bundles/org.simantics.db.common/src/org/simantics/db/common/request/ResourceSetGraph.java

   1 package org.simantics.db.common.request;\r
   2 \r
   3 import gnu.trove.map.hash.THashMap;\r
   4 \r
   5 import java.util.ArrayList;\r
   6 import java.util.Collections;\r
   7 import java.util.List;\r
   8 import java.util.Map;\r
   9 import java.util.Set;\r
  10 \r
  11 import org.simantics.db.ReadGraph;\r
  12 import org.simantics.db.Resource;\r
  13 import org.simantics.db.ResourceSet;\r
  14 import org.simantics.db.exception.DatabaseException;\r
  15 import org.simantics.db.service.CollectionSupport;\r
  16 \r
  17 public class ResourceSetGraph {\r
  18         \r
  19         final public CollectionSupport coll; \r
  20         final public List<ResourceSetGraph> references;\r
  21         final public Resource resource;\r
  22         final public Map<ResourceSet,Set<Resource>> cache = new THashMap<ResourceSet,Set<Resource>>();\r
  23         \r
  24         public ResourceSetGraph(ReadGraph graph, Resource result) {\r
  25                 this.resource = result;\r
  26                 this.references = new ArrayList<ResourceSetGraph>();\r
  27                 this.coll = graph.getService(CollectionSupport.class);\r
  28         }\r
  29 \r
  30         private Set<Resource> probe(ReadGraph graph, ResourceSet types) {\r
  31             return cache.get(types);\r
  32         }\r
  33         \r
  34         private Set<Resource> resolve(ReadGraph graph, ResourceSet types, Set<Resource> visited) throws DatabaseException {\r
  35 \r
  36             if(visited != null)\r
  37                 if(!visited.add(this.resource)) return Collections.emptySet();\r
  38 \r
  39             Set<Resource> cached = cache.get(types);\r
  40             if(cached != null) return cached;\r
  41             \r
  42                 boolean includeThis = !types.disjoint(graph.getTypes(this.resource));\r
  43                 \r
  44                 Set<Resource> allRefs = null;\r
  45                 for(ResourceSetGraph ref : references) {\r
  46                     Set<Resource> refs = ref.probe(graph, types);\r
  47                     if(refs == null) {\r
  48                         if(visited == null) {\r
  49                             visited = coll.createSet();\r
  50                             visited.add(this.resource);\r
  51                         }\r
  52                         refs = ref.resolve(graph, types, visited);\r
  53                     }\r
  54                     if(!refs.isEmpty()) {\r
  55                         if(allRefs == null) allRefs = coll.createSet(refs.size());\r
  56                         allRefs.addAll(refs);\r
  57                     }\r
  58                 }\r
  59                 \r
  60                 Set<Resource> result = Collections.emptySet();\r
  61                 if(allRefs != null) {\r
  62                     if(allRefs.size() == 1) {\r
  63                         if(includeThis) {\r
  64                             allRefs.add(resource);\r
  65                             if(allRefs.size() == 1) result =  Collections.singleton(allRefs.iterator().next());\r
  66                             else result = allRefs;\r
  67                         } else {\r
  68                            result = Collections.singleton(allRefs.iterator().next());\r
  69                         }\r
  70                     } else {\r
  71                 if(includeThis) allRefs.add(resource);\r
  72                 result = allRefs;\r
  73                     }\r
  74                 } else {\r
  75                     if(includeThis) result = Collections.singleton(resource);\r
  76                 }\r
  77                 \r
  78                 cache.put(types, result);\r
  79                 \r
  80                 return result;\r
  81                 \r
  82         }\r
  83         \r
  84         public Set<Resource> resolve(ReadGraph graph, ResourceSet types) throws DatabaseException {\r
  85                 Set<Resource> result = resolve(graph, types, null);\r
  86                 if(result == null) result = Collections.emptySet();\r
  87                 return result;\r
  88         }\r
  89         \r
  90 }