Struct RestrictedDecodeContext 

pub struct RestrictedDecodeContext { /* private fields */ }

Additional information passed to every distinguished decode/merge function.

The context should be passed by value and can be freely cloned. When passing to a function which is decoding a nested object, then use enter_recursion.

Implementations

impl RestrictedDecodeContext

pub fn new(min_canonicity: Canonicity) -> Self

Creates a new context with a given minimum canonicity.

pub fn enter_recursion(&self) -> Self

Call this function before recursively decoding.

There is no exit function since this function creates a new DecodeContext to be used at the next level of recursion. Continue to use the old context

pub fn limit_reached(&self) -> Result<(), DecodeError>

Checks whether the recursion limit has been reached in the stack of decodes described by the DecodeContext at self.ctx.

Returns Ok<()> if it is ok to continue recursing. Returns Err<DecodeError> if the recursion limit has been reached.

pub fn into_inner(self) -> DecodeContext

Returns the inner non-restricted context for relaxed decoding.

pub fn check(&self, canon: Canonicity) -> Result<Canonicity, DecodeError>

Checks the given canonicity against the minimum constraint that this context has.

This must be called and checked at a few specific times, whenever the canonicity is (possibly) being reduced and it hasn’t already been checked by some source that returned that canonicity value:

1. When decoding, and a non-canonical state is observed (such as a value that is represented in a non-canonical form, or an unknown field in the encoding), this can be called with a literal Canonicity value.
2. After calling one of the distinguished helper trait methods that does not have a restricted context in its parameters to check against, and therefore could not possibly have converted a non-canonical state into an error yet: 2a. DistinguishedProxiable::decode_proxy_distinguished 2b. DistinguishedCollection::insert_distinguished

After these canonicity values have been checked, and at all other times, it should be safe to directly update the canonicity that an implementation will itself return since each value it receives should already be tolerated by the context.

Trait Implementations

impl Clone for RestrictedDecodeContext

fn clone(&self) -> RestrictedDecodeContext

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RestrictedDecodeContext

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

Formats the value using the given formatter.