org.apache.cassandra.cql3.functions

Class UDFunction

java.lang.Object

org.apache.cassandra.cql3.functions.AbstractFunction

org.apache.cassandra.cql3.functions.UDFunction

All Implemented Interfaces:

AssignmentTestable, Function, ScalarFunction

public abstract class UDFunction
extends AbstractFunction
implements ScalarFunction

Base class for User Defined Functions.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.cassandra.cql3.AssignmentTestable

AssignmentTestable.TestResult

Field Summary

Fields

Modifier and Type	Field and Description
protected com.datastax.driver.core.DataType[]	argDataTypes
protected java.util.List<ColumnIdentifier>	argNames
protected java.lang.String	body
protected boolean	calledOnNullInput
protected java.lang.String	language
protected static org.slf4j.Logger	logger
protected com.datastax.driver.core.DataType	returnDataType

Fields inherited from class org.apache.cassandra.cql3.functions.AbstractFunction

argTypes, name, returnType

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	UDFunction(FunctionName name, java.util.List<ColumnIdentifier> argNames, java.util.List<AbstractType<?>> argTypes, AbstractType<?> returnType, boolean calledOnNullInput, java.lang.String language, java.lang.String body)
protected	UDFunction(FunctionName name, java.util.List<ColumnIdentifier> argNames, java.util.List<AbstractType<?>> argTypes, com.datastax.driver.core.DataType[] argDataTypes, AbstractType<?> returnType, com.datastax.driver.core.DataType returnDataType, boolean calledOnNullInput, java.lang.String language, java.lang.String body)

Method Summary

Modifier and Type	Method and Description
java.util.List<ColumnIdentifier>	argNames()
static void	assertUdfsEnabled(java.lang.String language)
java.lang.String	body()
protected static java.lang.Object	compose(com.datastax.driver.core.DataType[] argDataTypes, int protocolVersion, int argIndex, java.nio.ByteBuffer value)
protected java.lang.Object	compose(int protocolVersion, int argIndex, java.nio.ByteBuffer value) Used by UDF implementations (both Java code generated by JavaBasedUDFunction and script executor ScriptBasedUDFunction) to convert the C* serialized representation to the Java object representation.
static UDFunction	create(FunctionName name, java.util.List<ColumnIdentifier> argNames, java.util.List<AbstractType<?>> argTypes, AbstractType<?> returnType, boolean calledOnNullInput, java.lang.String language, java.lang.String body)
static UDFunction	createBrokenFunction(FunctionName name, java.util.List<ColumnIdentifier> argNames, java.util.List<AbstractType<?>> argTypes, AbstractType<?> returnType, boolean calledOnNullInput, java.lang.String language, java.lang.String body, InvalidRequestException reason) It can happen that a function has been declared (is listed in the scheam) but cannot be loaded (maybe only on some nodes).
protected static java.nio.ByteBuffer	decompose(com.datastax.driver.core.DataType dataType, int protocolVersion, java.lang.Object value)
protected java.nio.ByteBuffer	decompose(int protocolVersion, java.lang.Object value) Used by UDF implementations (both Java code generated by JavaBasedUDFunction and script executor ScriptBasedUDFunction) to convert the Java object representation for the return value to the C* serialized representation.
boolean	equals(java.lang.Object o)
java.nio.ByteBuffer	execute(int protocolVersion, java.util.List<java.nio.ByteBuffer> parameters) Applies this function to the specified parameter.
protected abstract java.nio.ByteBuffer	executeUserDefined(int protocolVersion, java.util.List<java.nio.ByteBuffer> parameters)
protected abstract java.util.concurrent.ExecutorService	executor()
int	hashCode()
boolean	isAggregate() Checks whether the function is an aggregate function or not.
boolean	isCallableWrtNullable(java.util.List<java.nio.ByteBuffer> parameters)
boolean	isCalledOnNullInput()
boolean	isNative() Checks whether the function is a native/hard coded one or not.
java.lang.String	language()
void	userTypeUpdated(java.lang.String ksName, java.lang.String typeName)

Methods inherited from class org.apache.cassandra.cql3.functions.AbstractFunction

argTypes, getFunctions, hasReferenceTo, name, returnType, testAssignment, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.cassandra.cql3.functions.Function

argTypes, getFunctions, hasReferenceTo, name, returnType

Methods inherited from interface org.apache.cassandra.cql3.AssignmentTestable

testAssignment

Field Detail

logger

protected static final org.slf4j.Logger logger

argNames

protected final java.util.List<ColumnIdentifier> argNames

language

protected final java.lang.String language

body

protected final java.lang.String body

argDataTypes

protected final com.datastax.driver.core.DataType[] argDataTypes

returnDataType

protected final com.datastax.driver.core.DataType returnDataType

calledOnNullInput

protected final boolean calledOnNullInput

Constructor Detail

UDFunction

protected UDFunction(FunctionName name,
                     java.util.List<ColumnIdentifier> argNames,
                     java.util.List<AbstractType<?>> argTypes,
                     AbstractType<?> returnType,
                     boolean calledOnNullInput,
                     java.lang.String language,
                     java.lang.String body)

UDFunction

protected UDFunction(FunctionName name,
                     java.util.List<ColumnIdentifier> argNames,
                     java.util.List<AbstractType<?>> argTypes,
                     com.datastax.driver.core.DataType[] argDataTypes,
                     AbstractType<?> returnType,
                     com.datastax.driver.core.DataType returnDataType,
                     boolean calledOnNullInput,
                     java.lang.String language,
                     java.lang.String body)

Method Detail

create

public static UDFunction create(FunctionName name,
                                java.util.List<ColumnIdentifier> argNames,
                                java.util.List<AbstractType<?>> argTypes,
                                AbstractType<?> returnType,
                                boolean calledOnNullInput,
                                java.lang.String language,
                                java.lang.String body)

createBrokenFunction

public static UDFunction createBrokenFunction(FunctionName name,
                                              java.util.List<ColumnIdentifier> argNames,
                                              java.util.List<AbstractType<?>> argTypes,
                                              AbstractType<?> returnType,
                                              boolean calledOnNullInput,
                                              java.lang.String language,
                                              java.lang.String body,
                                              InvalidRequestException reason)

It can happen that a function has been declared (is listed in the scheam) but cannot be loaded (maybe only on some nodes). This is the case for instance if the class defining the class is not on the classpath for some of the node, or after a restart. In that case, we create a "fake" function so that: 1) the broken function can be dropped easily if that is what people want to do. 2) we return a meaningful error message if the function is executed (something more precise than saying that the function doesn't exist)

execute

public final java.nio.ByteBuffer execute(int protocolVersion,
                                         java.util.List<java.nio.ByteBuffer> parameters)

Description copied from interface: ScalarFunction

Applies this function to the specified parameter.

Specified by:

execute in interface ScalarFunction

Parameters:

protocolVersion - protocol version used for parameters and return value

parameters - the input parameters

Returns:

the result of applying this function to the parameter

assertUdfsEnabled

public static void assertUdfsEnabled(java.lang.String language)

executor

protected abstract java.util.concurrent.ExecutorService executor()

isCallableWrtNullable

public boolean isCallableWrtNullable(java.util.List<java.nio.ByteBuffer> parameters)

executeUserDefined

protected abstract java.nio.ByteBuffer executeUserDefined(int protocolVersion,
                                                          java.util.List<java.nio.ByteBuffer> parameters)

isAggregate

public boolean isAggregate()

Description copied from interface: Function

Checks whether the function is an aggregate function or not.

Specified by:

isAggregate in interface Function

Returns:

true if the function is an aggregate function, false otherwise.

isNative

public boolean isNative()

Description copied from interface: Function

Checks whether the function is a native/hard coded one or not.

Specified by:

isNative in interface Function

Returns:

true if the function is a native/hard coded one, false otherwise.

isCalledOnNullInput

public boolean isCalledOnNullInput()

Specified by:

isCalledOnNullInput in interface ScalarFunction

argNames

public java.util.List<ColumnIdentifier> argNames()

body

public java.lang.String body()

language

public java.lang.String language()

compose

protected java.lang.Object compose(int protocolVersion,
                                   int argIndex,
                                   java.nio.ByteBuffer value)

Used by UDF implementations (both Java code generated by JavaBasedUDFunction and script executor ScriptBasedUDFunction) to convert the C* serialized representation to the Java object representation.

Parameters:

protocolVersion - the native protocol version used for serialization

argIndex - index of the UDF input argument

compose

protected static java.lang.Object compose(com.datastax.driver.core.DataType[] argDataTypes,
                                          int protocolVersion,
                                          int argIndex,
                                          java.nio.ByteBuffer value)

decompose

protected java.nio.ByteBuffer decompose(int protocolVersion,
                                        java.lang.Object value)

Used by UDF implementations (both Java code generated by JavaBasedUDFunction and script executor ScriptBasedUDFunction) to convert the Java object representation for the return value to the C* serialized representation.

Parameters:

protocolVersion - the native protocol version used for serialization

decompose

protected static java.nio.ByteBuffer decompose(com.datastax.driver.core.DataType dataType,
                                               int protocolVersion,
                                               java.lang.Object value)

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class AbstractFunction

hashCode

public int hashCode()

Overrides:

hashCode in class AbstractFunction

userTypeUpdated

public void userTypeUpdated(java.lang.String ksName,
                            java.lang.String typeName)