org.apache.tinkerpop.gremlin.server.op

Class AbstractEvalOpProcessor

java.lang.Object

org.apache.tinkerpop.gremlin.server.op.AbstractEvalOpProcessor

All Implemented Interfaces:

OpProcessor

Direct Known Subclasses:

SessionOpProcessor, StandardOpProcessor

public abstract class AbstractEvalOpProcessor
extends Object
implements OpProcessor

A base OpProcessor implementation that helps with operations that deal with script evaluation functions.

Author:

Stephen Mallette (http://stephen.genoprime.com)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	AbstractEvalOpProcessor.BindingSupplier<T>

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	manageTransactions

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractEvalOpProcessor(boolean manageTransactions)

Method Summary

Modifier and Type	Method and Description
protected void	evalOpInternal(Context context, Supplier<GremlinExecutor> gremlinExecutorSupplier, AbstractEvalOpProcessor.BindingSupplier<Bindings> bindingsSupplier) A generalized implementation of the "eval" operation.
abstract ThrowingConsumer<Context>	getEvalOp() Provides an operation for evaluating a Gremlin script.
protected void	handleIterator(Context context, Iterator itty) Called by evalOpInternal(org.apache.tinkerpop.gremlin.server.Context, java.util.function.Supplier<org.apache.tinkerpop.gremlin.groovy.engine.GremlinExecutor>, org.apache.tinkerpop.gremlin.server.op.AbstractEvalOpProcessor.BindingSupplier<javax.script.Bindings>) when iterating a result set.
ThrowingConsumer<Context>	select(Context ctx) Given the context (which contains the RequestMessage), return back a Consumer function that will be executed with the context.
protected Optional<ThrowingConsumer<Context>>	validateEvalMessage(RequestMessage message)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.tinkerpop.gremlin.server.OpProcessor

getName

Field Detail

manageTransactions

protected final boolean manageTransactions

Constructor Detail

AbstractEvalOpProcessor

protected AbstractEvalOpProcessor(boolean manageTransactions)

Method Detail

getEvalOp

public abstract ThrowingConsumer<Context> getEvalOp()

Provides an operation for evaluating a Gremlin script.

select

public ThrowingConsumer<Context> select(Context ctx)
                                 throws OpProcessorException

Description copied from interface: OpProcessor

Given the context (which contains the RequestMessage), return back a Consumer function that will be executed with the context. A typical implementation will simply check the "op" field on the RequestMessage and return the Consumer function for that particular operation.

Specified by:

select in interface OpProcessor

Throws:

OpProcessorException

validateEvalMessage

protected Optional<ThrowingConsumer<Context>> validateEvalMessage(RequestMessage message)
                                                           throws OpProcessorException

Throws:

OpProcessorException

evalOpInternal

protected void evalOpInternal(Context context,
                              Supplier<GremlinExecutor> gremlinExecutorSupplier,
                              AbstractEvalOpProcessor.BindingSupplier<Bindings> bindingsSupplier)
                       throws OpProcessorException

A generalized implementation of the "eval" operation. It handles script evaluation and iteration of results so as to write ResponseMessage objects down the Netty pipeline. It also handles script timeouts, iteration timeouts, metrics and building bindings. Note that result iteration is delegated to the handleIterator(org.apache.tinkerpop.gremlin.server.Context, java.util.Iterator) method, so those extending this class could override that method for better control over result iteration.

Parameters:

context - The current Gremlin Server Context

gremlinExecutorSupplier - A function that returns the GremlinExecutor to use in executing the script evaluation.

bindingsSupplier - A function that returns the Bindings to provide to the GremlinExecutor.eval(java.lang.String) method.

Throws:

OpProcessorException

handleIterator

protected void handleIterator(Context context,
                              Iterator itty)
                       throws TimeoutException,
                              InterruptedException

Called by evalOpInternal(org.apache.tinkerpop.gremlin.server.Context, java.util.function.Supplier<org.apache.tinkerpop.gremlin.groovy.engine.GremlinExecutor>, org.apache.tinkerpop.gremlin.server.op.AbstractEvalOpProcessor.BindingSupplier<javax.script.Bindings>) when iterating a result set. Implementers should respect the Settings.serializedResponseTimeout configuration and break the serialization process if it begins to take too long to do so, throwing a TimeoutException in such cases.

Parameters:

context - The Gremlin Server Context object containing settings, request message, etc.

itty - The result to iterator

Throws:

TimeoutException - if the time taken to serialize the entire result set exceeds the allowable time.

InterruptedException