Struct PostgresHandler 

pub struct PostgresHandler { /* private fields */ }

PostgreSQL database handler.

Composes one [PostgresConnection] (which owns every pool and the pool initialization logic) with the per-backend MCP tool router.

Implementations

impl PostgresHandler

pub fn new(config: &Config) -> Result<Self, RedactorInitError>

Creates a new PostgreSQL handler.

Constructs the [PostgresConnection] (which builds the lazy default pool and the per-database pool cache) and the MCP tool router. No network I/O happens here.

Errors

Returns dbmcp_pii::RedactorInitError when PII redaction is enabled with a NER model that fails to load (fail-closed startup).

impl PostgresHandler

pub async fn create_database( &self, __arg1: CreateDatabaseRequest, ) -> Result<MessageResponse, ErrorData>

Creates a database if it doesn’t exist.

Errors

Returns SqlError if read-only or the query fails.

impl PostgresHandler

pub async fn drop_database( &self, __arg1: DropDatabaseRequest, ) -> Result<MessageResponse, ErrorData>

Drops an existing database.

Refuses to drop the currently connected (default) database and evicts the corresponding pool cache entry after a successful drop.

Errors

Returns SqlError::ReadOnlyViolation in read-only mode, SqlError::InvalidIdentifier for invalid names, or SqlError::Query if the target is the active database or the backend reports an error.

impl PostgresHandler

pub async fn drop_table( &self, database: Option<String>, table: String, cascade: bool, ) -> Result<MessageResponse, ErrorData>

Drops a table from a database.

Validates identifiers, then executes DROP TABLE. When cascade is true the statement uses CASCADE to also remove dependent foreign-key constraints.

Errors

Returns SqlError::ReadOnlyViolation in read-only mode, SqlError::InvalidIdentifier for invalid names, or SqlError::Query if the backend reports an error.

impl PostgresHandler

pub async fn explain_query( &self, database: Option<String>, query: String, analyze: bool, ) -> Result<QueryResponse, ErrorData>

Returns the execution plan for a query.

The inner query must be a single statement. When analyze is true and read-only mode is enabled, it must also be read-only.

Errors

Returns [SqlError::MultiStatement] if the query holds more than one statement. Returns [SqlError::ReadOnlyViolation] if analyze is true, read-only mode is enabled, and the query is a write statement. Returns [SqlError::Query] if the backend reports an error.

impl PostgresHandler

pub async fn list_databases( &self, __arg1: ListDatabasesRequest, ) -> Result<ListDatabasesResponse, ErrorData>

Lists one page of accessible databases.

Uses the default pool intentionally — pg_database is a server-wide catalog that returns all databases regardless of which database the connection targets.

Errors

Returns ErrorData with code -32602 if cursor is malformed, or an internal-error ErrorData if the underlying query fails.

impl PostgresHandler

pub async fn list_functions( &self, database: Option<String>, cursor: Option<Cursor>, search: Option<String>, detailed: bool, ) -> Result<ListEntriesResponse, ErrorData>

Lists one page of user-defined functions, optionally filtered and/or detailed.

Errors

Returns ErrorData with code -32602 if cursor is malformed, or an internal-error ErrorData if database is invalid or the underlying query fails.

impl PostgresHandler

pub async fn list_materialized_views( &self, database: Option<String>, cursor: Option<Cursor>, search: Option<String>, detailed: bool, ) -> Result<ListEntriesResponse, ErrorData>

Lists one page of user-defined materialized views, optionally filtered and/or detailed.

Errors

Returns ErrorData with code -32602 if cursor is malformed, or an internal-error ErrorData if database is invalid or the underlying query fails.

impl PostgresHandler

pub async fn list_procedures( &self, database: Option<String>, cursor: Option<Cursor>, search: Option<String>, detailed: bool, ) -> Result<ListEntriesResponse, ErrorData>

Lists one page of user-defined procedures, optionally filtered and/or detailed.

Errors

Returns ErrorData with code -32602 if cursor is malformed, or an internal-error ErrorData if database is invalid or the underlying query fails.

impl PostgresHandler

pub async fn list_tables( &self, database: Option<String>, cursor: Option<Cursor>, search: Option<String>, detailed: bool, ) -> Result<ListEntriesResponse, ErrorData>

Lists one page of tables in a database, optionally filtered and/or detailed.

Errors

Returns ErrorData with code -32602 if cursor is malformed, or an internal-error ErrorData if database is invalid or the underlying query fails.

impl PostgresHandler

pub async fn list_triggers( &self, database: Option<String>, cursor: Option<Cursor>, search: Option<String>, detailed: bool, ) -> Result<ListEntriesResponse, ErrorData>

Lists one page of user-defined triggers, optionally filtered and/or detailed.

Errors

Returns ErrorData with code -32602 if cursor is malformed, or an internal-error ErrorData if database is invalid or the underlying query fails.

impl PostgresHandler

pub async fn list_views( &self, database: Option<String>, cursor: Option<Cursor>, search: Option<String>, detailed: bool, ) -> Result<ListEntriesResponse, ErrorData>

Lists one page of user-defined views, optionally filtered and/or detailed.

Errors

Returns ErrorData with code -32602 if cursor is malformed, or an internal-error ErrorData if database is invalid or the underlying query fails.

impl PostgresHandler

pub async fn read_query( &self, query: String, database: Option<String>, cursor: Option<Cursor>, ) -> Result<ReadQueryResponse, ErrorData>

Executes a read-only SQL query, paginating SELECT result rows.

Validates that the query is read-only, then dispatches on the classified StatementKind: Select is wrapped in a subquery with a server-controlled LIMIT/OFFSET; NonSelect (SHOW, EXPLAIN under the PG dialect) is executed as-is and returned in a single page. A malformed cursor is rejected by the serde deserializer before this method is called, producing JSON-RPC -32602.

Errors

Returns [SqlError::ReadOnlyViolation] if the query is not read-only, or [SqlError::Query] if the backend reports an error.

impl PostgresHandler

pub async fn write_query( &self, query: String, database: Option<String>, ) -> Result<QueryResponse, ErrorData>

Executes a write SQL query.

Errors

Returns [SqlError] if the query fails.

Trait Implementations

impl Clone for PostgresHandler

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PostgresHandler

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

Formats the value using the given formatter.

impl From<PostgresHandler> for Server

fn from(handler: PostgresHandler) -> Self

Wraps a PostgresHandler in the type-erased MCP server.

impl ServerHandler for PostgresHandler

fn get_info(&self) -> ServerConfig

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

Handle a tools/call request from a client.

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

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

Get a tool definition by name.

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

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

fn negotiate_initialize( &self, request: &InitializeRequestParams, ) -> Result<InitializeResult, ErrorData>

Build the initialize response for request, negotiating the protocol version against Self::supported_protocol_versions.

fn supported_protocol_versions(&self) -> Cow<'static, [ProtocolVersion]>

Return the protocol versions supported by this server.

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

Return this server’s discovery information.

fn complete( &self, request: CompleteRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<CompleteResult, ErrorData>> + MaybeSendFuture

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

fn get_prompt( &self, request: GetPromptRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<GetPromptResponse, ErrorData>> + MaybeSendFuture

fn list_prompts( &self, request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ListPromptsResult, ErrorData>> + MaybeSendFuture

fn list_resources( &self, request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ListResourcesResult, ErrorData>> + MaybeSendFuture

fn list_resource_templates( &self, request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ListResourceTemplatesResult, ErrorData>> + MaybeSendFuture

fn read_resource( &self, request: ReadResourceRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ReadResourceResponse, ErrorData>> + MaybeSendFuture

fn accepted_subscription_filter( &self, requested: &SubscriptionFilter, ) -> Option<SubscriptionFilter>

Return the subset of a requested notification filter this server accepts.

fn listen( &self, context: SubscriptionContext, ) -> impl Future<Output = Result<(), ErrorData>> + MaybeSendFuture

Run one established subscription until it is cancelled or closed gracefully.

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

👎Deprecated:

resources/subscribe is legacy-only; implement accepted_subscription_filter and listen for protocol version 2026-07-28

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

👎Deprecated:

resources/unsubscribe is legacy-only; subscriptions/listen is cancelled through its request lifecycle

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

fn on_cancelled( &self, notification: CancelledNotificationParam, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + MaybeSendFuture

fn on_progress( &self, notification: ProgressNotificationParam, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + MaybeSendFuture

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

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

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

fn get_task( &self, request: GetTaskParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<GetTaskResult, ErrorData>> + MaybeSendFuture

SEP-2663 tasks/get: return the current DetailedTask state.

fn update_task( &self, request: UpdateTaskParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + MaybeSendFuture

SEP-2663 tasks/update: accept responses to outstanding in-task input requests. Returns an empty acknowledgement on success.

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

SEP-2663 tasks/cancel: cooperative cancellation. Returns an empty acknowledgement; the task’s observable status may lag.

impl Shutdown for PostgresHandler

fn shutdown(&self) -> ShutdownFuture<'_>

Awaits a clean close of all pools. Idempotent.