Add support for un-managed content (std::string_view) in http reply object

apps/httpd/main.cc

@@ -42,7 +42,7 @@ class handl : public httpd::handler_base {
 public:
  virtual future<std::unique_ptr<reply> > handle(const sstring& path,
  std::unique_ptr<request> req, std::unique_ptr<reply> rep) {
- rep->_content = "hello";
+ rep->_content.append("hello");
  rep->done("html");
  return make_ready_future<std::unique_ptr<reply>>(std::move(rep));
  }

include/seastar/http/function_handlers.hh

@@ -70,7 +70,7 @@ public:
  function_handler(const handle_function & f_handle, const sstring& type)
  : _f_handle(
  [f_handle](std::unique_ptr<request> req, std::unique_ptr<reply> rep) {
- rep->_content += f_handle(*req.get(), *rep.get());
+ rep->_content.append(f_handle(*req.get(), *rep.get()));
  return make_ready_future<std::unique_ptr<reply>>(std::move(rep));
  }), _type(type) {
  }
@@ -82,7 +82,7 @@ public:
  function_handler(const request_function & _handle, const sstring& type)
  : _f_handle(
  [_handle](std::unique_ptr<request> req, std::unique_ptr<reply> rep) {
- rep->_content += _handle(*req.get());
+ rep->_content.append(_handle(*req.get()));
  return make_ready_future<std::unique_ptr<reply>>(std::move(rep));
  }), _type(type) {
  }
@@ -91,7 +91,7 @@ public:
  : _f_handle(
  [_handle](std::unique_ptr<request> req, std::unique_ptr<reply> rep) {
  json::json_return_type res = _handle(*req.get());
- rep->_content += res._res;
+ rep->_content.append(res._res);
  return make_ready_future<std::unique_ptr<reply>>(std::move(rep));
  }), _type("json") {
  }
@@ -103,7 +103,7 @@ public:
  if (res._body_writer) {
  rep->write_body("json", std::move(res._body_writer));
  } else {
- rep->_content += res._res;
+ rep->_content.append(res._res);
 
  }
  return make_ready_future<std::unique_ptr<reply>>(std::move(rep));

include/seastar/http/reply.hh

@@ -44,6 +44,42 @@ namespace httpd {
 class connection;
 class routes;
 
+struct reply_content {
+ friend class reply;
+private:
+ bool is_unmanaged;
+ sstring _content;
+ std::string_view _content_um;
+
+public:
+ reply_content() {
+ }
+ reply_content(sstring _content) : is_unmanaged(false), _content(_content) {
+ }
+ reply_content(std::string_view _content) : is_unmanaged(true), _content_um(_content) {
+ }
+
+ const char* data() {
+ if(is_unmanaged) {
+ return _content_um.data();
+ }
+ return _content.data();
+ }
+
+ size_t size() const noexcept {
+ if(is_unmanaged) {
+ return _content_um.size();
+ }
+ return _content.size();
+ }
+
+ void append(const sstring& cont) {
+ if(!is_unmanaged) {
+ _content += cont;
+ }
+ }
+};
+
 /**
  * A reply to be sent to a client.
  */
@@ -82,7 +118,7 @@ struct reply {
  /**
  * The content to be sent in the reply.
  */
- sstring _content;
+ reply_content _content;
 
  sstring _response_line;
  reply()
@@ -101,8 +137,9 @@ struct reply {
 
  reply& set_status(status_type status, const sstring& content = "") {
  _status = status;
- if (content != "") {
- _content = content;
+ if (content.size()>0) {
+ _content.is_unmanaged = false;
+ _content._content = content;
  }
  return *this;
  }
@@ -168,6 +205,17 @@ struct reply {
  */
  void write_body(const sstring& content_type, const sstring& content);
 
+ /*!
+ * \brief Write a string_view as the reply (un-managed string)
+ *
+ * \param content_type - is used to choose the content type of the body. Use the file extension
+ * you would have used for such a content, (i.e. "txt", "html", "json", etc')
+ * \param content - the message content.
+ * This would set the the content and content type of the message along
+ * with any additional information that is needed to send the message.
+ */
+ void write_body(const sstring& content_type, const std::string_view& content);
+
 private:
  future<> write_reply_to_connection(connection& con);
  future<> write_reply_headers(connection& connection);