Struct Waiters 

pub struct Waiters { /* private fields */ }

Every parked client, oldest first.

The order is the order they blocked in and it is the order they are served in, which is what makes a queue with several workers on it fair: two clients blocked on the same key take the two elements a RPUSH q first second adds in the order they arrived. A Vec is the right structure for that while the list is short, and it is short, because a waiter is a client doing nothing.

Implementations

impl Waiters

pub fn is_empty(&self) -> bool

Whether anybody is waiting.

pub fn len(&self) -> usize

How many clients are parked, which is what INFO clients calls blocked_clients.

pub fn mine(&self, thread: usize, into: &mut Vec<Parked>)

Copy out the waiters thread has to answer, oldest first.

The caller works from the copy rather than from the list, because answering a waiter needs a connection’s reply buffer and the list is behind a lock that another thread is waiting on. It brings its own vector, which after the first parked client is a vector it already has the room in.

Trait Implementations

impl Default for Waiters

fn default() -> Waiters

Returns the “default value” for a type.