Function makeCancel

packages/sql-pg/src/PgClient.ts:532–551

(pool: Pg.Pool, client: Pg.PoolClient)

const cancelEffects = new WeakMap<Pg.PoolClient, Effect.Effect<void> | undefined>()
const makeCancel = (pool: Pg.Pool, client: Pg.PoolClient) => {
  if (cancelEffects.has(client)) {
    return cancelEffects.get(client)!
  }
  const processId = (client as any).processID
  const eff = processId !== undefined
    // query cancelation is best-effort, so we don't fail if it doesn't work
    ? Effect.async<void>((resume) => {
      if (pool.ending) return resume(Effect.void)
      pool.query(`SELECT pg_cancel_backend(${processId})`, () => {
        resume(Effect.void)
      })
    }).pipe(
      Effect.interruptible,
      Effect.timeoutOption(5000)
    )
    : undefined
  cancelEffects.set(client, eff)
  return eff
}

/**
 * @category layers