org.htrace.TraceTree Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.htrace;
import com.google.common.collect.HashMultimap;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Multimap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.util.Collection;
/**
* Used to create the graph formed by spans.
*/
public class TraceTree {
public static final Log LOG = LogFactory.getLog(Tracer.class);
private Multimap spansByParentID;
private Collection spans;
private Multimap spansByPid;
/**
* Create a new TraceTree
*
* @param spans The collection of spans to use to create this TraceTree. Should
* have at least one root span (span with parentId =
* Span.ROOT_SPAN_ID
*/
public TraceTree(Collection spans) {
this.spans = ImmutableList.copyOf(spans);
this.spansByParentID = HashMultimap.create();
this.spansByPid = HashMultimap.create();
for (Span s : spans) {
if (s.getProcessId() != null) {
spansByPid.put(s.getProcessId(), s);
} else {
LOG.warn("Encountered span with null processId. This should not happen. Span: "
+ s);
}
spansByParentID.put(s.getParentId(), s);
}
}
/**
* @return The collection of spans given to this TraceTree at construction.
*/
public Collection getSpans() {
return spans;
}
/**
* @return A copy of the MultiMap from parent span ID -> children of span with
* that ID.
*/
public Multimap getSpansByParentIdMap() {
return HashMultimap.create(spansByParentID);
}
/**
* @return A collection of the root spans (spans with parent ID =
* Span.ROOT_SPAN_ID) in this tree.
*/
public Collection getRoots() {
Collection roots = spansByParentID.get(Span.ROOT_SPAN_ID);
if (roots != null) {
return roots;
}
throw new IllegalStateException(
"TraceTree is not correctly formed - there are no root spans in the collection provided at construction.");
}
/**
* @return A copy of the Multimap from String process ID -> spans with that
* process ID. If process ID was not set in Trace.java, all spans will
* have empty string process IDs.
*/
public Multimap getSpansByPidMap() {
return HashMultimap.create(spansByPid);
}
}