Package uk.gov.gchq.gaffer.operation

Class OperationChain<OUT>

java.lang.Object

uk.gov.gchq.gaffer.operation.OperationChain<OUT>

Type Parameters:

OUT - the output type of the OperationChain. This should match the output type of the last Operation in the chain.

All Implemented Interfaces:

Closeable, AutoCloseable, Output<OUT>, Operation, Operations<Operation>

Direct Known Subclasses:

OperationChainDAO

public class OperationChain<OUT>
extends Object
implements Output<OUT>, Operations<Operation>

An OperationChain holds a list of Operations that are chained together - ie. the output of one operation is passed to the input of the next. For the chaining to be successful the operations must be ordered correctly so the O and I types are compatible. The safest way to ensure they will be compatible is to use the OperationChain.Builder to construct the chain.

A couple of special cases:

• An operation with no output can come before any operation.
• An operation with no input can follow any operation - the output from the previous operation will just be lost.

See Also:

OperationChain.Builder

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	OperationChain.Builder	A Builder is a type safe way of building an OperationChain.
static class	OperationChain.NoOutputBuilder
static class	OperationChain.OutputBuilder<OUT>

Nested classes/interfaces inherited from interface uk.gov.gchq.gaffer.operation.Operation

Operation.BaseBuilder<OP extends Operation,B extends Operation.BaseBuilder<OP,?>>

Constructor Summary

Constructors

Constructor	Description
OperationChain()
OperationChain(List<Operation> operations)
OperationChain(List<Operation> operations, boolean flatten)
OperationChain(Output<OUT> operation)
OperationChain(Operation operation)
OperationChain(Operation... operations)

Method Summary

Modifier and Type	Method	Description
void	close()	Operation implementations should ensure that all closeable fields are closed in this method.
boolean	equals(Object obj)
List<Operation>	getOperations()	Should return a Collection of all operations contained within the Operations implementation.
Map<String,String>	getOptions()
com.fasterxml.jackson.core.type.TypeReference<OUT>	getOutputTypeReference()
int	hashCode()
void	setOptions(Map<String,String> options)
OperationChain<OUT>	shallowClone()	Operation implementations should ensure a ShallowClone method is implemented.
String	toOverviewString()
String	toString()
static <O> OperationChain<O>	wrap(Output<O> operation)
static OperationChain<?>	wrap(Operation operation)

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface uk.gov.gchq.gaffer.operation.Operation

_getNullOrOptions, addOption, containsOption, getOption, getOption, validate, validateRequiredFieldPresent

Methods inherited from interface uk.gov.gchq.gaffer.operation.Operations

flatten, getOperationsClass, updateOperations

Methods inherited from interface uk.gov.gchq.gaffer.operation.io.Output

castToOutputType, getOutputClass, getOutputType

Constructor Detail

OperationChain

public OperationChain()

OperationChain

public OperationChain(Operation operation)

OperationChain

public OperationChain(Output<OUT> operation)

OperationChain

public OperationChain(Operation... operations)

OperationChain

public OperationChain(List<Operation> operations)

OperationChain

public OperationChain(List<Operation> operations,
                      boolean flatten)

Method Detail

wrap

public static OperationChain<?> wrap(Operation operation)

wrap

public static <O> OperationChain<O> wrap(Output<O> operation)

getOutputTypeReference

public com.fasterxml.jackson.core.type.TypeReference<OUT> getOutputTypeReference()

Specified by:

getOutputTypeReference in interface Output<OUT>

getOperations

public List<Operation> getOperations()

Description copied from interface: Operations

Should return a Collection of all operations contained within the Operations implementation. The collection of operations may be modified by Gaffer.

Specified by:

getOperations in interface Operations<OUT>

Returns:

A Collection of Operations.

shallowClone

public OperationChain<OUT> shallowClone()
                                 throws org.apache.commons.lang3.exception.CloneFailedException

Description copied from interface: Operation

Operation implementations should ensure a ShallowClone method is implemented. Performs a shallow clone. Creates a new instance and copies the fields across. It does not clone the fields. If the operation contains nested operations, these must also be cloned.

Specified by:

shallowClone in interface Operation

Returns:

shallow clone

Throws:

org.apache.commons.lang3.exception.CloneFailedException - if a Clone error occurs

getOptions

public Map<String,String> getOptions()

Specified by:

getOptions in interface Operation

Returns:

the operation options. This may contain store specific options such as authorisation strings or and other properties required for the operation to be executed. Note these options will probably not be interpreted in the same way by every store implementation.

setOptions

public void setOptions(Map<String,String> options)

Specified by:

setOptions in interface Operation

Parameters:

options - the operation options. This may contain store specific options such as authorisation strings or and other properties required for the operation to be executed. Note these options will probably not be interpreted in the same way by every store implementation.

toString

public String toString()

Overrides:

toString in class Object

toOverviewString

public String toOverviewString()

close

public void close()
           throws IOException

Description copied from interface: Operation

Operation implementations should ensure that all closeable fields are closed in this method.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface Operation

Throws:

IOException - if an I/O error occurs

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object