/** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link SortRel}. */
public TrimResult trimFields(SortRel sort, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
final RelDataType rowType = sort.getRowType();
final int fieldCount = rowType.getFieldCount();
final RelCollation collation = sort.getCollation();
final RelNode input = sort.getChild();
// We use the fields used by the consumer, plus any fields used as sort
// keys.
BitSet inputFieldsUsed = (BitSet) fieldsUsed.clone();
for (RelFieldCollation field : collation.getFieldCollations()) {
inputFieldsUsed.set(field.getFieldIndex());
}
// Create input with trimmed columns.
final Set<RelDataTypeField> inputExtraFields = Collections.emptySet();
TrimResult trimResult = trimChild(sort, input, inputFieldsUsed, inputExtraFields);
RelNode newInput = trimResult.left;
final Mapping inputMapping = trimResult.right;
// If the input is unchanged, and we need to project all columns,
// there's nothing we can do.
if (newInput == input && inputMapping.isIdentity() && fieldsUsed.cardinality() == fieldCount) {
return new TrimResult(sort, Mappings.createIdentity(fieldCount));
}
final SortRel newSort =
sort.copy(sort.getTraitSet(), newInput, RexUtil.apply(inputMapping, collation));
assert newSort.getClass() == sort.getClass();
// The result has the same mapping as the input gave us. Sometimes we
// return fields that the consumer didn't ask for, because the filter
// needs them for its condition.
return new TrimResult(newSort, inputMapping);
}
/** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link TableFunctionRel}. */
public TrimResult trimFields(
TableFunctionRel tabFun, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
final RelDataType rowType = tabFun.getRowType();
final int fieldCount = rowType.getFieldCount();
List<RelNode> newInputs = new ArrayList<RelNode>();
for (RelNode input : tabFun.getInputs()) {
final int inputFieldCount = input.getRowType().getFieldCount();
BitSet inputFieldsUsed = Util.bitSetBetween(0, inputFieldCount);
// Create input with trimmed columns.
final Set<RelDataTypeField> inputExtraFields = Collections.emptySet();
TrimResult trimResult = trimChildRestore(tabFun, input, inputFieldsUsed, inputExtraFields);
assert trimResult.right.isIdentity();
newInputs.add(trimResult.left);
}
TableFunctionRel newTabFun = tabFun;
if (!tabFun.getInputs().equals(newInputs)) {
newTabFun = tabFun.copy(tabFun.getTraitSet(), newInputs);
}
assert newTabFun.getClass() == tabFun.getClass();
// Always project all fields.
Mapping mapping = Mappings.createIdentity(fieldCount);
return new TrimResult(newTabFun, mapping);
}
/** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link TableModificationRel}. */
public TrimResult trimFields(
TableModificationRel modifier, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
// Ignore what consumer wants. We always project all columns.
Util.discard(fieldsUsed);
final RelDataType rowType = modifier.getRowType();
final int fieldCount = rowType.getFieldCount();
RelNode input = modifier.getChild();
// We want all fields from the child.
final int inputFieldCount = input.getRowType().getFieldCount();
BitSet inputFieldsUsed = Util.bitSetBetween(0, inputFieldCount);
// Create input with trimmed columns.
final Set<RelDataTypeField> inputExtraFields = Collections.emptySet();
TrimResult trimResult = trimChild(modifier, input, inputFieldsUsed, inputExtraFields);
RelNode newInput = trimResult.left;
final Mapping inputMapping = trimResult.right;
if (!inputMapping.isIdentity()) {
// We asked for all fields. Can't believe that the child decided
// to permute them!
throw Util.newInternal("Expected identity mapping, got " + inputMapping);
}
TableModificationRel newModifier = modifier;
if (newInput != input) {
newModifier = modifier.copy(modifier.getTraitSet(), Collections.singletonList(newInput));
}
assert newModifier.getClass() == modifier.getClass();
// Always project all fields.
Mapping mapping = Mappings.createIdentity(fieldCount);
return new TrimResult(newModifier, mapping);
}
/**
* Burrows into a synthetic record and returns the underlying relation which provides the field
* called <code>fieldName</code>.
*/
public JavaRel implementFieldAccess(JavaRelImplementor implementor, String fieldName) {
if (!isBoxed()) {
return implementor.implementFieldAccess((JavaRel) getChild(), fieldName);
}
RelDataType type = getRowType();
int field = type.getFieldOrdinal(fieldName);
RexLocalRef ref = program.getProjectList().get(field);
final int index = ref.getIndex();
return implementor.findRel((JavaRel) this, program.getExprList().get(index));
}
/**
* Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link SetOpRel} (including UNION and
* UNION ALL).
*/
public TrimResult trimFields(
SetOpRel setOp, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
final RelDataType rowType = setOp.getRowType();
final int fieldCount = rowType.getFieldCount();
int changeCount = 0;
// Fennel abhors an empty row type, so pretend that the parent rel
// wants the last field. (The last field is the least likely to be a
// system field.)
if (fieldsUsed.isEmpty()) {
fieldsUsed.set(rowType.getFieldCount() - 1);
}
// Compute the desired field mapping. Give the consumer the fields they
// want, in the order that they appear in the bitset.
final Mapping mapping = createMapping(fieldsUsed, fieldCount);
// Create input with trimmed columns.
final List<RelNode> newInputs = new ArrayList<RelNode>();
for (RelNode input : setOp.getInputs()) {
TrimResult trimResult = trimChild(setOp, input, fieldsUsed, extraFields);
RelNode newInput = trimResult.left;
final Mapping inputMapping = trimResult.right;
// We want "mapping", the input gave us "inputMapping", compute
// "remaining" mapping.
// | | |
// |---------------- mapping ---------->|
// |-- inputMapping -->| |
// | |-- remaining -->|
//
// For instance, suppose we have columns [a, b, c, d],
// the consumer asked for mapping = [b, d],
// and the transformed input has columns inputMapping = [d, a, b].
// remaining will permute [b, d] to [d, a, b].
Mapping remaining = Mappings.divide(mapping, inputMapping);
// Create a projection; does nothing if remaining is identity.
newInput = CalcRel.projectMapping(newInput, remaining, null);
if (input != newInput) {
++changeCount;
}
newInputs.add(newInput);
}
// If the input is unchanged, and we need to project all columns,
// there's to do.
if (changeCount == 0 && mapping.isIdentity()) {
return new TrimResult(setOp, mapping);
}
RelNode newSetOp = setOp.copy(setOp.getTraitSet(), newInputs);
return new TrimResult(newSetOp, mapping);
}
/**
* Generates a cast from one row type to another
*
* @param rexBuilder RexBuilder to use for constructing casts
* @param lhsRowType target row type
* @param rhsRowType source row type; fields must be 1-to-1 with lhsRowType, in same order
* @return cast expressions
*/
public static RexNode[] generateCastExpressions(
RexBuilder rexBuilder, RelDataType lhsRowType, RelDataType rhsRowType) {
int n = rhsRowType.getFieldCount();
assert n == lhsRowType.getFieldCount()
: "field count: lhs [" + lhsRowType + "] rhs [" + rhsRowType + "]";
RexNode[] rhsExps = new RexNode[n];
for (int i = 0; i < n; ++i) {
rhsExps[i] = rexBuilder.makeInputRef(rhsRowType.getFields()[i].getType(), i);
}
return generateCastExpressions(rexBuilder, lhsRowType, rhsExps);
}
/**
* Creates an expression which references the <i> fieldOrdinal</i><sup>th</sup> field of the
* <i>ordinal</i><sup>th</sup> input.
*
* <p>(We can potentially optimize the generation process, so we can access field values without
* actually instantiating the row.)
*/
public Expression translateInputField(JavaRel rel, int ordinal, int fieldOrdinal) {
assert ordinal >= 0;
assert ordinal < rel.getInputs().size();
assert fieldOrdinal >= 0;
assert fieldOrdinal < rel.getInput(ordinal).getRowType().getFieldList().size();
RelDataType rowType = rel.getRowType();
final RelDataTypeField[] fields = rowType.getFields();
final int fieldIndex = computeFieldOffset(rel, ordinal) + fieldOrdinal;
assert fieldIndex >= 0;
assert fieldIndex < fields.length;
final RexNode expr = rexBuilder.makeInputRef(fields[fieldIndex].getType(), fieldIndex);
return translate(rel, expr);
}
/**
* Derives the list of column names suitable for NATURAL JOIN. These are the columns that occur
* exactly once on each side of the join.
*
* @param leftRowType Row type of left input to the join
* @param rightRowType Row type of right input to the join
* @return List of columns that occur once on each side
*/
public static List<String> deriveNaturalJoinColumnList(
RelDataType leftRowType, RelDataType rightRowType) {
List<String> naturalColumnNames = new ArrayList<String>();
final List<String> leftNames = leftRowType.getFieldNames();
final List<String> rightNames = rightRowType.getFieldNames();
for (String name : leftNames) {
if ((Collections.frequency(leftNames, name) == 1)
&& (Collections.frequency(rightNames, name) == 1)) {
naturalColumnNames.add(name);
}
}
return naturalColumnNames;
}
public static RelDataType createTypeFromProjection(
RelDataType type,
List<String> columnNameList,
RelDataTypeFactory typeFactory,
boolean caseSensitive) {
// If the names in columnNameList and type have case-sensitive differences,
// the resulting type will use those from type. These are presumably more
// canonical.
final List<RelDataTypeField> fields = new ArrayList<RelDataTypeField>(columnNameList.size());
for (String name : columnNameList) {
RelDataTypeField field = type.getField(name, caseSensitive);
fields.add(type.getFieldList().get(field.getIndex()));
}
return typeFactory.createStructType(fields);
}
public Void visitInputRef(RexInputRef inputRef) {
super.visitInputRef(inputRef);
if (inputRef.getIndex() >= inputRowType.getFieldCount()) {
throw new IllegalForwardRefException();
}
return null;
}
/** Creates an array of {@link RexLocalRef} objects, one for each field of a given rowtype. */
public static RexLocalRef[] toLocalRefs(RelDataType rowType) {
final RelDataTypeField[] fields = rowType.getFields();
final RexLocalRef[] refs = new RexLocalRef[fields.length];
for (int i = 0; i < refs.length; i++) {
refs[i] = new RexLocalRef(i, fields[i].getType());
}
return refs;
}
/**
* Generates a cast for a row type.
*
* @param rexBuilder RexBuilder to use for constructing casts
* @param lhsRowType target row type
* @param rhsExps expressions to be cast
* @return cast expressions
*/
public static RexNode[] generateCastExpressions(
RexBuilder rexBuilder, RelDataType lhsRowType, RexNode[] rhsExps) {
RelDataTypeField[] lhsFields = lhsRowType.getFields();
final int fieldCount = lhsFields.length;
RexNode[] castExps = new RexNode[fieldCount];
assert fieldCount == rhsExps.length;
for (int i = 0; i < fieldCount; ++i) {
RelDataTypeField lhsField = lhsFields[i];
RelDataType lhsType = lhsField.getType();
RelDataType rhsType = rhsExps[i].getType();
if (lhsType.equals(rhsType)) {
castExps[i] = rhsExps[i];
} else {
castExps[i] = rexBuilder.makeCast(lhsType, rhsExps[i]);
}
}
return castExps;
}
/**
* Creates an array of {@link RexInputRef} objects, one for each field of a given rowtype,
* according to a permutation.
*
* @param args Permutation
* @param rowType Input row type
* @return Array of input refs
*/
public static RexInputRef[] toInputRefs(int[] args, RelDataType rowType) {
final RelDataTypeField[] fields = rowType.getFields();
final RexInputRef[] rexNodes = new RexInputRef[args.length];
for (int i = 0; i < args.length; i++) {
int fieldOrdinal = args[i];
rexNodes[i] = new RexInputRef(fieldOrdinal, fields[fieldOrdinal].getType());
}
return rexNodes;
}
/**
* Determines whether a {@link RexCall} requires decimal expansion. It usually requires expansion
* if it has decimal operands.
*
* <p>Exceptions to this rule are:
*
* <ul>
* <li>isNull doesn't require expansion
* <li>It's okay to cast decimals to and from char types
* <li>It's okay to cast nulls as decimals
* <li>Casts require expansion if their return type is decimal
* <li>Reinterpret casts can handle a decimal operand
* </ul>
*
* @param expr expression possibly in need of expansion
* @param recurse whether to check nested calls
* @return whether the expression requires expansion
*/
public static boolean requiresDecimalExpansion(RexNode expr, boolean recurse) {
if (!(expr instanceof RexCall)) {
return false;
}
RexCall call = (RexCall) expr;
boolean localCheck = true;
switch (call.getKind()) {
case Reinterpret:
case IsNull:
localCheck = false;
break;
case Cast:
RelDataType lhsType = call.getType();
RelDataType rhsType = call.operands[0].getType();
if (rhsType.getSqlTypeName() == SqlTypeName.NULL) {
return false;
}
if (SqlTypeUtil.inCharFamily(lhsType) || SqlTypeUtil.inCharFamily(rhsType)) {
localCheck = false;
} else if (SqlTypeUtil.isDecimal(lhsType) && (lhsType != rhsType)) {
return true;
}
break;
default:
localCheck = call.getOperator().requiresDecimalExpansion();
}
if (localCheck) {
if (SqlTypeUtil.isDecimal(call.getType())) {
// NOTE jvs 27-Mar-2007: Depending on the type factory, the
// result of a division may be decimal, even though both inputs
// are integer.
return true;
}
for (int i = 0; i < call.operands.length; i++) {
if (SqlTypeUtil.isDecimal(call.operands[i].getType())) {
return true;
}
}
}
return (recurse && requiresDecimalExpansion(call.operands, recurse));
}
public static void checkCharsetAndCollateConsistentIfCharType(RelDataType type) {
// (every charset must have a default collation)
if (SqlTypeUtil.inCharFamily(type)) {
Charset strCharset = type.getCharset();
Charset colCharset = type.getCollation().getCharset();
assert null != strCharset;
assert null != colCharset;
if (!strCharset.equals(colCharset)) {
if (false) {
// todo: enable this checking when we have a charset to
// collation mapping
throw new Error(
type.toString()
+ " was found to have charset '"
+ strCharset.name()
+ "' and a mismatched collation charset '"
+ colCharset.name()
+ "'");
}
}
}
}
private List<RelCollation> deduceMonotonicity(SqlValidatorTable table) {
final RelDataType rowType = table.getRowType();
final List<RelCollation> collationList = new ArrayList<RelCollation>();
// Deduce which fields the table is sorted on.
int i = -1;
for (RelDataTypeField field : rowType.getFieldList()) {
++i;
final SqlMonotonicity monotonicity = table.getMonotonicity(field.getName());
if (monotonicity != SqlMonotonicity.NOT_MONOTONIC) {
final RelFieldCollation.Direction direction =
monotonicity.isDecreasing()
? RelFieldCollation.Direction.DESCENDING
: RelFieldCollation.Direction.ASCENDING;
collationList.add(
RelCollationImpl.of(
new RelFieldCollation(
i, direction, RelFieldCollation.NullDirection.UNSPECIFIED)));
}
}
return collationList;
}
/** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link FilterRel}. */
public TrimResult trimFields(
FilterRel filter, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
final RelDataType rowType = filter.getRowType();
final int fieldCount = rowType.getFieldCount();
final RexNode conditionExpr = filter.getCondition();
final RelNode input = filter.getChild();
// We use the fields used by the consumer, plus any fields used in the
// filter.
BitSet inputFieldsUsed = (BitSet) fieldsUsed.clone();
final Set<RelDataTypeField> inputExtraFields = new LinkedHashSet<RelDataTypeField>(extraFields);
RelOptUtil.InputFinder inputFinder =
new RelOptUtil.InputFinder(inputFieldsUsed, inputExtraFields);
conditionExpr.accept(inputFinder);
// Create input with trimmed columns.
TrimResult trimResult = trimChild(filter, input, inputFieldsUsed, inputExtraFields);
RelNode newInput = trimResult.left;
final Mapping inputMapping = trimResult.right;
// If the input is unchanged, and we need to project all columns,
// there's nothing we can do.
if (newInput == input && fieldsUsed.cardinality() == fieldCount) {
return new TrimResult(filter, Mappings.createIdentity(fieldCount));
}
// Build new project expressions, and populate the mapping.
final RexVisitor<RexNode> shuttle = new RexPermuteInputsShuttle(inputMapping, newInput);
RexNode newConditionExpr = conditionExpr.accept(shuttle);
final FilterRel newFilter = new FilterRel(filter.getCluster(), newInput, newConditionExpr);
assert newFilter.getClass() == filter.getClass();
// The result has the same mapping as the input gave us. Sometimes we
// return fields that the consumer didn't ask for, because the filter
// needs them for its condition.
return new TrimResult(newFilter, inputMapping);
}
/**
* Trims a child relational expression, then adds back a dummy project to restore the fields that
* were removed.
*
* <p>Sounds pointless? It causes unused fields to be removed further down the tree (towards the
* leaves), but it ensure that the consuming relational expression continues to see the same
* fields.
*
* @param rel Relational expression
* @param input Input relational expression, whose fields to trim
* @param fieldsUsed Bitmap of fields needed by the consumer
* @return New relational expression and its field mapping
*/
protected TrimResult trimChildRestore(
RelNode rel, RelNode input, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
TrimResult trimResult = trimChild(rel, input, fieldsUsed, extraFields);
if (trimResult.right.isIdentity()) {
return trimResult;
}
final RelDataType rowType = input.getRowType();
List<RelDataTypeField> fieldList = rowType.getFieldList();
final List<RexNode> exprList = new ArrayList<RexNode>();
final List<String> nameList = rowType.getFieldNames();
RexBuilder rexBuilder = rel.getCluster().getRexBuilder();
assert trimResult.right.getSourceCount() == fieldList.size();
for (int i = 0; i < fieldList.size(); i++) {
int source = trimResult.right.getTargetOpt(i);
RelDataTypeField field = fieldList.get(i);
exprList.add(
source < 0
? rexBuilder.makeZeroLiteral(field.getType())
: rexBuilder.makeInputRef(field.getType(), source));
}
RelNode project = CalcRel.createProject(trimResult.left, exprList, nameList);
return new TrimResult(project, Mappings.createIdentity(fieldList.size()));
}
private void reduceCasts(RexCall outerCast) {
RexNode[] operands = outerCast.getOperands();
if (operands.length != 1) {
return;
}
RelDataType outerCastType = outerCast.getType();
RelDataType operandType = operands[0].getType();
if (operandType.equals(outerCastType)) {
removableCasts.add(outerCast);
return;
}
// See if the reduction
// CAST((CAST x AS type) AS type NOT NULL)
// -> CAST(x AS type NOT NULL)
// applies. TODO jvs 15-Dec-2008: consider
// similar cases for precision changes.
if (!(operands[0] instanceof RexCall)) {
return;
}
RexCall innerCast = (RexCall) operands[0];
if (innerCast.getOperator() != SqlStdOperatorTable.castFunc) {
return;
}
if (innerCast.getOperands().length != 1) {
return;
}
RelDataTypeFactory typeFactory = preparingStmt.getFarragoTypeFactory();
RelDataType outerTypeNullable = typeFactory.createTypeWithNullability(outerCastType, true);
RelDataType innerTypeNullable = typeFactory.createTypeWithNullability(operandType, true);
if (outerTypeNullable != innerTypeNullable) {
return;
}
if (operandType.isNullable()) {
removableCasts.add(innerCast);
}
}
/**
* Returns whether the type of an array of expressions is compatible with a struct type.
*
* @param exprs Array of expressions
* @param type Type
* @param fail Whether to fail if there is a mismatch
* @return Whether every expression has the same type as the corresponding member of the struct
* type
* @see RelOptUtil#eq(String, RelDataType, String, RelDataType, boolean)
*/
public static boolean compatibleTypes(RexNode[] exprs, RelDataType type, boolean fail) {
final RelDataTypeField[] fields = type.getFields();
if (exprs.length != fields.length) {
assert !fail : "rowtype mismatches expressions";
return false;
}
for (int i = 0; i < fields.length; i++) {
final RelDataType exprType = exprs[i].getType();
final RelDataType fieldType = fields[i].getType();
if (!RelOptUtil.eq("type1", exprType, "type2", fieldType, fail)) {
return false;
}
}
return true;
}
/**
* Looks up a field with a given name, returning null if not found.
*
* @param rowType Row type
* @param columnName Field name
* @return Field, or null if not found
*/
public static RelDataTypeField lookupField(
boolean caseSensitive, final RelDataType rowType, String columnName) {
RelDataTypeField field = rowType.getField(columnName, caseSensitive);
if (field != null) {
return field;
}
// If record type is flagged as having "any field you ask for",
// return a type. (TODO: Better way to mark accommodating types.)
RelDataTypeField extra = RelDataTypeImpl.extra(rowType);
if (extra != null) {
return new RelDataTypeFieldImpl(columnName, -1, extra.getType());
}
return null;
}
/**
* Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link org.eigenbase.rel.ValuesRel}.
*/
public TrimResult trimFields(
ValuesRel values, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
final RelDataType rowType = values.getRowType();
final int fieldCount = rowType.getFieldCount();
// If they are asking for no fields, we can't give them what they want,
// because zero-column records are illegal. Give them the last field,
// which is unlikely to be a system field.
if (fieldsUsed.isEmpty()) {
fieldsUsed = Util.bitSetBetween(fieldCount - 1, fieldCount);
}
// If all fields are used, return unchanged.
if (fieldsUsed.equals(Util.bitSetBetween(0, fieldCount))) {
Mapping mapping = Mappings.createIdentity(fieldCount);
return new TrimResult(values, mapping);
}
List<List<RexLiteral>> newTuples = new ArrayList<List<RexLiteral>>();
for (List<RexLiteral> tuple : values.getTuples()) {
List<RexLiteral> newTuple = new ArrayList<RexLiteral>();
for (int field : Util.toIter(fieldsUsed)) {
newTuple.add(tuple.get(field));
}
newTuples.add(newTuple);
}
final Mapping mapping = createMapping(fieldsUsed, fieldCount);
RelDataType newRowType =
values
.getCluster()
.getTypeFactory()
.createStructType(Mappings.apply3(mapping, rowType.getFieldList()));
final ValuesRel newValues = new ValuesRel(values.getCluster(), newRowType, newTuples);
return new TrimResult(newValues, mapping);
}
/**
* Replaces the operands of a call. The new operands' types must match the old operands' types.
*/
public static RexCall replaceOperands(RexCall call, RexNode[] operands) {
if (call.operands == operands) {
return call;
}
for (int i = 0; i < operands.length; i++) {
RelDataType oldType = call.operands[i].getType();
RelDataType newType = operands[i].getType();
if (!oldType.isNullable() && newType.isNullable()) {
throw Util.newInternal("invalid nullability");
}
assert (oldType.toString().equals(newType.toString()));
}
return new RexCall(call.getType(), call.getOperator(), operands);
}
/**
* Returns whether the leading edge of a given array of expressions is wholly {@link RexInputRef}
* objects with types corresponding to the underlying datatype.
*/
public static boolean containIdentity(RexNode[] exprs, RelDataType rowType, boolean fail) {
final RelDataTypeField[] fields = rowType.getFields();
if (exprs.length < fields.length) {
assert !fail : "exprs/rowType length mismatch";
return false;
}
for (int i = 0; i < fields.length; i++) {
if (!(exprs[i] instanceof RexInputRef)) {
assert !fail : "expr[" + i + "] is not a RexInputRef";
return false;
}
RexInputRef inputRef = (RexInputRef) exprs[i];
if (inputRef.getIndex() != i) {
assert !fail : "expr[" + i + "] has ordinal " + inputRef.getIndex();
return false;
}
if (!RelOptUtil.eq("type1", exprs[i].getType(), "type2", fields[i].getType(), fail)) {
return false;
}
}
return true;
}
/**
* Generates code for a Java expression satisfying the {@link org.eigenbase.runtime.TupleIter}
* interface. The generated code allocates a {@link org.eigenbase.runtime.CalcTupleIter} with a
* dynamic {@link org.eigenbase.runtime.TupleIter#fetchNext()} method. If the "abort on error"
* flag is false, or an error handling tag is specified, then fetchNext is written to handle row
* errors.
*
* <p>Row errors are handled by wrapping expressions that can fail with a try/catch block. A
* caught RuntimeException is then published to an "connection variable." In the event that errors
* can overflow, an "error buffering" flag allows them to be posted again on the next iteration of
* fetchNext.
*
* @param implementor an object that implements relations as Java code
* @param rel the relation to be implemented
* @param childExp the implemented child of the relation
* @param varInputRow the Java variable to use for the input row
* @param inputRowType the rel data type of the input row
* @param outputRowType the rel data type of the output row
* @param program the rex program to implemented by the relation
* @param tag an error handling tag
* @return a Java expression satisfying the TupleIter interface
*/
public static Expression implementAbstractTupleIter(
JavaRelImplementor implementor,
JavaRel rel,
Expression childExp,
Variable varInputRow,
final RelDataType inputRowType,
final RelDataType outputRowType,
RexProgram program,
String tag) {
MemberDeclarationList memberList = new MemberDeclarationList();
// Perform error recovery if continuing on errors or if
// an error handling tag has been specified
boolean errorRecovery = !abortOnError || (tag != null);
// Error buffering should not be enabled unless error recovery is
assert !errorBuffering || errorRecovery;
// Allow backwards compatibility until all Farrago extensions are
// satisfied with the new error handling semantics. The new semantics
// include:
// (1) cast input object to input row object outside of try block,
// should be fine, at least for base Farrago
// (2) maintain a columnIndex counter to better locate of error,
// at the cost of a few cycles
// (3) publish errors to the runtime context. FarragoRuntimeContext
// now supports this API
boolean backwardsCompatible = true;
if (tag != null) {
backwardsCompatible = false;
}
RelDataTypeFactory typeFactory = implementor.getTypeFactory();
OJClass outputRowClass = OJUtil.typeToOJClass(outputRowType, typeFactory);
OJClass inputRowClass = OJUtil.typeToOJClass(inputRowType, typeFactory);
Variable varOutputRow = implementor.newVariable();
FieldDeclaration inputRowVarDecl =
new FieldDeclaration(
new ModifierList(ModifierList.PRIVATE),
TypeName.forOJClass(inputRowClass),
varInputRow.toString(),
null);
FieldDeclaration outputRowVarDecl =
new FieldDeclaration(
new ModifierList(ModifierList.PRIVATE),
TypeName.forOJClass(outputRowClass),
varOutputRow.toString(),
new AllocationExpression(outputRowClass, new ExpressionList()));
// The method body for fetchNext, a main target of code generation
StatementList nextMethodBody = new StatementList();
// First, post an error if it overflowed the previous time
// if (pendingError) {
// rc = handleRowError(...);
// if (rc instanceof NoDataReason) {
// return rc;
// }
// pendingError = false;
// }
if (errorBuffering) {
// add to next method body...
}
// Most of fetchNext falls within a while() block. The while block
// allows us to try multiple input rows against a filter condition
// before returning a single row.
// while (true) {
// Object varInputObj = inputIterator.fetchNext();
// if (varInputObj instanceof TupleIter.NoDataReason) {
// return varInputObj;
// }
// varInputRow = (InputRowClass) varInputObj;
// int columnIndex = 0;
// [calculation statements]
// }
StatementList whileBody = new StatementList();
Variable varInputObj = implementor.newVariable();
whileBody.add(
new VariableDeclaration(
OJUtil.typeNameForClass(Object.class),
varInputObj.toString(),
new MethodCall(new FieldAccess("inputIterator"), "fetchNext", new ExpressionList())));
StatementList ifNoDataReasonBody = new StatementList();
whileBody.add(
new IfStatement(
new InstanceofExpression(
varInputObj, OJUtil.typeNameForClass(TupleIter.NoDataReason.class)),
ifNoDataReasonBody));
ifNoDataReasonBody.add(new ReturnStatement(varInputObj));
// Push up the row declaration for new error handling so that the
// input row is available to the error handler
if (!backwardsCompatible) {
whileBody.add(assignInputRow(inputRowClass, varInputRow, varInputObj));
}
Variable varColumnIndex = null;
if (errorRecovery && !backwardsCompatible) {
// NOTE jvs 7-Oct-2006: Declare varColumnIndex as a member
// (rather than a local) in case in the future we want
// to decompose complex expressions into helper methods.
varColumnIndex = implementor.newVariable();
FieldDeclaration varColumnIndexDecl =
new FieldDeclaration(
new ModifierList(ModifierList.PRIVATE),
OJUtil.typeNameForClass(int.class),
varColumnIndex.toString(),
null);
memberList.add(varColumnIndexDecl);
whileBody.add(
new ExpressionStatement(
new AssignmentExpression(
varColumnIndex, AssignmentExpression.EQUALS, Literal.makeLiteral(0))));
}
// Calculator (projection, filtering) statements are later appended
// to calcStmts. Typically, this target will be the while list itself.
StatementList calcStmts;
if (!errorRecovery) {
calcStmts = whileBody;
} else {
// For error recovery, we wrap the calc statements
// (e.g., everything but the code that reads rows from the
// inputIterator) in a try/catch that publishes exceptions.
calcStmts = new StatementList();
// try { /* calcStmts */ }
// catch(RuntimeException ex) {
// Object rc = connection.handleRowError(...);
// [buffer error if necessary]
// }
StatementList catchStmts = new StatementList();
if (backwardsCompatible) {
catchStmts.add(
new ExpressionStatement(
new MethodCall(
new MethodCall(
OJUtil.typeNameForClass(EigenbaseTrace.class), "getStatementTracer", null),
"log",
new ExpressionList(
new FieldAccess(OJUtil.typeNameForClass(Level.class), "WARNING"),
Literal.makeLiteral("java calc exception"),
new FieldAccess("ex")))));
} else {
Variable varRc = implementor.newVariable();
ExpressionList handleRowErrorArgs =
new ExpressionList(varInputRow, new FieldAccess("ex"), varColumnIndex);
handleRowErrorArgs.add(Literal.makeLiteral(tag));
catchStmts.add(
new VariableDeclaration(
OJUtil.typeNameForClass(Object.class),
varRc.toString(),
new MethodCall(
implementor.getConnectionVariable(), "handleRowError", handleRowErrorArgs)));
// Buffer an error if it overflowed
// if (rc instanceof NoDataReason) {
// pendingError = true;
// [save error state]
// return rc;
// }
if (errorBuffering) {
// add to catch statements...
}
}
CatchList catchList =
new CatchList(
new CatchBlock(
new Parameter(OJUtil.typeNameForClass(RuntimeException.class), "ex"),
catchStmts));
TryStatement tryStmt = new TryStatement(calcStmts, catchList);
whileBody.add(tryStmt);
}
if (backwardsCompatible) {
calcStmts.add(assignInputRow(inputRowClass, varInputRow, varInputObj));
}
StatementList condBody;
RexToOJTranslator translator = implementor.newStmtTranslator(rel, calcStmts, memberList);
try {
translator.pushProgram(program);
if (program.getCondition() != null) {
// TODO jvs 8-Oct-2006: move condition to its own
// method if big, as below for project exprs.
condBody = new StatementList();
RexNode rexIsTrue =
rel.getCluster()
.getRexBuilder()
.makeCall(SqlStdOperatorTable.isTrueOperator, program.getCondition());
Expression conditionExp = translator.translateRexNode(rexIsTrue);
calcStmts.add(new IfStatement(conditionExp, condBody));
} else {
condBody = calcStmts;
}
RelDataTypeField[] fields = outputRowType.getFields();
final List<RexLocalRef> projectRefList = program.getProjectList();
int i = -1;
for (RexLocalRef rhs : projectRefList) {
// NOTE jvs 14-Sept-2006: Put complicated project expressions
// into their own method, otherwise a big select list can easily
// blow the 64K Java limit on method bytecode size. Make
// methods private final in the hopes that they will get inlined
// JIT. For now we decide "complicated" based on the size of
// the generated Java parse tree. A big enough select list of
// simple expressions could still blow the limit, so we may need
// to group them together, sub-divide, etc.
StatementList projMethodBody = new StatementList();
if (errorRecovery && !backwardsCompatible) {
projMethodBody.add(
new ExpressionStatement(
new UnaryExpression(varColumnIndex, UnaryExpression.POST_INCREMENT)));
}
++i;
RexToOJTranslator projTranslator = translator.push(projMethodBody);
String javaFieldName = Util.toJavaId(fields[i].getName(), i);
Expression lhs = new FieldAccess(varOutputRow, javaFieldName);
projTranslator.translateAssignment(fields[i], lhs, rhs);
int complexity = OJUtil.countParseTreeNodes(projMethodBody);
// REVIEW: HCP 5/18/2011
// The projMethod should be checked
// for causing possible compiler errors caused by the use of
// variables declared in other projMethods. Also the
// local declaration of variabled used by other proj methods
// should also be checked.
// Fixing for backswing integration 14270
// TODO: check if abstracting this method body will cause
// a compiler error
if (true) {
// No method needed; just append.
condBody.addAll(projMethodBody);
continue;
}
// Need a separate method.
String projMethodName = "calc_" + varOutputRow.toString() + "_f_" + i;
MemberDeclaration projMethodDecl =
new MethodDeclaration(
new ModifierList(ModifierList.PRIVATE | ModifierList.FINAL),
TypeName.forOJClass(OJSystem.VOID),
projMethodName,
new ParameterList(),
null,
projMethodBody);
memberList.add(projMethodDecl);
condBody.add(new ExpressionStatement(new MethodCall(projMethodName, new ExpressionList())));
}
} finally {
translator.popProgram(program);
}
condBody.add(new ReturnStatement(varOutputRow));
WhileStatement whileStmt = new WhileStatement(Literal.makeLiteral(true), whileBody);
nextMethodBody.add(whileStmt);
MemberDeclaration fetchNextMethodDecl =
new MethodDeclaration(
new ModifierList(ModifierList.PUBLIC),
OJUtil.typeNameForClass(Object.class),
"fetchNext",
new ParameterList(),
null,
nextMethodBody);
// The restart() method should reset variables used to buffer errors
// pendingError = false
if (errorBuffering) {
// declare refinement of restart() and add to member list...
}
memberList.add(inputRowVarDecl);
memberList.add(outputRowVarDecl);
memberList.add(fetchNextMethodDecl);
Expression newTupleIterExp =
new AllocationExpression(
OJUtil.typeNameForClass(CalcTupleIter.class), new ExpressionList(childExp), memberList);
return newTupleIterExp;
}
/** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link ProjectRel}. */
public TrimResult trimFields(
ProjectRel project, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
final RelDataType rowType = project.getRowType();
final int fieldCount = rowType.getFieldCount();
final RelNode input = project.getChild();
final RelDataType inputRowType = input.getRowType();
// Which fields are required from the input?
BitSet inputFieldsUsed = new BitSet(inputRowType.getFieldCount());
final Set<RelDataTypeField> inputExtraFields = new LinkedHashSet<RelDataTypeField>(extraFields);
RelOptUtil.InputFinder inputFinder =
new RelOptUtil.InputFinder(inputFieldsUsed, inputExtraFields);
for (Ord<RexNode> ord : Ord.zip(project.getProjects())) {
if (fieldsUsed.get(ord.i)) {
ord.e.accept(inputFinder);
}
}
// Create input with trimmed columns.
TrimResult trimResult = trimChild(project, input, inputFieldsUsed, inputExtraFields);
RelNode newInput = trimResult.left;
final Mapping inputMapping = trimResult.right;
// If the input is unchanged, and we need to project all columns,
// there's nothing we can do.
if (newInput == input && fieldsUsed.cardinality() == fieldCount) {
return new TrimResult(project, Mappings.createIdentity(fieldCount));
}
// Some parts of the system can't handle rows with zero fields, so
// pretend that one field is used.
if (fieldsUsed.cardinality() == 0) {
final Mapping mapping = Mappings.create(MappingType.InverseSurjection, fieldCount, 1);
final RexLiteral expr =
project.getCluster().getRexBuilder().makeExactLiteral(BigDecimal.ZERO);
RelDataType newRowType =
project
.getCluster()
.getTypeFactory()
.createStructType(
Collections.singletonList(expr.getType()), Collections.singletonList("DUMMY"));
ProjectRel newProject =
new ProjectRel(
project.getCluster(),
project.getCluster().traitSetOf(RelCollationImpl.EMPTY),
newInput,
Collections.<RexNode>singletonList(expr),
newRowType,
project.getFlags());
return new TrimResult(newProject, mapping);
}
// Build new project expressions, and populate the mapping.
List<RexNode> newProjectExprList = new ArrayList<RexNode>();
final RexVisitor<RexNode> shuttle = new RexPermuteInputsShuttle(inputMapping, newInput);
final Mapping mapping =
Mappings.create(MappingType.InverseSurjection, fieldCount, fieldsUsed.cardinality());
for (Ord<RexNode> ord : Ord.zip(project.getProjects())) {
if (fieldsUsed.get(ord.i)) {
mapping.set(ord.i, newProjectExprList.size());
RexNode newProjectExpr = ord.e.accept(shuttle);
newProjectExprList.add(newProjectExpr);
}
}
final RelDataType newRowType =
project
.getCluster()
.getTypeFactory()
.createStructType(Mappings.apply3(mapping, rowType.getFieldList()));
final List<RelCollation> newCollations =
RexUtil.apply(inputMapping, project.getCollationList());
final RelNode newProject;
if (RemoveTrivialProjectRule.isIdentity(
newProjectExprList, newRowType, newInput.getRowType())) {
// The new project would be the identity. It is equivalent to return
// its child.
newProject = newInput;
} else {
newProject =
new ProjectRel(
project.getCluster(),
project
.getCluster()
.traitSetOf(
newCollations.isEmpty() ? RelCollationImpl.EMPTY : newCollations.get(0)),
newInput,
newProjectExprList,
newRowType,
project.getFlags());
assert newProject.getClass() == project.getClass();
}
return new TrimResult(newProject, mapping);
}
/** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link JoinRel}. */
public TrimResult trimFields(JoinRel join, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
final RelDataType rowType = join.getRowType();
final int fieldCount = rowType.getFieldCount();
final RexNode conditionExpr = join.getCondition();
final int systemFieldCount = join.getSystemFieldList().size();
// Add in fields used in the condition.
BitSet fieldsUsedPlus = (BitSet) fieldsUsed.clone();
final Set<RelDataTypeField> combinedInputExtraFields =
new LinkedHashSet<RelDataTypeField>(extraFields);
RelOptUtil.InputFinder inputFinder =
new RelOptUtil.InputFinder(fieldsUsedPlus, combinedInputExtraFields);
conditionExpr.accept(inputFinder);
// If no system fields are used, we can remove them.
int systemFieldUsedCount = 0;
for (int i = 0; i < systemFieldCount; ++i) {
if (fieldsUsed.get(i)) {
++systemFieldUsedCount;
}
}
final int newSystemFieldCount;
if (systemFieldUsedCount == 0) {
newSystemFieldCount = 0;
} else {
newSystemFieldCount = systemFieldCount;
}
int offset = systemFieldCount;
int changeCount = 0;
int newFieldCount = newSystemFieldCount;
List<RelNode> newInputs = new ArrayList<RelNode>(2);
List<Mapping> inputMappings = new ArrayList<Mapping>();
List<Integer> inputExtraFieldCounts = new ArrayList<Integer>();
for (RelNode input : join.getInputs()) {
final RelDataType inputRowType = input.getRowType();
final int inputFieldCount = inputRowType.getFieldCount();
// Compute required mapping.
BitSet inputFieldsUsed = new BitSet(inputFieldCount);
for (int bit : Util.toIter(fieldsUsedPlus)) {
if (bit >= offset && bit < offset + inputFieldCount) {
inputFieldsUsed.set(bit - offset);
}
}
// If there are system fields, we automatically use the
// corresponding field in each input.
if (newSystemFieldCount > 0) {
// calling with newSystemFieldCount == 0 should be safe but hits
// http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6222207
inputFieldsUsed.set(0, newSystemFieldCount);
}
// FIXME: We ought to collect extra fields for each input
// individually. For now, we assume that just one input has
// on-demand fields.
Set<RelDataTypeField> inputExtraFields =
input.getRowType().getField("_extra") == null
? Collections.<RelDataTypeField>emptySet()
: combinedInputExtraFields;
inputExtraFieldCounts.add(inputExtraFields.size());
TrimResult trimResult = trimChild(join, input, inputFieldsUsed, 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.
offset += inputFieldCount;
newFieldCount += inputMapping.getTargetCount() + inputExtraFields.size();
}
Mapping mapping = Mappings.create(MappingType.InverseSurjection, fieldCount, newFieldCount);
for (int i = 0; i < newSystemFieldCount; ++i) {
mapping.set(i, i);
}
offset = systemFieldCount;
int newOffset = newSystemFieldCount;
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() + inputExtraFieldCounts.get(i);
}
if (changeCount == 0 && mapping.isIdentity()) {
return new TrimResult(join, Mappings.createIdentity(fieldCount));
}
// Build new join.
final RexVisitor<RexNode> shuttle =
new RexPermuteInputsShuttle(mapping, newInputs.get(0), newInputs.get(1));
RexNode newConditionExpr = conditionExpr.accept(shuttle);
final JoinRel newJoin =
join.copy(join.getTraitSet(), newConditionExpr, newInputs.get(0), newInputs.get(1));
return new TrimResult(newJoin, mapping);
}
/** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link AggregateRel}. */
public TrimResult trimFields(
AggregateRel aggregate, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
// Fields:
//
// | sys fields | group fields | agg functions |
//
// Two kinds of trimming:
//
// 1. If agg rel has system fields but none of these are used, create an
// agg rel with no system fields.
//
// 2. If aggregate functions are not used, remove them.
//
// But grouping fields stay, even if they are not used.
final RelDataType rowType = aggregate.getRowType();
// Compute which input fields are used.
BitSet inputFieldsUsed = new BitSet();
// 1. group fields are always used
for (int i : Util.toIter(aggregate.getGroupSet())) {
inputFieldsUsed.set(i);
}
// 2. agg functions
for (AggregateCall aggCall : aggregate.getAggCallList()) {
for (int i : aggCall.getArgList()) {
inputFieldsUsed.set(i);
}
}
// Create input with trimmed columns.
final RelNode input = aggregate.getInput(0);
final Set<RelDataTypeField> inputExtraFields = Collections.emptySet();
final TrimResult trimResult = trimChild(aggregate, input, inputFieldsUsed, inputExtraFields);
final RelNode newInput = trimResult.left;
final Mapping inputMapping = trimResult.right;
// If the input is unchanged, and we need to project all columns,
// there's nothing to do.
if (input == newInput && fieldsUsed.equals(Util.bitSetBetween(0, rowType.getFieldCount()))) {
return new TrimResult(aggregate, Mappings.createIdentity(rowType.getFieldCount()));
}
// Which agg calls are used by our consumer?
final int groupCount = aggregate.getGroupSet().cardinality();
int j = groupCount;
int usedAggCallCount = 0;
for (int i = 0; i < aggregate.getAggCallList().size(); i++) {
if (fieldsUsed.get(j++)) {
++usedAggCallCount;
}
}
// Offset due to the number of system fields having changed.
Mapping mapping =
Mappings.create(
MappingType.InverseSurjection, rowType.getFieldCount(), groupCount + usedAggCallCount);
final BitSet newGroupSet = Mappings.apply(inputMapping, aggregate.getGroupSet());
// Populate mapping of where to find the fields. System and grouping
// fields first.
for (IntPair pair : inputMapping) {
if (pair.source < groupCount) {
mapping.set(pair.source, pair.target);
}
}
// Now create new agg calls, and populate mapping for them.
final List<AggregateCall> newAggCallList = new ArrayList<AggregateCall>();
j = groupCount;
for (AggregateCall aggCall : aggregate.getAggCallList()) {
if (fieldsUsed.get(j)) {
AggregateCall newAggCall =
new AggregateCall(
aggCall.getAggregation(),
aggCall.isDistinct(),
Mappings.apply2(inputMapping, aggCall.getArgList()),
aggCall.getType(),
aggCall.getName());
if (newAggCall.equals(aggCall)) {
newAggCall = aggCall; // immutable -> canonize to save space
}
mapping.set(j, groupCount + newAggCallList.size());
newAggCallList.add(newAggCall);
}
++j;
}
RelNode newAggregate =
new AggregateRel(aggregate.getCluster(), newInput, newGroupSet, newAggCallList);
assert newAggregate.getClass() == aggregate.getClass();
return new TrimResult(newAggregate, mapping);
}