org.apache.calcite.adapter.enumerable

Class EnumUtils

java.lang.Object

org.apache.calcite.adapter.enumerable.EnumUtils

public class EnumUtils
extends Object

Utilities for generating programs in the Enumerable (functional) style.

Field Summary

Fields

Modifier and Type	Field and Description
static List<String>	LEFT_RIGHT

Method Summary

Modifier and Type	Method and Description
static org.apache.calcite.linq4j.tree.MethodCallExpression	call(Class clazz, String methodName, List<? extends org.apache.calcite.linq4j.tree.Expression> arguments)
static org.apache.calcite.linq4j.tree.MethodCallExpression	call(Class clazz, String methodName, List<? extends org.apache.calcite.linq4j.tree.Expression> arguments, org.apache.calcite.linq4j.tree.Expression targetExpression) The powerful version of {@code org.apache.calcite.linq4j.tree.Expressions#call( Type, String, Iterable
static org.apache.calcite.linq4j.tree.Expression	convert(org.apache.calcite.linq4j.tree.Expression operand, Type toType) Convert operand to target type toType.
static org.apache.calcite.linq4j.tree.Expression	convert(org.apache.calcite.linq4j.tree.Expression operand, Type fromType, Type toType) Convert operand to target type toType.
static <T> T	evaluate(Object o, Class<T> clazz) Converts a value to a given class.
static org.apache.calcite.linq4j.tree.Expression	generateCollatorExpression(SqlCollation collation)
static org.apache.calcite.linq4j.Enumerable<Object[]>	hopping(org.apache.calcite.linq4j.Enumerator<Object[]> inputEnumerator, int indexOfWatermarkedColumn, long emitFrequency, long windowSize, long offset) Create enumerable implementation that applies hopping on each element from the input enumerator and produces at least one element for each input element.
static org.apache.calcite.linq4j.tree.MethodDeclaration	overridingMethodDecl(Method method, Iterable<org.apache.calcite.linq4j.tree.ParameterExpression> parameters, org.apache.calcite.linq4j.tree.BlockStatement body) Declares a method that overrides another method.
static org.apache.calcite.linq4j.Enumerable<Object[]>	sessionize(org.apache.calcite.linq4j.Enumerator<Object[]> inputEnumerator, int indexOfWatermarkedColumn, int indexOfKeyColumn, long gap) Creates enumerable implementation that applies sessionization to elements from the input enumerator based on a specified key.
static <TSource,TResult> org.apache.calcite.linq4j.Enumerable<TResult>	tumbling(org.apache.calcite.linq4j.Enumerable<TSource> inputEnumerable, org.apache.calcite.linq4j.function.Function1<TSource,TResult> outSelector) Apply tumbling per row from the enumerable input.

Methods inherited from class java.lang.Object

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

Field Detail

LEFT_RIGHT

public static final List<String> LEFT_RIGHT

Method Detail

overridingMethodDecl

public static org.apache.calcite.linq4j.tree.MethodDeclaration overridingMethodDecl(Method method,
                                                                                    Iterable<org.apache.calcite.linq4j.tree.ParameterExpression> parameters,
                                                                                    org.apache.calcite.linq4j.tree.BlockStatement body)

Declares a method that overrides another method.

convert

public static org.apache.calcite.linq4j.tree.Expression convert(org.apache.calcite.linq4j.tree.Expression operand,
                                                                Type toType)

Convert operand to target type toType.

Parameters:

operand - The expression to convert

toType - Target type

Returns:

A new expression with type toType or original if there is no need to convert

convert

public static org.apache.calcite.linq4j.tree.Expression convert(org.apache.calcite.linq4j.tree.Expression operand,
                                                                Type fromType,
                                                                Type toType)

Convert operand to target type toType.

Parameters:

operand - The expression to convert

fromType - Field type

toType - Target type

Returns:

A new expression with type toType or original if there is no need to convert

evaluate

public static <T> T evaluate(Object o,
                             Class<T> clazz)

Converts a value to a given class.

call

public static org.apache.calcite.linq4j.tree.MethodCallExpression call(Class clazz,
                                                                       String methodName,
                                                                       List<? extends org.apache.calcite.linq4j.tree.Expression> arguments)

call

public static org.apache.calcite.linq4j.tree.MethodCallExpression call(Class clazz,
                                                                       String methodName,
                                                                       List<? extends org.apache.calcite.linq4j.tree.Expression> arguments,
                                                                       org.apache.calcite.linq4j.tree.Expression targetExpression)

The powerful version of org.apache.calcite.linq4j.tree.Expressions#call( Type, String, Iterable<? extends Expression>). Try best effort to convert the accepted arguments to match parameter type.

Parameters:

clazz - Class against which method is invoked

methodName - Name of method

arguments - argument expressions

targetExpression - target expression

Returns:

MethodCallExpression that call the given name method

Throws:

RuntimeException - if no suitable method found

sessionize

public static org.apache.calcite.linq4j.Enumerable<Object[]> sessionize(org.apache.calcite.linq4j.Enumerator<Object[]> inputEnumerator,
                                                                        int indexOfWatermarkedColumn,
                                                                        int indexOfKeyColumn,
                                                                        long gap)

Creates enumerable implementation that applies sessionization to elements from the input enumerator based on a specified key. Elements are windowed into sessions separated by periods with no input for at least the duration specified by gap parameter.

hopping

public static org.apache.calcite.linq4j.Enumerable<Object[]> hopping(org.apache.calcite.linq4j.Enumerator<Object[]> inputEnumerator,
                                                                     int indexOfWatermarkedColumn,
                                                                     long emitFrequency,
                                                                     long windowSize,
                                                                     long offset)

Create enumerable implementation that applies hopping on each element from the input enumerator and produces at least one element for each input element.

tumbling

public static <TSource,TResult> org.apache.calcite.linq4j.Enumerable<TResult> tumbling(org.apache.calcite.linq4j.Enumerable<TSource> inputEnumerable,
                                                                                       org.apache.calcite.linq4j.function.Function1<TSource,TResult> outSelector)

Apply tumbling per row from the enumerable input.

generateCollatorExpression

public static org.apache.calcite.linq4j.tree.Expression generateCollatorExpression(SqlCollation collation)