org.teiid.query.function

Class FunctionLibrary

java.lang.Object

org.teiid.query.function.FunctionLibrary

public class FunctionLibrary
extends Object

The function library is the primary way for the system to find out what functions are available, resolve function signatures, and invoke system and user-defined functions.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FunctionLibrary.ConversionResult

Field Summary

Fields

Modifier and Type	Field and Description
static String	ARRAY_GET
static String	CAST
static String	COALESCE
static String	COMMAND_PAYLOAD
static String	CONCAT
static String	CONCAT_OPERATOR
static String	CONCAT2
static String	CONVERT
static String	DECODEINTEGER
static String	DECODESTRING
static String	ENV
static String	ENV_VAR
static String	FORMATDATE
static String	FORMATTIME
static String	FROM_UNIXTIME
static String	IFNULL
static Set<String>	INTERNAL_SCHEMAS
static String	JSONARRAY
static String	LOOKUP
static String	MVSTATUS
static String	NULLIF
static String	NVL
static String	PARSEDATE
static String	PARSETIME
static String	SESSION_ID
static String	SPACE
static String	SUBSTRING
static String	SYS_PROP
static String	TIMESTAMPADD
static String	USER

Constructor Summary

Constructors

Constructor and Description
FunctionLibrary(FunctionTree systemFuncs, FunctionTree... userFuncs) Construct the function library.

Method Summary

Modifier and Type	Method and Description
FunctionDescriptor	copyFunctionChangeReturnType(FunctionDescriptor fd, Class<?> returnType) Return a copy of the given FunctionDescriptor with the specified return type.
FunctionLibrary.ConversionResult	determineNecessaryConversions(String name, Class<?> returnType, Expression[] args, Class<?>[] types, boolean hasUnknownType) Get the conversions that are needed to call the named function with arguments of the given type.
List<FunctionDescriptor>	findAllFunctions(String name, Class<?>[] types) Find a function descriptor given a name and the types of the arguments.
FunctionDescriptor	findFunction(String name, Class<?>[] types) Find a function descriptor given a name and the types of the arguments.
FunctionDescriptor	findTypedConversionFunction(Class<?> sourceType, Class<?> targetType) Find conversion function and set return type to proper type.
List<FunctionMethod>	getBuiltInAggregateFunctions(boolean includeAnalytic) Return a list of the most general forms of built-in aggregate functions.
FunctionDescriptor[]	getConverts(FunctionMethod method, Class<?>[] types)
List<String>	getFunctionCategories() Get all function categories, sorted in alphabetical order
List<FunctionMethod>	getFunctionsInCategory(String category) Get all function in a category.
FunctionTree	getSystemFunctions()
FunctionTree[]	getUserFunctions()
boolean	hasFunctionMethod(String name, int numArgs) Find function form based on function name and # of arguments.
static boolean	isConvert(Function function)
boolean	isVarArgArrayParam(FunctionMethod method, Class<?>[] types, int i, Class<?> targetType)
boolean	userFunctionExists(String resourceName)

Methods inherited from class java.lang.Object

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

Field Detail

CONVERT

public static final String CONVERT

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Constant Field Values

CAST

public static final String CAST

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Constant Field Values

LOOKUP

public static final String LOOKUP

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Constant Field Values

USER

public static final String USER

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Constant Field Values

ENV

public static final String ENV

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Constant Field Values

SYS_PROP

public static final String SYS_PROP

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Constant Field Values

ENV_VAR

public static final String ENV_VAR

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Constant Field Values

SESSION_ID

public static final String SESSION_ID

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Constant Field Values

DECODESTRING

public static final String DECODESTRING

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Constant Field Values

DECODEINTEGER

public static final String DECODEINTEGER

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Constant Field Values

COMMAND_PAYLOAD

public static final String COMMAND_PAYLOAD

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Constant Field Values

CONCAT

public static final String CONCAT

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Constant Field Values

CONCAT2

public static final String CONCAT2

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Constant Field Values

CONCAT_OPERATOR

public static final String CONCAT_OPERATOR

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Constant Field Values

SUBSTRING

public static final String SUBSTRING

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Constant Field Values

NVL

public static final String NVL

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Constant Field Values

IFNULL

public static final String IFNULL

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Constant Field Values

FROM_UNIXTIME

public static final String FROM_UNIXTIME

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Constant Field Values

TIMESTAMPADD

public static final String TIMESTAMPADD

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Constant Field Values

PARSETIME

public static final String PARSETIME

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Constant Field Values

PARSEDATE

public static final String PARSEDATE

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Constant Field Values

FORMATTIME

public static final String FORMATTIME

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Constant Field Values

FORMATDATE

public static final String FORMATDATE

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Constant Field Values

NULLIF

public static final String NULLIF

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Constant Field Values

COALESCE

public static final String COALESCE

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Constant Field Values

SPACE

public static final String SPACE

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Constant Field Values

ARRAY_GET

public static final String ARRAY_GET

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Constant Field Values

JSONARRAY

public static final String JSONARRAY

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Constant Field Values

MVSTATUS

public static final String MVSTATUS

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Constant Field Values

INTERNAL_SCHEMAS

public static final Set<String> INTERNAL_SCHEMAS

Constructor Detail

FunctionLibrary

public FunctionLibrary(FunctionTree systemFuncs,
                       FunctionTree... userFuncs)

Construct the function library. This should be called only once by the FunctionLibraryManager.

Method Detail

getUserFunctions

public FunctionTree[] getUserFunctions()

getSystemFunctions

public FunctionTree getSystemFunctions()

getFunctionCategories

public List<String> getFunctionCategories()

Get all function categories, sorted in alphabetical order

Returns:

List of function category names, sorted in alphabetical order

getFunctionsInCategory

public List<FunctionMethod> getFunctionsInCategory(String category)

Get all function in a category.

Parameters:

category - Category name

Returns:

List of FunctionMethods in a category

hasFunctionMethod

public boolean hasFunctionMethod(String name,
                                 int numArgs)

Find function form based on function name and # of arguments.

Parameters:

name - Function name

numArgs - Number of arguments

Returns:

Corresponding form or null if not found

findFunction

public FunctionDescriptor findFunction(String name,
                                       Class<?>[] types)

Find a function descriptor given a name and the types of the arguments. This method matches based on case-insensitive function name and an exact match of the number and types of parameter arguments.

Parameters:

name - Name of the function to resolve

types - Array of classes representing the types

Returns:

Descriptor if found, null if not found

findAllFunctions

public List<FunctionDescriptor> findAllFunctions(String name,
                                                 Class<?>[] types)

Find a function descriptor given a name and the types of the arguments. This method matches based on case-insensitive function name and an exact match of the number and types of parameter arguments.

Parameters:

name - Name of the function to resolve

types - Array of classes representing the types

Returns:

Descriptor if found, null if not found

determineNecessaryConversions

public FunctionLibrary.ConversionResult determineNecessaryConversions(String name,
                                                                      Class<?> returnType,
                                                                      Expression[] args,
                                                                      Class<?>[] types,
                                                                      boolean hasUnknownType)
                                                               throws InvalidFunctionException

Get the conversions that are needed to call the named function with arguments of the given type. In the case of an exact match, the list will contain all nulls. In other cases the list will contain one or more non-null values where the value is a conversion function that can be used to convert to the proper types for executing the function.

Parameters:

name - Name of function

returnType -

args -

types - Existing types passed to the function

Throws:

InvalidFunctionException

getConverts

public FunctionDescriptor[] getConverts(FunctionMethod method,
                                        Class<?>[] types)

isVarArgArrayParam

public boolean isVarArgArrayParam(FunctionMethod method,
                                  Class<?>[] types,
                                  int i,
                                  Class<?> targetType)

findTypedConversionFunction

public FunctionDescriptor findTypedConversionFunction(Class<?> sourceType,
                                                      Class<?> targetType)

Find conversion function and set return type to proper type.

Parameters:

sourceType - The source type class

targetType - The target type class

Returns:

A CONVERT function descriptor or null if not possible

copyFunctionChangeReturnType

public FunctionDescriptor copyFunctionChangeReturnType(FunctionDescriptor fd,
                                                       Class<?> returnType)

Return a copy of the given FunctionDescriptor with the specified return type.

Parameters:

fd - FunctionDescriptor to be copied.

returnType - The return type to apply to the copied FunctionDescriptor.

Returns:

The copy of FunctionDescriptor.

isConvert

public static boolean isConvert(Function function)

getBuiltInAggregateFunctions

public List<FunctionMethod> getBuiltInAggregateFunctions(boolean includeAnalytic)

Return a list of the most general forms of built-in aggregate functions.
count(*) - is not included
textagg - is not included due to its non standard syntax

Parameters:

includeAnalytic - - true to include analytic functions that must be windowed

Returns:

userFunctionExists

public boolean userFunctionExists(String resourceName)