Bigna Härdi
0e49ed72aa
* add serde_full feature flag add serde_full to sp_runtime add space to toml add serde_full to application-crypto add serde_full to arithmetic fix arithmetic add serde full to beefy add serde full to consensus add serde_full to core add serdefull to finality grandpa add serde_full to several primitives crates make rpc no_std compatible add scale info to runtime make serializer no_std compatible add serde full to storage add full serde to version add serde full to weights add all serde_full features add . to comment add missing impl-serde fix no-std build fix build add full_crypto to serde_full serde_full also implements crypto full_serde does not work with full_crytpo. needs std no no_std serde impl possible also for crypto std is necessary no serde full for application crypto fix arithmetic fix tomls fix some things impl fmt for Signature add serialize to Public add impl_maybe_marker_serde_full fix sp-application-crypto toml add serde feature flag fix clippy fix toml grandpa fix grandpa rename if_std to if_serde keystore is not no_std compatible make keystore vrf no_std compatible fix nopos-elections fix rpc fix serializer fix test-primitives fix version add comment add serde full only import for format string remove all(serde_full and full_crypot) as serde_full enforces full_crypto make comment better readable even better comment clean up rpc toml clean up toml clean up serializer toml clean up storage toml fix std build update .lock fix sp-version move sp_std import test extern crate alloc replace sp_std with core add missing core sp_core: serde feature do not enforce full crypto application-crypto: serde feature do not enforce full crypto rename serde_full to serde add dep:serde and alloc to default feature add full_crypto and remove unnecessary debu/fmt impls for serde update comment remove obolsete change in display AccountId32 remove extra changes minimize diff revert keystore changes remove std from keystore remove full-crypto feature fix serde import fix comment fix feature = serde * rename serde_full to serde * move #[doc(hidden)] back * remove feature = full crypto require frm MultiSigner * reorder serde and scale_info import * fix bs58 missing alloc import in serde feature * add `from_string` to serde feature and add unimplemented * remove serde feature from fixed_point display * Remove serde/alloc Co-authored-by: Davide Galassi <davxy@datawok.net> * Update primitives/consensus/babe/Cargo.toml Co-authored-by: Bastian Köcher <git@kchr.de> * Update primitives/arithmetic/src/fixed_point.rs Co-authored-by: Bastian Köcher <git@kchr.de> * revert `from_string`fixed impl back to std only * remove duplicate runtime string impl * use sp_std::alloc * remove no_std compatible rpc * remove no_std compatibility from serializer * rename mpl_maybe_marker_serde to std_or_serde * update .lock * add sp-std to executor * fix sp-std import * fix sp_std::format import * use crate import * add serde feature * Update primitives/core/src/lib.rs --------- Co-authored-by: Davide Galassi <davxy@datawok.net> Co-authored-by: Bastian Köcher <git@kchr.de>
A set of election algorithms to be used with a substrate runtime, typically within the staking sub-system. Notable implementation include:
- [
seq_phragmen]: Implements the Phragmén Sequential Method. An un-ranked, relatively fast election method that ensures PJR, but does not provide a constant factor approximation of the maximin problem. - [
phragmms]: Implements a hybrid approach inspired by Phragmén which is executed faster but it can achieve a constant factor approximation of the maximin problem, similar to that of the MMS algorithm. - [
balance_solution]: Implements the star balancing algorithm. This iterative process can push a solution toward being morebalanced, which in turn can increase its score.
Terminology
This crate uses context-independent words, not to be confused with staking. This is because the election algorithms of this crate, while designed for staking, can be used in other contexts as well.
Voter: The entity casting some votes to a number of Targets. This is the same as Nominator
in the context of staking. Target: The entities eligible to be voted upon. This is the same as
Validator in the context of staking. Edge: A mapping from a Voter to a Target.
The goal of an election algorithm is to provide an ElectionResult. A data composed of:
winners: A flat list of identifiers belonging to those who have won the election, usually ordered in some meaningful way. They are zipped with their total backing stake.assignment: A mapping from each voter to their winner-only targets, zipped with a ration denoting the amount of support given to that particular target.
// the winners.
let winners = vec![(1, 100), (2, 50)];
let assignments = vec![
// A voter, giving equal backing to both 1 and 2.
Assignment {
who: 10,
distribution: vec![(1, Perbill::from_percent(50)), (2, Perbill::from_percent(50))],
},
// A voter, Only backing 1.
Assignment { who: 20, distribution: vec![(1, Perbill::from_percent(100))] },
];
// the combination of the two makes the election result.
let election_result = ElectionResult { winners, assignments };
The Assignment field of the election result is voter-major, i.e. it is from the perspective of
the voter. The struct that represents the opposite is called a Support. This struct is usually
accessed in a map-like manner, i.e. keyed by voters, therefore it is stored as a mapping called
SupportMap.
Moreover, the support is built from absolute backing values, not ratios like the example above.
A struct similar to Assignment that has stake value instead of ratios is called an
StakedAssignment.
More information can be found at: https://arxiv.org/abs/2004.12990
License: Apache-2.0