Change API to remove the "Option" logic and keep only Builder. (#380)

1 files changed, 30 insertions, 37 deletions

diff --git a/api/src/main/java/io/opencensus/trace/Tracer.java b/api/src/main/java/io/opencensus/trace/Tracer.java
index e6172bed..ef5616a9 100644
--- a/api/src/main/java/io/opencensus/trace/Tracer.java
+++ b/api/src/main/java/io/opencensus/trace/Tracer.java
@@ -16,8 +16,6 @@ package io.opencensus.trace;
 import static com.google.common.base.Preconditions.checkNotNull;
 
 import io.opencensus.common.NonThrowingCloseable;
-import io.opencensus.trace.base.StartSpanOptions;
-import io.opencensus.trace.internal.SpanFactory;
 import javax.annotation.Nullable;
 
 /**
@@ -67,7 +65,6 @@ import javax.annotation.Nullable;
  */
 public abstract class Tracer {
   private static final NoopTracer noopTracer = new NoopTracer();
-  private final SpanFactory spanFactory;
 
   /**
    * Returns the no-op implementation of the {@code Tracer}.
@@ -142,7 +139,7 @@ public abstract class Tracer {
    * @param span The {@link Span} to be set to the current Context.
    * @return an object that defines a scope where the given {@link Span} will be set to the current
    *     Context.
-   * @throws NullPointerException if span is null.
+   * @throws NullPointerException if {@code span} is null.
    */
   public final NonThrowingCloseable withSpan(Span span) {
     return ContextUtils.withSpan(checkNotNull(span, "span"));
@@ -150,7 +147,7 @@ public abstract class Tracer {
 
   /**
    * Returns a {@link SpanBuilder} to create and start a new child {@link Span} as a child of to the
-   * current {@code Span} if any, otherwise create a root Span with the default options.
+   * current {@code Span} if any, otherwise creates a root {@code Span}.
    *
    * <p>See {@link SpanBuilder} for usage examples.
    *
@@ -159,7 +156,7 @@ public abstract class Tracer {
    *
    * @param name The name of the returned Span.
    * @return a {@code SpanBuilder} to create and start a new {@code Span}.
-   * @throws NullPointerException if name is null.
+   * @throws NullPointerException if {@code name} is null.
    */
   public final SpanBuilder spanBuilder(String name) {
     return spanBuilder(ContextUtils.getCurrentSpan(), name);
@@ -167,64 +164,60 @@ public abstract class Tracer {
 
   /**
    * Returns a {@link SpanBuilder} to create and start a new child {@link Span} (or root if parent
-   * is null), with parent being the designated {@code Span}.
+   * is {@code null} or has an invalid {@link SpanContext}), with parent being the designated {@code
+   * Span}.
    *
    * <p>See {@link SpanBuilder} for usage examples.
    *
-   * <p>This <b>must</b> be used to create a {@code Span} when manual Context propagation is used.
+   * <p>This <b>must</b> be used to create a {@code Span} when manual Context propagation is used
+   * OR when creating a root {@code Span} with a {@code null} parent.
    *
    * @param parent The parent of the returned Span. If null the {@code SpanBuilder} will build a
    *     root {@code Span}.
    * @param name The name of the returned Span.
    * @return a {@code SpanBuilder} to create and start a new {@code Span}.
-   * @throws NullPointerException if name is null.
+   * @throws NullPointerException if {@code name} is null.
    */
-  public final SpanBuilder spanBuilder(@Nullable Span parent, String name) {
-    return SpanBuilder.builder(spanFactory, parent, checkNotNull(name, "name"));
-  }
+  public abstract SpanBuilder spanBuilder(@Nullable Span parent, String name);
 
   /**
    * Returns a {@link SpanBuilder} to create and start a new child {@link Span} (or root if parent
-   * is null), with parent being the {@link Span} designated by the {@link SpanContext}.
+   * is an invalid {@link SpanContext}), with parent being the {@link Span} designated by the {@link
+   * SpanContext}.
    *
    * <p>See {@link SpanBuilder} for usage examples.
    *
    * <p>This <b>must</b> be used to create a {@code Span} when the parent is in a different process.
    * This is only intended for use by RPC systems or similar.
    *
-   * @param remoteParent The remote parent of the returned Span.
+   * <p>If no {@link SpanContext} OR fail to parse the {@link SpanContext} on the server side,
+   * users must call this method with an {@link SpanContext#INVALID} remote parent {@code
+   * SpanContext}.
+   *
+   * @param remoteParentSpanContext The remote parent of the returned Span.
    * @param name The name of the returned Span.
    * @return a {@code SpanBuilder} to create and start a new {@code Span}.
-   * @throws NullPointerException if name is null.
+   * @throws NullPointerException if {@code name} or {@code remoteParentSpanContext} are null.
    */
-  public final SpanBuilder spanBuilderWithRemoteParent(
-      @Nullable SpanContext remoteParent, String name) {
-    return SpanBuilder.builderWithRemoteParent(
-        spanFactory, remoteParent, checkNotNull(name, "name"));
-  }
+  public abstract SpanBuilder spanBuilderWithRemoteParent(
+      SpanContext remoteParentSpanContext, String name);
 
   // No-Op implementation of the Tracer.
   private static final class NoopTracer extends Tracer {
-    private NoopTracer() {
-      super(new NoopSpanFactory());
-    }
 
-    // No-op implementation of the SpanFactory
-    private static final class NoopSpanFactory extends SpanFactory {
-      @Override
-      public Span startSpan(@Nullable Span parent, String name, StartSpanOptions options) {
-        return BlankSpan.INSTANCE;
-      }
+    @Override
+    public SpanBuilder spanBuilder(@Nullable Span parent, String name) {
+      return new SpanBuilder.NoopSpanBuilder(parent, name);
+    }
 
-      @Override
-      public Span startSpanWithRemoteParent(
-          @Nullable SpanContext remoteParent, String name, StartSpanOptions options) {
-        return BlankSpan.INSTANCE;
-      }
+    @Override
+    public SpanBuilder spanBuilderWithRemoteParent(
+        SpanContext remoteParentSpanContext, String name) {
+      return new SpanBuilder.NoopSpanBuilder(remoteParentSpanContext, name);
     }
-  }
 
-  protected Tracer(SpanFactory spanFactory) {
-    this.spanFactory = checkNotNull(spanFactory, "spanFactory");
+    private NoopTracer() {}
   }
+
+  protected Tracer() {}
 }