svn commit: r1550797 - /incubator/vxquery/trunk/vxquery/vxquery-core/src/main/java/org/apache/vxquery/compiler/rewriter/rules/RemoveRedundantDataExpressionsRule.java

[pr...@apache.org]

Author: prestonc
Date: Fri Dec 13 18:31:18 2013
New Revision: 1550797

URL: http://svn.apache.org/r1550797
Log:
Added a rule to remove data function when the data is already atomic.

Added:
    incubator/vxquery/trunk/vxquery/vxquery-core/src/main/java/org/apache/vxquery/compiler/rewriter/rules/RemoveRedundantDataExpressionsRule.java   (with props)

Added: incubator/vxquery/trunk/vxquery/vxquery-core/src/main/java/org/apache/vxquery/compiler/rewriter/rules/RemoveRedundantDataExpressionsRule.java
URL: http://svn.apache.org/viewvc/incubator/vxquery/trunk/vxquery/vxquery-core/src/main/java/org/apache/vxquery/compiler/rewriter/rules/RemoveRedundantDataExpressionsRule.java?rev=1550797&view=auto
==============================================================================
--- incubator/vxquery/trunk/vxquery/vxquery-core/src/main/java/org/apache/vxquery/compiler/rewriter/rules/RemoveRedundantDataExpressionsRule.java (added)
+++ incubator/vxquery/trunk/vxquery/vxquery-core/src/main/java/org/apache/vxquery/compiler/rewriter/rules/RemoveRedundantDataExpressionsRule.java Fri Dec 13 18:31:18 2013
@@ -0,0 +1,109 @@
+/*
+ * 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 org.apache.vxquery.compiler.rewriter.rules;
+
+import java.util.List;
+
+import org.apache.commons.lang3.mutable.Mutable;
+import org.apache.vxquery.compiler.rewriter.rules.util.ExpressionToolbox;
+import org.apache.vxquery.compiler.rewriter.rules.util.OperatorToolbox;
+import org.apache.vxquery.context.RootStaticContextImpl;
+import org.apache.vxquery.context.StaticContextImpl;
+import org.apache.vxquery.functions.BuiltinFunctions;
+import org.apache.vxquery.functions.Function;
+import org.apache.vxquery.types.SequenceType;
+
+import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
+import edu.uci.ics.hyracks.algebricks.core.algebra.base.IOptimizationContext;
+import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AbstractFunctionCallExpression;
+import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule;
+
+/**
+ * The rule searches for where the xquery data function is used. When the
+ * expression's return type is atomic, the data function is removed.
+ * 
+ * <pre>
+ * Before
+ * 
+ *   plan__parent
+ *   %OPERATOR( $v1 : data( \@input_expression ) )
+ *   plan__child
+ *   
+ *   Where \@input_expression creates an atomic value.
+ *   
+ * After 
+ * 
+ *   plan__parent
+ *   %OPERATOR( $v1 : \@input_expression )
+ *   plan__child
+ * </pre>
+ * 
+ * @author prestonc
+ */
+public class RemoveRedundantDataExpressionsRule implements IAlgebraicRewriteRule {
+    final StaticContextImpl dCtx = new StaticContextImpl(RootStaticContextImpl.INSTANCE);
+    final int ARG_DATA = 0;
+
+    @Override
+    public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) throws AlgebricksException {
+        return false;
+    }
+
+    @Override
+    public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context)
+            throws AlgebricksException {
+        boolean modified = false;
+        List<Mutable<ILogicalExpression>> expressions = OperatorToolbox.getExpression(opRef);
+        for (Mutable<ILogicalExpression> expression : expressions) {
+            if (processDataExpression(expression)) {
+                modified = true;
+            }
+        }
+        return modified;
+    }
+
+    private boolean processDataExpression(Mutable<ILogicalExpression> search) {
+        boolean modified = false;
+        Mutable<ILogicalExpression> dataM = ExpressionToolbox.findFunctionExpression(search,
+                BuiltinFunctions.FN_DATA_1.getFunctionIdentifier());
+        if (dataM != null) {
+            // Get input function
+            AbstractFunctionCallExpression promoteFunction = (AbstractFunctionCallExpression) dataM.getValue();
+            Mutable<ILogicalExpression> argDataM = promoteFunction.getArguments().get(ARG_DATA);
+
+            // Find the input return type.
+            SequenceType inputSequenceType = null;
+            Function function = ExpressionToolbox.getBuiltIn(argDataM);
+            if (function == null) {
+                return false;
+            } else {
+                inputSequenceType = function.getSignature().getReturnType();
+            }
+
+            // remove
+            if (inputSequenceType != null && inputSequenceType.getItemType().isAtomicType()) {
+                dataM.setValue(argDataM.getValue());
+                modified = true;
+                processDataExpression(argDataM);
+            }
+        }
+        return modified;
+    }
+
+}

Propchange: incubator/vxquery/trunk/vxquery/vxquery-core/src/main/java/org/apache/vxquery/compiler/rewriter/rules/RemoveRedundantDataExpressionsRule.java
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