Update AlwaysOffSampler to new sampler spec

sdk/include/opentelemetry/sdk/trace/always_off_sampler.h

@@ -15,13 +15,11 @@ namespace trace_api = opentelemetry::trace;
 class AlwaysOffSampler : public Sampler
 {
 public:
-  explicit AlwaysOffSampler() noexcept;
-
   /**
    * @return Returns NOT_RECORD always
    */
   SamplingResult ShouldSample(
-    std::shared_ptr<SpanContext> parent_context,
+    const SpanContext *parent_context,
     trace_api::TraceId trace_id,
     nostd::string_view name,
     trace_api::SpanKind span_kind,
@@ -31,9 +29,6 @@ class AlwaysOffSampler : public Sampler
    * @return Description MUST be AlwaysOffSampler
    */
   std::string GetDescription() const noexcept override;
-
-private:
-  SamplingResult sampling_result_;
 };
 }  // namespace trace
 }  // namespace sdk

sdk/include/opentelemetry/sdk/trace/sampler.h

@@ -19,72 +19,72 @@ namespace sdk
 namespace trace
 {
 namespace trace_api = opentelemetry::trace;
-class Sampler
+/**
+ * NOT_RECORD - IsRecording() == false,
+ *    span will not be recorded and all events and attributes will be dropped.
+ * RECORD - IsRecording() == true, but Sampled flag MUST NOT be set.
+ * RECORD_AND_SAMPLED - IsRecording() == true AND Sampled flag` MUST be set.
+ */
+enum class Decision
 {
-private:
-  // Placeholder
-  class SpanContext
-  {};
+  NOT_RECORD,
+  RECORD,
+  RECORD_AND_SAMPLE
+};
 
+/**
+ * A placeholder for common::AttributeKeyValue
+ * A key/value pair that can be used to set attributes.
+ */
+struct AttributeKeyValue {
+    nostd::string_view key;
+    common::AttributeValue value;
+};
+
+struct SamplingResult
+{
+  Decision decision;
+  // TODO: Change AttributeKeyValue to common::AttributeKeyValue
+  std::unique_ptr<nostd::span<AttributeKeyValue>> attributes;
+};
+
+class Sampler
+{
 public:
+  // Placeholder
+  class SpanContext;
   virtual ~Sampler() = default;
   /**
    * Called during Span creation to make a sampling decision.
    *
-   * @param parent_context TODO: a shared pointer of the SpanContext of a parent Span. 
+   * @param parent_context TODO: a shared pointer of the SpanContext of a parent Span.
    *     null if this is a root span.
    * @param trace_id the TraceId for the new Span. This will be identical to that in
    *     the parentContext, unless this is a root span.
    * @param name the name of the new Span.
    * @param spanKind the trace_api::SpanKind of the Span.
-   * @param attributes TODO: current map is a placeholder.
+   * @param attributes TODO: Change AttributeKeyValue to common::AttributeKeyValue
    *     list of AttributeValue with their keys.
    * @param links TODO: Collection of links that will be associated with the Span to be created.
    * @return sampling result whether span should be sampled or not.
    * @since 0.1.0
    */
 
   virtual SamplingResult ShouldSample(
-      std::shared_ptr<SpanContext> parent_context,
+      const SpanContext *parent_context,
       trace_api::TraceId trace_id,
       nostd::string_view name,
       trace_api::SpanKind span_kind,
-      nostd::span<std::pair<nostd::string_view, common::AttributeValue>> attributes) noexcept = 0;
+      const nostd::span<AttributeKeyValue> &attributes) noexcept = 0;
 
   /**
-   * Returns the sampler name or short description with the configuration. 
+   * Returns the sampler name or short description with the configuration.
    * This may be displayed on debug pages or in the logs.
    *
    * @return the description of this Sampler.
    */
   virtual std::string GetDescription() const noexcept = 0;
 };
-
-class SamplingResult
-{
-public:
-  enum Decision
-  {
-    NOT_RECORD,
-    RECORD,
-    RECORD_AND_SAMPLE
-  };
-  virtual ~SamplingResult() = default;
-  /**
-   * Return sampling decision.
-   *
-   * @return Decision.
-   */
-  virtual Decision GetDecision() const noexcept = 0;
-
-  /**
-   * Return attributes which will be attached to the span.
-   *
-   * @return the immutable list of attributes added to span.
-   */
-  virtual nostd::span<std::pair<nostd::string_view, common::AttributeValue>> GetAttributes() const
-      noexcept = 0;
-};
 }  // namespace trace
 }  // namespace sdk
-OPENTELEMETRY_END_NAMESPACE
+OPENTELEMETRY_END_NAMESPACE

sdk/src/trace/always_off_sampler.cc

@@ -7,38 +7,24 @@ namespace trace
 {
 namespace trace_api = opentelemetry::trace;
 
-AlwaysOffSampler::AlwaysOffSampler() noexcept
-  : sampling_result_(new AlwaysOffSamplingResultImpl()) {}
-
 SamplingResult AlwaysOffSampler::ShouldSample(
-    std::shared_ptr<SpanContext> parent_context,
+    const SpanContext *parent_context,
     trace_api::TraceId trace_id,
     nostd::string_view name,
     trace_api::SpanKind span_kind,
-    const nostd::span<AttributeKeyValue> &attributes) noexcept override
+    const nostd::span<AttributeKeyValue> &attributes) noexcept
   {
-    return sampling_result_;
+    return
+    {
+      Decision::NOT_RECORD,
+      std::unique_ptr<nostd::span<AttributeKeyValue>>(new nostd::span<AttributeKeyValue>())
+    };
   }
 
-std::string GetDescription() const noexcept override
+std::string AlwaysOffSampler::GetDescription() const noexcept
 {
   return "AlwaysOffSampler";
 }
-
-class AlwaysOffSamplingResultImpl : public SamplingResult
-{
-public:
-  Decision GetDecision() const noexcept override
-  {
-    return decision_;
-  }
-
-  nostd::span<AttributeKeyValue> GetAttributes() const noexcept override
-  {
-    return attributes_;
-  }
-
-private:
-  Decision decision_ = Decision::NOT_RECORD;
-  nostd::span<AttributeKeyValue> attributes_ = nostd::span();
-};
+}  // namespace trace
+}  // namespace sdk
+OPENTELEMETRY_END_NAMESPACE