Files
pezkuwi-subxt/substrate/frame/randomness-collective-flip
Xiliang Chen d346028a9d reset events before apply runtime upgrade (#10620)
* reset events before apply runtime upgrade

* fix tests

* add test

* update comment

* Update frame/system/src/lib.rs

* trigger CI

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
2022-01-12 08:22:29 +00:00
..

Randomness Module

The Randomness Collective Flip module provides a random function that generates low-influence random values based on the block hashes from the previous 81 blocks. Low-influence randomness can be useful when defending against relatively weak adversaries. Using this pallet as a randomness source is advisable primarily in low-security situations like testing.

Public Functions

See the Module struct for details of publicly available functions.

Usage

Prerequisites

Import the Randomness Collective Flip module and derive your module's configuration trait from the system trait.

Example - Get random seed for the current block

use frame_support::traits::Randomness;

#[frame_support::pallet]
pub mod pallet {
    use super::*;
    use frame_support::pallet_prelude::*;
    use frame_system::pallet_prelude::*;

    #[pallet::pallet]
    pub struct Pallet<T>(_);

    #[pallet::config]
    pub trait Config: frame_system::Config + pallet_randomness_collective_flip::Config {}

    #[pallet::call]
    impl<T: Config> Pallet<T> {
        #[pallet::weight(0)]
        pub fn random_module_example(origin: OriginFor<T>) -> DispatchResult {
            let _random_value = <pallet_randomness_collective_flip::Pallet<T>>::random(&b"my context"[..]);
            Ok(())
        }
    }
}

License: Apache-2.0