Helper method CurlHandle::setopt

Introduced helper method CurlHandle::setopt to automate error checking
of curl_easy_setopt call.

Author: turchanov

zipkin/src/zipkin_http_transporter.cc

@@ -13,43 +13,37 @@ static std::string getUrl(const char *collector_host, uint32_t collector_port) {
          ZipkinCoreConstants::get().DEFAULT_COLLECTOR_ENDPOINT;
 }
 
+template <class... Types> void CurlHandle::setopt(CURLoption option, Types... args) {
+  auto rcode = curl_easy_setopt(handle_, option, args...);
+   if (rcode != CURLE_OK) {
+     throw CurlError{rcode};
+   }
+}
+
 ZipkinHttpTransporter::ZipkinHttpTransporter(const char *collector_host,
                                              uint32_t collector_port,
                                              std::chrono::milliseconds collector_timeout) {
-  auto rcode = curl_easy_setopt(handle_, CURLOPT_URL,
-                                getUrl(collector_host, collector_port).c_str());
-  if (rcode != CURLE_OK) {
-    throw CurlError{rcode};
-  }
+  handle_.setopt(CURLOPT_URL, getUrl(collector_host, collector_port).c_str());
 
   headers_.append("Content-Type: application/json");
-  rcode = curl_easy_setopt(handle_, CURLOPT_HTTPHEADER,
-                           static_cast<curl_slist *>(headers_));
-  if (rcode != CURLE_OK) {
-    throw CurlError{rcode};
-  }
+  handle_.setopt(CURLOPT_HTTPHEADER, static_cast<curl_slist *>(headers_));
 
-  rcode = curl_easy_setopt(handle_, CURLOPT_ERRORBUFFER, error_buffer_);
-  if (rcode != CURLE_OK) {
-    throw CurlError{rcode};
-  }
+  handle_.setopt(CURLOPT_ERRORBUFFER, error_buffer_);
 
-  rcode = curl_easy_setopt(handle_, CURLOPT_TIMEOUT_MS, collector_timeout.count());
-  if (rcode != CURLE_OK) {
-    throw CurlError{rcode};
-  }
+  handle_.setopt(CURLOPT_TIMEOUT_MS, collector_timeout.count());
 }
 
 ZipkinHttpTransporter::~ZipkinHttpTransporter() {}
 
 void ZipkinHttpTransporter::transportSpans(SpanBuffer &spans) try {
   auto data = spans.toStringifiedJsonArray();
-  auto rcode = curl_easy_setopt(handle_, CURLOPT_POSTFIELDS, data.c_str());
-  if (rcode != CURLE_OK) {
-    std::cerr << curl_easy_strerror(rcode) << '\n';
+  try {
+    handle_.setopt(CURLOPT_POSTFIELDS, data.c_str());
+  } catch(const CurlError &e) {
+    std::cerr << e.what() << '\n';
     return;
   }
-  rcode = curl_easy_perform(handle_);
+  auto rcode = curl_easy_perform(handle_);
   if (rcode != CURLE_OK) {
     std::cerr << error_buffer_ << '\n';
   }

zipkin/src/zipkin_http_transporter.h

@@ -46,6 +46,8 @@ class CurlHandle {
 
   CURL *operator->() { return handle_; }
 
+  template <class... Types> void setopt(CURLoption option, Types... args);
+
 private:
   CURL *handle_;
 };