1 files changed, 43 insertions, 0 deletions

diff --git a/language/src/main/java/tools/refinery/language/resource/ReferenceCounter.java b/language/src/main/java/tools/refinery/language/resource/ReferenceCounter.java
new file mode 100644
index 00000000..56186bc9
--- /dev/null
+++ b/language/src/main/java/tools/refinery/language/resource/ReferenceCounter.java
@@ -0,0 +1,43 @@
+package tools.refinery.language.resource;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.xtext.util.IResourceScopeCache;
+
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+import tools.refinery.language.model.problem.Problem;
+
+@Singleton
+public class ReferenceCounter {
+        @Inject
+        private IResourceScopeCache cache;
+
+        public Map<EObject, Integer> getReferenceCounts(Problem problem) {
+                var resource = problem.eResource();
+                if (resource == null) {
+                        return doGetReferenceCounts(problem);
+                }
+                return cache.get(problem, resource, () -> doGetReferenceCounts(problem));
+        }
+
+        protected Map<EObject, Integer> doGetReferenceCounts(Problem problem) {
+                var map = new HashMap<EObject, Integer>();
+                countCrossReferences(problem, map);
+                var iterator = problem.eAllContents();
+                while (iterator.hasNext()) {
+                        var eObject = iterator.next();
+                        countCrossReferences(eObject, map);
+                }
+                return map;
+        }
+
+        protected void countCrossReferences(EObject eObject, Map<EObject, Integer> map) {
+                for (var referencedObject : eObject.eCrossReferences()) {
+                        map.compute(referencedObject, (key, currentValue) -> currentValue == null ? 1 : currentValue + 1);
+                }
+        }
+}