Struct gstd::ReservationId

pub struct ReservationId(_);

Reservation identifier.

The identifier is used to reserve and unreserve gas amount for program execution later.

Examples

use gstd::ReservationId;

static mut RESERVED: Option<ReservationId> = None;

extern "C" fn init() {
    let reservation_id = ReservationId::reserve(50_000_000, 7).expect("Unable to reserve");
    unsafe { RESERVED = Some(reservation_id) };
}

extern "C" fn handle() {
    let reservation_id = unsafe { RESERVED.take().expect("Empty `RESERVED`") };
    reservation_id.unreserve();
}

Implementations

impl ReservationId

pub fn reserve(amount: u64, duration: u32) -> Result<Self>

Reserve the amount of gas for further usage.

duration is the block count within which the reserve must be used.

This function returns ReservationId, which one can use for gas unreserving.

Examples

Reserve 50 million of gas for one block, send a reply, then unreserve gas back:

use gstd::{msg, ReservationId};

#[no_mangle]
extern "C" fn handle() {
    let reservation_id = ReservationId::reserve(50_000_000, 1).expect("Unable to reserve");
    msg::reply_bytes_from_reservation(reservation_id.clone(), b"PONG", 0)
        .expect("Unable to reply");
    let reservation_left = reservation_id.unreserve().expect("Unable to unreserve");
}

pub fn unreserve(self) -> Result<u64>

Unreserve unused gas from the reservation.

If successful, it returns the reserved amount of gas.

Trait Implementations

impl AsRef<[u8]> for ReservationId

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

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

impl Clone for ReservationId

fn clone(&self) -> ReservationId

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ReservationId

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

Formats the value using the given formatter.

impl Decode for ReservationId

fn decode<__CodecInputEdqy: Input>( __codec_input_edqy: &mut __CodecInputEdqy ) -> Result<Self, Error>

Attempt to deserialise the value from input.

fn skip<I>(input: &mut I) -> Result<(), Error>where I: Input,

Attempt to skip the encoded value from input.

fn encoded_fixed_size() -> Option<usize>

Returns the fixed encoded size of the type.

impl Encode for ReservationId

fn encode_to<__CodecOutputEdqy: Output + ?Sized>( &self, __codec_dest_edqy: &mut __CodecOutputEdqy )

Convert self to a slice and append it to the destination.

fn encode(&self) -> Vec<u8>

Convert self to an owned vector.

fn using_encoded<R, F: FnOnce(&[u8]) -> R>(&self, f: F) -> R

Convert self to a slice and then invoke the given closure with it.

fn size_hint(&self) -> usize

If possible give a hint of expected size of the encoding.

fn encoded_size(&self) -> usize

Calculates the encoded size.

impl From<ReservationId> for ReservationId

fn from(id: ReservationId) -> Self

Converts to this type from the input type.

impl From<ReservationId> for ReservationId

fn from(id: ReservationId) -> Self

Converts to this type from the input type.

impl Hash for ReservationId

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 Ord for ReservationId

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

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl PartialEq<ReservationId> for ReservationId

fn eq(&self, other: &ReservationId) -> 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 PartialOrd<ReservationId> for ReservationId

fn partial_cmp(&self, other: &ReservationId) -> 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 TypeInfo for ReservationId

type Identity = ReservationId

The type identifying for which type info is provided.

fn type_info() -> Type

Returns the static type identifier for Self.

impl Copy for ReservationId

impl EncodeLike<ReservationId> for ReservationId

impl Eq for ReservationId

impl StructuralEq for ReservationId

impl StructuralPartialEq for ReservationId