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FilterLayer

ntex::io

Trait FilterLayer 

Source 
pub trait FilterLayer: Debug + 'static {
    // Required methods
    fn process_read_buf(&self, buf: &FilterBuf<'_>) -> Result<(), Error>;
    fn process_write_buf(&self, buf: &FilterBuf<'_>) -> Result<(), Error>;

    // Provided methods
    fn query(&self, id: TypeId) -> Option<Box<dyn Any>> { ... }
    fn shutdown(&self, buf: &FilterBuf<'_>) -> Result<Poll<()>, Error> { ... }
}
Expand description

A processing layer that transforms an I/O stream’s read and write buffers.

Read processing runs from the transport toward the application. Write and shutdown processing run from the application toward the transport. Each callback receives the buffers immediately before and after this layer.

Implementations must move or transform all bytes they consume. Bytes left in a source buffer remain available to the layer on a later callback.

Required Methods§

Source

fn process_read_buf(&self, buf: &FilterBuf<'_>) -> Result<(), Error>

Processes incoming data from the transport-facing source buffer into the application-facing destination buffer.

This is also called once after clean transport read EOF, with IoRef::is_read_eof returning true.

Source

fn process_write_buf(&self, buf: &FilterBuf<'_>) -> Result<(), Error>

Processes outgoing data from the application-facing source buffer into the transport-facing destination buffer.

Provided Methods§

Source

fn query(&self, id: TypeId) -> Option<Box<dyn Any>>

Returns type-indexed information exposed by this layer.

Returning None allows the query to continue through the remaining filter chain.

Source

fn shutdown(&self, buf: &FilterBuf<'_>) -> Result<Poll<()>, Error>

Performs graceful filter shutdown.

Returning Poll::Pending keeps the filter active and causes shutdown to be polled again after the I/O task is notified. A ready result allows shutdown to continue toward the transport.

A filter that waits for input from the peer must check IoRef::is_read_eof and return a ready result once it is set: after a clean read EOF no further input can arrive, so pending forever would only stall the close until the shutdown timeout expires. The runtime also ends the shutdown phase itself in that case, but it cannot know whether the filter considers the shutdown complete.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§