Struct CancelToken 

pub struct CancelToken { /* private fields */ }

A token that can cancel a running query on a specific backend. Cloneable and Send, can be passed to another task or stored for timeout handling.

The backend secret is held internally and is not exposed through any accessor; obtain a token from an AsyncConn / WireConn rather than constructing one with raw fields.

Implementations

impl CancelToken

pub fn new(addr: String, pid: i32, secret: i32) -> CancelToken

Construct a cancel token from raw parts. Intended for callers that persisted the three values across processes; most users should get a token from AsyncConn::cancel_token() instead.

pub fn addr(&self) -> &str

Server address this token targets.

pub fn pid(&self) -> i32

Backend process ID this token cancels.

pub async fn cancel(&self) -> Result<(), PgWireError>

Send a cancel request to PostgreSQL.

Opens a new TCP connection, sends the 16-byte CancelRequest, and closes. The server will attempt to cancel the current query on the target backend.

Note: cancellation is best-effort. The query may complete before the cancel arrives, or the server may not be able to cancel it immediately.

Times out after 5 seconds to prevent hanging if the server is unreachable.

Trait Implementations

impl Clone for CancelToken

fn clone(&self) -> CancelToken

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CancelToken

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

Formats the value using the given formatter.