Struct s2n_quic_core::counter::Counter

pub struct Counter<T, Behavior = ()>(/* private fields */);

A checked-overflow counter

Rather than silently wrapping, we want to ensure counting errors stay somewhat isolated so the counter will saturate rather than wrap. The counter operates in 3 modes:

• If debug_assertions are enabled, the counter will panic on overflow
• If the checked-counters feature flag is defined, the counter will panic on overflow, even in release builds.
• Otherwise, the counter will saturate

The counter can also be configured to always saturate by passing the Saturating behavior:

use s2n_quic_core::counter::{Counter, Saturating};

let counter: Counter<u32, Saturating> = Default::default();

Implementations

impl<T, Behavior> Counter<T, Behavior>

pub const fn new(value: T) -> Self

Creates a new counter with an initial value

pub fn set(&mut self, value: T)

pub fn try_add<V>(&mut self, value: V) -> Result<(), T::Error>

where T: TryFrom<V>, Self: AddAssign<T>,

Tries to convert V to T and add it to the current counter value

pub fn try_sub<V>(&mut self, value: V) -> Result<(), T::Error>

where T: TryFrom<V>, Self: SubAssign<T>,

Tries to convert V to T and subtract it from the current counter value

Trait Implementations

impl<T, R> AddAssign<R> for Counter<T, ()>

where T: SaturatingAddAssign<R> + CheckedAddAssign<R> + AddAssign + UpcastFrom<R>,

fn add_assign(&mut self, rhs: R)

Performs the += operation.

impl<T, R> AddAssign<R> for Counter<T, Saturating>

where T: SaturatingAddAssign<R>,

fn add_assign(&mut self, rhs: R)

Performs the += operation.

impl<T: Clone, Behavior: Clone> Clone for Counter<T, Behavior>

fn clone(&self) -> Counter<T, Behavior>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug, Behavior: Debug> Debug for Counter<T, Behavior>

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

Formats the value using the given formatter.

impl<T: Default, Behavior: Default> Default for Counter<T, Behavior>

fn default() -> Counter<T, Behavior>

Returns the “default value” for a type.

impl<T, B> Deref for Counter<T, B>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<T: Hash, Behavior: Hash> Hash for Counter<T, Behavior>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T, R> MulAssign<R> for Counter<T, ()>

where T: SaturatingMulAssign<R> + CheckedMulAssign<R> + MulAssign + UpcastFrom<R>,

fn mul_assign(&mut self, rhs: R)

Performs the *= operation.

impl<T, R> MulAssign<R> for Counter<T, Saturating>

where T: SaturatingMulAssign<R>,

fn mul_assign(&mut self, rhs: R)

Performs the *= operation.

impl<T, B> Ord for Counter<T, B>

where T: Ord,

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl<T, B, R> PartialEq<R> for Counter<T, B>

where Self: PartialOrd<R>,

fn eq(&self, other: &R) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T, B> PartialOrd<T> for Counter<T, B>

where T: PartialOrd<T>,

fn partial_cmp(&self, other: &T) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T, B> PartialOrd for Counter<T, B>

where T: PartialOrd<T>,

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T, R> SubAssign<R> for Counter<T, ()>

where T: SaturatingSubAssign<R> + CheckedSubAssign<R> + SubAssign + UpcastFrom<R>,

fn sub_assign(&mut self, rhs: R)

Performs the -= operation.

impl<T, R> SubAssign<R> for Counter<T, Saturating>

where T: SaturatingSubAssign<R>,

fn sub_assign(&mut self, rhs: R)

Performs the -= operation.

impl<T, B> UpcastFrom<&Counter<T, B>> for T

where T: for<'a> UpcastFrom<&'a T>,

fn upcast_from(value: &Counter<T, B>) -> Self

impl<T: Copy, Behavior: Copy> Copy for Counter<T, Behavior>

impl<T, B> Eq for Counter<T, B>

where Self: Ord,