Add response builder to simplify the response build; refine the service interfaces.

webcc/response_builder.cc

@@ -0,0 +1,57 @@
+#include "webcc/response_builder.h"
+
+#include "webcc/base64.h"
+#include "webcc/logger.h"
+#include "webcc/utility.h"
+
+#if WEBCC_ENABLE_GZIP
+#include "webcc/gzip.h"
+#endif
+
+namespace webcc {
+
+ResponsePtr ResponseBuilder::operator()() {
+  assert(headers_.size() % 2 == 0);
+
+  auto request = std::make_shared<Response>(code_);
+
+  for (std::size_t i = 1; i < headers_.size(); i += 2) {
+    request->SetHeader(std::move(headers_[i - 1]), std::move(headers_[i]));
+  }
+
+  if (!data_.empty()) {
+    SetContent(request, std::move(data_));
+
+    // TODO: charset.
+    if (json_) {
+      request->SetContentType(media_types::kApplicationJson, "");
+    }
+  }
+
+  return request;
+}
+
+ResponseBuilder& ResponseBuilder::Date() {
+  headers_.push_back(headers::kDate);
+  headers_.push_back(utility::GetTimestamp());
+  return *this;
+}
+
+void ResponseBuilder::SetContent(ResponsePtr response, std::string&& data) {
+#if WEBCC_ENABLE_GZIP
+  if (gzip_ && data.size() > kGzipThreshold) {
+    std::string compressed;
+    if (gzip::Compress(data, &compressed)) {
+      response->SetContent(std::move(compressed), true);
+      response->SetHeader(headers::kContentEncoding, "gzip");
+      return;
+    }
+
+    LOG_WARN("Cannot compress the content data!");
+  }
+#endif  // WEBCC_ENABLE_GZIP
+
+  response->SetContent(std::move(data), true);
+}
+
+}  // namespace webcc