From 27b8c0341498053f62beb5c3e97203e52f12eb95 Mon Sep 17 00:00:00 2001 From: Paul Hauner Date: Fri, 13 Jul 2018 15:37:21 +1000 Subject: [PATCH] Add work on crosslinks --- src/state/transition/crosslinks.rs | 186 +++++++++++++++++++++++++++++ src/state/transition/mod.rs | 4 +- 2 files changed, 189 insertions(+), 1 deletion(-) create mode 100644 src/state/transition/crosslinks.rs diff --git a/src/state/transition/crosslinks.rs b/src/state/transition/crosslinks.rs new file mode 100644 index 000000000..e05111ff4 --- /dev/null +++ b/src/state/transition/crosslinks.rs @@ -0,0 +1,186 @@ +use std::collections::HashMap; +use std::cmp::min; + +use super::crystallized_state::CrystallizedState; +use super::partial_crosslink_record::PartialCrosslinkRecord; +use super::config::Config; + +// Returns the maximum possible shards for a given validator_count +// and configuration. +pub fn get_crosslink_shards_count( + active_validator_count: &usize, + config: &Config) + -> u16 +{ + let system_shard_count: u16 = config.shard_count; + let notaries_per_crosslink: u16 = config.notaries_per_crosslink; + + assert!(notaries_per_crosslink > 0, "Shards must require > 0 notaries."); + + let notarisable_shard_count = + *active_validator_count as u64 / notaries_per_crosslink as u64; + + min(notarisable_shard_count, system_shard_count as u64) as u16 +} + +pub fn get_crosslink_shards( + cry_state: &CrystallizedState, + config: &Config) + -> Vec +{ + let max_shard_count: u16 = config.shard_count; + let first_shard: u16 = cry_state.next_shard; + assert!(first_shard < max_shard_count, "CrystallizedState.next_shard \ + must be less than Config.shard_count."); + + let shard_count = get_crosslink_shards_count( + &cry_state.num_active_validators(), + &config); + + let unwrapped_shards: u16 = min(first_shard + shard_count, max_shard_count); + let wrapped_shards: u16 = (first_shard + shard_count) % max_shard_count; + let mut crosslink_shards: Vec = (first_shard..unwrapped_shards).collect(); + crosslink_shards.append(&mut (0_u16..wrapped_shards).collect()); + crosslink_shards +} + +/* Work in progres... +pub fn process_crosslinks( + cry_state: &CrystallizedState, + partial_crosslinks: &Vec, + config: &Config) + -> (Vec, Vec) +{ + assert!(partial_crosslinks.len() > 0, "No crosslinks present."); + + let mut map: HashMap = HashMap::new(); + + for pc in partial_crosslinks { + let vote_count = pc.voter_bitfield.num_true_bits(); + let mut competiting_vote_count = 0; + match map.get(&pc.shard_id) { + Some(&competitor) => competiting_vote_count = competitor.1, + None => {} + } + // Here we implicitly avoid adding crosslinks with 0 votes + // to our map. + if vote_count > competiting_vote_count { + map.insert(pc.shard_id, (pc, vote_count)); + } + } + + let mut new_partial_crosslinks: Vec<&PartialCrosslinkRecord> = Vec::new(); + map.iter_mut() + .for_each(|(_, v)| new_partial_crosslinks.push(v.0)); + + // To be completed... + + (Vec::new(), Vec::new()) +} +*/ + + +#[cfg(test)] +mod tests { + use super::*; + use super::super::super::validator_record::ValidatorRecord; + + #[test] + fn test_crosslink_shard_count_with_varying_active_vals() { + let mut config = Config::standard(); + + config.shard_count = 10; + config.notaries_per_crosslink = 10; + + let mut c = get_crosslink_shards_count( + &100, + &config); + assert_eq!(c, 10); + + c = get_crosslink_shards_count( + &101, + &config); + assert_eq!(c, 10); + + c = get_crosslink_shards_count( + &99, + &config); + assert_eq!(c, 9); + + c = get_crosslink_shards_count( + &0, + &config); + assert_eq!(c, 0); + } + + #[test] + #[should_panic(expected = "must require > 0 notaries.")] + fn test_crosslink_shard_count_with_zero_notaries_per_crosslink() { + let mut config = Config::standard(); + + config.shard_count = 10; + config.notaries_per_crosslink = 0; + + let validators: u16 = 10; + + let c = get_crosslink_shards_count( + &(validators as usize), + &config); + } + + #[test] + fn test_crosslink_shard_getter_with_5_shards() { + let mut cry_state = CrystallizedState::zero(); + let mut config = Config::standard(); + + config.shard_count = 5; + config.notaries_per_crosslink = 2; + + (0..10).for_each( + |_| cry_state.active_validators.push( + ValidatorRecord::zero_with_thread_rand_pub_key())); + + cry_state.next_shard = 0; + let c = get_crosslink_shards( + &cry_state, + &config); + assert_eq!(c, [0, 1, 2, 3, 4]); + + cry_state.next_shard = 4; + let c = get_crosslink_shards( + &cry_state, + &config); + assert_eq!(c, [4, 0, 1, 2, 3]); + + cry_state.next_shard = 1; + let c = get_crosslink_shards( + &cry_state, + &config); + assert_eq!(c, [1, 2, 3, 4, 0]); + + cry_state.next_shard = 3; + let c = get_crosslink_shards( + &cry_state, + &config); + assert_eq!(c, [3, 4, 0, 1, 2]); + } + + #[test] + #[should_panic(expected = "next_shard must be less than Config.shard_count")] + fn test_crosslink_shard_getter_with_too_large_next_shard() { + let mut cry_state = CrystallizedState::zero(); + let mut config = Config::standard(); + + config.shard_count = 1; + config.notaries_per_crosslink = 2; + + (0..2).for_each( + |_| cry_state.active_validators.push( + ValidatorRecord::zero_with_thread_rand_pub_key())); + + cry_state.next_shard = 6; + let c = get_crosslink_shards( + &cry_state, + &config); + } +} diff --git a/src/state/transition/mod.rs b/src/state/transition/mod.rs index 6f2308f3c..d02d9e6e6 100644 --- a/src/state/transition/mod.rs +++ b/src/state/transition/mod.rs @@ -2,6 +2,8 @@ use super::config; use super::utils; use super::blake2; use super::crystallized_state; +use super::partial_crosslink_record; -pub mod shuffling; +pub mod crosslinks; pub mod deposits; +pub mod shuffling;