| /* |
| * 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.apache.htrace.core; |
| |
| import java.io.IOException; |
| import java.util.Arrays; |
| import java.util.List; |
| import java.util.Map; |
| |
| import com.fasterxml.jackson.core.JsonGenerator; |
| import com.fasterxml.jackson.databind.JsonSerializer; |
| import com.fasterxml.jackson.databind.SerializerProvider; |
| import com.fasterxml.jackson.databind.annotation.JsonSerialize; |
| |
| /** |
| * Base interface for gathering and reporting statistics about a block of |
| * execution. |
| * |
| * <p>Spans should form a directed acyclic graph structure. It should be |
| * possible to keep following the parents of a span until you arrive at a |
| * span with no parents.</p> |
| */ |
| @JsonSerialize(using = Span.SpanSerializer.class) |
| public interface Span { |
| /** |
| * The block has completed, stop the clock |
| */ |
| void stop(); |
| |
| /** |
| * Get the span start time. |
| * |
| * @return The start time, in approximate milliseconds since the epoch. |
| */ |
| long getStartTimeMillis(); |
| |
| /** |
| * Get the span stop time. |
| * |
| * @return The stop time, in approximate milliseconds since the epoch. |
| */ |
| long getStopTimeMillis(); |
| |
| /** |
| * Return the total amount of time elapsed since start was called, if running, |
| * or difference between stop and start |
| * |
| * @return The elapsed time in milliseconds. |
| */ |
| long getAccumulatedMillis(); |
| |
| /** |
| * Has the span been started and not yet stopped? |
| * |
| * @return True if the span is still running (has no stop time). |
| */ |
| boolean isRunning(); |
| |
| /** |
| * Return a textual description of this span. |
| * |
| * @return The description of this span. Will never be null. |
| */ |
| String getDescription(); |
| |
| /** |
| * A pseudo-unique (random) number assigned to this span instance. |
| * |
| * @return The spanID. This object is immutable and is safe to access |
| * from multiple threads. |
| */ |
| SpanId getSpanId(); |
| |
| /** |
| * Create a child span of this span with the given description |
| * @deprecated Since 4.0.0. Use {@link MilliSpan.Builder} |
| * @param description The description to set on the child span. |
| * @return A new child span. |
| */ |
| @Deprecated |
| Span child(String description); |
| |
| @Override |
| String toString(); |
| |
| /** |
| * Returns the parent IDs of the span. |
| * |
| * @return The array of parents, or an empty array if there are no parents. |
| */ |
| SpanId[] getParents(); |
| |
| /** |
| * Set the parents of this span. |
| * |
| * <p>Any existing parents will be cleared by this call.</p> |
| * |
| * @param parents The parents to set. |
| */ |
| void setParents(SpanId[] parents); |
| |
| /** |
| * Add a data annotation associated with this span |
| * |
| * @param key The key to set. |
| * @param value The value to set. |
| */ |
| void addKVAnnotation(String key, String value); |
| |
| /** |
| * Add a timeline annotation associated with this span |
| * |
| * @param msg The annotation to set. It will be associated with |
| * the current time. |
| */ |
| void addTimelineAnnotation(String msg); |
| |
| /** |
| * Get the key-value annotations associated with this span. |
| * |
| * @return The annotation map in read-only form. |
| * Will never be null. |
| */ |
| Map<String, String> getKVAnnotations(); |
| |
| /** |
| * Get the timeline annotation list. |
| * |
| * @return The annotation list in read-only form. |
| * Will never be null. |
| */ |
| List<TimelineAnnotation> getTimelineAnnotations(); |
| |
| /** |
| * Return a unique id for the process from which this Span originated. |
| * |
| * @return The tracer id. Will never be null. |
| */ |
| String getTracerId(); |
| |
| /** |
| * Set the tracer id of a span. |
| * |
| * @param s The tracer ID to set. |
| */ |
| void setTracerId(String s); |
| |
| /** |
| * Serialize to Json |
| * |
| * @return A JSON string with the span data. |
| */ |
| String toJson(); |
| |
| public static class SpanSerializer extends JsonSerializer<Span> { |
| @Override |
| public void serialize(Span span, JsonGenerator jgen, SerializerProvider provider) |
| throws IOException { |
| jgen.writeStartObject(); |
| if (span.getSpanId().isValid()) { |
| jgen.writeStringField("a", span.getSpanId().toString()); |
| } |
| if (span.getStartTimeMillis() != 0) { |
| jgen.writeNumberField("b", span.getStartTimeMillis()); |
| } |
| if (span.getStopTimeMillis() != 0) { |
| jgen.writeNumberField("e", span.getStopTimeMillis()); |
| } |
| if (!span.getDescription().isEmpty()) { |
| jgen.writeStringField("d", span.getDescription()); |
| } |
| String tracerId = span.getTracerId(); |
| if (!tracerId.isEmpty()) { |
| jgen.writeStringField("r", tracerId); |
| } |
| jgen.writeArrayFieldStart("p"); |
| for (SpanId parent : span.getParents()) { |
| jgen.writeString(parent.toString()); |
| } |
| jgen.writeEndArray(); |
| Map<String, String> traceInfoMap = span.getKVAnnotations(); |
| if (!traceInfoMap.isEmpty()) { |
| jgen.writeObjectFieldStart("n"); |
| String[] keys = traceInfoMap.keySet(). |
| toArray(new String[traceInfoMap.size()]); |
| Arrays.sort(keys); |
| for (String key : keys) { |
| jgen.writeStringField(key, traceInfoMap.get(key)); |
| } |
| jgen.writeEndObject(); |
| } |
| List<TimelineAnnotation> timelineAnnotations = |
| span.getTimelineAnnotations(); |
| if (!timelineAnnotations.isEmpty()) { |
| jgen.writeArrayFieldStart("t"); |
| for (TimelineAnnotation tl : timelineAnnotations) { |
| jgen.writeStartObject(); |
| jgen.writeNumberField("t", tl.getTime()); |
| jgen.writeStringField("m", tl.getMessage()); |
| jgen.writeEndObject(); |
| } |
| jgen.writeEndArray(); |
| } |
| jgen.writeEndObject(); |
| } |
| } |
| } |