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// Copyright (C) 2019-2023 Aleo Systems Inc.
// This file is part of the snarkVM library.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at:
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use super::*;
impl<N: Network, C: ConsensusStorage<N>> Ledger<N, C> {
/// Returns a candidate for the next block in the ledger, using a committed subdag and its transmissions.
pub fn prepare_advance_to_next_quorum_block(
&self,
subdag: Subdag<N>,
transmissions: IndexMap<TransmissionID<N>, Transmission<N>>,
) -> Result<Block<N>> {
// Retrieve the latest block as the previous block (for the next block).
let previous_block = self.latest_block();
// Decouple the transmissions into ratifications, solutions, and transactions.
let (ratifications, solutions, transactions) = decouple_transmissions(transmissions.into_iter())?;
// Currently, we do not support ratifications from the memory pool.
ensure!(ratifications.is_empty(), "Ratifications are currently unsupported from the memory pool");
// Construct the block template.
let (header, ratifications, solutions, transactions, aborted_transaction_ids) =
self.construct_block_template(&previous_block, Some(&subdag), ratifications, solutions, transactions)?;
// Construct the new quorum block.
Block::new_quorum(
previous_block.hash(),
header,
subdag,
ratifications,
solutions,
transactions,
aborted_transaction_ids,
)
}
/// Returns a candidate for the next block in the ledger.
pub fn prepare_advance_to_next_beacon_block<R: Rng + CryptoRng>(
&self,
private_key: &PrivateKey<N>,
candidate_ratifications: Vec<Ratify<N>>,
candidate_solutions: Vec<ProverSolution<N>>,
candidate_transactions: Vec<Transaction<N>>,
rng: &mut R,
) -> Result<Block<N>> {
// Currently, we do not support ratifications from the memory pool.
ensure!(candidate_ratifications.is_empty(), "Ratifications are currently unsupported from the memory pool");
// Retrieve the latest block as the previous block (for the next block).
let previous_block = self.latest_block();
// Construct the block template.
let (header, ratifications, solutions, transactions, aborted_transaction_ids) = self.construct_block_template(
&previous_block,
None,
candidate_ratifications,
candidate_solutions,
candidate_transactions,
)?;
// Construct the new beacon block.
Block::new_beacon(
private_key,
previous_block.hash(),
header,
ratifications,
solutions,
transactions,
aborted_transaction_ids,
rng,
)
}
/// Adds the given block as the next block in the ledger.
pub fn advance_to_next_block(&self, block: &Block<N>) -> Result<()> {
// Acquire the write lock on the current block.
let mut current_block = self.current_block.write();
// Update the VM.
self.vm.add_next_block(block)?;
// Update the current block.
*current_block = block.clone();
// Drop the write lock on the current block.
drop(current_block);
// Update the cached committee from storage.
if let Ok(current_committee) = self.vm.finalize_store().committee_store().current_committee() {
*self.current_committee.write() = Some(current_committee);
}
// If the block is the start of a new epoch, or the epoch challenge has not been set, update the current epoch challenge.
if block.height() % N::NUM_BLOCKS_PER_EPOCH == 0 || self.current_epoch_challenge.read().is_none() {
// Update the current epoch challenge.
self.current_epoch_challenge.write().clone_from(&self.get_epoch_challenge(block.height()).ok());
}
Ok(())
}
}
impl<N: Network, C: ConsensusStorage<N>> Ledger<N, C> {
/// Constructs a block template for the next block in the ledger.
#[allow(clippy::type_complexity)]
fn construct_block_template(
&self,
previous_block: &Block<N>,
subdag: Option<&Subdag<N>>,
candidate_ratifications: Vec<Ratify<N>>,
candidate_solutions: Vec<ProverSolution<N>>,
candidate_transactions: Vec<Transaction<N>>,
) -> Result<(Header<N>, Ratifications<N>, Option<CoinbaseSolution<N>>, Transactions<N>, Vec<N::TransactionID>)>
{
// Construct the solutions.
let (solutions, solutions_root, combined_proof_target) = match candidate_solutions.is_empty() {
true => (None, Field::<N>::zero(), 0u128),
false => {
// Retrieve the coinbase verifying key.
let coinbase_verifying_key = self.coinbase_puzzle.coinbase_verifying_key();
// Retrieve the latest epoch challenge.
let latest_epoch_challenge = self.latest_epoch_challenge()?;
// TODO: For mainnet - Add `aborted_solution_ids` to the block. And optimize this logic.
// Verify the candidate solutions.
let verification_results: Vec<_> = cfg_into_iter!(candidate_solutions)
.map(|solution| {
(
solution,
solution
.verify(coinbase_verifying_key, &latest_epoch_challenge, self.latest_proof_target())
.unwrap_or(false),
)
})
.collect();
// Separate the candidate solutions into valid and aborted solutions.
let mut valid_candidate_solutions = Vec::with_capacity(N::MAX_SOLUTIONS);
let mut aborted_candidate_solutions = Vec::new();
for (solution, is_valid) in verification_results.into_iter() {
if is_valid && valid_candidate_solutions.len() < N::MAX_SOLUTIONS {
valid_candidate_solutions.push(solution);
} else {
aborted_candidate_solutions.push(solution);
}
}
// Check if there are any valid solutions.
match valid_candidate_solutions.is_empty() {
true => (None, Field::<N>::zero(), 0u128),
false => {
// Construct the solutions.
let solutions = CoinbaseSolution::new(valid_candidate_solutions)?;
// Compute the solutions root.
let solutions_root = solutions.to_accumulator_point()?;
// Compute the combined proof target.
let combined_proof_target = solutions.to_combined_proof_target()?;
// Output the solutions, solutions root, and combined proof target.
(Some(solutions), solutions_root, combined_proof_target)
}
}
}
};
// Retrieve the latest state root.
let latest_state_root = self.latest_state_root();
// Retrieve the latest cumulative proof target.
let latest_cumulative_proof_target = previous_block.cumulative_proof_target();
// Retrieve the latest coinbase target.
let latest_coinbase_target = previous_block.coinbase_target();
// Compute the next round number.
let next_round = match subdag {
Some(subdag) => subdag.anchor_round(),
None => previous_block.round().saturating_add(1),
};
// Compute the next height.
let next_height = previous_block.height().saturating_add(1);
// Determine the timestamp for the next block.
let next_timestamp = match subdag {
Some(subdag) => subdag.timestamp(),
None => OffsetDateTime::now_utc().unix_timestamp(),
};
// Compute the next cumulative weight.
let next_cumulative_weight = previous_block.cumulative_weight().saturating_add(combined_proof_target);
// Compute the next cumulative proof target.
let next_cumulative_proof_target = latest_cumulative_proof_target.saturating_add(combined_proof_target);
// Determine if the coinbase target is reached.
let is_coinbase_target_reached = next_cumulative_proof_target >= latest_coinbase_target as u128;
// Update the next cumulative proof target, if necessary.
let next_cumulative_proof_target = match is_coinbase_target_reached {
true => 0,
false => next_cumulative_proof_target,
};
// Construct the next coinbase target.
let next_coinbase_target = coinbase_target(
previous_block.last_coinbase_target(),
previous_block.last_coinbase_timestamp(),
next_timestamp,
N::ANCHOR_TIME,
N::NUM_BLOCKS_PER_EPOCH,
N::GENESIS_COINBASE_TARGET,
)?;
// Construct the next proof target.
let next_proof_target = proof_target(next_coinbase_target, N::GENESIS_PROOF_TARGET);
// Construct the next last coinbase target and next last coinbase timestamp.
let (next_last_coinbase_target, next_last_coinbase_timestamp) = match is_coinbase_target_reached {
true => (next_coinbase_target, next_timestamp),
false => (previous_block.last_coinbase_target(), previous_block.last_coinbase_timestamp()),
};
// Calculate the coinbase reward.
let coinbase_reward = coinbase_reward(
next_height,
N::STARTING_SUPPLY,
N::ANCHOR_HEIGHT,
N::BLOCK_TIME,
combined_proof_target,
u64::try_from(latest_cumulative_proof_target)?,
latest_coinbase_target,
)?;
// Construct the finalize state.
let state = FinalizeGlobalState::new::<N>(
next_round,
next_height,
next_cumulative_weight,
next_cumulative_proof_target,
previous_block.hash(),
)?;
// Speculate over the ratifications, solutions, and transactions.
let (ratifications, transactions, aborted_transaction_ids, ratified_finalize_operations) = self.vm.speculate(
state,
Some(coinbase_reward),
candidate_ratifications,
solutions.as_ref(),
candidate_transactions.iter(),
)?;
// Compute the ratifications root.
let ratifications_root = ratifications.to_ratifications_root()?;
// Construct the subdag root.
let subdag_root = match subdag {
Some(subdag) => subdag.to_subdag_root()?,
None => Field::zero(),
};
// Construct the metadata.
let metadata = Metadata::new(
N::ID,
next_round,
next_height,
next_cumulative_weight,
next_cumulative_proof_target,
next_coinbase_target,
next_proof_target,
next_last_coinbase_target,
next_last_coinbase_timestamp,
next_timestamp,
)?;
// Construct the header.
let header = Header::from(
latest_state_root,
transactions.to_transactions_root()?,
transactions.to_finalize_root(ratified_finalize_operations)?,
ratifications_root,
solutions_root,
subdag_root,
metadata,
)?;
// Return the block template.
Ok((header, ratifications, solutions, transactions, aborted_transaction_ids))
}
}