Struct coap_message_utils::option_value::Block2RequestData

pub struct Block2RequestData(/* private fields */);

Request data from a Block2 request

As the M flag is unused in requests, it is not captured in here (and ignored at construction).

Implementations

impl Block2RequestData

pub fn from_message( message: &impl ReadableMessage, ) -> Result<Self, BadBlock2Option>

Extract a request block 2 value from a request message.

Absence of the option is not an error and results in the default value to be returned; exceeding length or duplicate entries are an error and are indicated by returning an error, which should be responded to with a Bad Option error.

pub fn from_option(option: &impl MessageOption) -> Result<Self, BadBlock2Option>

Extract a request block 2 value from a single option. An error is indicated on a malformed (ie. overly long) option.

Compared to Block2RequestData::from_message(), this can easily be packed into a single loop that processes all options and fails on unknown critical ones; on the other hand, this does not automate the check for duplicate options.

Panics

In debug mode if the option is not Block2

pub fn to_option_value(&self, more: bool) -> u32

pub fn size(&self) -> u16

Size of a single block

pub fn start(&self) -> usize

Number of bytes before the indicated block

pub fn shrink(self, size: u16) -> Option<Self>

Return a block that has identical .start(), but a block size smaller or equal to the given one.

Returns None if the given size is not expressible as a CoAP block (ie. is less than 16).

Trait Implementations

impl Default for Block2RequestData

fn default() -> Self

Returns the “default value” for a type.

impl TryFromOption for Block2RequestData

fn try_from(value: &impl MessageOption) -> Option<Self>

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 8 bytes