Struct netidx::publisher::Val

pub struct Val(_);

This represents a published value. Internally it is wrapped in an Arc, so cloning it is free. When all references to a given published value have been dropped it will be unpublished. However you must call flush before references to it will be removed from the resolver server.

Implementations

impl Val

pub fn downgrade(&self) -> ValWeak

pub fn update(&self, v: Value)

Queue an update to the published value, it will not be sent out until you call flush on the publisher, however new subscribers will receive the last value passed to update when they subscribe regardless of flush. Multiple updates can be queued before flush is called, in which case on flush subscribers will receive all the queued values in order. If updates are queued on multiple different published values before flush is called, they will all be sent out as a batch and are guarenteed to arrive in the order update was called.

pub fn update_changed(&self, v: Value)

update the current value only if the new value is different from the existing one. Otherwise exactly the same as update.

pub fn update_subscriber(&self, subscriber: &SocketAddr, v: Value)

Send v as an update ONLY to the specified subscriber, and do not update current. You can use this to implement a simple unicast side channel in parallel with the existing multicast update mechanism.

One example use for this function is implementing a query response value, where the query is encoded in the name of the value (perhaps passed via publish_default), and the full response set is sent to each client as it subscribes.

pub fn writes(&self, tx: Sender<Pooled<Vec<WriteRequest>>>)

Register tx to receive writes. You can register multiple channels, and you can register the same channel on multiple Val objects. If no channels are registered to receive writes they will return an error to the subscriber.

If the send_result struct member of WriteRequest is set then the client has requested that an explicit reply be made to the write. In that case the included SendReply object can be used to send the reply back to the write client. If the SendReply object is dropped without any reply being sent then Value::Ok will be sent. SendReply::send may only be called once, further calls will be silently ignored.

If you no longer wish to accept writes, simply drop all registered channels.

pub fn subscribers(
    &self,
    include_existing: bool,
    tx: UnboundedSender<(Id, SocketAddr)>
)

Register tx to receive a message when a new client subscribes to this value. If include_existing is true, then current subscribers will be sent to the channel immediatly, otherwise it will only receive new subscribers.

pub fn unsubscribe(&self, subscriber: &SocketAddr)

Unsubscribe the specified client.

pub fn current(&self) -> Value

Get a copy of the current value

pub fn id(&self) -> Id

Get the unique Id of this Val

pub fn path(&self) -> &Path

Get a reference to the Path of this published value.

pub fn subscribed(&self) -> Vec<SocketAddr>

pub fn subscribed_len(&self) -> usize

Trait Implementations

impl Clone for Val

fn clone(&self) -> Val

Returns a copy of the value.

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

Performs copy-assignment from source.