import org.simantics.db.common.request.WriteRequest;
			import org.simantics.db.common.request.WriteResultRequest;
			import org.simantics.db.common.utils.NameUtils;
			import org.simantics.db.exception.DatabaseException;
			import org.simantics.db.service.VirtualGraphSupport;
			import org.simantics.layer0.Layer0;

			public class VirtualGraphTests {

			public Resource createLibrary(RequestProcessor processor, VirtualGraph vg, final String libraryName) throws DatabaseException {
			return processor.syncRequest(new WriteResultRequest<Resource>(vg) {
			@Override
			public Resource perform(WriteGraph graph) throws DatabaseException {
			Layer0 L0 = Layer0.getInstance(graph);
			Resource r = graph.newResource();
			graph.claim(r, L0.InstanceOf, null, L0.Library);
			graph.claimLiteral(r, L0.HasName, libraryName);
			return r;
			}
			});
			}

			public void testVirtualGraphs(Session session) throws DatabaseException {
			VirtualGraphSupport vgSupport = session.getService(VirtualGraphSupport.class);
			VirtualGraph memory = vgSupport.getMemoryPersistent("memory");
			VirtualGraph workspace = vgSupport.getWorkspacePersistent("workspace");
			// NOTICE: resource are created in difference virtual graphs in separate
			// transactions through Session.syncRequest.
			Resource memResource = createLibrary(session, memory, "memory");
			Resource workspaceResource = createLibrary(session, workspace, "workspace");
			printVirtualGraphs(session);
			}

			public void testMultipleVirtualGraphsInSameTransaction(Session session) throws DatabaseException {
			final VirtualGraphSupport vgSupport = session.getService(VirtualGraphSupport.class);
			session.syncRequest(new WriteRequest() {
			@Override
			public void perform(WriteGraph graph) throws DatabaseException {
			VirtualGraph memory = vgSupport.getMemoryPersistent("memory");
			VirtualGraph workspace = vgSupport.getWorkspacePersistent("workspace");
			// NOTICE: resource are created in different virtual graphs in
			// the same transaction through WriteGraph.syncRequest
			Resource memResource = createLibrary(graph, memory, "memory");
			Resource workspaceResource = createLibrary(graph, workspace, "workspace");
			}
			});
			printVirtualGraphs(session);
			}

			public void printVirtualGraphs(Session session) throws DatabaseException {
			session.syncRequest(new ReadRequest() {
			@Override
			public void run(ReadGraph graph) throws DatabaseException {
			VirtualGraphSupport vgSupport = graph.getService(VirtualGraphSupport.class);
			for (VirtualGraph vg : vgSupport.listGraphs()) {
			for (Statement stm : vgSupport.listStatements(vg)) {
			System.out.println("Statement: " + NameUtils.toString(graph, stm));
			}
			for (Resource r : vgSupport.listValues(vg)) {
			System.out.println("Literal value: " + graph.getValue(r));
			}
			}
			}
			});
			}

			}
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