Struct HostFunction

pub struct HostFunction<T> { /* private fields */ }

Available on crate feature std only.

Representation of a host function cost.

The total gas cost is equal to cost + sum of each argument weight multiplied by the byte size of the data.

Implementations

impl<T> HostFunction<T>

pub const fn new(cost: Cost, arguments: T) -> Self

Creates a new instance of HostFunction with a fixed call cost and argument weights.

pub fn with_new_static_cost(self, cost: Cost) -> Self

pub fn cost(&self) -> Cost

Returns the base gas fee for calling the host function.

impl<T> HostFunction<T>

where T: Default,

pub fn fixed(cost: Cost) -> Self

Creates a new fixed host function cost with argument weights of zero.

impl<T> HostFunction<T>

where T: AsRef<[Cost]>,

pub fn arguments(&self) -> &[Cost]

Returns a slice containing the argument weights.

pub fn calculate_gas_cost(&self, weights: T) -> Option<Gas>

Calculate gas cost for a host function

Trait Implementations

impl<const COUNT: usize> Add for HostFunction<[Cost; COUNT]>

type Output = HostFunction<[u32; COUNT]>

The resulting type after applying the + operator.

fn add(self, rhs: Self) -> Self::Output

Performs the + operation.

impl<T: Clone> Clone for HostFunction<T>

fn clone(&self) -> HostFunction<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> DataSize for HostFunction<T>

where T: DataSize,

const IS_DYNAMIC: bool

If true, the type has a heap size that can vary at runtime, depending on the actual value.

const STATIC_HEAP_SIZE: usize

The amount of space a value of the type always occupies. If IS_DYNAMIC is false, this is the total amount of heap memory occupied by the value. Otherwise this is a lower bound.

fn estimate_heap_size(&self) -> usize

Estimates the size of heap memory taken up by this value.

impl<T: Debug> Debug for HostFunction<T>

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

Formats the value using the given formatter.

impl<T> Default for HostFunction<T>

where T: Default,

fn default() -> Self

Returns the “default value” for a type.

impl<'de, T> Deserialize<'de> for HostFunction<T>

where T: Deserialize<'de>,

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<T> Distribution<HostFunction<T>> for Standard

where Standard: Distribution<T>, T: AsRef<[Cost]>,

fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> HostFunction<T>

Generate a random value of T, using rng as the source of randomness.

fn sample_iter<R>(self, rng: R) -> DistIter<Self, R, T>

where R: Rng, Self: Sized,

Create an iterator that generates random values of T, using rng as the source of randomness.

fn map<F, S>(self, func: F) -> DistMap<Self, F, T, S>

where F: Fn(T) -> S, Self: Sized,

Create a distribution of values of ‘S’ by mapping the output of Self through the closure F

impl<T> FromBytes for HostFunction<T>

where T: Default + AsMut<[Cost]>,

fn from_bytes(bytes: &[u8]) -> Result<(Self, &[u8]), Error>

Deserializes the slice into Self.

fn from_vec(bytes: Vec<u8>) -> Result<(Self, Vec<u8>), Error>

Deserializes the Vec<u8> into Self.

impl<T: PartialEq> PartialEq for HostFunction<T>

fn eq(&self, other: &HostFunction<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

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

impl<T> Serialize for HostFunction<T>

where T: Serialize,

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl<T> ToBytes for HostFunction<T>

where T: AsRef<[Cost]>,

fn to_bytes(&self) -> Result<Vec<u8>, Error>

Serializes &self to a Vec<u8>.

fn serialized_length(&self) -> usize

Returns the length of the Vec<u8> which would be returned from a successful call to to_bytes() or into_bytes(). The data is not actually serialized, so this call is relatively cheap.

fn into_bytes(self) -> Result<Vec<u8>, Error>

where Self: Sized,

Consumes self and serializes to a Vec<u8>.

fn write_bytes(&self, writer: &mut Vec<u8>) -> Result<(), Error>

Writes &self into a mutable writer.

impl<const COUNT: usize> Zero for HostFunction<[Cost; COUNT]>

fn zero() -> Self

Returns the additive identity element of Self, 0.

fn is_zero(&self) -> bool

Returns true if self is equal to the additive identity.

fn set_zero(&mut self)

Sets self to the additive identity element of Self, 0.

impl<T: Copy> Copy for HostFunction<T>

impl<T: Eq> Eq for HostFunction<T>

impl<T> StructuralPartialEq for HostFunction<T>