Struct ChainBuilder 

pub struct ChainBuilder { /* private fields */ }

Builds one chain segment (a run of elements that all execute on the same thread). Call ChainBuilder::queue to close the current segment behind a Queue and start a new one on its own worker thread.

Because each element needs a handle to its downstream to be constructed, the chain is assembled back-to-front: elements are collected in call order, then folded right-to-left starting from the terminal Sink at ChainBuilder::to time.

Implementations

impl ChainBuilder

pub fn new(context: Arc<Context>) -> Self

Starts a detached branch plan. Prefer Context::branch at call sites; it makes the owning pipeline explicit without cloning the context manually.

pub fn pipe<T: Filter + 'static>(self, element: T) -> Self

Adds a single-output Filter (decoder, encoder, filter, …) that receives via Sink and produces through its own (single) src pad. It runs on the same thread as whatever is upstream of it — direct function call, no queue.

pub fn queue(self, name: impl Into<String>, capacity: usize) -> Self

Introduces a thread boundary (blocking when full — see OverflowPolicy::Block): everything added after this runs on its own worker thread instead of the thread that feeds this queue.

pub fn queue_with_policy( self, name: impl Into<String>, capacity: usize, policy: OverflowPolicy, ) -> Self

Same as ChainBuilder::queue, but lets you choose what happens when the queue is full (e.g. OverflowPolicy::DropNewest for a live source that shouldn’t stall upstream).

pub fn to(self, terminal: Box<dyn Sink>) -> Result<DetachedBranch>

Terminates the chain with a Sink (muxer, file sink, …) and assembles everything into a single Box<dyn Sink> ready to be linked into a source’s src pad. The terminal’s own Element::name() is what shows up on the bus when it reports EOS.

pub fn build(self, terminal: Box<dyn Sink>) -> Result<DetachedBranch>