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