Examples with ReturnValueExpression org.apache.drill.exec.physical.impl.filter.ReturnValueExpression used on opensource projects

Example 1 with ReturnValueExpression

use of org.apache.drill.exec.physical.impl.filter.ReturnValueExpression in project drill by apache.

the class NestedLoopJoinBatch method setupWorker.

/**
   * Method generates the runtime code needed for NLJ. Other than the setup method to set the input and output value
   * vector references we implement three more methods
   * 1. doEval() -> Evaluates if record from left side matches record from the right side
   * 2. emitLeft() -> Project record from the left side
   * 3. emitRight() -> Project record from the right side (which is a hyper container)
   * @return the runtime generated class that implements the NestedLoopJoin interface
   */
private NestedLoopJoin setupWorker() throws IOException, ClassTransformationException, SchemaChangeException {
    final CodeGenerator<NestedLoopJoin> nLJCodeGenerator = CodeGenerator.get(NestedLoopJoin.TEMPLATE_DEFINITION, context.getFunctionRegistry(), context.getOptions());
    nLJCodeGenerator.plainJavaCapable(true);
    // Uncomment out this line to debug the generated code.
    //    nLJCodeGenerator.saveCodeForDebugging(true);
    final ClassGenerator<NestedLoopJoin> nLJClassGenerator = nLJCodeGenerator.getRoot();
    // generate doEval
    final ErrorCollector collector = new ErrorCollectorImpl();
    /*
        Logical expression may contain fields from left and right batches. During code generation (materialization)
        we need to indicate from which input field should be taken.

        Non-equality joins can belong to one of below categories. For example:
        1. Join on non-equality join predicates:
        select * from t1 inner join t2 on (t1.c1 between t2.c1 AND t2.c2) AND (...)
        2. Join with an OR predicate:
        select * from t1 inner join t2 on on t1.c1 = t2.c1 OR t1.c2 = t2.c2
     */
    Map<VectorAccessible, BatchReference> batches = ImmutableMap.<VectorAccessible, BatchReference>builder().put(left, new BatchReference("leftBatch", "leftIndex")).put(rightContainer, new BatchReference("rightContainer", "rightBatchIndex", "rightRecordIndexWithinBatch")).build();
    LogicalExpression materialize = ExpressionTreeMaterializer.materialize(popConfig.getCondition(), batches, collector, context.getFunctionRegistry(), false, false);
    if (collector.hasErrors()) {
        throw new SchemaChangeException(String.format("Failure while trying to materialize join condition. Errors:\n %s.", collector.toErrorString()));
    }
    nLJClassGenerator.addExpr(new ReturnValueExpression(materialize), ClassGenerator.BlkCreateMode.FALSE);
    // generate emitLeft
    nLJClassGenerator.setMappingSet(emitLeftMapping);
    JExpression outIndex = JExpr.direct("outIndex");
    JExpression leftIndex = JExpr.direct("leftIndex");
    int fieldId = 0;
    int outputFieldId = 0;
    // Set the input and output value vector references corresponding to the left batch
    for (MaterializedField field : leftSchema) {
        final TypeProtos.MajorType fieldType = field.getType();
        // Add the vector to the output container
        container.addOrGet(field);
        JVar inVV = nLJClassGenerator.declareVectorValueSetupAndMember("leftBatch", new TypedFieldId(fieldType, false, fieldId));
        JVar outVV = nLJClassGenerator.declareVectorValueSetupAndMember("outgoing", new TypedFieldId(fieldType, false, outputFieldId));
        nLJClassGenerator.getEvalBlock().add(outVV.invoke("copyFromSafe").arg(leftIndex).arg(outIndex).arg(inVV));
        nLJClassGenerator.rotateBlock();
        fieldId++;
        outputFieldId++;
    }
    // generate emitRight
    fieldId = 0;
    nLJClassGenerator.setMappingSet(emitRightMapping);
    JExpression batchIndex = JExpr.direct("batchIndex");
    JExpression recordIndexWithinBatch = JExpr.direct("recordIndexWithinBatch");
    // Set the input and output value vector references corresponding to the right batch
    for (MaterializedField field : rightSchema) {
        final TypeProtos.MajorType inputType = field.getType();
        TypeProtos.MajorType outputType;
        // if join type is LEFT, make sure right batch output fields data mode is optional
        if (popConfig.getJoinType() == JoinRelType.LEFT && inputType.getMode() == TypeProtos.DataMode.REQUIRED) {
            outputType = Types.overrideMode(inputType, TypeProtos.DataMode.OPTIONAL);
        } else {
            outputType = inputType;
        }
        MaterializedField newField = MaterializedField.create(field.getPath(), outputType);
        container.addOrGet(newField);
        JVar inVV = nLJClassGenerator.declareVectorValueSetupAndMember("rightContainer", new TypedFieldId(inputType, true, fieldId));
        JVar outVV = nLJClassGenerator.declareVectorValueSetupAndMember("outgoing", new TypedFieldId(outputType, false, outputFieldId));
        nLJClassGenerator.getEvalBlock().add(outVV.invoke("copyFromSafe").arg(recordIndexWithinBatch).arg(outIndex).arg(inVV.component(batchIndex)));
        nLJClassGenerator.rotateBlock();
        fieldId++;
        outputFieldId++;
    }
    return context.getImplementationClass(nLJCodeGenerator);
}