Struct h2::proto::streams::flow_control::FlowControl

pub struct FlowControl {
    window_size: Window,
    available: Window,
}

Fields

window_size: Window

Window the peer knows about.

This can go negative if a SETTINGS_INITIAL_WINDOW_SIZE is received.

For example, say the peer sends a request and uses 32kb of the window. We send a SETTINGS_INITIAL_WINDOW_SIZE of 16kb. The peer has to adjust its understanding of the capacity of the window, and that would be:

default (64kb) - used (32kb) - settings_diff (64kb - 16kb): -16kb

available: Window

Window that we know about.

This can go negative if a user declares a smaller target window than the peer knows about.

Implementations

impl FlowControl

pub fn new() -> FlowControl

pub fn window_size(&self) -> u32

Returns the window size as known by the peer

pub fn available(&self) -> Window

Returns the window size available to the consumer

pub fn has_unavailable(&self) -> bool

Returns true if there is unavailable window capacity

pub fn claim_capacity(&mut self, capacity: u32) -> Result<(), Reason>

pub fn assign_capacity(&mut self, capacity: u32) -> Result<(), Reason>

pub fn unclaimed_capacity(&self) -> Option<u32>

If a WINDOW_UPDATE frame should be sent, returns a positive number representing the increment to be used.

If there is no available bytes to be reclaimed, or the number of available bytes does not reach the threshold, this returns None.

This represents pending outbound WINDOW_UPDATE frames.

pub fn inc_window(&mut self, sz: u32) -> Result<(), Reason>

Increase the window size.

This is called after receiving a WINDOW_UPDATE frame

pub fn dec_send_window(&mut self, sz: u32) -> Result<(), Reason>

Decrement the send-side window size.

This is called after receiving a SETTINGS frame with a lower INITIAL_WINDOW_SIZE value.

pub fn dec_recv_window(&mut self, sz: u32) -> Result<(), Reason>

Decrement the recv-side window size.

This is called after receiving a SETTINGS ACK frame with a lower INITIAL_WINDOW_SIZE value.

pub fn send_data(&mut self, sz: u32) -> Result<(), Reason>

Decrements the window reflecting data has actually been sent. The caller must ensure that the window has capacity.

Trait Implementations

impl Clone for FlowControl

fn clone(&self) -> FlowControl

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for FlowControl

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for FlowControl