package com.tinkerpop.gremlin.server.handler;
import com.codahale.metrics.Meter;
import com.tinkerpop.gremlin.driver.MessageSerializer;
import com.tinkerpop.gremlin.driver.message.ResponseMessage;
import com.tinkerpop.gremlin.driver.message.ResponseStatusCode;
import com.tinkerpop.gremlin.driver.ser.MessageTextSerializer;
import com.tinkerpop.gremlin.server.GremlinServer;
import com.tinkerpop.gremlin.server.op.session.Session;
import com.tinkerpop.gremlin.server.util.MetricManager;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToMessageEncoder;
import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.List;
import java.util.concurrent.atomic.AtomicReference;
import static com.codahale.metrics.MetricRegistry.name;
/**
* @author Stephen Mallette (http://stephen.genoprime.com)
*/
public class WsGremlinResponseEncoder extends MessageToMessageEncoder<ResponseMessage> {
private static final Logger logger = LoggerFactory.getLogger(WsGremlinResponseEncoder.class);
static final Meter errorMeter = MetricManager.INSTANCE.getMeter(name(GremlinServer.class, "errors"));
@Override
protected void encode(final ChannelHandlerContext channelHandlerContext, final ResponseMessage o, final List<Object> objects) throws Exception {
final MessageSerializer serializer = channelHandlerContext.channel().attr(StateKey.SERIALIZER).get();
final boolean useBinary = channelHandlerContext.channel().attr(StateKey.USE_BINARY).get();
final Session session = channelHandlerContext.channel().attr(StateKey.SESSION).get();
try {
if (useBinary) {
final ByteBuf serialized;
// if the request came in on a session then the serialization must occur in that same thread.
if (null == session)
serialized = serializer.serializeResponseAsBinary(o, channelHandlerContext.alloc());
else
serialized = session.getExecutor().submit(() -> serializer.serializeResponseAsBinary(o, channelHandlerContext.alloc())).get();
if (o.getStatus().getCode().isSuccess())
objects.add(new BinaryWebSocketFrame(serialized));
else {
objects.add(new BinaryWebSocketFrame(serialized));
final ResponseMessage terminator = ResponseMessage.build(o.getRequestId()).code(ResponseStatusCode.SUCCESS_TERMINATOR).create();
objects.add(new BinaryWebSocketFrame(serializer.serializeResponseAsBinary(terminator, channelHandlerContext.alloc())));
errorMeter.mark();
}
} else {
// the expectation is that the GremlinTextRequestDecoder will have placed a MessageTextSerializer
// instance on the channel.
final MessageTextSerializer textSerializer = (MessageTextSerializer) serializer;
final String serialized;
// if the request came in on a session then the serialization must occur in that same thread.
if (null == session)
serialized = textSerializer.serializeResponseAsString(o);
else
serialized = session.getExecutor().submit(() -> textSerializer.serializeResponseAsString(o)).get();
if (o.getStatus().getCode().isSuccess())
objects.add(new TextWebSocketFrame(true, 0, serialized));
else {
objects.add(new TextWebSocketFrame(true, 0, serialized));
final ResponseMessage terminator = ResponseMessage.build(o.getRequestId()).code(ResponseStatusCode.SUCCESS_TERMINATOR).create();
objects.add(new TextWebSocketFrame(true, 0, textSerializer.serializeResponseAsString(terminator)));
errorMeter.mark();
}
}
} catch (Exception ex) {
errorMeter.mark();
logger.warn("The result [{}] in the request {} could not be serialized and returned.", o.getResult(), o.getRequestId(), ex);
final String errorMessage = String.format("Error during serialization: %s",
ex.getCause() != null ? ex.getCause().getMessage() : ex.getMessage());
final ResponseMessage error = ResponseMessage.build(o.getRequestId())
.statusMessage(errorMessage)
.code(ResponseStatusCode.SERVER_ERROR_SERIALIZATION).create();
if (useBinary) {
channelHandlerContext.write(new BinaryWebSocketFrame(serializer.serializeResponseAsBinary(error, channelHandlerContext.alloc())));
final ResponseMessage terminator = ResponseMessage.build(o.getRequestId()).code(ResponseStatusCode.SUCCESS_TERMINATOR).create();
channelHandlerContext.writeAndFlush(new BinaryWebSocketFrame(serializer.serializeResponseAsBinary(terminator, channelHandlerContext.alloc())));
} else {
final MessageTextSerializer textSerializer = (MessageTextSerializer) serializer;
channelHandlerContext.write(new TextWebSocketFrame(textSerializer.serializeResponseAsString(error)));
final ResponseMessage terminator = ResponseMessage.build(o.getRequestId()).code(ResponseStatusCode.SUCCESS_TERMINATOR).create();
channelHandlerContext.writeAndFlush(new TextWebSocketFrame(textSerializer.serializeResponseAsString(terminator)));
}
}
}
}