Struct MessageQueue 

pub struct MessageQueue<D: MessageData = Vec<u8>> { /* private fields */ }

A MessageQueue stores a FIFO sequence of messages.

Implementations

impl<D: MessageData> MessageQueue<D>

pub fn new(capacity: usize) -> Self

pub fn available_capacity(&self) -> usize

Returns the number of bytes that can be written to the message queue before the buffer is full.

pub fn capacity(&self) -> usize

Returns the total number of bytes this message queue can store, regardless of the current amount of data in the buffer.

pub fn messages(&self) -> impl Iterator<Item = &Message<D>>

pub fn set_capacity(&mut self, requested_capacity: usize) -> Result<(), Errno>

Sets the capacity of the message queue to the provided number of bytes.

Reurns an error if the requested capacity could not be set (e.g., if the requested capacity was less than the current number of bytes stored).

pub fn is_empty(&self) -> bool

Returns true if the message queue is empty, or it only contains empty messages.

pub fn len(&self) -> usize

Returns the total length of all the messages in the message queue.

pub fn read_stream( &mut self, data: &mut dyn OutputBuffer, ) -> Result<MessageReadInfo, Errno>

Reads messages until there are no more messages, a message with ancillary data is encountered, or data are full.

To read data from the queue without consuming the messages, see peek_stream.

Parameters

• data: The OutputBuffer to write the data to.

Returns the number of bytes that were read into the buffer, and any ancillary data that was read.

pub fn peek_stream( &self, data: &mut dyn OutputBuffer, ) -> Result<MessageReadInfo, Errno>

Peeks messages until there are no more messages, a message with ancillary data is encountered, or data are full.

Unlike read_stream, this function does not remove the messages from the queue.

Used to implement MSG_PEEK.

Parameters

• data: The OutputBuffer to write the data to.

Returns the number of bytes that were read into the buffer, and any ancillary data that was read.

pub fn read_datagram( &mut self, data: &mut dyn OutputBuffer, ) -> Result<MessageReadInfo, Errno>

pub fn peek_datagram( &mut self, data: &mut dyn OutputBuffer, ) -> Result<MessageReadInfo, Errno>

pub fn read_message(&mut self) -> Option<Message<D>>

Reads the next message in the buffer, if such a message exists.

pub fn peek_queue(&self) -> &VecDeque<Message<D>>

pub fn write_stream( &mut self, data: &mut dyn InputBuffer, address: Option<SocketAddress>, ancillary_data: &mut Vec<AncillaryData>, ) -> Result<usize, Errno>

Writes the the contents of InputBuffer into this socket. Will return EAGAIN if not enough capacity is available.

Parameters

• task: The task to read memory from.
• data: The InputBuffer to read the data from.

Returns the number of bytes that were written to the socket.

pub fn write_stream_with_filter( &mut self, data: &mut dyn InputBuffer, address: Option<SocketAddress>, ancillary_data: &mut Vec<AncillaryData>, filter: impl FnOnce(Message<D>) -> Option<Message<D>>, ) -> Result<usize, Errno>

Writes the the contents of InputBuffer into this socket. Will return EAGAIN if not enough capacity is available.

Parameters

• task: The task to read memory from.
• data: The InputBuffer to read the data from.
• filter: A filter to run on the message before inserting it into the queue. If it returns None, no message is enqueued.

Returns the number of bytes that were written to the socket.

pub fn write_datagram( &mut self, data: &mut dyn InputBuffer, address: Option<SocketAddress>, ancillary_data: &mut Vec<AncillaryData>, ) -> Result<usize, Errno>

Writes the the contents of InputBuffer into this socket as single message. Will return EAGAIN if not enough capacity is available.

Parameters

• task: The task to read memory from.
• data: The InputBuffer to read the data from.

Returns the number of bytes that were written to the socket.

pub fn write_datagram_with_filter( &mut self, data: &mut dyn InputBuffer, address: Option<SocketAddress>, ancillary_data: &mut Vec<AncillaryData>, filter: impl FnOnce(Message<D>) -> Option<Message<D>>, ) -> Result<usize, Errno>

Writes the the contents of InputBuffer into this socket as single message. Will return EAGAIN if not enough capacity is available.

Parameters

• task: The task to read memory from.
• data: The InputBuffer to read the data from.
• filter: A filter to run on the message before inserting it into the queue. If it returns None, no message is enqueued.

Returns the number of bytes that were written to the socket.

pub fn write_front(&mut self, message: Message<D>)

Writes a message to the front of the message queue.

pub fn write_message(&mut self, message: Message<D>)

Writes a message to the back of the message queue.

pub fn query_events(&self) -> FdEvents

Trait Implementations

impl<D: Debug + MessageData> Debug for MessageQueue<D>

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

Formats the value using the given formatter.