Package org.apache.calcite.adapter.enumerable

Class RexToLixTranslator

java.lang.Object

org.apache.calcite.adapter.enumerable.RexToLixTranslator

All Implemented Interfaces:

RexVisitor<RexToLixTranslator.Result>

public class RexToLixTranslator
extends Object
implements RexVisitor<RexToLixTranslator.Result>

Translates REX expressions to linq4j expressions.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
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).
static class	RexToLixTranslator.Result	Result of translating a RexNode.

Field Summary

Fields

Modifier and Type	Field	Description
static final Map<Method,SqlOperator>	JAVA_TO_SQL_METHOD_MAP

Method Summary

Modifier and Type	Method	Description
RexNode	deref(RexNode expr)	Dereferences an expression if it is a RexLocalRef.
static RexToLixTranslator	forAggregation(JavaTypeFactory typeFactory, BlockBuilder list, @Nullable RexToLixTranslator.InputGetter inputGetter, SqlConformance conformance)	Creates a translator for translating aggregate functions.
Expression	getRoot()
boolean	isNullable(RexNode e)	Returns whether an expression is nullable.
RexToLixTranslator	setBlock(BlockBuilder list)
RexToLixTranslator	setCorrelates(@Nullable Function1<String,RexToLixTranslator.InputGetter> correlates)
static Expression	translateCondition(RexProgram program, JavaTypeFactory typeFactory, BlockBuilder list, RexToLixTranslator.InputGetter inputGetter, Function1<String,RexToLixTranslator.InputGetter> correlates, SqlConformance conformance)
List<Expression>	translateList(List<? extends RexNode> operandList)	Translates the list of RexNode, using the default output types.
List<Expression>	translateList(List<? extends RexNode> operandList, @Nullable List<? extends @Nullable 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 @Nullable Type> storageTypes)
static Expression	translateLiteral(RexLiteral literal, RelDataType type, JavaTypeFactory typeFactory, RexImpTable.NullAs nullAs)	Translates a literal.
static List<Expression>	translateProjects(RexProgram program, JavaTypeFactory typeFactory, SqlConformance conformance, BlockBuilder list, @Nullable PhysType outputPhysType, Expression root, RexToLixTranslator.InputGetter inputGetter, @Nullable Function1<String,RexToLixTranslator.InputGetter> correlates)	Deprecated.
static List<Expression>	translateProjects(RexProgram program, JavaTypeFactory typeFactory, SqlConformance conformance, BlockBuilder list, @Nullable BlockBuilder staticList, @Nullable PhysType outputPhysType, Expression root, RexToLixTranslator.InputGetter inputGetter, @Nullable Function1<String,RexToLixTranslator.InputGetter> correlates)	Translates a RexProgram to a sequence of expressions and declarations.
static Expression	translateTableFunction(JavaTypeFactory typeFactory, SqlConformance conformance, BlockBuilder list, Expression root, RexCall rexCall, Expression inputEnumerable, PhysType inputPhysType, PhysType outputPhysType)
RexToLixTranslator.Result	visitCall(RexCall call)	Visit RexCall.
RexToLixTranslator.Result	visitCorrelVariable(RexCorrelVariable correlVariable)
RexToLixTranslator.Result	visitDynamicParam(RexDynamicParam dynamicParam)
RexToLixTranslator.Result	visitFieldAccess(RexFieldAccess fieldAccess)
RexToLixTranslator.Result	visitInputRef(RexInputRef inputRef)	Visit RexInputRef.
RexToLixTranslator.Result	visitLiteral(RexLiteral literal)	Visit RexLiteral.
RexToLixTranslator.Result	visitLocalRef(RexLocalRef localRef)
RexToLixTranslator.Result	visitOver(RexOver over)
RexToLixTranslator.Result	visitPatternFieldRef(RexPatternFieldRef fieldRef)
RexToLixTranslator.Result	visitRangeRef(RexRangeRef rangeRef)
RexToLixTranslator.Result	visitSubQuery(RexSubQuery subQuery)
RexToLixTranslator.Result	visitTableInputRef(RexTableInputRef fieldRef)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.calcite.rex.RexVisitor

visitEach, visitList, visitList

Field Details

JAVA_TO_SQL_METHOD_MAP

public static final Map<Method,SqlOperator> JAVA_TO_SQL_METHOD_MAP

Method Details

translateProjects

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

Translates a RexProgram to a sequence of expressions and declarations.

Parameters:

program - Program to be translated

typeFactory - Type factory

conformance - SQL conformance

list - List of statements, populated with declarations

staticList - List of member 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

translateProjects

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

Deprecated.

translateTableFunction

public static Expression translateTableFunction(JavaTypeFactory typeFactory,
 SqlConformance conformance,
 BlockBuilder list,
 Expression root,
 RexCall rexCall,
 Expression inputEnumerable,
 PhysType inputPhysType,
 PhysType outputPhysType)

forAggregation

public static RexToLixTranslator forAggregation(JavaTypeFactory typeFactory,
 BlockBuilder list,
 @Nullable RexToLixTranslator.InputGetter inputGetter,
 SqlConformance conformance)

Creates a translator for translating aggregate functions.

deref

public RexNode deref(RexNode expr)

Dereferences an expression if it is a RexLocalRef.

translateLiteral

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

Translates a literal.

Throws:

ControlFlowException - 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 @Nullable 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,
 @Nullable List<? extends @Nullable 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,
 SqlConformance conformance)

isNullable

public boolean isNullable(RexNode e)

Returns whether an expression is nullable.

Parameters:

e - Expression

Returns:

Whether expression is nullable

setBlock

public RexToLixTranslator setBlock(BlockBuilder list)

setCorrelates

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

getRoot

public Expression getRoot()

visitInputRef

public RexToLixTranslator.Result visitInputRef(RexInputRef inputRef)

Visit RexInputRef. If it has never been visited under current storage type before, RexToLixTranslator generally produces three lines of code.

For example, when visiting a column (named commission) in table Employee, the generated code snippet is:

 final Employee current = (Employee) inputEnumerator.current();
 final Integer input_value = current.commission;
 final boolean input_isNull = input_value == null;
 

Specified by:

visitInputRef in interface RexVisitor<RexToLixTranslator.Result>

visitLocalRef

public RexToLixTranslator.Result visitLocalRef(RexLocalRef localRef)

Specified by:

visitLocalRef in interface RexVisitor<RexToLixTranslator.Result>

visitLiteral

public RexToLixTranslator.Result visitLiteral(RexLiteral literal)

Visit RexLiteral. If it has never been visited before, RexToLixTranslator will generate two lines of code. For example, when visiting a primitive int (10), the generated code snippet is: final int literal_value = 10; final boolean literal_isNull = false;

Specified by:

visitLiteral in interface RexVisitor<RexToLixTranslator.Result>

visitCall

public RexToLixTranslator.Result visitCall(RexCall call)

Visit RexCall. For most SqlOperators, we can get the implementor from RexImpTable. Several operators (e.g., CaseWhen) with special semantics need to be implemented separately.

Specified by:

visitCall in interface RexVisitor<RexToLixTranslator.Result>

visitDynamicParam

public RexToLixTranslator.Result visitDynamicParam(RexDynamicParam dynamicParam)

Specified by:

visitDynamicParam in interface RexVisitor<RexToLixTranslator.Result>

visitFieldAccess

public RexToLixTranslator.Result visitFieldAccess(RexFieldAccess fieldAccess)

Specified by:

visitFieldAccess in interface RexVisitor<RexToLixTranslator.Result>

visitOver

public RexToLixTranslator.Result visitOver(RexOver over)

Specified by:

visitOver in interface RexVisitor<RexToLixTranslator.Result>

visitCorrelVariable

public RexToLixTranslator.Result visitCorrelVariable(RexCorrelVariable correlVariable)

Specified by:

visitCorrelVariable in interface RexVisitor<RexToLixTranslator.Result>

visitRangeRef

public RexToLixTranslator.Result visitRangeRef(RexRangeRef rangeRef)

Specified by:

visitRangeRef in interface RexVisitor<RexToLixTranslator.Result>

visitSubQuery

public RexToLixTranslator.Result visitSubQuery(RexSubQuery subQuery)

Specified by:

visitSubQuery in interface RexVisitor<RexToLixTranslator.Result>

visitTableInputRef

public RexToLixTranslator.Result visitTableInputRef(RexTableInputRef fieldRef)

Specified by:

visitTableInputRef in interface RexVisitor<RexToLixTranslator.Result>

visitPatternFieldRef

public RexToLixTranslator.Result visitPatternFieldRef(RexPatternFieldRef fieldRef)

Specified by:

visitPatternFieldRef in interface RexVisitor<RexToLixTranslator.Result>