Merge pull request open-telemetry#6 from Tianlin-Zhao/origin/propagators

Origin/propagators

.bazelrc

@@ -1,6 +1,9 @@
 # bazel configurations for running tests under sanitizers.
 # Based on https://github.com/bazelment/trunk/blob/master/tools/bazel.rc
 
+# Needed by gRPC to build on some platforms.
+build --copt -DGRPC_BAZEL_BUILD
+
 # --config=asan : Address Sanitizer.
 common:asan --copt -fsanitize=address
 common:asan --copt -DADDRESS_SANITIZER

.bazelversion

@@ -1 +1 @@
-3.2.0
+3.4.1

.github/.codecov.yaml

@@ -22,7 +22,7 @@ comment:
 
 # Relative file path fixing.
 # CI file paths must match Git file paths.
-# This fix removes the "/home/runner/" prefix 
+# This fix removes the "/home/runner/" prefix
 # to coverage report file paths.
 fixes:
   - "/home/runner/::"

.github/workflows/ci.yml

@@ -55,6 +55,8 @@ jobs:
         sudo ./ci/install_gcc48.sh
     - name: run tests
       run: ./ci/do_ci.sh bazel.legacy.test
+      env:
+        CC: /usr/bin/gcc-4.8
 
   bazel_test:
     name: Bazel

CMakeLists.txt

@@ -56,3 +56,4 @@ add_subdirectory(sdk)
 include_directories(.)
 add_subdirectory(exporters)
 add_subdirectory(examples)
+add_subdirectory(ext)

README.md

@@ -1,9 +1,9 @@
 # OpenTelemetry C++
 
-[![Gitter chat][gitter-image]][gitter-url]
-
-[gitter-image]: https://badges.gitter.im/open-telemetry/opentelemetry-cpp.svg
-[gitter-url]: https://gitter.im/open-telemetry/opentelemetry-cpp?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge
+[![Gitter chat](https://badges.gitter.im/open-telemetry/opentelemetry-cpp.svg)](https://gitter.im/open-telemetry/opentelemetry-cpp?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[![codecov.io](https://codecov.io/gh/open-telemetry/opentelemetry-cpp/branch/master/graphs/badge.svg?)](https://codecov.io/gh/open-telemetry/opentelemetry-cpp/)
+[![Build Status](https://action-badges.now.sh/open-telemetry/opentelemetry-cpp)](https://github.com/open-telemetry/opentelemetry-cpp/actions)
+[![Release](https://img.shields.io/github/v/release/open-telemetry/opentelemetry-cpp?include_prereleases&style=)](https://github.com/open-telemetry/opentelemetry-cpp/releases/)
 
 The C++ [OpenTelemetry](https://opentelemetry.io/) client.
 

WORKSPACE

@@ -16,6 +16,30 @@ workspace(name = "io_opentelemetry_cpp")
 
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
+# Load gRPC dependency
+# Note that this dependency needs to be loaded first due to
+# https://github.com/bazelbuild/bazel/issues/6664
+http_archive(
+    name = "com_github_grpc_grpc",
+    strip_prefix = "grpc-1.28.0",
+    urls = [
+        "https://github.com/grpc/grpc/archive/v1.28.0.tar.gz",
+    ],
+)
+
+load("@com_github_grpc_grpc//bazel:grpc_deps.bzl", "grpc_deps")
+
+grpc_deps()
+
+# Load extra gRPC dependencies due to https://github.com/grpc/grpc/issues/20511
+load("@com_github_grpc_grpc//bazel:grpc_extra_deps.bzl", "grpc_extra_deps")
+
+grpc_extra_deps()
+
+load("@upb//bazel:repository_defs.bzl", "bazel_version_repository")
+
+bazel_version_repository(name = "upb_bazel_version")
+
 # Uses older protobuf version because of
 # https://github.com/protocolbuffers/protobuf/issues/7179
 http_archive(
@@ -54,3 +78,12 @@ http_archive(
     strip_prefix = "benchmark-1.5.0",
     urls = ["https://github.com/google/benchmark/archive/v1.5.0.tar.gz"],
 )
+
+http_archive(
+    name = "github_nlohmann_json",
+    build_file = "//third_party:nlohmann_json.BUILD",
+    sha256 = "69cc88207ce91347ea530b227ff0776db82dcb8de6704e1a3d74f4841bc651cf",
+    urls = [
+        "https://github.com/nlohmann/json/releases/download/v3.6.1/include.zip",
+    ],
+)

api/include/opentelemetry/context/context.h

@@ -16,6 +16,7 @@ class Context
 {
 
 public:
+  Context() = default;
   // Creates a context object from a map of keys and identifiers, this will
   // hold a shared_ptr to the head of the DataList linked list
   template <class T>
@@ -89,9 +90,9 @@ class Context
     return false;
   }
 
-private:
-  Context() = default;
+  bool operator==(const Context &other) { return (head_ == other.head_); }
 
+private:
   // A linked list to contain the keys and values of this context node
   class DataList
   {
@@ -163,4 +164,4 @@ class Context
   nostd::shared_ptr<DataList> head_;
 };
 }  // namespace context
-OPENTELEMETRY_END_NAMESPACE
+OPENTELEMETRY_END_NAMESPACE

api/include/opentelemetry/context/runtime_context.h

@@ -0,0 +1,61 @@
+#pragma once
+
+#include "opentelemetry/context/context.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace context
+{
+// Provides a wrapper for propagating the context object globally. In order
+// to use either the threadlocal_context.h file must be included or another
+// implementation which must be derived from the RuntimeContext can be
+// provided.
+class RuntimeContext
+{
+public:
+  class Token
+  {
+  public:
+    bool operator==(const Context &other) noexcept { return context_ == other; }
+
+    ~Token() noexcept { Detach(*this); }
+
+  private:
+    friend class RuntimeContext;
+
+    // A constructor that sets the token's Context object to the
+    // one that was passed in.
+    Token(Context context) noexcept : context_(context){};
+
+    Token() noexcept = default;
+
+    Context context_;
+  };
+
+  // Return the current context.
+  static Context GetCurrent() noexcept { return context_handler_->InternalGetCurrent(); }
+
+  // Sets the current 'Context' object. Returns a token
+  // that can be used to reset to the previous Context.
+  static Token Attach(Context context) noexcept
+  {
+    return context_handler_->InternalAttach(context);
+  }
+
+  // Resets the context to a previous value stored in the
+  // passed in token. Returns true if successful, false otherwise
+  static bool Detach(Token &token) noexcept { return context_handler_->InternalDetach(token); }
+
+  static RuntimeContext *context_handler_;
+
+protected:
+  // Provides a token with the passed in context
+  Token CreateToken(Context context) noexcept { return Token(context); }
+
+  virtual Context InternalGetCurrent() noexcept = 0;
+
+  virtual Token InternalAttach(Context context) noexcept = 0;
+
+  virtual bool InternalDetach(Token &token) noexcept = 0;
+};
+}  // namespace context
+OPENTELEMETRY_END_NAMESPACE

api/include/opentelemetry/context/threadlocal_context.h

@@ -0,0 +1,116 @@
+#pragma once
+
+#include "opentelemetry/context/context.h"
+#include "opentelemetry/context/runtime_context.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace context
+{
+
+// The ThreadLocalContext class is a derived class from RuntimeContext and
+// provides a wrapper for propogating context through cpp thread locally.
+// This file must be included to use the RuntimeContext class if another
+// implementation has not been registered.
+class ThreadLocalContext : public RuntimeContext
+{
+public:
+  ThreadLocalContext() noexcept = default;
+
+  // Return the current context.
+  Context InternalGetCurrent() noexcept override { return stack_.Top(); }
+
+  // Resets the context to a previous value stored in the
+  // passed in token. Returns true if successful, false otherwise
+  bool InternalDetach(Token &token) noexcept override
+  {
+    if (!(token == stack_.Top()))
+    {
+      return false;
+    }
+    stack_.Pop();
+    return true;
+  }
+
+  // Sets the current 'Context' object. Returns a token
+  // that can be used to reset to the previous Context.
+  Token InternalAttach(Context context) noexcept override
+  {
+    stack_.Push(context);
+    Token old_context = CreateToken(context);
+    return old_context;
+  }
+
+private:
+  // A nested class to store the attached contexts in a stack.
+  class Stack
+  {
+    friend class ThreadLocalContext;
+
+    Stack() noexcept : size_(0), capacity_(0), base_(nullptr){};
+
+    // Pops the top Context off the stack and returns it.
+    Context Pop() noexcept
+    {
+      if (size_ <= 0)
+      {
+        return Context();
+      }
+      int index = size_ - 1;
+      size_--;
+      return base_[index];
+    }
+
+    // Returns the Context at the top of the stack.
+    Context Top() const noexcept
+    {
+      if (size_ <= 0)
+      {
+        return Context();
+      }
+      return base_[size_ - 1];
+    }
+
+    // Pushes the passed in context pointer to the top of the stack
+    // and resizes if necessary.
+    void Push(Context context) noexcept
+    {
+      size_++;
+      if (size_ > capacity_)
+      {
+        Resize(size_ * 2);
+      }
+      base_[size_ - 1] = context;
+    }
+
+    // Reallocates the storage array to the pass in new capacity size.
+    void Resize(int new_capacity) noexcept
+    {
+      int old_size = size_ - 1;
+      if (new_capacity == 0)
+      {
+        new_capacity = 2;
+      }
+      Context *temp = new Context[new_capacity];
+      if (base_ != nullptr)
+      {
+        std::copy(base_, base_ + old_size, temp);
+        delete[] base_;
+      }
+      base_ = temp;
+    }
+
+    ~Stack() noexcept { delete[] base_; }
+
+    size_t size_;
+    size_t capacity_;
+    Context *base_;
+  };
+
+  static thread_local Stack stack_;
+};
+thread_local ThreadLocalContext::Stack ThreadLocalContext::stack_ = ThreadLocalContext::Stack();
+
+// Registers the ThreadLocalContext as the context handler for the RuntimeContext
+RuntimeContext *RuntimeContext::context_handler_ = new ThreadLocalContext();
+}  // namespace context
+OPENTELEMETRY_END_NAMESPACE

api/include/opentelemetry/metrics/async_instruments.h

@@ -0,0 +1,83 @@
+#pragma once
+
+#include "instrument.h"
+#include "observer_result.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace metrics
+{
+
+template <class T>
+class ValueObserver : virtual public AsynchronousInstrument<T>
+{
+
+public:
+  ValueObserver() = default;
+
+  ValueObserver(nostd::string_view name,
+                nostd::string_view description,
+                nostd::string_view unit,
+                bool enabled,
+                void (*callback)(ObserverResult<T>))
+  {}
+
+  /*
+   * Updates the instruments aggregator with the new value. The labels should
+   * contain the keys and values to be associated with this value.
+   *
+   * @param value is the numerical representation of the metric being captured
+   * @param labels the set of labels, as key-value pairs
+   */
+  virtual void observe(T value, const trace::KeyValueIterable &labels) override = 0;
+
+  /**
+   * Captures data by activating the callback function associated with the
+   * instrument and storing its return value.  Callbacks for asynchronous
+   * instruments are defined during construction.
+   *
+   * @param none
+   * @return none
+   */
+  virtual void run() override = 0;
+};
+
+template <class T>
+class SumObserver : virtual public AsynchronousInstrument<T>
+{
+
+public:
+  SumObserver() = default;
+
+  SumObserver(nostd::string_view name,
+              nostd::string_view description,
+              nostd::string_view unit,
+              bool enabled,
+              void (*callback)(ObserverResult<T>))
+  {}
+
+  virtual void observe(T value, const trace::KeyValueIterable &labels) override = 0;
+
+  virtual void run() override = 0;
+};
+
+template <class T>
+class UpDownSumObserver : virtual public AsynchronousInstrument<T>
+{
+
+public:
+  UpDownSumObserver() = default;
+
+  UpDownSumObserver(nostd::string_view name,
+                    nostd::string_view description,
+                    nostd::string_view unit,
+                    bool enabled,
+                    void (*callback)(ObserverResult<T>))
+  {}
+
+  virtual void observe(T value, const trace::KeyValueIterable &labels) override = 0;
+
+  virtual void run() override = 0;
+};
+
+}  // namespace metrics
+OPENTELEMETRY_END_NAMESPACE