Examples with IntPair org.apache.calcite.util.mapping.IntPair used on opensource projects

Example 1 with IntPair

use of org.apache.calcite.util.mapping.IntPair in project hive by apache.

the class HiveRelFieldTrimmer method trimFields.

/**
   * Variant of {@link #trimFields(RelNode, ImmutableBitSet, Set)} for
   * {@link org.apache.hadoop.hive.ql.optimizer.calcite.reloperators.HiveMultiJoin}.
   */
public TrimResult trimFields(HiveMultiJoin join, ImmutableBitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
    final int fieldCount = join.getRowType().getFieldCount();
    final RexNode conditionExpr = join.getCondition();
    final List<RexNode> joinFilters = join.getJoinFilters();
    // Add in fields used in the condition.
    final Set<RelDataTypeField> combinedInputExtraFields = new LinkedHashSet<RelDataTypeField>(extraFields);
    RelOptUtil.InputFinder inputFinder = new RelOptUtil.InputFinder(combinedInputExtraFields);
    inputFinder.inputBitSet.addAll(fieldsUsed);
    conditionExpr.accept(inputFinder);
    final ImmutableBitSet fieldsUsedPlus = inputFinder.inputBitSet.build();
    int inputStartPos = 0;
    int changeCount = 0;
    int newFieldCount = 0;
    List<RelNode> newInputs = new ArrayList<RelNode>();
    List<Mapping> inputMappings = new ArrayList<Mapping>();
    for (RelNode input : join.getInputs()) {
        final RelDataType inputRowType = input.getRowType();
        final int inputFieldCount = inputRowType.getFieldCount();
        // Compute required mapping.
        ImmutableBitSet.Builder inputFieldsUsed = ImmutableBitSet.builder();
        for (int bit : fieldsUsedPlus) {
            if (bit >= inputStartPos && bit < inputStartPos + inputFieldCount) {
                inputFieldsUsed.set(bit - inputStartPos);
            }
        }
        Set<RelDataTypeField> inputExtraFields = Collections.<RelDataTypeField>emptySet();
        TrimResult trimResult = trimChild(join, input, inputFieldsUsed.build(), inputExtraFields);
        newInputs.add(trimResult.left);
        if (trimResult.left != input) {
            ++changeCount;
        }
        final Mapping inputMapping = trimResult.right;
        inputMappings.add(inputMapping);
        // Move offset to point to start of next input.
        inputStartPos += inputFieldCount;
        newFieldCount += inputMapping.getTargetCount();
    }
    Mapping mapping = Mappings.create(MappingType.INVERSE_SURJECTION, fieldCount, newFieldCount);
    int offset = 0;
    int newOffset = 0;
    for (int i = 0; i < inputMappings.size(); i++) {
        Mapping inputMapping = inputMappings.get(i);
        for (IntPair pair : inputMapping) {
            mapping.set(pair.source + offset, pair.target + newOffset);
        }
        offset += inputMapping.getSourceCount();
        newOffset += inputMapping.getTargetCount();
    }
    if (changeCount == 0 && mapping.isIdentity()) {
        return new TrimResult(join, Mappings.createIdentity(fieldCount));
    }
    // Build new join.
    final RexVisitor<RexNode> shuttle = new RexPermuteInputsShuttle(mapping, newInputs.toArray(new RelNode[newInputs.size()]));
    RexNode newConditionExpr = conditionExpr.accept(shuttle);
    List<RexNode> newJoinFilters = Lists.newArrayList();
    for (RexNode joinFilter : joinFilters) {
        newJoinFilters.add(joinFilter.accept(shuttle));
    }
    final RelDataType newRowType = RelOptUtil.permute(join.getCluster().getTypeFactory(), join.getRowType(), mapping);
    final RelNode newJoin = new HiveMultiJoin(join.getCluster(), newInputs, newConditionExpr, newRowType, join.getJoinInputs(), join.getJoinTypes(), newJoinFilters);
    return new TrimResult(newJoin, mapping);
}