org.apache.tinkerpop.gremlin.server.op

Class AbstractOpProcessor

java.lang.Object

org.apache.tinkerpop.gremlin.server.op.AbstractOpProcessor

All Implemented Interfaces:

AutoCloseable, OpProcessor

Direct Known Subclasses:

AbstractEvalOpProcessor, TraversalOpProcessor

public abstract class AbstractOpProcessor
extends Object
implements OpProcessor

A base OpProcessor implementation that processes an Iterator of results in a generalized way while ensuring that graph transactions are properly managed.

Author:

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

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	manageTransactions When set to true, transactions are always managed otherwise they can be overridden by the request.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractOpProcessor(boolean manageTransactions)

Method Summary

Modifier and Type	Method and Description
protected static void	attemptCommit(RequestMessage msg, GraphManager graphManager, boolean strict)
protected static void	attemptRollback(RequestMessage msg, GraphManager graphManager, boolean strict)
protected Map<String,Object>	generateMetaData(ChannelHandlerContext ctx, RequestMessage msg, ResponseStatusCode code, Iterator itty) Generates meta-data to put on a ResponseMessage.
protected void	handleIterator(Context context, Iterator itty) Provides a generic way of iterating a result set back to the client.
protected void	handleIterator(ResponseHandlerContext rhc, Iterator itty) A variant of handleIterator(Context, Iterator) that is suitable for use in situations when multiple threads may produce final response messages concurrently.
protected boolean	isForceFlushed(ChannelHandlerContext ctx, RequestMessage msg, Iterator itty) Determines if a Frame should be force flushed outside of the resultIterationBatchSize and the termination of the iterator.
protected void	iterateComplete(ChannelHandlerContext ctx, RequestMessage msg, Iterator itty) Called when iteration within handleIterator(Context, Iterator) is on its final pass and the final frame is about to be sent back to the client.
protected static Frame	makeFrame(ChannelHandlerContext ctx, RequestMessage msg, MessageSerializer serializer, boolean useBinary, List<Object> aggregate, ResponseStatusCode code) Deprecated. As of release 3.2.2, replaced by makeFrame(ChannelHandlerContext, RequestMessage, MessageSerializer, boolean, List, ResponseStatusCode, Map).
protected static Frame	makeFrame(ChannelHandlerContext ctx, RequestMessage msg, MessageSerializer serializer, boolean useBinary, List<Object> aggregate, ResponseStatusCode code, Map<String,Object> responseMetaData) Caution: #makeFrame(ResponseHandlerContext, RequestMessage, MessageSerializer, boolean, List, ResponseStatusCode, Map) should be used instead of this method whenever a ResponseHandlerContext is available.

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, init, select

Methods inherited from interface java.lang.AutoCloseable

close

Field Detail

manageTransactions

protected final boolean manageTransactions

When set to true, transactions are always managed otherwise they can be overridden by the request.

Constructor Detail

AbstractOpProcessor

protected AbstractOpProcessor(boolean manageTransactions)

Method Detail

handleIterator

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

Provides a generic way of iterating a result set back to the client. 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

See Also:

handleIterator(ResponseHandlerContext, Iterator)

handleIterator

protected void handleIterator(ResponseHandlerContext rhc,
                              Iterator itty)
                       throws TimeoutException,
                              InterruptedException

A variant of handleIterator(Context, Iterator) that is suitable for use in situations when multiple threads may produce final response messages concurrently.

Throws:

TimeoutException

InterruptedException

See Also:

handleIterator(Context, Iterator)

iterateComplete

protected void iterateComplete(ChannelHandlerContext ctx,
                               RequestMessage msg,
                               Iterator itty)

Called when iteration within handleIterator(Context, Iterator) is on its final pass and the final frame is about to be sent back to the client. This method only gets called on successful iteration of the entire result.

isForceFlushed

protected boolean isForceFlushed(ChannelHandlerContext ctx,
                                 RequestMessage msg,
                                 Iterator itty)

Determines if a Frame should be force flushed outside of the resultIterationBatchSize and the termination of the iterator. By default this method return false.

Parameters:

itty - a reference to the current Iterator of results - it is not meant to be forwarded in this method

generateMetaData

protected Map<String,Object> generateMetaData(ChannelHandlerContext ctx,
                                              RequestMessage msg,
                                              ResponseStatusCode code,
                                              Iterator itty)

Generates meta-data to put on a ResponseMessage.

Parameters:

itty - a reference to the current Iterator of results - it is not meant to be forwarded in this method

makeFrame

@Deprecated
protected static Frame makeFrame(ChannelHandlerContext ctx,
                                             RequestMessage msg,
                                             MessageSerializer serializer,
                                             boolean useBinary,
                                             List<Object> aggregate,
                                             ResponseStatusCode code)
                                      throws Exception

Deprecated. As of release 3.2.2, replaced by makeFrame(ChannelHandlerContext, RequestMessage, MessageSerializer, boolean, List, ResponseStatusCode, Map).

Throws:

Exception

makeFrame

protected static Frame makeFrame(ChannelHandlerContext ctx,
                                 RequestMessage msg,
                                 MessageSerializer serializer,
                                 boolean useBinary,
                                 List<Object> aggregate,
                                 ResponseStatusCode code,
                                 Map<String,Object> responseMetaData)
                          throws Exception

Caution: #makeFrame(ResponseHandlerContext, RequestMessage, MessageSerializer, boolean, List, ResponseStatusCode, Map) should be used instead of this method whenever a ResponseHandlerContext is available.

Throws:

Exception

attemptCommit

protected static void attemptCommit(RequestMessage msg,
                                    GraphManager graphManager,
                                    boolean strict)

attemptRollback

protected static void attemptRollback(RequestMessage msg,
                                      GraphManager graphManager,
                                      boolean strict)