Author: rvesse
Date: Tue Aug 12 16:36:29 2014
New Revision: 1617524
URL: http://svn.apache.org/r1617524
Log:
Make TransformQuadGraph a public class (JENA-763)
Added:
jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/algebra/TransformQuadGraph.java
Modified:
jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/algebra/AlgebraQuad.java
Modified:
jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/algebra/AlgebraQuad.java
URL:
http://svn.apache.org/viewvc/jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/algebra/AlgebraQuad.java?rev=1617524&r1=1617523&r2=1617524&view=diff
==============================================================================
---
jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/algebra/AlgebraQuad.java
(original)
+++
jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/algebra/AlgebraQuad.java
Tue Aug 12 16:36:29 2014
@@ -28,10 +28,11 @@ import com.hp.hpl.jena.sparql.algebra.op
import com.hp.hpl.jena.sparql.core.Quad ;
import com.hp.hpl.jena.sparql.core.Var ;
import com.hp.hpl.jena.sparql.core.VarAlloc ;
-import com.hp.hpl.jena.sparql.expr.* ;
-/** Convert an algebra expression into a quad form */
-public class AlgebraQuad extends TransformCopy
+/**
+ * Helper class for converting an algebra expression into a quad form
+ * */
+public class AlgebraQuad
{
// Transform to a quad form:
// + BGPs go to quad patterns
@@ -63,7 +64,7 @@ public class AlgebraQuad extends Transfo
* If they are different (and that means they are variables)
* an assign is done after the execution of the graph pattern block.
*/
- private static class QuadSlot
+ static class QuadSlot
{ // Oh scala, where art thou!
final Node actualGraphName ;
final Node rewriteGraphName ;
@@ -110,100 +111,5 @@ public class AlgebraQuad extends Transfo
// rewritten.
stack.pop() ;
}
- }
-
- private static class TransformQuadGraph extends TransformCopy
- {
- private Deque<QuadSlot> tracker ;
-
- public TransformQuadGraph(Deque<QuadSlot> tracker) { this.tracker =
tracker ; }
-
- private Node getNode() { return tracker.peek().rewriteGraphName ; }
-
- @Override
- public Op transform(OpGraph opGraph, Op op)
- {
- // ?? Could just leave the (graph) in place always - just rewrite
BGPs.
- boolean noPattern = false ;
-
- /* One case to consider is when the pattern for the GRAPH
- * statement includes uses the variable inside the GRAPH clause.
- * In this case, we must rename away the inner variable
- * to allow stream execution via index joins,
- * and then put back the value via an assign.
- * (This is what QueryIterGraph does using a streaming join
- * for triples)
- */
-
- // Note: op is already quads by this point.
- // Must test scoping by the subOp of GRAPH
-
- QuadSlot qSlot = tracker.peek() ;
- Node actualName= qSlot.actualGraphName ;
- Node rewriteName= qSlot.rewriteGraphName ;
-
- if ( OpBGP.isBGP(op) )
- {
- // Empty BGP
- if ( ((OpBGP)op).getPattern().isEmpty() )
- noPattern = true ;
- }
- else if ( op instanceof OpTable )
- {
- // Empty BGP compiled to a unit table
- if ( ((OpTable)op).isJoinIdentity() )
- noPattern = true ;
- }
-
- if ( noPattern )
- {
- // The case of something like:
- // GRAPH ?g {} or GRAPH <v> {}
- // which are ways of accessing the names in the dataset.
- return new OpDatasetNames(opGraph.getNode()) ;
- }
-
- if ( actualName != rewriteName )
- op = OpAssign.assign(op, Var.alloc(actualName), new
ExprVar(rewriteName)) ;
-
- // Drop (graph...) because inside nodes
- // have been converted to quads.
- return op ;
- }
-
- @Override
- public Op transform(OpPropFunc opPropFunc, Op subOp)
- {
- if ( opPropFunc.getSubOp() != subOp )
- opPropFunc = new OpPropFunc(opPropFunc.getProperty(),
opPropFunc.getSubjectArgs(), opPropFunc.getObjectArgs(), subOp) ;
- // Put the (graph) back round it so the property function works on
the named graph.
- return new OpGraph(getNode() , opPropFunc) ;
- }
-
- @Override
- public Op transform(OpPath opPath)
- {
- // Put the (graph) back round it
- // ?? inc default graph node.
- return new OpGraph(getNode() , opPath) ;
- // Does not get removed by transform above because this is
- // not the OpGraph that gets walked by the transform.
- }
-
- @Override
- public Op transform(OpBGP opBGP)
- {
- return new OpQuadPattern(getNode(), opBGP.getPattern()) ;
- }
-
-// static class X extends ExprTransformBase
-// {
-// @Override public Expr transform(ExprFunctionOp funcOp, ExprList
args, Op opArg)
-// {
-// System.out.println("****") ;
-//
-// return funcOp ; }
-// }
-
}
}
Added:
jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/algebra/TransformQuadGraph.java
URL:
http://svn.apache.org/viewvc/jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/algebra/TransformQuadGraph.java?rev=1617524&view=auto
==============================================================================
---
jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/algebra/TransformQuadGraph.java
(added)
+++
jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/algebra/TransformQuadGraph.java
Tue Aug 12 16:36:29 2014
@@ -0,0 +1,123 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.hp.hpl.jena.sparql.algebra;
+
+import java.util.Deque;
+
+import com.hp.hpl.jena.graph.Node;
+import com.hp.hpl.jena.sparql.algebra.AlgebraQuad.QuadSlot;
+import com.hp.hpl.jena.sparql.algebra.op.OpAssign;
+import com.hp.hpl.jena.sparql.algebra.op.OpBGP;
+import com.hp.hpl.jena.sparql.algebra.op.OpDatasetNames;
+import com.hp.hpl.jena.sparql.algebra.op.OpGraph;
+import com.hp.hpl.jena.sparql.algebra.op.OpPath;
+import com.hp.hpl.jena.sparql.algebra.op.OpPropFunc;
+import com.hp.hpl.jena.sparql.algebra.op.OpQuadPattern;
+import com.hp.hpl.jena.sparql.algebra.op.OpTable;
+import com.hp.hpl.jena.sparql.core.Var;
+import com.hp.hpl.jena.sparql.expr.ExprVar;
+
+/**
+ * Transform that rewrites an algebra into quad form
+ *
+ */
+public class TransformQuadGraph extends TransformCopy
+{
+ private Deque<QuadSlot> tracker ;
+
+ public TransformQuadGraph(Deque<QuadSlot> tracker) { this.tracker =
tracker ; }
+
+ private Node getNode() { return tracker.peek().rewriteGraphName ; }
+
+ @Override
+ public Op transform(OpGraph opGraph, Op op)
+ {
+ // ?? Could just leave the (graph) in place always - just rewrite
BGPs.
+ boolean noPattern = false ;
+
+ /* One case to consider is when the pattern for the GRAPH
+ * statement includes uses the variable inside the GRAPH clause.
+ * In this case, we must rename away the inner variable
+ * to allow stream execution via index joins,
+ * and then put back the value via an assign.
+ * (This is what QueryIterGraph does using a streaming join
+ * for triples)
+ */
+
+ // Note: op is already quads by this point.
+ // Must test scoping by the subOp of GRAPH
+
+ QuadSlot qSlot = tracker.peek() ;
+ Node actualName= qSlot.actualGraphName ;
+ Node rewriteName= qSlot.rewriteGraphName ;
+
+ if ( OpBGP.isBGP(op) )
+ {
+ // Empty BGP
+ if ( ((OpBGP)op).getPattern().isEmpty() )
+ noPattern = true ;
+ }
+ else if ( op instanceof OpTable )
+ {
+ // Empty BGP compiled to a unit table
+ if ( ((OpTable)op).isJoinIdentity() )
+ noPattern = true ;
+ }
+
+ if ( noPattern )
+ {
+ // The case of something like:
+ // GRAPH ?g {} or GRAPH <v> {}
+ // which are ways of accessing the names in the dataset.
+ return new OpDatasetNames(opGraph.getNode()) ;
+ }
+
+ if ( actualName != rewriteName )
+ op = OpAssign.assign(op, Var.alloc(actualName), new
ExprVar(rewriteName)) ;
+
+ // Drop (graph...) because inside nodes
+ // have been converted to quads.
+ return op ;
+ }
+
+ @Override
+ public Op transform(OpPropFunc opPropFunc, Op subOp)
+ {
+ if ( opPropFunc.getSubOp() != subOp )
+ opPropFunc = new OpPropFunc(opPropFunc.getProperty(),
opPropFunc.getSubjectArgs(), opPropFunc.getObjectArgs(), subOp) ;
+ // Put the (graph) back round it so the property function works on the
named graph.
+ return new OpGraph(getNode() , opPropFunc) ;
+ }
+
+ @Override
+ public Op transform(OpPath opPath)
+ {
+ // Put the (graph) back round it
+ // ?? inc default graph node.
+ return new OpGraph(getNode() , opPath) ;
+ // Does not get removed by transform above because this is
+ // not the OpGraph that gets walked by the transform.
+ }
+
+ @Override
+ public Op transform(OpBGP opBGP)
+ {
+ return new OpQuadPattern(getNode(), opBGP.getPattern()) ;
+ }
+}
\ No newline at end of file
