Provide nice error messages on constraint failure

Also add testing to ensure that Community Edition fails to start
when the database contains a PEC.

community/kernel/src/main/java/org/neo4j/kernel/api/constraints/NodePropertyExistenceConstraint.java

@@ -26,6 +26,7 @@
 import org.neo4j.kernel.api.ReadOperations;
 import org.neo4j.kernel.api.StatementTokenNameLookup;
 import org.neo4j.kernel.api.TokenNameLookup;
+import org.neo4j.kernel.api.exceptions.schema.CreateConstraintFailureException;
 import org.neo4j.kernel.impl.coreapi.schema.InternalSchemaActions;
 import org.neo4j.kernel.impl.coreapi.schema.NodePropertyExistenceConstraintDefinition;
 
@@ -37,7 +38,7 @@ public NodePropertyExistenceConstraint( int labelId, int propertyKeyId )
     }
 
     @Override
-    public void added( ChangeVisitor visitor )
+    public void added( ChangeVisitor visitor ) throws CreateConstraintFailureException
     {
         visitor.visitAddedNodePropertyExistenceConstraint( this );
     }

community/kernel/src/main/java/org/neo4j/kernel/api/constraints/PropertyConstraint.java

@@ -23,6 +23,7 @@
 import org.neo4j.graphdb.schema.ConstraintType;
 import org.neo4j.kernel.api.ReadOperations;
 import org.neo4j.kernel.api.TokenNameLookup;
+import org.neo4j.kernel.api.exceptions.schema.CreateConstraintFailureException;
 import org.neo4j.kernel.impl.coreapi.schema.InternalSchemaActions;
 
 public abstract class PropertyConstraint
@@ -33,11 +34,13 @@ public interface ChangeVisitor
 
         void visitRemovedUniquePropertyConstraint( UniquenessConstraint constraint );
 
-        void visitAddedNodePropertyExistenceConstraint( NodePropertyExistenceConstraint constraint );
+        void visitAddedNodePropertyExistenceConstraint( NodePropertyExistenceConstraint constraint )
+                throws CreateConstraintFailureException;
 
         void visitRemovedNodePropertyExistenceConstraint( NodePropertyExistenceConstraint constraint );
 
-        void visitAddedRelationshipPropertyExistenceConstraint( RelationshipPropertyExistenceConstraint constraint );
+        void visitAddedRelationshipPropertyExistenceConstraint( RelationshipPropertyExistenceConstraint constraint )
+                throws CreateConstraintFailureException;
 
         void visitRemovedRelationshipPropertyExistenceConstraint( RelationshipPropertyExistenceConstraint constraint );
     }
@@ -49,7 +52,7 @@ public PropertyConstraint( int propertyKeyId )
         this.propertyKeyId = propertyKeyId;
     }
 
-    public abstract void added( ChangeVisitor visitor );
+    public abstract void added( ChangeVisitor visitor ) throws CreateConstraintFailureException;
 
     public abstract void removed( ChangeVisitor visitor );
 

community/kernel/src/main/java/org/neo4j/kernel/api/constraints/RelationshipPropertyExistenceConstraint.java

@@ -25,6 +25,7 @@
 import org.neo4j.kernel.api.ReadOperations;
 import org.neo4j.kernel.api.StatementTokenNameLookup;
 import org.neo4j.kernel.api.TokenNameLookup;
+import org.neo4j.kernel.api.exceptions.schema.CreateConstraintFailureException;
 import org.neo4j.kernel.impl.coreapi.schema.InternalSchemaActions;
 import org.neo4j.kernel.impl.coreapi.schema.RelationshipPropertyExistenceConstraintDefinition;
 
@@ -36,7 +37,7 @@ public RelationshipPropertyExistenceConstraint( int relTypeId, int propertyKeyId
     }
 
     @Override
-    public void added( ChangeVisitor visitor )
+    public void added( ChangeVisitor visitor ) throws CreateConstraintFailureException
     {
         visitor.visitAddedRelationshipPropertyExistenceConstraint( this );
     }

community/kernel/src/main/java/org/neo4j/kernel/api/exceptions/schema/ConstraintViolationKernelException.java

@@ -25,7 +25,7 @@
  *
  * @see ConstraintVerificationFailedKernelException
  */
-public class ConstraintViolationKernelException extends ConstraintValidationKernelException
+public abstract class ConstraintViolationKernelException extends ConstraintValidationKernelException
 {
     public ConstraintViolationKernelException( String message, Object... parameters )
     {

community/kernel/src/main/java/org/neo4j/kernel/api/txstate/ReadableTxState.java

@@ -34,6 +34,7 @@
 import org.neo4j.kernel.api.cursor.PropertyItem;
 import org.neo4j.kernel.api.cursor.RelationshipItem;
 import org.neo4j.kernel.api.exceptions.schema.ConstraintValidationKernelException;
+import org.neo4j.kernel.api.exceptions.schema.CreateConstraintFailureException;
 import org.neo4j.kernel.api.index.IndexDescriptor;
 import org.neo4j.kernel.api.properties.DefinedProperty;
 import org.neo4j.kernel.impl.api.RelationshipVisitor;
@@ -53,7 +54,7 @@
  */
 public interface ReadableTxState
 {
-    void accept( TxStateVisitor visitor ) throws ConstraintValidationKernelException;
+    void accept( TxStateVisitor visitor ) throws ConstraintValidationKernelException, CreateConstraintFailureException;
 
     boolean hasChanges();
 

community/kernel/src/main/java/org/neo4j/kernel/api/txstate/TxStateVisitor.java

@@ -27,6 +27,7 @@
 import org.neo4j.kernel.api.constraints.RelationshipPropertyExistenceConstraint;
 import org.neo4j.kernel.api.constraints.UniquenessConstraint;
 import org.neo4j.kernel.api.exceptions.schema.ConstraintValidationKernelException;
+import org.neo4j.kernel.api.exceptions.schema.CreateConstraintFailureException;
 import org.neo4j.kernel.api.index.IndexDescriptor;
 import org.neo4j.kernel.api.properties.DefinedProperty;
 import org.neo4j.kernel.impl.api.state.RelationshipChangesForNode;
@@ -68,11 +69,13 @@ void visitNodeLabelChanges( long id, Set<Integer> added, Set<Integer> removed )
 
     void visitRemovedUniquePropertyConstraint( UniquenessConstraint element );
 
-    void visitAddedNodePropertyExistenceConstraint( NodePropertyExistenceConstraint element );
+    void visitAddedNodePropertyExistenceConstraint( NodePropertyExistenceConstraint element )
+            throws CreateConstraintFailureException;
 
     void visitRemovedNodePropertyExistenceConstraint( NodePropertyExistenceConstraint element );
 
-    void visitAddedRelationshipPropertyExistenceConstraint( RelationshipPropertyExistenceConstraint element );
+    void visitAddedRelationshipPropertyExistenceConstraint( RelationshipPropertyExistenceConstraint element )
+            throws CreateConstraintFailureException;
 
     void visitRemovedRelationshipPropertyExistenceConstraint( RelationshipPropertyExistenceConstraint element );
 
@@ -227,6 +230,7 @@ public void visitRemovedUniquePropertyConstraint( UniquenessConstraint element )
 
         @Override
         public void visitAddedNodePropertyExistenceConstraint( NodePropertyExistenceConstraint element )
+                throws CreateConstraintFailureException
         {
             if ( next != null )
             {
@@ -245,6 +249,7 @@ public void visitRemovedNodePropertyExistenceConstraint( NodePropertyExistenceCo
 
         @Override
         public void visitAddedRelationshipPropertyExistenceConstraint( RelationshipPropertyExistenceConstraint element )
+                throws CreateConstraintFailureException
         {
             if ( next != null )
             {

community/kernel/src/main/java/org/neo4j/kernel/impl/api/KernelTransactionImplementation.java

@@ -30,6 +30,7 @@
 import org.neo4j.cursor.Cursor;
 import org.neo4j.helpers.Clock;
 import org.neo4j.helpers.ThisShouldNotHappenError;
+import org.neo4j.kernel.api.exceptions.schema.CreateConstraintFailureException;
 import org.neo4j.kernel.impl.constraints.ConstraintSemantics;
 import org.neo4j.kernel.api.KernelTransaction;
 import org.neo4j.kernel.api.KeyReadTokenNameLookup;
@@ -382,7 +383,8 @@ private void assertTransactionNotClosing()
         }
     }
 
-    private void prepareRecordChangesFromTransactionState() throws ConstraintValidationKernelException
+    private void prepareRecordChangesFromTransactionState()
+            throws ConstraintValidationKernelException, CreateConstraintFailureException
     {
         if ( hasTxStateWithChanges() )
         {
@@ -554,7 +556,7 @@ private void commit() throws TransactionFailureException
             }
             success = true;
         }
-        catch ( ConstraintValidationKernelException e )
+        catch ( ConstraintValidationKernelException | CreateConstraintFailureException e )
         {
             throw new ConstraintViolationTransactionFailureException(
                     e.getUserMessage( new KeyReadTokenNameLookup( operations.keyReadOperations() ) ), e );
@@ -606,7 +608,7 @@ public void visitCreatedRelationship( long id, int type, long startNode, long en
                         }
                     } );
                 }
-                catch ( ConstraintValidationKernelException e )
+                catch ( ConstraintValidationKernelException | CreateConstraintFailureException e )
                 {
                     throw new IllegalStateException(
                             "Releasing locks during rollback should perform no constraints checking.", e );
@@ -953,6 +955,7 @@ public void visitRemovedUniquePropertyConstraint( UniquenessConstraint element )
 
         @Override
         public void visitAddedNodePropertyExistenceConstraint( NodePropertyExistenceConstraint element )
+                throws CreateConstraintFailureException
         {
             clearState = true;
             recordState.createSchemaRule( constraintSemantics.writeNodePropertyExistenceConstraint(
@@ -983,6 +986,7 @@ public void visitRemovedNodePropertyExistenceConstraint( NodePropertyExistenceCo
 
         @Override
         public void visitAddedRelationshipPropertyExistenceConstraint( RelationshipPropertyExistenceConstraint element )
+                throws CreateConstraintFailureException
         {
             clearState = true;
             recordState.createSchemaRule( constraintSemantics.writeRelationshipPropertyExistenceConstraint(

community/kernel/src/main/java/org/neo4j/kernel/impl/api/state/TxState.java

@@ -47,6 +47,7 @@
 import org.neo4j.kernel.api.cursor.PropertyItem;
 import org.neo4j.kernel.api.cursor.RelationshipItem;
 import org.neo4j.kernel.api.exceptions.schema.ConstraintValidationKernelException;
+import org.neo4j.kernel.api.exceptions.schema.CreateConstraintFailureException;
 import org.neo4j.kernel.api.index.IndexDescriptor;
 import org.neo4j.kernel.api.properties.DefinedProperty;
 import org.neo4j.kernel.api.properties.Property;
@@ -250,7 +251,8 @@ protected TxIteratorRelationshipCursor create()
     }
 
     @Override
-    public void accept( final TxStateVisitor visitor ) throws ConstraintValidationKernelException
+    public void accept( final TxStateVisitor visitor )
+            throws ConstraintValidationKernelException, CreateConstraintFailureException
     {
         // Created nodes
         if ( nodes != null )
@@ -409,7 +411,7 @@ static class ConstraintDiffSetsVisitor implements PropertyConstraint.ChangeVisit
         }
 
         @Override
-        public void visitAdded( PropertyConstraint element )
+        public void visitAdded( PropertyConstraint element ) throws CreateConstraintFailureException
         {
             element.added( this );
         }
@@ -434,6 +436,7 @@ public void visitRemovedUniquePropertyConstraint( UniquenessConstraint constrain
 
         @Override
         public void visitAddedNodePropertyExistenceConstraint( NodePropertyExistenceConstraint constraint )
+                throws CreateConstraintFailureException
         {
             visitor.visitAddedNodePropertyExistenceConstraint( constraint );
         }
@@ -446,7 +449,7 @@ public void visitRemovedNodePropertyExistenceConstraint( NodePropertyExistenceCo
 
         @Override
         public void visitAddedRelationshipPropertyExistenceConstraint(
-                RelationshipPropertyExistenceConstraint constraint )
+                RelationshipPropertyExistenceConstraint constraint ) throws CreateConstraintFailureException
         {
             visitor.visitAddedRelationshipPropertyExistenceConstraint( constraint );
         }

community/kernel/src/main/java/org/neo4j/kernel/impl/constraints/ConstraintSemantics.java

@@ -46,9 +46,11 @@ void validateRelationshipPropertyExistenceConstraint( Cursor<RelationshipItem> a
 
     PropertyConstraintRule writeUniquePropertyConstraint( long ruleId, int label, int propertyKey, long indexId );
 
-    PropertyConstraintRule writeNodePropertyExistenceConstraint( long ruleId, int label, int propertyKey );
+    PropertyConstraintRule writeNodePropertyExistenceConstraint( long ruleId, int label, int propertyKey )
+            throws CreateConstraintFailureException;
 
-    PropertyConstraintRule writeRelationshipPropertyExistenceConstraint( long ruleId, int type, int propertyKey );
+    PropertyConstraintRule writeRelationshipPropertyExistenceConstraint( long ruleId, int type, int propertyKey )
+            throws CreateConstraintFailureException;
 
     TxStateVisitor decorateTxStateVisitor( StatementOperationParts operations, StoreStatement storeStatement,
             StoreReadLayer storeLayer, TxStateHolder holder, TxStateVisitor visitor );

community/kernel/src/main/java/org/neo4j/kernel/impl/constraints/StandardConstraintSemantics.java

@@ -20,7 +20,9 @@
 package org.neo4j.kernel.impl.constraints;
 
 import org.neo4j.cursor.Cursor;
+import org.neo4j.kernel.api.constraints.NodePropertyExistenceConstraint;
 import org.neo4j.kernel.api.constraints.PropertyConstraint;
+import org.neo4j.kernel.api.constraints.RelationshipPropertyExistenceConstraint;
 import org.neo4j.kernel.api.cursor.NodeItem;
 import org.neo4j.kernel.api.cursor.RelationshipItem;
 import org.neo4j.kernel.api.exceptions.schema.CreateConstraintFailureException;
@@ -38,14 +40,14 @@ public class StandardConstraintSemantics implements ConstraintSemantics
     public void validateNodePropertyExistenceConstraint( Cursor<NodeItem> allNodes, int label, int propertyKey )
             throws CreateConstraintFailureException
     {
-        throw propertyExistenceConstraintsNotAllowed();
+        throw propertyExistenceConstraintsNotAllowed( new NodePropertyExistenceConstraint( label, propertyKey ) );
     }
 
     @Override
     public void validateRelationshipPropertyExistenceConstraint( Cursor<RelationshipItem> allRels, int type,
-            int propertyKey ) throws CreateConstraintFailureException
+            int key ) throws CreateConstraintFailureException
     {
-        throw propertyExistenceConstraintsNotAllowed();
+        throw propertyExistenceConstraintsNotAllowed( new RelationshipPropertyExistenceConstraint( type, key ) );
     }
 
     @Override
@@ -60,14 +62,15 @@ public PropertyConstraint readConstraint( PropertyConstraintRule rule )
 
     protected PropertyConstraint readNonStandardConstraint( PropertyConstraintRule rule )
     {
-        // todo: message and new exception type
-        throw new IllegalStateException( "Property existence constraints can only be used on Neo4j enterprise" );
+        // When opening a store in Community Edition that contains a Property Existence Constraint
+        throw new IllegalStateException( "Property existence constraint requires Neo4j Enterprise Edition");
     }
 
-    private IllegalStateException propertyExistenceConstraintsNotAllowed()
+    private CreateConstraintFailureException propertyExistenceConstraintsNotAllowed( PropertyConstraint constraint )
     {
-        // todo: message and new exception type
-        return new IllegalStateException( "Property existence constraints can only be used on Neo4j enterprise" );
+        // When creating a Property Existence Constraint in Community Edition
+        return new CreateConstraintFailureException( constraint, new IllegalStateException(
+                "Property existence constraint requires Neo4j Enterprise Edition" ) );
     }
 
     @Override
@@ -77,15 +80,17 @@ public PropertyConstraintRule writeUniquePropertyConstraint( long ruleId, int la
     }
 
     @Override
-    public PropertyConstraintRule writeNodePropertyExistenceConstraint( long ruleId, int type, int propertyKey )
+    public PropertyConstraintRule writeNodePropertyExistenceConstraint( long ruleId, int label, int propertyKey )
+            throws CreateConstraintFailureException
     {
-        throw propertyExistenceConstraintsNotAllowed();
+        throw propertyExistenceConstraintsNotAllowed( new NodePropertyExistenceConstraint( label, propertyKey ) );
     }
 
     @Override
-    public PropertyConstraintRule writeRelationshipPropertyExistenceConstraint( long ruleId, int type, int propertyKey )
+    public PropertyConstraintRule writeRelationshipPropertyExistenceConstraint( long ruleId, int type, int key )
+            throws CreateConstraintFailureException
     {
-        throw propertyExistenceConstraintsNotAllowed();
+        throw propertyExistenceConstraintsNotAllowed( new RelationshipPropertyExistenceConstraint( type, key ) );
     }
 
     @Override

community/kernel/src/main/java/org/neo4j/kernel/impl/util/diffsets/DiffSetsVisitor.java

@@ -20,10 +20,11 @@
 package org.neo4j.kernel.impl.util.diffsets;
 
 import org.neo4j.kernel.api.exceptions.schema.ConstraintValidationKernelException;
+import org.neo4j.kernel.api.exceptions.schema.CreateConstraintFailureException;
 
 public interface DiffSetsVisitor<T>
 {
-    void visitAdded( T element ) throws ConstraintValidationKernelException;
+    void visitAdded( T element ) throws ConstraintValidationKernelException, CreateConstraintFailureException;
 
     void visitRemoved( T element ) throws ConstraintValidationKernelException;
 

community/kernel/src/main/java/org/neo4j/kernel/impl/util/diffsets/SuperDiffSets.java

@@ -27,6 +27,7 @@
 import org.neo4j.function.Predicate;
 import org.neo4j.helpers.collection.Iterables;
 import org.neo4j.kernel.api.exceptions.schema.ConstraintValidationKernelException;
+import org.neo4j.kernel.api.exceptions.schema.CreateConstraintFailureException;
 import org.neo4j.kernel.impl.util.VersionedHashMap;
 
 import static java.lang.String.format;
@@ -56,7 +57,8 @@ public SuperDiffSets( Set<T> addedElements, Set<T> removedElements )
     }
 
     @Override
-    public void accept( DiffSetsVisitor<T> visitor ) throws ConstraintValidationKernelException
+    public void accept( DiffSetsVisitor<T> visitor )
+            throws ConstraintValidationKernelException, CreateConstraintFailureException
     {
         for ( T element : added( false ) )
         {

community/kernel/src/main/java/org/neo4j/kernel/impl/util/diffsets/SuperReadableDiffSets.java

@@ -26,6 +26,7 @@
 import org.neo4j.collection.primitive.PrimitiveLongIterator;
 import org.neo4j.function.Predicate;
 import org.neo4j.kernel.api.exceptions.schema.ConstraintValidationKernelException;
+import org.neo4j.kernel.api.exceptions.schema.CreateConstraintFailureException;
 
 /**
  * Super class of diff sets where use of {@link PrimitiveLongIterator} can be parameterized
@@ -55,5 +56,6 @@ public interface SuperReadableDiffSets<T,LONGITERATOR extends PrimitiveLongItera
 
     SuperReadableDiffSets<T,LONGITERATOR> filterAdded( Predicate<T> addedFilter );
 
-    void accept( DiffSetsVisitor<T> visitor ) throws ConstraintValidationKernelException;
+    void accept( DiffSetsVisitor<T> visitor )
+            throws ConstraintValidationKernelException, CreateConstraintFailureException;
 }