ParentResolver.java
/*
* Copyright (c) 2019, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
*
* WSO2 Inc. licenses this file to you under the Apache License,
* Version 2.0 (the "License"); you may not use this file except
* in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.synapse.aspects.flow.statistics.tracing.opentelemetry.management.parentresolving;
import org.apache.synapse.MessageContext;
import org.apache.synapse.aspects.flow.statistics.data.raw.StatisticDataUnit;
import org.apache.synapse.aspects.flow.statistics.tracing.opentelemetry.stores.SpanStore;
import org.apache.synapse.aspects.flow.statistics.tracing.opentelemetry.models.SpanWrapper;
/**
* Resolves parent spans before a child span starts.
*/
public class ParentResolver {
/**
* Prevents instantiation.
*/
private ParentResolver() {}
/**
* Resolves parent spans before a child span starts.
*
* The message flow parent index which is explicitly reported by the statistic data unit is checked first.
* The parent is finalized if it gives an acceptable parent as implemented inside.
*
* During an unacceptable parent in the above case, the component's unique id will be examined in the
* artifact holder's structuring elements stack, in order to track the parent holder.
*
* In case if both of the above fail, the most recent active span will be chosen as the parent.
*
* The very first span of the scope will always return null as the parent, which creates a new trace.
*
* @param child Statistic data unit of the child.
* @param spanStore Span store from where, existing spans are referred.
* @param synCtx Message context.
* @return Resolved parent span wrapper. Null if no parent.
*/
public static SpanWrapper resolveParent(StatisticDataUnit child,
SpanStore spanStore,
MessageContext synCtx) {
// Try resolving based on statistic data unit message flow representation
SpanWrapper parent = MessageFlowRepresentationBasedParentResolver.resolveParent(child, spanStore);
if (parent != null && parent.getSpan() != null) {
return parent;
}
// Try resolving based on the structuring element stack of the artifact holder
parent = ArtifactHolderBasedParentResolver.resolveParent(child, spanStore, synCtx);
if (parent != null && parent.getSpan() != null) {
return parent;
}
// Resolve based on latest active span
return LatestActiveParentResolver.resolveParent(spanStore);
}
}