org.apache.calcite.adapter.enumerable

Class RexToLixTranslator

java.lang.Object

org.apache.calcite.adapter.enumerable.RexToLixTranslator

public class RexToLixTranslator
extends Object

Translates REX expressions to linq4j expressions.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) static class	RexToLixTranslator.AlwaysNull Thrown in the unusual (but not erroneous) situation where the expression we are translating is the null literal but we have already checked that it is not null.
static interface	RexToLixTranslator.InputGetter Translates a field of an input to an expression.
static class	RexToLixTranslator.InputGetterImpl Implementation of RexToLixTranslator.InputGetter that calls PhysType.fieldReference(org.apache.calcite.linq4j.tree.Expression, int).

Field Summary

Fields

Modifier and Type	Field and Description
(package private) RexBuilder	builder
private Function1<String,RexToLixTranslator.InputGetter>	correlates
private Map<? extends RexNode,Boolean>	exprNullableMap
private RexToLixTranslator.InputGetter	inputGetter
static Map<Method,SqlOperator>	JAVA_TO_SQL_METHOD_MAP
private BlockBuilder	list
private RexToLixTranslator	parent
private RexProgram	program
private Expression	root
(package private) JavaTypeFactory	typeFactory

Constructor Summary

Constructors

Modifier	Constructor and Description
private	RexToLixTranslator(RexProgram program, JavaTypeFactory typeFactory, Expression root, RexToLixTranslator.InputGetter inputGetter, BlockBuilder list)
private	RexToLixTranslator(RexProgram program, JavaTypeFactory typeFactory, Expression root, RexToLixTranslator.InputGetter inputGetter, BlockBuilder list, Map<? extends RexNode,Boolean> exprNullableMap, RexBuilder builder, RexToLixTranslator parent)
private	RexToLixTranslator(RexProgram program, JavaTypeFactory typeFactory, Expression root, RexToLixTranslator.InputGetter inputGetter, BlockBuilder list, Map<? extends RexNode,Boolean> exprNullableMap, RexBuilder builder, RexToLixTranslator parent, Function1<String,RexToLixTranslator.InputGetter> correlates)
private	RexToLixTranslator(RexProgram program, JavaTypeFactory typeFactory, Expression root, RexToLixTranslator.InputGetter inputGetter, BlockBuilder list, Map<RexNode,Boolean> exprNullableMap, RexBuilder builder)

Method Summary

Modifier and Type	Method and Description
static Expression	convert(Expression operand, Type toType)
static Expression	convert(Expression operand, Type fromType, Type toType)
RexNode	deref(RexNode expr) Dereferences an expression if it is a RexLocalRef.
private static Method	findMethod(Class<?> clazz, String name, Class... parameterTypes)
static RexToLixTranslator	forAggregation(JavaTypeFactory typeFactory, BlockBuilder list, RexToLixTranslator.InputGetter inputGetter) Creates a translator for translating aggregate functions.
Expression	getRoot()
Expression	handleNull(Expression input, RexImpTable.NullAs nullAs) Adapts an expression with "normal" result to one that adheres to this particular policy.
(package private) static boolean	isA(Type fromType, Primitive primitive)
protected Boolean	isKnownNullable(RexNode node) Walks parent translator chain and verifies if the expression is nullable.
boolean	isNullable(RexNode e) Returns whether an expression is nullable.
private Primitive	javaPrimitive(RelDataType type)
RelDataType	nullifyType(RelDataType type, boolean nullable)
RexToLixTranslator	setBlock(BlockBuilder block)
RexToLixTranslator	setCorrelates(Function1<String,RexToLixTranslator.InputGetter> correlates)
RexToLixTranslator	setNullable(Map<? extends RexNode,Boolean> nullable) Creates a read-only copy of this translator that records that a given expression is nullable.
RexToLixTranslator	setNullable(RexNode e, boolean nullable) Creates a read-only copy of this translator that records that a given expression is nullable.
(package private) Expression	translate(RexNode expr)
(package private) Expression	translate(RexNode expr, RexImpTable.NullAs nullAs)
(package private) Expression	translate(RexNode expr, RexImpTable.NullAs nullAs, Type storageType)
(package private) Expression	translate(RexNode expr, Type storageType)
private Expression	translate0(RexNode expr, RexImpTable.NullAs nullAs, Type storageType) Translates an expression that is not in the cache.
private Expression	translateCall(RexCall call, RexImpTable.NullAs nullAs) Translates a call to an operator or function.
(package private) Expression	translateCast(RelDataType sourceType, RelDataType targetType, Expression operand)
static Expression	translateCondition(RexProgram program, JavaTypeFactory typeFactory, BlockBuilder list, RexToLixTranslator.InputGetter inputGetter, Function1<String,RexToLixTranslator.InputGetter> correlates)
Expression	translateConstructor(List<RexNode> operandList, SqlKind kind)
List<Expression>	translateList(List<? extends RexNode> operandList) Translates the list of RexNode, using the default output types.
List<Expression>	translateList(List<? extends RexNode> operandList, List<? extends Type> storageTypes) Translates the list of RexNode, while optimizing for output storage.
List<Expression>	translateList(List<RexNode> operandList, RexImpTable.NullAs nullAs)
List<Expression>	translateList(List<RexNode> operandList, RexImpTable.NullAs nullAs, List<? extends Type> storageTypes)
static Expression	translateLiteral(RexLiteral literal, RelDataType type, JavaTypeFactory typeFactory, RexImpTable.NullAs nullAs) Translates a literal.
private Expression	translateParameter(RexDynamicParam expr, RexImpTable.NullAs nullAs, Type storageType) Translates a parameter.
static List<Expression>	translateProjects(RexProgram program, JavaTypeFactory typeFactory, BlockBuilder list, PhysType outputPhysType, Expression root, RexToLixTranslator.InputGetter inputGetter, Function1<String,RexToLixTranslator.InputGetter> correlates) Translates a RexProgram to a sequence of expressions and declarations.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

JAVA_TO_SQL_METHOD_MAP

public static final Map<Method,SqlOperator> JAVA_TO_SQL_METHOD_MAP

typeFactory

final JavaTypeFactory typeFactory

builder

final RexBuilder builder

program

private final RexProgram program

root

private final Expression root

inputGetter

private final RexToLixTranslator.InputGetter inputGetter

list

private final BlockBuilder list

exprNullableMap

private final Map<? extends RexNode,Boolean> exprNullableMap

parent

private final RexToLixTranslator parent

correlates

private final Function1<String,RexToLixTranslator.InputGetter> correlates

Constructor Detail

RexToLixTranslator

private RexToLixTranslator(RexProgram program,
                           JavaTypeFactory typeFactory,
                           Expression root,
                           RexToLixTranslator.InputGetter inputGetter,
                           BlockBuilder list)

RexToLixTranslator

private RexToLixTranslator(RexProgram program,
                           JavaTypeFactory typeFactory,
                           Expression root,
                           RexToLixTranslator.InputGetter inputGetter,
                           BlockBuilder list,
                           Map<RexNode,Boolean> exprNullableMap,
                           RexBuilder builder)

RexToLixTranslator

private RexToLixTranslator(RexProgram program,
                           JavaTypeFactory typeFactory,
                           Expression root,
                           RexToLixTranslator.InputGetter inputGetter,
                           BlockBuilder list,
                           Map<? extends RexNode,Boolean> exprNullableMap,
                           RexBuilder builder,
                           RexToLixTranslator parent)

RexToLixTranslator

private RexToLixTranslator(RexProgram program,
                           JavaTypeFactory typeFactory,
                           Expression root,
                           RexToLixTranslator.InputGetter inputGetter,
                           BlockBuilder list,
                           Map<? extends RexNode,Boolean> exprNullableMap,
                           RexBuilder builder,
                           RexToLixTranslator parent,
                           Function1<String,RexToLixTranslator.InputGetter> correlates)

Method Detail

findMethod

private static Method findMethod(Class<?> clazz,
                                 String name,
                                 Class... parameterTypes)

translateProjects

public static List<Expression> translateProjects(RexProgram program,
                                                 JavaTypeFactory typeFactory,
                                                 BlockBuilder list,
                                                 PhysType outputPhysType,
                                                 Expression root,
                                                 RexToLixTranslator.InputGetter inputGetter,
                                                 Function1<String,RexToLixTranslator.InputGetter> correlates)

Translates a RexProgram to a sequence of expressions and declarations.

Parameters:

program - Program to be translated

typeFactory - Type factory

list - List of statements, populated with declarations

outputPhysType - Output type, or null

root - Root expression

inputGetter - Generates expressions for inputs

correlates - Provider of references to the values of correlated variables

Returns:

Sequence of expressions, optional condition

forAggregation

public static RexToLixTranslator forAggregation(JavaTypeFactory typeFactory,
                                                BlockBuilder list,
                                                RexToLixTranslator.InputGetter inputGetter)

Creates a translator for translating aggregate functions.

translate

Expression translate(RexNode expr)

translate

Expression translate(RexNode expr,
                     RexImpTable.NullAs nullAs)

translate

Expression translate(RexNode expr,
                     Type storageType)

translate

Expression translate(RexNode expr,
                     RexImpTable.NullAs nullAs,
                     Type storageType)

translateCast

Expression translateCast(RelDataType sourceType,
                         RelDataType targetType,
                         Expression operand)

handleNull

public Expression handleNull(Expression input,
                             RexImpTable.NullAs nullAs)

Adapts an expression with "normal" result to one that adheres to this particular policy. Wraps the result expression into a new parameter if need be.

Parameters:

input - Expression

nullAs - If false, if expression is definitely not null at runtime. Therefore we can optimize. For example, we can cast to int using x.intValue().

Returns:

Translated expression

translate0

private Expression translate0(RexNode expr,
                              RexImpTable.NullAs nullAs,
                              Type storageType)

Translates an expression that is not in the cache.

Parameters:

expr - Expression

nullAs - If false, if expression is definitely not null at runtime. Therefore we can optimize. For example, we can cast to int using x.intValue().

Returns:

Translated expression

deref

public RexNode deref(RexNode expr)

Dereferences an expression if it is a RexLocalRef.

translateCall

private Expression translateCall(RexCall call,
                                 RexImpTable.NullAs nullAs)

Translates a call to an operator or function.

translateParameter

private Expression translateParameter(RexDynamicParam expr,
                                      RexImpTable.NullAs nullAs,
                                      Type storageType)

Translates a parameter.

translateLiteral

public static Expression translateLiteral(RexLiteral literal,
                                          RelDataType type,
                                          JavaTypeFactory typeFactory,
                                          RexImpTable.NullAs nullAs)

Translates a literal.

Throws:

RexToLixTranslator.AlwaysNull - if literal is null but nullAs is RexImpTable.NullAs.NOT_POSSIBLE.

translateList

public List<Expression> translateList(List<RexNode> operandList,
                                      RexImpTable.NullAs nullAs)

translateList

public List<Expression> translateList(List<RexNode> operandList,
                                      RexImpTable.NullAs nullAs,
                                      List<? extends Type> storageTypes)

translateList

public List<Expression> translateList(List<? extends RexNode> operandList)

Translates the list of RexNode, using the default output types. This might be suboptimal in terms of additional box-unbox when you use the translation later. If you know the java class that will be used to store the results, use translateList(java.util.List, java.util.List) version.

Parameters:

operandList - list of RexNodes to translate

Returns:

translated expressions

translateList

public List<Expression> translateList(List<? extends RexNode> operandList,
                                      List<? extends Type> storageTypes)

Translates the list of RexNode, while optimizing for output storage. For instance, if the result of translation is going to be stored in Object[], and the input is Object[] as well, then translator will avoid casting, boxing, etc.

Parameters:

operandList - list of RexNodes to translate

storageTypes - hints of the java classes that will be used to store translation results. Use null to use default storage type

Returns:

translated expressions

translateCondition

public static Expression translateCondition(RexProgram program,
                                            JavaTypeFactory typeFactory,
                                            BlockBuilder list,
                                            RexToLixTranslator.InputGetter inputGetter,
                                            Function1<String,RexToLixTranslator.InputGetter> correlates)

convert

public static Expression convert(Expression operand,
                                 Type toType)

convert

public static Expression convert(Expression operand,
                                 Type fromType,
                                 Type toType)

isA

static boolean isA(Type fromType,
                   Primitive primitive)

translateConstructor

public Expression translateConstructor(List<RexNode> operandList,
                                       SqlKind kind)

isNullable

public boolean isNullable(RexNode e)

Returns whether an expression is nullable. Even if its type says it is nullable, if we have previously generated a check to make sure that it is not null, we will say so.

For example, WHERE a == b translates to a != null && b != null && a.equals(b). When translating the 3rd part of the disjunction, we already know a and b are not null.

Parameters:

e - Expression

Returns:

Whether expression is nullable in the current translation context

isKnownNullable

protected Boolean isKnownNullable(RexNode node)

Walks parent translator chain and verifies if the expression is nullable.

Parameters:

node - RexNode to check if it is nullable or not

Returns:

null when nullability is not known, true or false otherwise

setNullable

public RexToLixTranslator setNullable(RexNode e,
                                      boolean nullable)

Creates a read-only copy of this translator that records that a given expression is nullable.

setNullable

public RexToLixTranslator setNullable(Map<? extends RexNode,Boolean> nullable)

Creates a read-only copy of this translator that records that a given expression is nullable.

setBlock

public RexToLixTranslator setBlock(BlockBuilder block)

setCorrelates

public RexToLixTranslator setCorrelates(Function1<String,RexToLixTranslator.InputGetter> correlates)

nullifyType

public RelDataType nullifyType(RelDataType type,
                               boolean nullable)

javaPrimitive

private Primitive javaPrimitive(RelDataType type)

getRoot

public Expression getRoot()