Struct yaque::Receiver

pub struct Receiver { /* fields omitted */ }

The receiver part of the queue. This part is asynchronous and therefore needs an executor that will the poll the futures to completion.

Implementations

impl Receiver

pub fn open<P: AsRef<Path>>(base: P) -> Result<Receiver>

Opens a queue for reading. The access will be exclusive, based on the existence of the temporary file recv.lock inside the queue folder.

Errors

This function will return an IO error if the queue is already in use for receiving, which is indicated by a lock file. Also, any other IO error encountered while opening will be sent.

Panics

This function will panic if it is not able to set up the notification handler to watch for file changes.

pub fn save(&mut self) -> Result<()>

Saves the receiver queue state. You do not need to use method in most circumstances, since it is automatically done on drop (yes, it will be called eve if your thread panics). However, you can use this function to

1. Make periodical backups. Use an external timer implementation for this.

2. Handle possible IO errors in sending. The drop implementation will ignore (but log) any io errors, which may lead to data loss in an unreliable filesystem. This happens because no errors are allowed to propagate on drop and panicking will abort the program if drop is called during a panic.

pub async fn recv<'_, '_>(&'_ mut self) -> Result<RecvGuard<'_, Vec<u8>>>

Tries to retrieve an element from the queue. The returned value is a guard that will only commit state changes to the queue when dropped.

Panics

This function will panic if it has to start reading a new segment and it is not able to set up the notification handler to watch for file changes.

pub async fn recv_batch<'_, '_>(
    &'_ mut self,
    n: usize
) -> Result<RecvGuard<'_, Vec<Vec<u8>>>>

Tries to remove a number of elements from the queue. The returned value is a guard that will only commit state changes to the queue when dropped.

Panics

This function will panic if it has to start reading a new segment and it is not able to set up the notification handler to watch for file changes.

pub async fn recv_until<'_, '_, P, Fut>(
    &'_ mut self,
    __arg1: P
) -> Result<RecvGuard<'_, Vec<Vec<u8>>>> where
    P: FnMut(Option<&[u8]>) -> Fut,
    Fut: Future<Output = bool>, 

Takes a number of elements from the queue until a certain asynchronous condition is met. You will receive a None as the first element so that you may return early and leave the queue intact (this would not be possible otherwise). The returned value is a guard that will only commit state changes to the queue when dropped.

Panics

This function will panic if it has to start reading a new segment and it is not able to set up the notification handler to watch for file changes.

Trait Implementations

impl Drop for Receiver

fn drop(&mut self)

Executes the destructor for this type.