Setup dispatcher interface

WORKSPACE

@@ -37,6 +37,27 @@ new_local_repository(
     path = "third_party/opentelemetry-proto",
 )
 
+http_archive(
+   name = "rules_foreign_cc",
+   strip_prefix = "rules_foreign_cc-ed3db61a55c13da311d875460938c42ee8bbc2a5",
+   url = "https://github.com/bazelbuild/rules_foreign_cc/archive/ed3db61a55c13da311d875460938c42ee8bbc2a5.zip",
+)
+
+load("@rules_foreign_cc//:workspace_definitions.bzl", "rules_foreign_cc_dependencies")
+
+rules_foreign_cc_dependencies([
+])
+
+http_archive(
+    name = "com_github_libevent_libevent",
+    urls = [
+        "https://github.com/libevent/libevent/archive/release-2.1.8-stable.zip"
+    ],
+    sha256 = "70158101eab7ed44fd9cc34e7f247b3cae91a8e4490745d9d6eb7edc184e4d96",
+    strip_prefix = "libevent-release-2.1.8-stable",
+    build_file = "//bazel:libevent.BUILD",
+)
+
 # GoogleTest framework.
 # Only needed for tests, not to build the OpenTelemetry library.
 http_archive(

bazel/libevent.BUILD

@@ -0,0 +1,23 @@
+load("@rules_foreign_cc//tools/build_defs:cmake.bzl", "cmake_external")
+
+
+filegroup(
+    name = "srcs", 
+    srcs = glob(["**"]), 
+)
+
+cmake_external(
+    name = "libevent",
+    cache_entries = {
+      "CMAKE_BUILD_TYPE": "Release",
+      "CMAKE_POSITION_INDEPENDENT_CODE" : "on",
+      "BUILD_SHARED_LIBS": "off",
+      "BUILD_STATIC_LIBS": "on",
+      "EVENT__DISABLE_OPENSSL": "on",
+      "EVENT__DISABLE_REGRESS": "on",
+      "EVENT__DISABLE_TESTS": "on",
+    },
+    lib_source = ":srcs",
+    static_libraries = ["libevent.a"],
+    visibility = ["//visibility:public"],
+)

sdk/include/opentelemetry/sdk/common/file_descriptor.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include <cstdint>
+
+#include "opentelemetry/version.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace sdk {
+namespace common {
+#ifdef _WIN32
+using FileDescriptor = intptr_t;
+#else
+using FileDescriptor = int;
+#endif
+} // namespace common
+} // namespace sdk
+OPENTELEMETRY_END_NAMESPACE

sdk/include/opentelemetry/sdk/event/dispatcher.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <memory>
+
+#include "opentelemetry/sdk/common/file_descriptor.h"
+#include "opentelemetry/sdk/event/file_event.h"
+#include "opentelemetry/sdk/event/timer.h"
+#include "opentelemetry/version.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace sdk {
+namespace event {
+class Dispatcher {
+ public:
+  virtual ~Dispatcher() = default;
+
+  virtual std::unique_ptr<FileEvent> CreateFileEvent(FileDescriptor file_descriptor,
+                                                     FileReadyCallback callback,
+                                                     uint32_t events) noexcept = 0;
+
+  virtual std::unique_ptr<Timer> CreateTimer(TimerCallback callback) noexcept = 0;
+
+  virtual void Exit() noexcept = 0;
+
+  virtual void Run() noexcept = 0;
+};
+} // namespace event
+} // namespace sdk
+OPENTELEMETRY_END_NAMESPACE

sdk/include/opentelemetry/sdk/event/file_event.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <chrono>
+#include <system_error>
+#include <cstdint>
+#include <functional>
+
+#include "opentelemetry/version.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace sdk {
+namespace event {
+struct FileReadyType {
+  static const uint32_t kRead = 1;
+  static const uint32_t kWrite = 2;
+  static const uint32_t kClosed = 3;
+  static const uint32_t kTimeout = 4;
+};
+
+using FileReadyCallback = std::function<void(uint32_t)>;
+
+class FileEvent {
+ public:
+   virtual ~FileEvent() = default;
+
+};
+} // namespace event
+} // namespace sdk
+OPENTELEMETRY_END_NAMESPACE

sdk/include/opentelemetry/sdk/event/timer.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <chrono>
+#include <system_error>
+#include <functional>
+
+#include "opentelemetry/version.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace sdk {
+namespace event {
+using TimerCallback = std::function<void()>;
+
+class Timer {
+ public:
+   virtual ~Timer() = default;
+
+   virtual void EnableTimer(std::chrono::microseconds timeout,
+                            std::error_code &error_code) noexcept = 0;
+};
+} // namespace event
+} // namespace sdk
+OPENTELEMETRY_END_NAMESPACE