replace config with protobuf (#35)

Author: Shikugawa

README.md

@@ -39,7 +39,7 @@ cpp2sky provides simple configuration for tracer and segment. We can set `servic
 The detail information is described in [official protobuf definition](https://github.com/apache/skywalking-data-collect-protocol/blob/master/language-agent/Tracing.proto#L57-L67).
 
 ```cpp
-#include <cpp2sky/config.h>
+#include <cpp2sky/config.pb.h>
 
 int main() {
   using namespace cpp2sky;

cpp2sky/BUILD

@@ -1,70 +1,47 @@
-load("@rules_cc//cc:defs.bzl", "cc_library")
+load("@rules_cc//cc:defs.bzl", "cc_library", "cc_proto_library")
+load("@rules_proto//proto:defs.bzl", "proto_library")
 
-cc_library(
-  name = "config_interface",
-  hdrs = ["config.h"],
-  visibility = ["//visibility:public"],
-)
-
-cc_library(
-  name = "random_interface",
-  hdrs = ["internal/random_generator.h"],
-  visibility = ["//visibility:public"],
-)
+licenses(["notice"])  # Apache 2
 
-cc_library(
-  name = "propagation_interface",
-  hdrs = ["propagation.h"],
-  visibility = ["//visibility:public"],
+proto_library(
+  name = "config_proto_lib",
+  srcs = ["config.proto"],
 )
 
-cc_library(
-  name = "segment_context_interface",
-  hdrs = ["segment_context.h"],
-  deps = [
-    ":config_interface",
-    ":propagation_interface",
-  ],
+cc_proto_library(
+  name = "config_cc_proto",
+  deps = [":config_proto_lib"],
   visibility = ["//visibility:public"],
 )
 
 cc_library(
-  name = "async_client_interface",
-  hdrs = ["internal/async_client.h"],
-  deps = [
-    "@com_github_grpc_grpc//:grpc++",
-    "@com_google_protobuf//:protobuf",
+  name = "cpp2sky_interface",
+  hdrs = [
+    "tracer.h",
+    "segment_context.h",
+    "propagation.h",
+    "well_known_names.h",
+    "exception.h",
+    "time.h",
   ],
-  visibility = ["//visibility:public"],
-)
-
-cc_library(
-  name = "tracer_interface",
-  hdrs = ["tracer.h"],
   deps = [
     "@com_github_grpc_grpc//:grpc++",
     "@skywalking_data_collect_protocol//language-agent:tracing_protocol_cc_grpc",
+    ":config_cc_proto",
   ],
   visibility = ["//visibility:public"],
 )
 
 cc_library(
-  name = "time_interface",
-  hdrs = ["time.h"],
-  visibility = ["//visibility:public"],
-)
-
-cc_library(
-  name = "cpp2sky_interface",
+  name = "cpp2sky_internal_interface",
   hdrs = [
-    "tracer.h",
-    "segment_context.h",
-    "propagation.h",
-    "config.h",
+    "internal/async_client.h",
+    "internal/random_generator.h",
   ],
   deps = [
     "@com_github_grpc_grpc//:grpc++",
     "@skywalking_data_collect_protocol//language-agent:tracing_protocol_cc_grpc",
+    ":config_cc_proto",
   ],
   visibility = ["//visibility:public"],
 )

cpp2sky/config.h

@@ -0,0 +1,28 @@
+syntax = "proto3";
+
+package cpp2sky;
+
+enum Protocol {
+  GRPC = 0;
+  REST = 1;
+}
+
+message TracerConfig {
+  // Tracer protocol.
+  Protocol protocol = 1;
+
+  // Service name
+  string service_name = 2;
+
+  // Instance name
+  string instance_name = 3;
+
+  // OAP address.
+  string address = 4;
+
+  // OAP token.
+  string token = 5;
+
+  // The size of buffer it stores pending messages.
+  uint32 delayed_buffer_size = 6;
+}

cpp2sky/config.proto

@@ -18,7 +18,7 @@
 #include <memory>
 #include <string_view>
 
-#include "cpp2sky/config.h"
+#include "cpp2sky/config.pb.h"
 #include "cpp2sky/propagation.h"
 #include "cpp2sky/time.h"
 #include "language-agent/Tracing.pb.h"
@@ -276,15 +276,32 @@ class SegmentContext {
   virtual SegmentObject createSegmentObject() = 0;
 };
 
-using SegmentContextPtr = std::unique_ptr<SegmentContext>;
+using SegmentContextPtr = std::shared_ptr<SegmentContext>;
 
-SegmentContextPtr createSegmentContext(SegmentConfig& config,
-                                       SpanContextPtr span_ctx,
-                                       SpanContextExtensionPtr span_ctx_ext);
+class SegmentContextFactory {
+ public:
+  virtual ~SegmentContextFactory() = default;
+
+  /**
+   * Create segment context that doesn't have propagated info.
+   */
+  virtual SegmentContextPtr create() = 0;
+
+  /**
+   * Create segment context with propagated span context.
+   */
+  virtual SegmentContextPtr create(SpanContextPtr span_context) = 0;
+
+  /**
+   * Create segment context with propagated span context and extensions.
+   */
+  virtual SegmentContextPtr create(
+      SpanContextPtr span_context,
+      SpanContextExtensionPtr ext_span_context) = 0;
+};
 
-SegmentContextPtr createSegmentContext(SegmentConfig& config,
-                                       SpanContextPtr span_ctx);
+using SegmentContextFactoryPtr = std::unique_ptr<SegmentContextFactory>;
 
-SegmentContextPtr createSegmentContext(SegmentConfig& config);
+SegmentContextFactoryPtr createSegmentContextFactory(const TracerConfig& cfg);
 
 }  // namespace cpp2sky

source/utils/exception.h renamed to cpp2sky/exception.h

@@ -16,7 +16,7 @@
 
 #include <memory>
 
-#include "cpp2sky/config.h"
+#include "cpp2sky/config.pb.h"
 #include "cpp2sky/segment_context.h"
 
 namespace cpp2sky {

cpp2sky/segment_context.h

@@ -0,0 +1,24 @@
+// Copyright 2020 SkyAPM
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <string_view>
+
+namespace cpp2sky {
+
+static constexpr std::string_view kPropagationHeader = "sw8";
+static constexpr std::string_view kPropagationExtensionHeader = "sw8-x";
+
+}  // namespace cpp2sky

cpp2sky/tracer.h

@@ -22,27 +22,26 @@
 
 using namespace cpp2sky;
 
-static const std::string service_name = "";
-static const std::string instance_name = "node_0";
-static const std::string address = "0.0.0.0:11800";
+TracerConfig config;
 
-SegmentConfig seg_config(service_name, instance_name);
-TracerConfig tracer_config(address);
-
-uint64_t now() {
-  using namespace std::chrono;
-  return duration_cast<milliseconds>(system_clock::now().time_since_epoch())
-      .count();
+void init() {
+  config.set_instance_name("node_0");
+  config.set_service_name("");
+  config.set_address("0.0.0.0:11800");
 }
 
 int main() {
+  init();
+
   httplib::Server svr;
   // 1. Create tracer object to send span data to OAP.
-  auto tracer = createInsecureGrpcTracer(tracer_config);
+  auto tracer = createInsecureGrpcTracer(config);
+
+  SegmentContextFactoryPtr factory = createSegmentContextFactory(config);
 
   svr.Get("/ping", [&](const httplib::Request& req, httplib::Response& res) {
     // 2. Create segment context
-    auto current_segment = createSegmentContext(seg_config);
+    auto current_segment = factory->create();
 
     // 3. Initialize span data to track root workload on current service.
     auto current_span = current_segment->createCurrentSegmentRootSpan();

cpp2sky/well_known_names.h

@@ -18,28 +18,28 @@
 #include "cpp2sky/propagation.h"
 #include "cpp2sky/segment_context.h"
 #include "cpp2sky/tracer.h"
+#include "cpp2sky/well_known_names.h"
 #include "httplib.h"
 
 using namespace cpp2sky;
 
-static const std::string service_name = "";
-static const std::string instance_name = "client_0";
-static const std::string address = "0.0.0.0:11800";
+TracerConfig config;
 
-SegmentConfig seg_config(service_name, instance_name);
-TracerConfig tracer_config(address);
-
-uint64_t now() {
-  using namespace std::chrono;
-  return duration_cast<milliseconds>(system_clock::now().time_since_epoch())
-      .count();
+void init() {
+  config.set_instance_name("client_0");
+  config.set_service_name("");
+  config.set_address("0.0.0.0:11800");
 }
 
 int main() {
+  init();
+
+  SegmentContextFactoryPtr factory = createSegmentContextFactory(config);
+
   // 1. Create tracer object to send span data to OAP.
-  auto tracer = createInsecureGrpcTracer(tracer_config);
+  auto tracer = createInsecureGrpcTracer(config);
   // 2. Create segment context
-  auto current_segment = createSegmentContext(seg_config);
+  auto current_segment = factory->create();
 
   // 3. Initialize span data to track root workload on current service.
   auto current_span = current_segment->createCurrentSegmentRootSpan();
@@ -49,8 +49,9 @@ int main() {
   current_span->setOperationName("/ping");
 
   httplib::Client cli("remote", 8082);
-  httplib::Headers headers = {{"sw8", current_segment->createSW8HeaderValue(
-                                          current_span, "remote:8082")}};
+  httplib::Headers headers = {
+      {kPropagationHeader.data(),
+       current_segment->createSW8HeaderValue(current_span, "remote:8082")}};
   auto res = cli.Get("/ping", headers);
 
   current_span->endSpan();