Add Span.Kind to the trace API. (#1223)

* Add Span.Kind to the trace API.

* Add @Nullable annotation where needed.

* Add changes to changelog.

2 files changed, 28 insertions, 0 deletions

diff --git a/impl_core/src/main/java/io/opencensus/implcore/trace/SpanBuilderImpl.java b/impl_core/src/main/java/io/opencensus/implcore/trace/SpanBuilderImpl.java
index 45cf4261..f5d74393 100644
--- a/impl_core/src/main/java/io/opencensus/implcore/trace/SpanBuilderImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/SpanBuilderImpl.java
@@ -25,6 +25,7 @@ import io.opencensus.trace.Link;
 import io.opencensus.trace.Link.Type;
 import io.opencensus.trace.Sampler;
 import io.opencensus.trace.Span;
+import io.opencensus.trace.Span.Kind;
 import io.opencensus.trace.SpanBuilder;
 import io.opencensus.trace.SpanContext;
 import io.opencensus.trace.SpanId;
@@ -48,6 +49,7 @@ final class SpanBuilderImpl extends SpanBuilder {
   @Nullable private Sampler sampler;
   private List<Span> parentLinks = Collections.<Span>emptyList();
   @Nullable private Boolean recordEvents;
+  @Nullable private Kind kind;
 
   private SpanImpl startSpanInternal(
       @Nullable SpanContext parent,
@@ -56,6 +58,7 @@ final class SpanBuilderImpl extends SpanBuilder {
       @Nullable Sampler sampler,
       List<Span> parentLinks,
       @Nullable Boolean recordEvents,
+      @Nullable Kind kind,
       @Nullable TimestampConverter timestampConverter) {
     TraceParams activeTraceParams = options.traceConfig.getActiveTraceParams();
     Random random = options.randomHandler.current();
@@ -95,6 +98,7 @@ final class SpanBuilderImpl extends SpanBuilder {
             SpanContext.create(traceId, spanId, traceOptions),
             spanOptions,
             name,
+            kind,
             parentSpanId,
             hasRemoteParent,
             activeTraceParams,
@@ -196,6 +200,7 @@ final class SpanBuilderImpl extends SpanBuilder {
         sampler,
         parentLinks,
         recordEvents,
+        kind,
         timestampConverter);
   }
 
@@ -234,4 +239,10 @@ final class SpanBuilderImpl extends SpanBuilder {
     this.recordEvents = recordEvents;
     return this;
   }
+
+  @Override
+  public SpanBuilderImpl setSpanKind(Kind kind) {
+    this.kind = kind;
+    return this;
+  }
 }
diff --git a/impl_core/src/main/java/io/opencensus/implcore/trace/SpanImpl.java b/impl_core/src/main/java/io/opencensus/implcore/trace/SpanImpl.java
index 59291685..75509a7f 100644
--- a/impl_core/src/main/java/io/opencensus/implcore/trace/SpanImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/SpanImpl.java
@@ -66,6 +66,8 @@ public final class SpanImpl extends Span implements Element<SpanImpl> {
   private final StartEndHandler startEndHandler;
   // The displayed name of the span.
   private final String name;
+  // The kind of the span.
+  @Nullable private final Kind kind;
   // The clock used to get the time.
   private final Clock clock;
   // The time converter used to convert nano time to Timestamp. This is needed because Java has
@@ -132,6 +134,7 @@ public final class SpanImpl extends Span implements Element<SpanImpl> {
       SpanContext context,
       @Nullable EnumSet<Options> options,
       String name,
+      @Nullable Kind kind,
       @Nullable SpanId parentSpanId,
       @Nullable Boolean hasRemoteParent,
       TraceParams traceParams,
@@ -143,6 +146,7 @@ public final class SpanImpl extends Span implements Element<SpanImpl> {
             context,
             options,
             name,
+            kind,
             parentSpanId,
             hasRemoteParent,
             traceParams,
@@ -214,6 +218,16 @@ public final class SpanImpl extends Span implements Element<SpanImpl> {
   }
 
   /**
+   * Returns the kind of this {@code Span}.
+   *
+   * @return the kind of this {@code Span}.
+   */
+  @Nullable
+  public Kind getKind() {
+    return kind;
+  }
+
+  /**
    * Returns the {@code TimestampConverter} used by this {@code Span}.
    *
    * @return the {@code TimestampConverter} used by this {@code Span}.
@@ -253,6 +267,7 @@ public final class SpanImpl extends Span implements Element<SpanImpl> {
           parentSpanId,
           hasRemoteParent,
           name,
+          kind,
           CheckerFrameworkUtils.castNonNull(timestampConverter).convertNanoTime(startNanoTime),
           attributesSpanData,
           annotationsSpanData,
@@ -575,6 +590,7 @@ public final class SpanImpl extends Span implements Element<SpanImpl> {
       SpanContext context,
       @Nullable EnumSet<Options> options,
       String name,
+      @Nullable Kind kind,
       @Nullable SpanId parentSpanId,
       @Nullable Boolean hasRemoteParent,
       TraceParams traceParams,
@@ -585,6 +601,7 @@ public final class SpanImpl extends Span implements Element<SpanImpl> {
     this.parentSpanId = parentSpanId;
     this.hasRemoteParent = hasRemoteParent;
     this.name = name;
+    this.kind = kind;
     this.traceParams = traceParams;
     this.startEndHandler = startEndHandler;
     this.clock = clock;