org.cloudera.htrace.Span 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.cloudera.htrace;
import java.util.List;
import java.util.Map;
/**
* Base interface for gathering and reporting statistics about a block of
* execution.
*
* Spans form a tree structure with the parent relationship. The first span in a
* trace has no parent span.
*/
public interface Span {
public static final long ROOT_SPAN_ID = 0x74ace;
/**
* The block has completed, stop the clock
*/
void stop();
/**
* Get the start time, in milliseconds
*/
long getStartTimeMillis();
/**
* Get the stop time, in milliseconds
*/
long getStopTimeMillis();
/**
* Return the total amount of time elapsed since start was called, if running,
* or difference between stop and start
*/
long getAccumulatedMillis();
/**
* Has the span been started and not yet stopped?
*/
boolean isRunning();
/**
* Return a textual description of this span
*/
String getDescription();
/**
* A pseudo-unique (random) number assigned to this span instance
*/
long getSpanId();
/**
* A pseudo-unique (random) number assigned to the trace associated with this
* span
*/
long getTraceId();
/**
* Create a child span of this span with the given description
*/
Span child(String description);
@Override
String toString();
/**
* Return the pseudo-unique (random) number of the parent span, returns
* ROOT_SPAN_ID if this is the root span
*/
long getParentId();
/**
* Add a data annotation associated with this span
*/
void addKVAnnotation(byte[] key, byte[] value);
/**
* Add a timeline annotation associated with this span
*/
void addTimelineAnnotation(String msg);
/**
* Get data associated with this span (read only)
*/
Map getKVAnnotations();
/**
* Get any timeline annotations (read only)
*/
List getTimelineAnnotations();
/**
* Return a unique id for the node or process from which this Span originated.
* IP address is a reasonable choice.
*
* @return
*/
String getProcessId();
}