Merge "Remove unnecessary getComparableKey from HashMapBinding"

[simantics/platform.git] / bundles / org.simantics.db.impl / src / org / simantics / db / impl / query / QueryCache.java

diff --git a/bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/QueryCache.java b/bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/QueryCache.java
index ee65998d36d701d0149fc843139d8cd63d5e4c22..48d5646c27eaa3aaeee3ac636f78e165d968e7c9 100644 (file)
--- a/bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/QueryCache.java
+++ b/bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/QueryCache.java
@@ -19,6 +19,9 @@ import org.simantics.db.request.Read;
 
 public class QueryCache extends QueryCacheBase {
 
+    // Using QueryChaching breaks Diagram Editor (and probably something else). 
+       private static final boolean SINGLE = false;
+    
     public QueryCache(QuerySupport querySupport, int threads) {
         super(querySupport, threads);
     }
@@ -53,6 +56,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerObjects(ReadGraphImpl graph, int r1, int r2, CacheEntry parent, ListenerBase listener, final IntProcedure procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r1,r2)) {
+            if (SINGLE) {
+                Objects e = cache.peekObjects(r1,r2);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             Objects.computeForEach(graph, r1,r2, null, procedure);
             return;
         }
@@ -67,6 +77,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private Objects peekObjects(int r1, int r2) {
+        synchronized(objectsMap) {
+            return (Objects) objectsMap.get(r1,r2);
+        }
+    }
+    
     Statements getOrCreateStatements(ReadGraphImpl graph, int r1, int r2) throws DatabaseException {
         Statements existing = null;
         synchronized(statementsMap) {
@@ -97,6 +113,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerStatements(ReadGraphImpl graph, int r1, int r2, CacheEntry parent, ListenerBase listener, final TripleIntProcedure procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r1,r2)) {
+            if (SINGLE) {
+                Statements e = cache.peekStatements(r1,r2);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             Statements.computeForEach(graph, r1,r2, null, procedure);
             return;
         }
@@ -111,6 +134,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private Statements peekStatements(int r1, int r2) {
+        synchronized(statementsMap) {
+            return (Statements) statementsMap.get(r1,r2);
+        }
+    }
+    
     DirectObjects getOrCreateDirectObjects(ReadGraphImpl graph, int r1, int r2) throws DatabaseException {
         DirectObjects existing = null;
         synchronized(directObjectsMap) {
@@ -141,6 +170,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerDirectObjects(ReadGraphImpl graph, int r1, int r2, CacheEntry parent, ListenerBase listener, final IntProcedure procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r1,r2)) {
+            if (SINGLE) {
+                DirectObjects e = cache.peekDirectObjects(r1,r2);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             DirectObjects.computeForEach(graph, r1,r2, null, procedure);
             return;
         }
@@ -155,6 +191,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private DirectObjects peekDirectObjects(int r1, int r2) {
+        synchronized(directObjectsMap) {
+            return (DirectObjects) directObjectsMap.get(r1,r2);
+        }
+    }
+    
     RelationInfoQuery getOrCreateRelationInfoQuery(ReadGraphImpl graph, int r) throws DatabaseException {
         RelationInfoQuery existing = null;
         synchronized(relationInfoQueryMap) {
@@ -185,6 +227,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerRelationInfoQuery(ReadGraphImpl graph, int r, CacheEntry parent, ListenerBase listener, final InternalProcedure<RelationInfo> procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r)) {
+            if (SINGLE) {
+                RelationInfoQuery e = cache.peekRelationInfoQuery(r);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             RelationInfoQuery.computeForEach(graph, r, null, procedure);
             return;
         }
@@ -199,6 +248,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private RelationInfoQuery peekRelationInfoQuery(int r) {
+        synchronized(relationInfoQueryMap) {
+            return (RelationInfoQuery) relationInfoQueryMap.get(r);
+        }
+    }
+    
     URIToResource getOrCreateURIToResource(ReadGraphImpl graph, String id) throws DatabaseException {
         URIToResource existing = null;
         synchronized(uRIToResourceMap) {
@@ -229,6 +284,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerURIToResource(ReadGraphImpl graph, String id, CacheEntry parent, ListenerBase listener, final InternalProcedure<Integer> procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, id)) {
+            if (SINGLE) {
+                URIToResource e = cache.peekURIToResource(id);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             URIToResource.computeForEach(graph, id, null, procedure);
             return;
         }
@@ -243,6 +305,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private URIToResource peekURIToResource(String id) {
+        synchronized(uRIToResourceMap) {
+            return (URIToResource) uRIToResourceMap.get(id);
+        }
+    }
+    
     ValueQuery getOrCreateValueQuery(ReadGraphImpl graph, int r) throws DatabaseException {
         ValueQuery existing = null;
         synchronized(valueQueryMap) {
@@ -273,6 +341,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerValueQuery(ReadGraphImpl graph, int r, CacheEntry parent, ListenerBase listener, final InternalProcedure<byte[]> procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r)) {
+            if (SINGLE) {
+                ValueQuery e = cache.peekValueQuery(r);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             ValueQuery.computeForEach(graph, r, null, procedure);
             return;
         }
@@ -287,6 +362,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private ValueQuery peekValueQuery(int r) {
+        synchronized(valueQueryMap) {
+            return (ValueQuery) valueQueryMap.get(r);
+        }
+    }
+    
     OrderedSet getOrCreateOrderedSet(ReadGraphImpl graph, int r) throws DatabaseException {
         OrderedSet existing = null;
         synchronized(orderedSetMap) {
@@ -317,6 +398,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerOrderedSet(ReadGraphImpl graph, int r, CacheEntry parent, ListenerBase listener, final IntProcedure procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r)) {
+            if (SINGLE) {
+                OrderedSet e = cache.peekOrderedSet(r);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             OrderedSet.computeForEach(graph, r, null, procedure);
             return;
         }
@@ -331,6 +419,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private OrderedSet peekOrderedSet(int r) {
+        synchronized(orderedSetMap) {
+            return (OrderedSet) orderedSetMap.get(r);
+        }
+    }
+    
     PrincipalTypes getOrCreatePrincipalTypes(ReadGraphImpl graph, int r) throws DatabaseException {
         PrincipalTypes existing = null;
         synchronized(principalTypesMap) {
@@ -361,6 +455,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerPrincipalTypes(ReadGraphImpl graph, int r, CacheEntry parent, ListenerBase listener, final IntProcedure procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r)) {
+            if (SINGLE) {
+                PrincipalTypes e = cache.peekPrincipalTypes(r);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             PrincipalTypes.computeForEach(graph, r, null, procedure);
             return;
         }
@@ -375,6 +476,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private PrincipalTypes peekPrincipalTypes(int r) {
+        synchronized(principalTypesMap) {
+            return (PrincipalTypes) principalTypesMap.get(r);
+        }
+    }
+    
     DirectPredicates getOrCreateDirectPredicates(ReadGraphImpl graph, int r) throws DatabaseException {
         DirectPredicates existing = null;
         synchronized(directPredicatesMap) {
@@ -405,6 +512,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerDirectPredicates(ReadGraphImpl graph, int r, CacheEntry parent, ListenerBase listener, final InternalProcedure<IntSet> procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r)) {
+            if (SINGLE) {
+                DirectPredicates e = cache.peekDirectPredicates(r);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             DirectPredicates.computeForEach(graph, r, null, procedure);
             return;
         }
@@ -419,6 +533,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private DirectPredicates peekDirectPredicates(int r) {
+        synchronized(directPredicatesMap) {
+            return (DirectPredicates) directPredicatesMap.get(r);
+        }
+    }
+    
     Predicates getOrCreatePredicates(ReadGraphImpl graph, int r) throws DatabaseException {
         Predicates existing = null;
         synchronized(predicatesMap) {
@@ -449,6 +569,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerPredicates(ReadGraphImpl graph, int r, CacheEntry parent, ListenerBase listener, final InternalProcedure<IntSet> procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r)) {
+            if (SINGLE) {
+                Predicates e = cache.peekPredicates(r);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             Predicates.computeForEach(graph, r, null, procedure);
             return;
         }
@@ -463,6 +590,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private Predicates peekPredicates(int r) {
+        synchronized(predicatesMap) {
+            return (Predicates) predicatesMap.get(r);
+        }
+    }
+    
     ReadEntry getOrCreateReadEntry(ReadGraphImpl graph, Read<?> r, boolean needsToBlock) throws DatabaseException {
         ReadEntry existing = null;
         synchronized(readEntryMap) {
@@ -486,6 +619,7 @@ public class QueryCache extends QueryCacheBase {
         }
         return existing;
     }
+
     
     void remove(ReadEntry entry) {
         synchronized(readEntryMap) {
@@ -496,6 +630,12 @@ public class QueryCache extends QueryCacheBase {
     public static Object runnerReadEntry(ReadGraphImpl graph, Read<?> r, CacheEntry parent, ListenerBase listener, final AsyncProcedure procedure, final boolean needsToBlock) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r)) {
+            if (SINGLE) {
+                ReadEntry e = cache.peekReadEntry(r);
+                if (e != null && e.isReady()) {
+                    return e.performFromCache(graph, procedure);
+                }
+            }
             return ReadEntry.computeForEach(graph, r, null, procedure);
         }
         ReadEntry entry = (ReadEntry)cache.getOrCreateReadEntry(graph, r, needsToBlock);
@@ -522,6 +662,13 @@ public class QueryCache extends QueryCacheBase {
           return result;
         }
     }
+
+    
+    private ReadEntry peekReadEntry(Read<?> r) {
+        synchronized(readEntryMap) {
+            return (ReadEntry) readEntryMap.get(r);
+        }
+    }
     
     AsyncReadEntry getOrCreateAsyncReadEntry(ReadGraphImpl graph, AsyncRead<?> r, boolean needsToBlock) throws DatabaseException {
         AsyncReadEntry existing = null;
@@ -546,6 +693,7 @@ public class QueryCache extends QueryCacheBase {
         }
         return existing;
     }
+
     
     void remove(AsyncReadEntry entry) {
         synchronized(asyncReadEntryMap) {
@@ -556,6 +704,12 @@ public class QueryCache extends QueryCacheBase {
     public static Object runnerAsyncReadEntry(ReadGraphImpl graph, AsyncRead<?> r, CacheEntry parent, ListenerBase listener, final AsyncProcedure procedure, final boolean needsToBlock) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r)) {
+            if (SINGLE) {
+                AsyncReadEntry e = cache.peekAsyncReadEntry(r);
+                if (e != null && e.isReady()) {
+                    return e.performFromCache(graph, procedure);
+                }
+            }
             return AsyncReadEntry.computeForEach(graph, r, null, procedure, needsToBlock);
         }
         AsyncReadEntry entry = (AsyncReadEntry)cache.getOrCreateAsyncReadEntry(graph, r, needsToBlock);
@@ -582,6 +736,13 @@ public class QueryCache extends QueryCacheBase {
           return result;
         }
     }
+
+    
+    private AsyncReadEntry peekAsyncReadEntry(AsyncRead<?> r) {
+        synchronized(asyncReadEntryMap) {
+            return (AsyncReadEntry) asyncReadEntryMap.get(r);
+        }
+    }
     
     Types getOrCreateTypes(ReadGraphImpl graph, int r) throws DatabaseException {
         Types existing = null;
@@ -613,6 +774,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerTypes(ReadGraphImpl graph, int r, CacheEntry parent, ListenerBase listener, final InternalProcedure<IntSet> procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r)) {
+            if (SINGLE) {
+                Types e = cache.peekTypes(r);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             Types.computeForEach(graph, r, null, procedure);
             return;
         }
@@ -627,6 +795,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private Types peekTypes(int r) {
+        synchronized(typesMap) {
+            return (Types) typesMap.get(r);
+        }
+    }
+    
     ChildMap getOrCreateChildMap(ReadGraphImpl graph, int r) throws DatabaseException {
         ChildMap existing = null;
         synchronized(childMapMap) {
@@ -657,6 +831,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerChildMap(ReadGraphImpl graph, int r, CacheEntry parent, ListenerBase listener, final InternalProcedure<ObjectResourceIdMap<String>> procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r)) {
+            if (SINGLE) {
+                ChildMap e = cache.peekChildMap(r);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             ChildMap.computeForEach(graph, r, null, procedure);
             return;
         }
@@ -671,6 +852,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private ChildMap peekChildMap(int r) {
+        synchronized(childMapMap) {
+            return (ChildMap) childMapMap.get(r);
+        }
+    }
+    
     TypeHierarchy getOrCreateTypeHierarchy(ReadGraphImpl graph, int r) throws DatabaseException {
         TypeHierarchy existing = null;
         synchronized(typeHierarchyMap) {
@@ -701,6 +888,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerTypeHierarchy(ReadGraphImpl graph, int r, CacheEntry parent, ListenerBase listener, final InternalProcedure<IntSet> procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r)) {
+            if (SINGLE) {
+                TypeHierarchy e = cache.peekTypeHierarchy(r);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             TypeHierarchy.computeForEach(graph, r, null, procedure);
             return;
         }
@@ -715,6 +909,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private TypeHierarchy peekTypeHierarchy(int r) {
+        synchronized(typeHierarchyMap) {
+            return (TypeHierarchy) typeHierarchyMap.get(r);
+        }
+    }
+    
     SuperTypes getOrCreateSuperTypes(ReadGraphImpl graph, int r) throws DatabaseException {
         SuperTypes existing = null;
         synchronized(superTypesMap) {
@@ -745,6 +945,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerSuperTypes(ReadGraphImpl graph, int r, CacheEntry parent, ListenerBase listener, final InternalProcedure<IntSet> procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r)) {
+            if (SINGLE) {
+                SuperTypes e = cache.peekSuperTypes(r);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             SuperTypes.computeForEach(graph, r, null, procedure);
             return;
         }
@@ -759,6 +966,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private SuperTypes peekSuperTypes(int r) {
+        synchronized(superTypesMap) {
+            return (SuperTypes) superTypesMap.get(r);
+        }
+    }
+    
     SuperRelations getOrCreateSuperRelations(ReadGraphImpl graph, int r) throws DatabaseException {
         SuperRelations existing = null;
         synchronized(superRelationsMap) {
@@ -789,6 +1002,13 @@ public class QueryCache extends QueryCacheBase {
     public static void runnerSuperRelations(ReadGraphImpl graph, int r, CacheEntry parent, ListenerBase listener, final InternalProcedure<IntSet> procedure) throws DatabaseException {
         QueryCache cache  = graph.processor.cache;
         if(parent == null && listener == null && !cache.shouldCache(graph.processor, r)) {
+            if (SINGLE) {
+                SuperRelations e = cache.peekSuperRelations(r);
+                if (e != null && e.isReady()) {
+                    e.performFromCache(graph, procedure);
+                    return;
+                }
+            }
             SuperRelations.computeForEach(graph, r, null, procedure);
             return;
         }
@@ -803,6 +1023,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private SuperRelations peekSuperRelations(int r) {
+        synchronized(superRelationsMap) {
+            return (SuperRelations) superRelationsMap.get(r);
+        }
+    }
+    
     AssertedPredicates getOrCreateAssertedPredicates(ReadGraphImpl graph, int r) throws DatabaseException {
         AssertedPredicates existing = null;
         synchronized(assertedPredicatesMap) {
@@ -843,6 +1069,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private AssertedPredicates peekAssertedPredicates(int r) {
+        synchronized(assertedPredicatesMap) {
+            return (AssertedPredicates) assertedPredicatesMap.get(r);
+        }
+    }
+    
     AssertedStatements getOrCreateAssertedStatements(ReadGraphImpl graph, int r1, int r2) throws DatabaseException {
         AssertedStatements existing = null;
         synchronized(assertedStatementsMap) {
@@ -883,6 +1115,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private AssertedStatements peekAssertedStatements(int r1, int r2) {
+        synchronized(assertedStatementsMap) {
+            return (AssertedStatements) assertedStatementsMap.get(r1,r2);
+        }
+    }
+    
     DirectSuperRelations getOrCreateDirectSuperRelations(ReadGraphImpl graph, int r) throws DatabaseException {
         DirectSuperRelations existing = null;
         synchronized(directSuperRelationsMap) {
@@ -923,6 +1161,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private DirectSuperRelations peekDirectSuperRelations(int r) {
+        synchronized(directSuperRelationsMap) {
+            return (DirectSuperRelations) directSuperRelationsMap.get(r);
+        }
+    }
+    
     MultiReadEntry getOrCreateMultiReadEntry(ReadGraphImpl graph, MultiRead<?> r) throws DatabaseException {
         MultiReadEntry existing = null;
         synchronized(multiReadEntryMap) {
@@ -963,6 +1207,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private MultiReadEntry peekMultiReadEntry(MultiRead<?> r) {
+        synchronized(multiReadEntryMap) {
+            return (MultiReadEntry) multiReadEntryMap.get(r);
+        }
+    }
+    
     AsyncMultiReadEntry getOrCreateAsyncMultiReadEntry(ReadGraphImpl graph, AsyncMultiRead<?> r) throws DatabaseException {
         AsyncMultiReadEntry existing = null;
         synchronized(asyncMultiReadEntryMap) {
@@ -1003,6 +1253,12 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private AsyncMultiReadEntry peekAsyncMultiReadEntry(AsyncMultiRead<?> r) {
+        synchronized(asyncMultiReadEntryMap) {
+            return (AsyncMultiReadEntry) asyncMultiReadEntryMap.get(r);
+        }
+    }
+    
     ExternalReadEntry getOrCreateExternalReadEntry(ReadGraphImpl graph, ExternalRead<?> r) throws DatabaseException {
         ExternalReadEntry existing = null;
         synchronized(externalReadEntryMap) {
@@ -1023,6 +1279,7 @@ public class QueryCache extends QueryCacheBase {
         if(existing.isPending()) waitPending(graph, existing);
         return existing;
     }
+
     
     void remove(ExternalReadEntry entry) {
         synchronized(externalReadEntryMap) {
@@ -1043,4 +1300,10 @@ public class QueryCache extends QueryCacheBase {
         }
     }
     
+    private ExternalReadEntry peekExternalReadEntry(ExternalRead<?> r) {
+        synchronized(externalReadEntryMap) {
+            return (ExternalReadEntry) externalReadEntryMap.get(r);
+        }
+    }
+    
 }