Create a folder for tributary, the micro-blockchain

Moves tendermint again, this time under tributary.

coordinator/tributary/tendermint/src/block.rs

@@ -0,0 +1,139 @@
+use std::{
+  sync::Arc,
+  collections::{HashSet, HashMap},
+};
+
+use crate::{
+  time::CanonicalInstant,
+  ext::{RoundNumber, BlockNumber, Block, Network},
+  round::RoundData,
+  message_log::MessageLog,
+  Step, Data, DataFor, Message, MessageFor,
+};
+
+pub(crate) struct BlockData<N: Network> {
+  pub(crate) number: BlockNumber,
+  pub(crate) validator_id: Option<N::ValidatorId>,
+  pub(crate) proposal: Option<N::Block>,
+
+  pub(crate) log: MessageLog<N>,
+  pub(crate) slashes: HashSet<N::ValidatorId>,
+  // We track the end times of each round for two reasons:
+  // 1) Knowing the start time of the next round
+  // 2) Validating precommits, which include the end time of the round which produced it
+  // This HashMap contains the end time of the round we're currently in and every round prior
+  pub(crate) end_time: HashMap<RoundNumber, CanonicalInstant>,
+
+  pub(crate) round: Option<RoundData<N>>,
+
+  pub(crate) locked: Option<(RoundNumber, <N::Block as Block>::Id)>,
+  pub(crate) valid: Option<(RoundNumber, N::Block)>,
+}
+
+impl<N: Network> BlockData<N> {
+  pub(crate) fn new(
+    weights: Arc<N::Weights>,
+    number: BlockNumber,
+    validator_id: Option<N::ValidatorId>,
+    proposal: Option<N::Block>,
+  ) -> BlockData<N> {
+    BlockData {
+      number,
+      validator_id,
+      proposal,
+
+      log: MessageLog::new(weights),
+      slashes: HashSet::new(),
+      end_time: HashMap::new(),
+
+      // The caller of BlockData::new is expected to be populated after by the caller
+      round: None,
+
+      locked: None,
+      valid: None,
+    }
+  }
+
+  pub(crate) fn round(&self) -> &RoundData<N> {
+    self.round.as_ref().unwrap()
+  }
+
+  pub(crate) fn round_mut(&mut self) -> &mut RoundData<N> {
+    self.round.as_mut().unwrap()
+  }
+
+  // Populate the end time up to the specified round
+  // This is generally used when moving to the next round, where this will only populate one time,
+  // yet is also used when jumping rounds (when 33% of the validators are on a round ahead of us)
+  pub(crate) fn populate_end_time(&mut self, round: RoundNumber) {
+    // Starts from the current round since we only start the current round once we have have all
+    // the prior time data
+    for r in (self.round().number.0 + 1) ..= round.0 {
+      self.end_time.insert(
+        RoundNumber(r),
+        RoundData::<N>::new(RoundNumber(r), self.end_time[&RoundNumber(r - 1)]).end_time(),
+      );
+    }
+  }
+
+  // Start a new round. Optionally takes in the time for when this is the first round, and the time
+  // isn't simply the time of the prior round (yet rather the prior block). Returns the proposal
+  // data, if we are the proposer.
+  pub(crate) fn new_round(
+    &mut self,
+    round: RoundNumber,
+    proposer: N::ValidatorId,
+    time: Option<CanonicalInstant>,
+  ) -> Option<DataFor<N>> {
+    debug_assert_eq!(round.0 == 0, time.is_some());
+
+    // If this is the first round, we don't have a prior round's end time to use as the start
+    // We use the passed in time instead
+    // If this isn't the first round, ensure we have the prior round's end time by populating the
+    // map with all rounds till this round
+    // This can happen we jump from round x to round x+n, where n != 1
+    // The paper says to do so whenever you observe a sufficient amount of peers on a higher round
+    if round.0 != 0 {
+      self.populate_end_time(round);
+    }
+
+    // 11-13
+    self.round = Some(RoundData::<N>::new(
+      round,
+      time.unwrap_or_else(|| self.end_time[&RoundNumber(round.0 - 1)]),
+    ));
+    self.end_time.insert(round, self.round().end_time());
+
+    // 14-21
+    if Some(proposer) == self.validator_id {
+      let (round, block) = self.valid.clone().unzip();
+      block.or_else(|| self.proposal.clone()).map(|block| Data::Proposal(round, block))
+    } else {
+      self.round_mut().set_timeout(Step::Propose);
+      None
+    }
+  }
+
+  // Transform Data into an actual Message, using the contextual data from this block
+  pub(crate) fn message(&mut self, data: DataFor<N>) -> Option<MessageFor<N>> {
+    debug_assert_eq!(
+      self.round().step,
+      match data.step() {
+        Step::Propose | Step::Prevote => Step::Propose,
+        Step::Precommit => Step::Prevote,
+      },
+    );
+    // Tendermint always sets the round's step to whatever it just broadcasted
+    // Consolidate all of those here to ensure they aren't missed by an oversight
+    // 27, 33, 41, 46, 60, 64
+    self.round_mut().step = data.step();
+
+    // Only return a message to if we're actually a current validator
+    self.validator_id.map(|validator_id| Message {
+      sender: validator_id,
+      block: self.number,
+      round: self.round().number,
+      data,
+    })
+  }
+}