Struct Message 

pub struct Message<EM: MessageBuffer> { /* private fields */ }

A CoAP message that resides in contiguous readable memory.

This implementation does not attempt to do any early validation. On encoding errors discovered at runtime, it simply emits the critical-and-not-safe-to-forward CoAP option 65535 (OPTION_INVALID), which to the indication indicates that something went wrong

Message is covariant over its lifetime because it only reads from there, effectively fulfilling the expectations of LifetimesMatterLittle. That property is currently not exposed.

Implementation details

When used with coap_message::helpers::RefWithStaticType, it always uses Message<EMS> where EMS is the type inside the LifetimesMatterLittle of the EM::static_variant() result. This is needed to run Self::downcast_from, and restores the lifetime based on the given impl Trait reference’s lifetime using its covariance property.

Implementations

impl<'a> Message<SliceBuffer<'a>>

pub fn new_from_slice(code: u8, options_and_payload: &'a [u8]) -> Self

Creates a message that is parsed from a slice.

This is a short-cut for creating a SliceBuffer and passing it to Self::new().

impl<EM: MessageBuffer> Message<EM>

pub fn new(inner: EM) -> Self

Creates a new instance backed by an encoded message buffer.

Decoding assumes that the full tail of the buffer contains options and payload.

pub fn new_until(inner: EM, length: usize) -> Self

Creates a new instance backed by an encoded message buffer.

Decoding assumes that the first length bytes contain options and payload. (The buffer having the option to be longer is mostly useful when it is also an MessageBufferMut, and might later get turned .into_mutable()).

pub fn downcast_from<M: ReadableMessage>(generic: &M) -> Option<&Self>

Available on crate feature downcast only.

pub fn into_mutable(self) -> Result<MessageMut<EM>, ParsingError>

where EM: MessageBufferMut,

Converts the message into a mutable writable message.

This can be useful to reuse a buffer that has been passed to the application, e.g. for in-place decryption or to shove around indefinite-length CBOR encoding inside payloads.

Errors

… are only raised if the message contains parsing errors (for a mutable message is stricter in that regard).

Trait Implementations

impl<EM: MessageBuffer> AsRef<EM> for Message<EM>

When the inner item stores more than just the code and encoded options, this can be used to gain read-only access to any additional data.

Note that no matter whether access is shared or exclusive, the MessageBuffer must uphold its promise to always return the same content.

fn as_ref(&self) -> &EM

Converts this type into a shared reference of the (usually inferred) input type.

impl<EM: Clone + MessageBuffer> Clone for Message<EM>

fn clone(&self) -> Message<EM>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<EM: Debug + MessageBuffer> Debug for Message<EM>

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

Formats the value using the given formatter.

impl<EM> Format for Message<EM>

where EM: Format + MessageBuffer, Cell<Option<Processing>>: Format,

fn format(&self, f: Formatter<'_>)

Writes the defmt representation of self to fmt.

impl<EM: MessageBuffer> ReadableMessage for Message<EM>

type Code = u8

See Self::code()

type MessageOption<'a> = MessageOption<'a> where Self: 'a

Type of an individual option, indicating its option number and value

type OptionsIter<'a> = OptionsIter<'a> where Self: 'a

See Self::options()

fn code(&self) -> u8

Get the code (request method or response code) of the message

fn payload(&self) -> &[u8]

Get the payload set in the message

fn options(&self) -> OptionsIter<'_>

Produce all options in arbitrary order as an iterator

fn with_static_type_annotation(&self) -> Option<RefWithStaticType<'_, Self>>

Type ID of Self or a ’static version of Self

impl<EM: MessageBuffer> WithSortedOptions for Message<EM>