Crate pallet_timestamp
source · [−]Expand description
Timestamp Pallet
The Timestamp pallet provides functionality to get and set the on-chain time.
Overview
The Timestamp pallet allows the validators to set and validate a timestamp with each block.
It uses inherents for timestamp data, which is provided by the block author and validated/verified by other validators. The timestamp can be set only once per block and must be set each block. There could be a constraint on how much time must pass before setting the new timestamp.
NOTE: The Timestamp pallet is the recommended way to query the on-chain time instead of using an approach based on block numbers. The block number based time measurement can cause issues because of cumulative calculation errors and hence should be avoided.
Interface
Dispatchable Functions
set- Sets the current time.
Public functions
get- Gets the current time for the current block. If this function is called prior to setting the timestamp, it will return the timestamp of the previous block.
Config Getters
MinimumPeriod- Gets the minimum (and advised) period between blocks for the chain.
Usage
The following example shows how to use the Timestamp pallet in your custom pallet to query the current timestamp.
Prerequisites
Import the Timestamp pallet into your custom pallet and derive the pallet configuration trait from the timestamp trait.
Get current timestamp
use frame_support::{decl_module, dispatch};
use frame_system::ensure_signed;
pub trait Config: timestamp::Config {}
decl_module! {
pub struct Module<T: Config> for enum Call where origin: T::Origin {
#[weight = 0]
pub fn get_time(origin) -> dispatch::DispatchResult {
let _sender = ensure_signed(origin)?;
let _now = <timestamp::Module<T>>::get();
Ok(())
}
}
}Example from the FRAME
The Session pallet uses the Timestamp pallet for session management.
Related Pallets
Re-exports
pub use weights::WeightInfo;pub use pallet::*;