Add a SpanBuilder class. (#123)

* Add a SpanBuilder to avoid exponential increase in the number of startSpan[XXX] methods in the Tracer class.

* Modify examples and comments based on Adrian's feedback.

6 files changed, 11 insertions, 11 deletions

diff --git a/examples/src/main/java/com/google/instrumentation/trace/BasicContextTracing.java b/examples/src/main/java/com/google/instrumentation/trace/BasicContextTracing.java
index ef776473..b3411b62 100644
--- a/examples/src/main/java/com/google/instrumentation/trace/BasicContextTracing.java
+++ b/examples/src/main/java/com/google/instrumentation/trace/BasicContextTracing.java
@@ -29,7 +29,7 @@ public final class BasicContextTracing {
   }
 
   public static void main(String[] args) {
-    Span span = tracer.startSpan(null, "MyRootSpan", StartSpanOptions.getDefault());
+    Span span = tracer.spanBuilder("MyRootSpan").becomeRoot().startSpan();
     try (NonThrowingCloseable ws = tracer.withSpan(span)) {
       doWork();
     }
diff --git a/examples/src/main/java/com/google/instrumentation/trace/BasicScopedTracing.java b/examples/src/main/java/com/google/instrumentation/trace/BasicScopedTracing.java
index 1c1c8c05..8987f262 100644
--- a/examples/src/main/java/com/google/instrumentation/trace/BasicScopedTracing.java
+++ b/examples/src/main/java/com/google/instrumentation/trace/BasicScopedTracing.java
@@ -29,7 +29,8 @@ public final class BasicScopedTracing {
   }
 
   public static void main(String[] args) {
-    try (NonThrowingCloseable ss = tracer.startScopedSpan(null, "MyRootSpan")) {
+    try (NonThrowingCloseable ss =
+        tracer.spanBuilder("MyRootSpan").becomeRoot().startScopedSpan()) {
       doWork();
     }
   }
diff --git a/examples/src/main/java/com/google/instrumentation/trace/BasicTracing.java b/examples/src/main/java/com/google/instrumentation/trace/BasicTracing.java
index 1bb60e44..edd1e7e0 100644
--- a/examples/src/main/java/com/google/instrumentation/trace/BasicTracing.java
+++ b/examples/src/main/java/com/google/instrumentation/trace/BasicTracing.java
@@ -19,7 +19,7 @@ public final class BasicTracing {
   private static final Tracer tracer = Tracer.getTracer();
 
   private static void doWork() {
-    try (Span span = tracer.startSpan(null, "MyRootSpan", StartSpanOptions.getDefault())) {
+    try (Span span = tracer.spanBuilder(null, "MyRootSpan").startSpan()) {
       span.addAnnotation("This annotation is added directly to the span.");
     }
   }
diff --git a/examples/src/main/java/com/google/instrumentation/trace/MultiSpansContextTracing.java b/examples/src/main/java/com/google/instrumentation/trace/MultiSpansContextTracing.java
index db1312da..b5721d38 100644
--- a/examples/src/main/java/com/google/instrumentation/trace/MultiSpansContextTracing.java
+++ b/examples/src/main/java/com/google/instrumentation/trace/MultiSpansContextTracing.java
@@ -29,8 +29,7 @@ public final class MultiSpansContextTracing {
 
   private static void doSomeMoreWork() {
     // Create a child Span of the current Span.
-    Span span =
-        tracer.startSpan(tracer.getCurrentSpan(), "MyChildSpan", StartSpanOptions.getDefault());
+    Span span = tracer.spanBuilder("MyChildSpan").startSpan();
     try (NonThrowingCloseable ws = tracer.withSpan(span)) {
       doSomeOtherWork();
     }
@@ -44,7 +43,7 @@ public final class MultiSpansContextTracing {
   }
 
   public static void main(String[] args) {
-    Span span = tracer.startSpan(null, "MyRootSpan", StartSpanOptions.getDefault());
+    Span span = tracer.spanBuilder("MyRootSpan").becomeRoot().startSpan();
     try (NonThrowingCloseable ws = tracer.withSpan(span)) {
       doWork();
     }
diff --git a/examples/src/main/java/com/google/instrumentation/trace/MultiSpansScopedTracing.java b/examples/src/main/java/com/google/instrumentation/trace/MultiSpansScopedTracing.java
index ceadb289..827fbb6e 100644
--- a/examples/src/main/java/com/google/instrumentation/trace/MultiSpansScopedTracing.java
+++ b/examples/src/main/java/com/google/instrumentation/trace/MultiSpansScopedTracing.java
@@ -29,7 +29,7 @@ public final class MultiSpansScopedTracing {
 
   private static void doSomeMoreWork() {
     // Create a child Span of the current Span.
-    try (NonThrowingCloseable ss = tracer.startScopedSpan("MyChildSpan")) {
+    try (NonThrowingCloseable ss = tracer.spanBuilder("MyChildSpan").startScopedSpan()) {
       doSomeOtherWork();
     }
   }
@@ -41,7 +41,8 @@ public final class MultiSpansScopedTracing {
   }
 
   public static void main(String[] args) {
-    try (NonThrowingCloseable ss = tracer.startScopedSpan(null, "MyRootSpan")) {
+    try (NonThrowingCloseable ss =
+        tracer.spanBuilder("MyRootSpan").becomeRoot().startScopedSpan()) {
       doWork();
     }
   }
diff --git a/examples/src/main/java/com/google/instrumentation/trace/MultiSpansTracing.java b/examples/src/main/java/com/google/instrumentation/trace/MultiSpansTracing.java
index 2351198f..74b017cd 100644
--- a/examples/src/main/java/com/google/instrumentation/trace/MultiSpansTracing.java
+++ b/examples/src/main/java/com/google/instrumentation/trace/MultiSpansTracing.java
@@ -19,10 +19,9 @@ public final class MultiSpansTracing {
   private static final Tracer tracer = Tracer.getTracer();
 
   private static void doWork() {
-    try (Span rootSpan = tracer.startSpan(null, "MyRootSpan", StartSpanOptions.getDefault())) {
+    try (Span rootSpan = tracer.spanBuilder(null, "MyRootSpan").startSpan()) {
       rootSpan.addAnnotation("Annotation to the root Span before child is created.");
-      try (Span childSpan =
-          tracer.startSpan(rootSpan, "MyChildSpan", StartSpanOptions.getDefault())) {
+      try (Span childSpan = tracer.spanBuilder(rootSpan, "MyChildSpan").startSpan()) {
         childSpan.addAnnotation("Annotation to the child Span");
       }
       rootSpan.addAnnotation("Annotation to the root Span after child is ended.");