X-Git-Url: https://gerrit.simantics.org/r/gitweb?a=blobdiff_plain;f=bundles%2Forg.simantics.db.common%2Fsrc%2Forg%2Fsimantics%2Fdb%2Fcommon%2Frequest%2FResourceSetGraph.java;fp=bundles%2Forg.simantics.db.common%2Fsrc%2Forg%2Fsimantics%2Fdb%2Fcommon%2Frequest%2FResourceSetGraph.java;h=e00ff7f7090705c82d9ec237e5e5b20e23f64f48;hb=969bd23cab98a79ca9101af33334000879fb60c5;hp=0000000000000000000000000000000000000000;hpb=866dba5cd5a3929bbeae85991796acb212338a08;p=simantics%2Fplatform.git

diff --git a/bundles/org.simantics.db.common/src/org/simantics/db/common/request/ResourceSetGraph.java b/bundles/org.simantics.db.common/src/org/simantics/db/common/request/ResourceSetGraph.java
new file mode 100644
index 000000000..e00ff7f70
--- /dev/null
+++ b/bundles/org.simantics.db.common/src/org/simantics/db/common/request/ResourceSetGraph.java
@@ -0,0 +1,90 @@
+package org.simantics.db.common.request;
+
+import gnu.trove.map.hash.THashMap;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import org.simantics.db.ReadGraph;
+import org.simantics.db.Resource;
+import org.simantics.db.ResourceSet;
+import org.simantics.db.exception.DatabaseException;
+import org.simantics.db.service.CollectionSupport;
+
+public class ResourceSetGraph {
+	
+	final public CollectionSupport coll; 
+	final public List<ResourceSetGraph> references;
+	final public Resource resource;
+	final public Map<ResourceSet,Set<Resource>> cache = new THashMap<ResourceSet,Set<Resource>>();
+	
+	public ResourceSetGraph(ReadGraph graph, Resource result) {
+		this.resource = result;
+		this.references = new ArrayList<ResourceSetGraph>();
+		this.coll = graph.getService(CollectionSupport.class);
+	}
+
+	private Set<Resource> probe(ReadGraph graph, ResourceSet types) {
+	    return cache.get(types);
+	}
+	
+	private Set<Resource> resolve(ReadGraph graph, ResourceSet types, Set<Resource> visited) throws DatabaseException {
+
+	    if(visited != null)
+	        if(!visited.add(this.resource)) return Collections.emptySet();
+
+	    Set<Resource> cached = cache.get(types);
+	    if(cached != null) return cached;
+	    
+		boolean includeThis = !types.disjoint(graph.getTypes(this.resource));
+		
+		Set<Resource> allRefs = null;
+		for(ResourceSetGraph ref : references) {
+		    Set<Resource> refs = ref.probe(graph, types);
+		    if(refs == null) {
+		        if(visited == null) {
+		            visited = coll.createSet();
+		            visited.add(this.resource);
+		        }
+		        refs = ref.resolve(graph, types, visited);
+		    }
+		    if(!refs.isEmpty()) {
+		        if(allRefs == null) allRefs = coll.createSet(refs.size());
+		        allRefs.addAll(refs);
+		    }
+		}
+		
+		Set<Resource> result = Collections.emptySet();
+		if(allRefs != null) {
+		    if(allRefs.size() == 1) {
+		        if(includeThis) {
+		            allRefs.add(resource);
+		            if(allRefs.size() == 1) result =  Collections.singleton(allRefs.iterator().next());
+		            else result = allRefs;
+		        } else {
+		           result = Collections.singleton(allRefs.iterator().next());
+		        }
+		    } else {
+                if(includeThis) allRefs.add(resource);
+                result = allRefs;
+		    }
+		} else {
+		    if(includeThis) result = Collections.singleton(resource);
+		}
+		
+		cache.put(types, result);
+		
+		return result;
+		
+	}
+	
+	public Set<Resource> resolve(ReadGraph graph, ResourceSet types) throws DatabaseException {
+		Set<Resource> result = resolve(graph, types, null);
+		if(result == null) result = Collections.emptySet();
+		return result;
+	}
+	
+}
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