Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.db.common / src / org / simantics / db / common / request / ResourceSetGraph.java

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 (file)
index 0000000..e00ff7f
--- /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;\r
+\r
+import gnu.trove.map.hash.THashMap;\r
+\r
+import java.util.ArrayList;\r
+import java.util.Collections;\r
+import java.util.List;\r
+import java.util.Map;\r
+import java.util.Set;\r
+\r
+import org.simantics.db.ReadGraph;\r
+import org.simantics.db.Resource;\r
+import org.simantics.db.ResourceSet;\r
+import org.simantics.db.exception.DatabaseException;\r
+import org.simantics.db.service.CollectionSupport;\r
+\r
+public class ResourceSetGraph {\r
+       \r
+       final public CollectionSupport coll; \r
+       final public List<ResourceSetGraph> references;\r
+       final public Resource resource;\r
+       final public Map<ResourceSet,Set<Resource>> cache = new THashMap<ResourceSet,Set<Resource>>();\r
+       \r
+       public ResourceSetGraph(ReadGraph graph, Resource result) {\r
+               this.resource = result;\r
+               this.references = new ArrayList<ResourceSetGraph>();\r
+               this.coll = graph.getService(CollectionSupport.class);\r
+       }\r
+\r
+       private Set<Resource> probe(ReadGraph graph, ResourceSet types) {\r
+           return cache.get(types);\r
+       }\r
+       \r
+       private Set<Resource> resolve(ReadGraph graph, ResourceSet types, Set<Resource> visited) throws DatabaseException {\r
+\r
+           if(visited != null)\r
+               if(!visited.add(this.resource)) return Collections.emptySet();\r
+\r
+           Set<Resource> cached = cache.get(types);\r
+           if(cached != null) return cached;\r
+           \r
+               boolean includeThis = !types.disjoint(graph.getTypes(this.resource));\r
+               \r
+               Set<Resource> allRefs = null;\r
+               for(ResourceSetGraph ref : references) {\r
+                   Set<Resource> refs = ref.probe(graph, types);\r
+                   if(refs == null) {\r
+                       if(visited == null) {\r
+                           visited = coll.createSet();\r
+                           visited.add(this.resource);\r
+                       }\r
+                       refs = ref.resolve(graph, types, visited);\r
+                   }\r
+                   if(!refs.isEmpty()) {\r
+                       if(allRefs == null) allRefs = coll.createSet(refs.size());\r
+                       allRefs.addAll(refs);\r
+                   }\r
+               }\r
+               \r
+               Set<Resource> result = Collections.emptySet();\r
+               if(allRefs != null) {\r
+                   if(allRefs.size() == 1) {\r
+                       if(includeThis) {\r
+                           allRefs.add(resource);\r
+                           if(allRefs.size() == 1) result =  Collections.singleton(allRefs.iterator().next());\r
+                           else result = allRefs;\r
+                       } else {\r
+                          result = Collections.singleton(allRefs.iterator().next());\r
+                       }\r
+                   } else {\r
+                if(includeThis) allRefs.add(resource);\r
+                result = allRefs;\r
+                   }\r
+               } else {\r
+                   if(includeThis) result = Collections.singleton(resource);\r
+               }\r
+               \r
+               cache.put(types, result);\r
+               \r
+               return result;\r
+               \r
+       }\r
+       \r
+       public Set<Resource> resolve(ReadGraph graph, ResourceSet types) throws DatabaseException {\r
+               Set<Resource> result = resolve(graph, types, null);\r
+               if(result == null) result = Collections.emptySet();\r
+               return result;\r
+       }\r
+       \r
+}
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