Make LightStep's Tracer fall in line with OpenTracing changes

.gitignore

@@ -1,4 +1,4 @@
-/.idea/
+.idea/
 .gradle/
 **/.idea/workspace.xml
 **/.idea/tasks.xml

common/src/main/java/com/lightstep/tracer/shared/AbstractTracer.java

@@ -37,6 +37,7 @@
 import com.lightstep.tracer.shared.Span;
 
 import io.opentracing.Tracer;
+import io.opentracing.References;
 
 public abstract class AbstractTracer implements Tracer {
   // Delay before sending the initial report
@@ -71,12 +72,12 @@ protected enum InternalLogLevel {
   /**
    * The tag key used to define traces which are joined based on a GUID.
    */
-	public static final String TRACE_GUID_KEY = "join:trace_guid";
+  public static final String TRACE_GUID_KEY = "join:trace_guid";
   /**
    * The tag key used to record the relationship between child and parent
    * spans.
    */
-	public static final String PARENT_SPAN_GUID_KEY = "parent_span_guid";
+  public static final String PARENT_SPAN_GUID_KEY = "parent_span_guid";
 
   // copied from options
   private final int maxBufferedSpans;
@@ -295,12 +296,12 @@ public Tracer.SpanBuilder buildSpan(String operationName) {
     return this.new SpanBuilder(operationName);
   }
 
-  public <T> void inject(io.opentracing.Span span, T carrier) {
+  public void inject(io.opentracing.SpanContext spanContext, Object carrier) {
     // TODO implement
     throw new RuntimeException("inject: unimplemented");
   }
 
-  public <T> Tracer.SpanBuilder join(T carrier) {
+  public io.opentracing.SpanContext extract(Object carrier) {
     // TODO implement
     throw new RuntimeException("join: unimplemented");
   }
@@ -460,7 +461,7 @@ void addSpan(SpanRecord span) {
     }
   }
 
-  private static final String generateGUID() {
+  static final String generateGUID() {
     // Note that ThreadLocalRandom is a singleton, thread safe Random Generator
     long guid = ThreadLocalRandom.current().nextLong(Long.MAX_VALUE);
     return Long.toHexString(guid);
@@ -473,7 +474,7 @@ protected void addTracerTag(String key, String value) {
 
   class SpanBuilder implements Tracer.SpanBuilder{
     private String operationName;
-    private io.opentracing.Span parent;
+    private SpanContext parent;
     private Map<String, String> tags;
     private long startTimestampMicros;
 
@@ -482,13 +483,18 @@ class SpanBuilder implements Tracer.SpanBuilder{
       this.tags = new HashMap<String, String>();
     }
 
-    public Tracer.SpanBuilder withOperationName(String operationName) {
-      this.operationName = operationName;
-      return this;
+    public Tracer.SpanBuilder asChildOf(Span parent) {
+      return this.asChildOf(parent.context());
+    }
+
+    public Tracer.SpanBuilder asChildOf(io.opentracing.SpanContext parent) {
+      return this.addReference(References.CHILD_OF, parent);
     }
 
-    public Tracer.SpanBuilder withParent(io.opentracing.Span parent) {
-      this.parent = parent;
+    public Tracer.SpanBuilder addReference(String type, io.opentracing.SpanContext referredTo) {
+      if (type == References.CHILD_OF || type == References.FOLLOWS_FROM) {
+        this.parent = (SpanContext)referredTo;
+      }
       return this;
     }
 
@@ -528,17 +534,18 @@ public io.opentracing.Span start() {
       record.setOldest_micros(this.startTimestampMicros);
       record.setSpan_guid(generateGUID());
 
-      String traceID;
-      if (this.parent instanceof io.opentracing.Span) {
-        Span parentSpan = (Span)parent;
-        traceID = parentSpan.getTraceID();
-        record.addToAttributes(new KeyValue(PARENT_SPAN_GUID_KEY, parentSpan.getGUID()));
-      } else {
-        traceID = generateGUID();
+      String traceId = null;
+      if (this.parent != null && this.parent instanceof SpanContext) {
+        traceId = this.parent.getTraceId();
+        record.addToAttributes(new KeyValue(
+              PARENT_SPAN_GUID_KEY,
+              this.parent.getSpanId()));
       }
-      record.addToJoin_ids(new TraceJoinId(TRACE_GUID_KEY, traceID));
+      SpanContext newSpanContext = new SpanContext(traceId); // traceId may be null
+      // Record the eventual TraceId in the SpanRecord.
+      record.setTrace_guid(newSpanContext.getTraceId());
 
-      Span span = new Span(AbstractTracer.this, record, traceID);
+      Span span = new Span(AbstractTracer.this, newSpanContext, record);
       for (Map.Entry<String, String> pair : this.tags.entrySet()) {
            span.setTag(pair.getKey(), pair.getValue());
       }

common/src/main/java/com/lightstep/tracer/shared/NoopSpan.java

@@ -1,14 +1,19 @@
 package com.lightstep.tracer.shared;
 
 import io.opentracing.Span;
+import io.opentracing.SpanContext;
 
 // A span which is returned when the tracer is disabled.
 class NoopSpan implements Span {
 
     static final Span INSTANCE = new NoopSpan();
+    static final SpanContext CONTEXT = new NoopSpanContext();
 
     private NoopSpan(){}
 
+    @Override
+    public SpanContext context() { return CONTEXT; }
+
     @Override
     public void finish() {}
 
@@ -30,16 +35,6 @@ public Span setTag(String key, Number value) {
       return this;
     }
 
-    @Override
-    public Span setBaggageItem(String key, String value) {
-      return this;
-    }
-
-    @Override
-    public String getBaggageItem(String key) {
-      return null;
-    }
-
     @Override
     public Span log(String message, /* @Nullable */ Object payload) {
       return this;
@@ -49,4 +44,12 @@ public Span log(String message, /* @Nullable */ Object payload) {
     public Span log(long instantMicroseconds, String message, /* @Nullable */ Object payload) {
       return this;
     }
+
+    private static class NoopSpanContext implements SpanContext {
+      @Override
+      public String getBaggageItem(String key) { return null; }
+
+      @Override
+      public SpanContext setBaggageItem(String key, String value) { return this; }
+    }
 }

common/src/main/java/com/lightstep/tracer/shared/Span.java

@@ -16,51 +16,34 @@ public class Span implements io.opentracing.Span {
 
   private final Object mutex = new Object();
   private final AbstractTracer tracer;
+  private final SpanContext context;
   private final SpanRecord record;
-  private final String traceID;
   private final ObjectMapper objectToJsonMapper;
 
-  Span (AbstractTracer tracer, SpanRecord record, String traceID) {
+  Span (AbstractTracer tracer, SpanContext context, SpanRecord record) {
+    this.context = context;
     this.tracer = tracer;
     this.record = record;
-    this.traceID = traceID;
 
     this.objectToJsonMapper = new ObjectMapper();
     this.objectToJsonMapper.setSerializationInclusion(
       com.fasterxml.jackson.annotation.JsonInclude.Include.NON_EMPTY);
   }
 
-  public String getTraceID() {
-    synchronized (this.mutex) {
-      return this.traceID;
-    }
-  }
-
-  public String getGUID() {
-    synchronized (this.mutex) {
-      return this.record.getSpan_guid();
-    }
-  }
-
-  public AbstractTracer getTracer() {
-    return this.tracer;
+  @Override
+  public io.opentracing.SpanContext context() {
+    return this.context;
   }
 
+  @Override
   public void finish() {
     synchronized (this.mutex) {
       this.record.setYoungest_micros(System.currentTimeMillis() * 1000);
       this.tracer.addSpan(record);
     }
   }
 
-  public void close() {
-    this.finish();
-  }
-
-  private static final boolean isJoinKey(String key) {
-    return key.startsWith("join:");
-  }
-
+  @Override
   public Span setTag(String key, String value) {
     synchronized (this.mutex) {
       if (isJoinKey(key)) {
@@ -72,6 +55,7 @@ public Span setTag(String key, String value) {
     return this;
   }
 
+  @Override
   public Span setTag(String key, boolean value){
     synchronized (this.mutex) {
       if (isJoinKey(key)) {
@@ -83,6 +67,7 @@ public Span setTag(String key, boolean value){
     return this;
   }
 
+  @Override
   public Span setTag(String key, Number value) {
     synchronized (this.mutex) {
       if (isJoinKey(key)) {
@@ -94,14 +79,16 @@ public Span setTag(String key, Number value) {
     return this;
   }
 
-  public Span setBaggageItem(String key, String value) {
-    // TODO implement baggage
-    return this;
+  public void close() {
+    this.finish();
   }
 
-  public String getBaggageItem(String key) {
-    // TODO implement baggage
-    return "";
+  private static final boolean isJoinKey(String key) {
+    return key.startsWith("join:");
+  }
+
+  public AbstractTracer getTracer() {
+    return this.tracer;
   }
 
   public Span log(String message, /* @Nullable */ Object payload) {
@@ -124,7 +111,8 @@ public Span log(long timestampMicroseconds, String message, /* @Nullable */ Obje
           log.setPayload_json(payloadString);
         } catch (JsonProcessingException e) {
           // Just use a string.
-          this.tracer.debug("Payload not serializable to JSON. Setting as String. (Span GUID=" + this.getGUID() + ")");
+          this.tracer.debug("Payload not serializable to JSON. Setting as String. (SpanId=" +
+              ((SpanContext)this.context()).getSpanId() + ")");
           log.setPayload_json(payload.toString());
         }
       }
@@ -139,7 +127,7 @@ public Span log(long timestampMicroseconds, String message, /* @Nullable */ Obje
   public String generateTraceURL() {
     synchronized (this.mutex) {
       return "https://app.lightstep.com/" + tracer.getAccessToken() +
-        "/trace?span_guid=" + this.getGUID() +
+        "/trace?span_guid=" + this.context.getSpanId() +
         "&at_micros=" + (System.currentTimeMillis() * 1000);
     }
   }

common/src/main/java/com/lightstep/tracer/shared/SpanContext.java

@@ -0,0 +1,43 @@
+package com.lightstep.tracer.shared;
+
+import java.util.Map;
+import java.util.HashMap;
+
+public class SpanContext implements io.opentracing.SpanContext {
+  private final String traceId;
+  private final String spanId;
+  private Map<String, String> baggage;
+
+  public SpanContext(String traceId) {
+    if (traceId == null) {
+      this.traceId = AbstractTracer.generateGUID();
+    } else {
+      this.traceId = traceId;
+    }
+    this.spanId = AbstractTracer.generateGUID();
+  }
+
+  public String getSpanId() {
+    return this.spanId;
+  }
+  public String getTraceId() {
+    return this.traceId;
+  }
+
+  @Override
+  public synchronized String getBaggageItem(String key) {
+    if (this.baggage == null) {
+      return null;
+    }
+    return this.baggage.get(key);
+  }
+
+  @Override
+  public synchronized SpanContext setBaggageItem(String key, String value) {
+    if (this.baggage == null) {
+      this.baggage = new HashMap<String, String>();
+    }
+    this.baggage.put(key, value);
+    return this;
+  }
+}

lightstep-tracer-jre/build.gradle

@@ -50,7 +50,7 @@ repositories {
 
 // Dependencies to build this JAR archive
 dependencies {
-    compile 'io.opentracing:opentracing-api:0.1.0-SNAPSHOT'
+    compile 'io.opentracing:opentracing-api:0.9.0'
     compile 'org.apache.thrift:libthrift:0.9.2'
     compile 'com.fasterxml.jackson.core:jackson-databind:2.7.3'
     compile 'org.json:json:20160212'

lightstep-tracer-jre/lightstep-tracer.iml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_5" inherit-compiler-output="false">
+    <output url="file://$MODULE_DIR$/target/classes" />
+    <output-test url="file://$MODULE_DIR$/target/test-classes" />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
+      <excludeFolder url="file://$MODULE_DIR$/target" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" scope="TEST" name="Maven: junit:junit:3.8.1" level="project" />
+    <orderEntry type="library" name="Maven: org.json:json:20090211" level="project" />
+  </component>
+</module>