Struct RoundingError 

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

This type defines a rounding error to use when fetching the current slot from Solana using the JSON-RPC interface, meaning slots will be rounded down to the nearest multiple of this error when being fetched.

This is done to achieve consensus on the HTTP outcalls whose responses contain Solana slots despite Solana’s fast blocktime and hence fast-changing slot value. However, this solution does not guarantee consensus on the slot value across nodes and different consensus rates will be achieved depending on the rounding error value used. A higher rounding error will lead to a higher consensus rate, but also means the slot value may differ more from the actual value on the Solana blockchain. This means, for example, that setting a large rounding error and then fetching the corresponding block with the Solana getBlock RPC method can result in obtaining a block whose hash is too old to use in a valid Solana transaction (see more details about using recent blockhashes here.

The default value given by RoundingError::default has been experimentally shown to achieve a high HTTP outcall consensus rate.

See the RoundingError::round method for more details and examples.

Implementations

impl RoundingError

pub fn new(rounding_error: u64) -> Self

Create a new instance of RoundingError with the given value.

pub fn round(&self, slot: u64) -> u64

Round the given value down to the nearest multiple of the rounding error. A rounding error of 0 or 1 leads to this method returning the input unchanged.

Examples

use sol_rpc_types::RoundingError;

assert_eq!(RoundingError::new(0).round(19), 19);
assert_eq!(RoundingError::new(1).round(19), 19);
assert_eq!(RoundingError::new(10).round(19), 10);
assert_eq!(RoundingError::new(20).round(19), 0);

Trait Implementations

impl AsRef<u64> for RoundingError

fn as_ref(&self) -> &u64

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

impl CandidType for RoundingError

fn _ty() -> Type

fn id() -> TypeId

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

where __S: Serializer,

fn ty() -> Type

impl Clone for RoundingError

fn clone(&self) -> RoundingError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RoundingError

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

Formats the value using the given formatter.

impl Default for RoundingError

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for RoundingError

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<RoundingError> for u64

fn from(value: RoundingError) -> Self

Converts to this type from the input type.

impl From<u64> for RoundingError

fn from(value: u64) -> Self

Converts to this type from the input type.

impl Ord for RoundingError

fn cmp(&self, other: &RoundingError) -> 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,

Restrict a value to a certain interval.

impl PartialEq for RoundingError

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

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

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl Serialize for RoundingError

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for RoundingError

impl Eq for RoundingError

impl StructuralPartialEq for RoundingError