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/**
* Copyright (c) 2020, 2022 Contributors to the Eclipse Foundation
*
* See the NOTICE file(s) distributed with this work for additional
* information regarding copyright ownership.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0
*
* SPDX-License-Identifier: EPL-2.0
*/
package org.eclipse.hono.client.command;
import java.net.HttpURLConnection;
import java.util.Objects;
import org.eclipse.hono.client.ClientErrorException;
import org.eclipse.hono.client.ServerErrorException;
import org.eclipse.hono.tracing.TracingHelper;
import org.eclipse.hono.util.ExecutionContext;
import org.eclipse.hono.util.MessageHelper;
import io.opentracing.References;
import io.opentracing.Span;
import io.opentracing.SpanContext;
import io.opentracing.Tracer;
import io.opentracing.tag.Tags;
/**
* A context for processing a command that is targeted at a device.
*
*/
public interface CommandContext extends ExecutionContext {
/**
* The key under which the current CommandContext is stored in an ExecutionContext container.
*/
String KEY_COMMAND_CONTEXT = "command-context";
String KEY_TENANT_CONFIG = "tenant-config";
/**
* Checks if the context has already been completed.
*
* @return {@code true} if the context has already been completed.
*/
boolean isCompleted();
/**
* Logs information about the command.
*
* @param span The span to log to.
* @throws NullPointerException if span is {@code null}.
*/
void logCommandToSpan(Span span);
/**
* Gets the command to process.
*
* @return The command.
*/
Command getCommand();
/**
* Indicates to the sender that the command message has been delivered to its target.
*/
void accept();
/**
* Indicates to the sender that the command message could not be delivered to its target or could
* not be processed by its target due to reasons that are not the responsibility of the sender
* of the command.
*/
default void release() {
release(new ServerErrorException(HttpURLConnection.HTTP_UNAVAILABLE));
}
/**
* Indicates to the sender that the command message could not be delivered to its target or could
* not be processed by its target due to reasons that are not the responsibility of the sender
* of the command.
*
* @param error The delivery error.
* @throws NullPointerException if error is {@code null}.
*/
void release(Throwable error);
/**
* Indicates to the sender that the command message could not be delivered to its target due to
* reasons that are not the responsibility of the sender of the command.
*
* @param deliveryFailed {@code true} if the attempt to send the command to the target device has failed.
* @param undeliverableHere {@code true} if the component processing the context has no access to the command's
* target device.
*/
void modify(boolean deliveryFailed, boolean undeliverableHere);
/**
* Indicates to the sender that the command message cannot be delivered to or processed by its target due to
* reasons that are the responsibility of the sender of the command.
*
* The reason for a command being rejected often is that the command is invalid, e.g. lacking a
* subject or having a malformed address.
*
* @param error The error that caused the command to be rejected or {@code null} if the cause is unknown.
*/
default void reject(final String error) {
reject(new ClientErrorException(HttpURLConnection.HTTP_BAD_REQUEST, error));
}
/**
* Indicates to the sender that the command message cannot be delivered to or processed by its target due to
* reasons that are the responsibility of the sender of the command.
*
* The reason for a command being rejected often is that the command is invalid, e.g. lacking a
* subject or having a malformed address.
*
* @param error The error that caused the command to be rejected or {@code null} if the cause is unknown.
*/
void reject(Throwable error);
/**
* Creates and starts an OpenTracing span for the command handling operation.
*
* @param tracer The tracer to use.
* @param command The command for which the span should be started.
* @param parentSpanContext The context of the span to reference as parent span.
* @param followsFromSpanContext A span context for which to add a follows-from reference,
* e.g. the span context for the operation to create the command consumer.
* @param componentName The component to set for the span.
* @return The created span.
* @throws NullPointerException if tracer or command is {@code null}.
*/
static Span createSpan(final Tracer tracer, final Command command, final SpanContext parentSpanContext,
final SpanContext followsFromSpanContext, final String componentName) {
Objects.requireNonNull(tracer);
Objects.requireNonNull(command);
// we set the component tag to the class name because we have no access to
// the name of the enclosing component we are running in
final Tracer.SpanBuilder spanBuilder = TracingHelper
.buildChildSpan(tracer, parentSpanContext, "handle command", componentName)
.withTag(Tags.SPAN_KIND.getKey(), Tags.SPAN_KIND_CONSUMER)
.withTag(TracingHelper.TAG_TENANT_ID, command.getTenant())
.withTag(TracingHelper.TAG_DEVICE_ID, command.getDeviceId());
if (command.getGatewayId() != null) {
spanBuilder.withTag(MessageHelper.APP_PROPERTY_GATEWAY_ID, command.getGatewayId());
}
spanBuilder.addReference(References.FOLLOWS_FROM, followsFromSpanContext);
final Span currentSpan = spanBuilder.start();
command.logToSpan(currentSpan);
return currentSpan;
}
}