websocket_handler.hpp

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#pragma once
 
/// @file userver/server/websocket/websocket_handler.hpp
/// @brief @copybrief websocket::WebsocketHandlerBase
 
#include <userver/components/component_config.hpp>
#include <userver/components/component_context.hpp>
#include <userver/server/handlers/http_handler_base.hpp>
#include <userver/server/websocket/server.hpp>
 
USERVER_NAMESPACE_BEGIN
 
namespace server::websocket {
 
// clang-format off
 
/// @ingroup userver_components userver_http_handlers userver_base_classes
///
/// @brief Base class for WebSocket handler
///
/// ## Static options:
/// Inherits all the options from server::handlers::HandlerBase and adds the
/// following ones:
///
/// Name | Description | Default value
/// ---- | ----------- | -------------
/// log-level | overrides log level for this handle | <no override>
/// status-codes-log-level | map of "status": log_level items to override span log level for specific status codes | {}
/// max-remote-payload | max remote payload size | 65536
/// fragment-size | max output fragment size | 65536
///
/// ## Example usage:
///
/// @snippet samples/websocket_service/websocket_service.cpp Websocket service sample - component
 
// clang-format on
class WebsocketHandlerBase : public server::handlers::HttpHandlerBase {
 public:
  WebsocketHandlerBase(const components::ComponentConfig&,
                       const components::ComponentContext&);
 
  /// @brief Websocket handler code belongs here.
  virtual void Handle(WebSocketConnection& websocket,
                      server::request::RequestContext&) const = 0;
 
  /// @brief If any code is required for handshake validation,
  /// it goes here.
  virtual bool HandleHandshake(const server::http::HttpRequest&,
                               server::http::HttpResponse&,
                               server::request::RequestContext&) const {
    return true;
  }
 
  /// @cond
  void WriteMetrics(utils::statistics::Writer& writer) const;
 
  static yaml_config::Schema GetStaticConfigSchema();
  /// @endcond
 
  /// @brief If \a request isn't a websocket request the function handles a
  /// request.
  virtual void HandleNonWebsocketRequest(
      [[maybe_unused]] const server::http::HttpRequest& request,
      [[maybe_unused]] server::request::RequestContext& context) const {
    LOG_WARNING()
        << "Not a GET 'Upgrade: websocket' and 'Connection: Upgrade' request";
    throw server::handlers::ClientError();
  }
 
 private:
  std::string HandleRequestThrow(
      const server::http::HttpRequest& request,
      server::request::RequestContext& context) const override;
 
  websocket::Config config_;
  mutable Statistics stats_;
  utils::statistics::Entry statistics_holder_;
};
 
}  // namespace server::websocket
 
USERVER_NAMESPACE_END