Update shuffling function
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@ -1,13 +1,13 @@
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pub struct Config {
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pub attester_count: u32,
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pub max_validators: u32
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pub attester_count: u64,
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pub max_validators: u64
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}
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impl Config {
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pub fn standard() -> Self {
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Self {
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attester_count: 32,
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max_validators: 2u32.pow(24)
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max_validators: 2u64.pow(24)
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}
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}
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}
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@ -8,52 +8,57 @@ use super::config::Config;
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const AGG_VOTE_MSG_SIZE: i32 = 2 + 32 + 32 + 8 + 8;
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// Interprets a 3-byte slice from a [u8] as an integer.
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fn get_shift_from_source(source: &[u8], offset: usize) -> u32 {
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(source[offset + 2] as u32) |
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((source[offset + 1] as u32) << 8) |
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((source[offset ] as u32) << 16)
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fn get_shift_from_source(source: &[u8], offset: usize) -> usize {
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(source[offset + 2] as usize) |
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((source[offset + 1] as usize) << 8) |
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((source[offset ] as usize) << 16)
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}
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// Given entropy in the form of `seed`, return a shuffled list of validators
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// of size `validator_count` or `sample`.
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// indicies of size `validator_count` or `sample`.
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pub fn get_shuffling(
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seed: &Sha256Digest,
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validator_count: &u32,
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sample: &Option<u32>,
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validator_count: &usize,
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sample_size: &Option<usize>,
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config: &Config)
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-> Vec<u32>
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-> Vec<usize>
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{
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let max_validators = config.max_validators;
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assert!(*validator_count <= max_validators);
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assert!(*validator_count > 0);
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let mut output: Vec<usize> = (0..*validator_count).collect();
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assert!(*validator_count <= (config.max_validators as usize));
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// TODO: figure out why the Python implementation uses
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// this `rand_max` var.
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// let rand_max = max_validators - (max_validators % validator_count);
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let validator_range = match sample {
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Some(x) => x,
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// Use a reduced "sample_size" output range if specified
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let output_range: &usize = match sample_size {
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Some(x) => {
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assert!(x <= validator_count,
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"sample_size should be <= validator_count");
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x
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},
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None => validator_count
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};
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let mut output: Vec<u32> = (0..*validator_range).collect();
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// Do the first blake hash round
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let mut source = Blake2s::new();
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source.input(&seed);
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let mut v = 0;
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while v < *validator_range {
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while v < *output_range {
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let current_source = source.result();
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let mut source_offset = 0;
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while source_offset < 30 {
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let m = get_shift_from_source(¤t_source, source_offset);
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let shuffled_position = (m % (validator_count - v)) + v;
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let shuffled_position: usize = (m % (validator_count - v)) + v;
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output.swap(v as usize, shuffled_position as usize);
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v += 1;
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if v >= *validator_count { break; }
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source_offset += 3;
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}
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// Re-hash the source
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// Re-hash the source (TODO: this does one extra hash, can be optimised)
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source = Blake2s::new();
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source.input(¤t_source);
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}
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output
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output[0..*output_range].to_vec()
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}
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// Given an aggregate_vote and a crystallized_state,
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