Package com.yahoo.processing.execution

Class Execution

java.lang.Object

com.yahoo.processing.execution.Execution

Direct Known Subclasses:

ExecutionWithResponse

public class Execution
extends Object

An execution of a chain. This keeps tracks of the progress of the execution and is called by the processors (using process(com.yahoo.processing.Request) to move the execution to the next one.

Author:

bratseth

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Execution.Environment<COMPONENT extends Processor>	Holds the static execution environment for the duration of an execution
static class	Execution.Trace	Tre trace of this execution.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Execution(Chain<? extends Processor> chain, int startIndex, Execution.Trace trace, Execution.Environment<? extends Processor> environment)	Creates a new execution by setting the internal state directly.
	Execution(Chain<? extends Processor> chain, Execution execution)	Creates an execution of a chain
	Execution(Execution startPoint)	Creates an execution from another.
	Execution(Processor processor, Execution execution)	Creates an execution of a single processor

Method Summary

Modifier and Type	Method	Description
Chain<? extends Processor>	chain()	Returns the chain this executes
static Execution	createRoot(Chain<? extends Processor> chain, int traceLevel, Execution.Environment<? extends Processor> environment)	Creates an execution which is not in the context of an existing execution
static Execution	createRoot(Processor processor, int traceLevel, Execution.Environment<? extends Processor> environment)	Creates an execution of a single processor which is not in the context of an existing execution
protected Response	defaultResponse(Request request)	Creates the default response to return from this kind of execution when there are no further processors.
Execution.Environment<? extends Processor>	environment()
protected Processor	next()	Returns the next searcher to be invoked in this chain, or null if we are at the last
protected int	nextIndex()	Returns the index into the chain of processors which is currently next
protected void	nextProcessor()	Move this execution to the next processor
protected void	onInvoking(Request request, Processor next)	A hook called when a processor is to be invoked.
protected void	onReturning(Request request, Processor processor, Response response)	A hook called when a processor returns, either normally or by throwing.
protected void	previousProcessor()	Move this execution to the previous processor
Response	process(Request request)	Calls process on the next processor in this chain.
String	toString()
Execution.Trace	trace()

Methods inherited from class java.lang.Object

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

Constructor Details

Execution

public Execution(Processor processor,
 Execution execution)

Creates an execution of a single processor

Parameters:

processor - the processor to execute in this

execution - the parent execution of this

Execution

public Execution(Chain<? extends Processor> chain,
 Execution execution)

Creates an execution of a chain

Parameters:

chain - the chain to execute in this, starting from the first processor

execution - the parent execution of this

Execution

public Execution(Execution startPoint)

Creates an execution from another. This execution will start at the next processor of the given execution. The given execution can continue independently of this.

Execution

protected Execution(Chain<? extends Processor> chain,
 int startIndex,
 Execution.Trace trace,
 Execution.Environment<? extends Processor> environment)

Creates a new execution by setting the internal state directly.

Parameters:

chain - the chain to execute

startIndex - the start index into that chain

trace - the context of this. If this is created from an existing execution/context, be sure to do new Context<COMPONENT>(startPoint.context) first!

environment - the static execution environment to use

Method Details

createRoot

public static Execution createRoot(Processor processor,
 int traceLevel,
 Execution.Environment<? extends Processor> environment)

Creates an execution of a single processor which is not in the context of an existing execution

createRoot

public static Execution createRoot(Chain<? extends Processor> chain,
 int traceLevel,
 Execution.Environment<? extends Processor> environment)

Creates an execution which is not in the context of an existing execution

Parameters:

chain - the chain to execute

traceLevel - the level to emit trace at

environment - the execution environment to use

process

public Response process(Request request)

Calls process on the next processor in this chain. If there is no next, an empty response is returned.

nextIndex

protected int nextIndex()

Returns the index into the chain of processors which is currently next

onInvoking

protected void onInvoking(Request request,
 Processor next)

A hook called when a processor is to be invoked. Overriding methods must call super.onInvoking

onReturning

protected void onReturning(Request request,
 Processor processor,
 Response response)

A hook called when a processor returns, either normally or by throwing. Overriding methods must call super.onReturning

Parameters:

request - the processing request

processor - the processor which returned

response - the response returned, or null if the processor returned by throwing

previousProcessor

protected void previousProcessor()

Move this execution to the previous processor

nextProcessor

protected void nextProcessor()

Move this execution to the next processor

next

protected Processor next()

Returns the next searcher to be invoked in this chain, or null if we are at the last

chain

public Chain<? extends Processor> chain()

Returns the chain this executes

defaultResponse

protected Response defaultResponse(Request request)

Creates the default response to return from this kind of execution when there are no further processors. If this is overridden, make sure to propagate any freezeListener from this to the returned response top-level DataList.

toString

public String toString()

Overrides:

toString in class Object

trace

public Execution.Trace trace()

environment

public Execution.Environment<? extends Processor> environment()