Struct StreamProxyHandler 

pub struct StreamProxyHandler { /* private fields */ }

A proxy handler that forwards requests to a client based on the server’s capabilities 使用 ArcSwap 实现后端热替换，支持断开时立即返回错误

增强功能：

• 后端版本控制：每次 swap_backend 都会递增版本号
• 支持 Session 版本跟踪：配合 ProxyAwareSessionManager 使用

Implementations

impl ProxyHandler

pub fn new_disconnected( mcp_id: String, tool_filter: ToolFilter, default_info: InitializeResult, ) -> ProxyHandler

创建断开状态的 handler（用于初始化） 后续通过 swap_backend() 注入实际的后端连接

pub fn new( client: RunningService<RoleClient, InitializeRequestParams>, ) -> ProxyHandler

pub fn with_mcp_id( client: RunningService<RoleClient, InitializeRequestParams>, mcp_id: String, ) -> ProxyHandler

pub fn with_tool_filter( client: RunningService<RoleClient, InitializeRequestParams>, mcp_id: String, tool_filter: ToolFilter, ) -> ProxyHandler

创建带工具过滤器的 ProxyHandler（带初始后端连接）

pub fn swap_backend( &self, new_client: Option<RunningService<RoleClient, InitializeRequestParams>>, )

原子性替换后端连接

• Some(client): 设置新的后端连接
• None: 标记后端断开

版本控制：每次调用都会递增 backend_version，使旧 session 失效

pub fn is_backend_available(&self) -> bool

检查后端是否可用（快速检查，不发送请求）

pub async fn is_mcp_server_ready(&self) -> bool

检查 mcp 服务是否正常（异步版本，会发送验证请求）

pub fn is_terminated(&self) -> bool

检查后端连接是否已关闭（同步版本，仅检查 transport 状态）

pub async fn is_terminated_async(&self) -> bool

异步检查后端连接是否已断开（会发送验证请求）

pub fn mcp_id(&self) -> &str

获取 MCP ID

pub fn get_backend_version(&self) -> u64

获取当前后端版本号

版本号用于跟踪后端连接变化：

• 0: 断开状态
• 1+: 已连接，每次 swap_backend 递增

用途：配合 ProxyAwareSessionManager 实现 session 版本控制

pub fn swap_backend_from_connection(&self, conn: Option<StreamClientConnection>)

Update backend from a StreamClientConnection

This method allows updating the backend connection using the high-level StreamClientConnection type, which is more convenient than the raw RunningService type.

Arguments

• conn - Some(connection) to set new backend, None to mark disconnected

Trait Implementations

impl Clone for ProxyHandler

fn clone(&self) -> ProxyHandler

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ProxyHandler

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl From<ProxyHandler> for McpHandler

fn from(handler: StreamProxyHandler) -> Self

Converts to this type from the input type.

impl ServerHandler for ProxyHandler

fn get_info(&self) -> InitializeResult

async fn list_tools( &self, request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> Result<ListToolsResult, ErrorData>

async fn call_tool( &self, request: CallToolRequestParams, context: RequestContext<RoleServer>, ) -> Result<CallToolResult, ErrorData>

async fn list_resources( &self, request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> Result<ListResourcesResult, ErrorData>

async fn read_resource( &self, request: ReadResourceRequestParams, context: RequestContext<RoleServer>, ) -> Result<ReadResourceResult, ErrorData>

async fn list_resource_templates( &self, request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> Result<ListResourceTemplatesResult, ErrorData>

async fn list_prompts( &self, request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> Result<ListPromptsResult, ErrorData>

async fn get_prompt( &self, request: GetPromptRequestParams, context: RequestContext<RoleServer>, ) -> Result<GetPromptResult, ErrorData>

async fn complete( &self, request: CompleteRequestParams, context: RequestContext<RoleServer>, ) -> Result<CompleteResult, ErrorData>

async fn on_progress( &self, notification: ProgressNotificationParam, _context: NotificationContext<RoleServer>, )

async fn on_cancelled( &self, notification: CancelledNotificationParam, _context: NotificationContext<RoleServer>, )

fn enqueue_task( &self, _request: CallToolRequestParams, _context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<CreateTaskResult, ErrorData>> + Send

fn ping( &self, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + Send

fn initialize( &self, request: InitializeRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<InitializeResult, ErrorData>> + Send

fn set_level( &self, request: SetLevelRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + Send

fn subscribe( &self, request: SubscribeRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + Send

fn unsubscribe( &self, request: UnsubscribeRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + Send

fn get_tool(&self, _name: &str) -> Option<Tool>

Get a tool definition by name.

fn on_custom_request( &self, request: CustomRequest, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<CustomResult, ErrorData>> + Send

fn on_initialized( &self, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + Send

fn on_roots_list_changed( &self, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + Send

fn on_custom_notification( &self, notification: CustomNotification, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + Send

fn list_tasks( &self, request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ListTasksResult, ErrorData>> + Send

fn get_task_info( &self, request: GetTaskInfoParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<GetTaskResult, ErrorData>> + Send

fn get_task_result( &self, request: GetTaskResultParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<GetTaskPayloadResult, ErrorData>> + Send

fn cancel_task( &self, request: CancelTaskParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<CancelTaskResult, ErrorData>> + Send