Struct ChannelMap 

pub struct ChannelMap<T> { /* private fields */ }

Defines independently queued Channel instances under one name.

Supply an instance string for every publish, read, condition, and completion guard. Add the map definition once to crate::PersistenceSchema. Slash is prohibited in instance keys because it is a reserved character.

Implementations

impl<T> ChannelMap<T>

pub fn new(name: impl Into<String>) -> Self

Defines a Channel map with a stable name.

Slash is prohibited because it is a reserved character.

pub fn load_messages(&self, instance: impl Into<String>) -> ChannelMapLoad

Selects one slash-free map instance’s pending messages for a handler Context.

pub fn publish( &self, context: &mut Context, instance: &str, value: T, ) -> HandlerResult<()>

where T: Value,

Stages one message for instance from the current invocation.

Errors

Returns a crate::HandlerError when value cannot be encoded.

pub fn delete( &self, context: &mut Context, instance: &str, message_id: &str, ) -> HandlerResult<()>

Stages best-effort deletion of one pending message from a Channel-map instance.

pub fn size(&self, context: &Context, instance: &str) -> HandlerResult<usize>

Returns the invocation snapshot’s message count for instance.

pub fn pending_messages( &self, context: &Context, instance: &str, ) -> HandlerResult<Vec<ChannelMessage<T>>>

where T: Value,

Returns one instance’s loaded pending messages in FIFO order.

Errors

Returns a crate::HandlerError when the instance was not selected by the handler options or when a Value cannot be decoded.

pub fn find_pending_message( &self, context: &Context, instance: &str, message_id: &str, ) -> HandlerResult<Option<ChannelMessage<T>>>

where T: Value,

Finds one pending message by ID within one loaded map instance.

Returns Ok(None) when the loaded snapshot does not contain message_id.

Errors

Returns the same errors as Self::pending_messages.

pub fn map_size(&self, context: &Context) -> HandlerResult<usize>

Returns the number of non-empty instances visible to the current handler.

pub fn all_instance_keys(&self, context: &Context) -> HandlerResult<Vec<String>>

Returns sorted decoded non-empty keys, including buffered publishes.

pub fn condition_results( &self, context: &Context, instance: &str, ) -> HandlerResult<Vec<T>>

where T: Value,

Decodes messages consumed by instance’s satisfied condition.

Errors

Returns a crate::HandlerError when a message cannot be decoded.

pub fn for_one(&self, instance: &str) -> Condition

Creates an instance condition that consumes exactly one message.

pub fn for_n(&self, instance: &str, count: usize) -> Condition

Creates an instance condition that consumes exactly count messages.

pub fn at_least(&self, instance: &str, count: usize) -> Condition

Creates an instance condition with an inclusive lower queue-size bound.

pub fn at_most(&self, instance: &str, count: usize) -> Condition

Creates a non-blocking instance condition consuming up to count queued messages.

When its surrounding Wait completes, it consumes messages queued then. An empty queue yields no messages.

pub fn range( &self, instance: &str, at_least: Option<usize>, at_most: Option<usize>, ) -> Condition

Creates an instance condition that waits for the lower bound, then consumes to its upper.

Omitting the lower bound makes the condition complete immediately. Consumption uses only messages queued when the condition completes.

pub fn when_empty(&self, instance: &str) -> ChannelGuard

Creates a conditional-completion guard requiring instance to be empty.

Trait Implementations

impl<T> Clone for ChannelMap<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.