1003 lines
39 KiB
Rust
1003 lines
39 KiB
Rust
//! Chain that is a part of the non-finalized state.
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use std::{
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cmp::Ordering,
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collections::{BTreeMap, HashMap, HashSet},
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ops::Deref,
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};
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use mset::MultiSet;
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use tracing::instrument;
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use zebra_chain::{
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amount::{NegativeAllowed, NonNegative},
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block,
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history_tree::HistoryTree,
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orchard,
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parameters::Network,
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primitives::Groth16Proof,
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sapling, sprout, transaction,
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transaction::Transaction::*,
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transparent,
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value_balance::ValueBalance,
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work::difficulty::PartialCumulativeWork,
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};
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use crate::{service::check, ContextuallyValidBlock, ValidateContextError};
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#[derive(Debug, Clone)]
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pub struct Chain {
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// The function `eq_internal_state` must be updated every time a field is added to `Chain`.
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network: Network,
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/// The contextually valid blocks which form this non-finalized partial chain, in height order.
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pub(crate) blocks: BTreeMap<block::Height, ContextuallyValidBlock>,
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/// An index of block heights for each block hash in `blocks`.
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pub height_by_hash: HashMap<block::Hash, block::Height>,
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/// An index of block heights and transaction indexes for each transaction hash in `blocks`.
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pub tx_by_hash: HashMap<transaction::Hash, (block::Height, usize)>,
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/// The [`Utxo`]s created by `blocks`.
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///
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/// Note that these UTXOs may not be unspent.
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/// Outputs can be spent by later transactions or blocks in the chain.
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pub(crate) created_utxos: HashMap<transparent::OutPoint, transparent::Utxo>,
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/// The [`OutPoint`]s spent by `blocks`,
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/// including those created by earlier transactions or blocks in the chain.
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pub(crate) spent_utxos: HashSet<transparent::OutPoint>,
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/// The Sprout note commitment tree of the tip of this `Chain`,
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/// including all finalized notes, and the non-finalized notes in this chain.
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pub(super) sprout_note_commitment_tree: sprout::tree::NoteCommitmentTree,
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/// The Sapling note commitment tree of the tip of this `Chain`,
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/// including all finalized notes, and the non-finalized notes in this chain.
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pub(super) sapling_note_commitment_tree: sapling::tree::NoteCommitmentTree,
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/// The Orchard note commitment tree of the tip of this `Chain`,
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/// including all finalized notes, and the non-finalized notes in this chain.
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pub(super) orchard_note_commitment_tree: orchard::tree::NoteCommitmentTree,
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/// The ZIP-221 history tree of the tip of this `Chain`,
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/// including all finalized blocks, and the non-finalized `blocks` in this chain.
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pub(crate) history_tree: HistoryTree,
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/// The Sprout anchors created by `blocks`.
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pub(crate) sprout_anchors: MultiSet<sprout::tree::Root>,
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/// The Sprout anchors created by each block in `blocks`.
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pub(crate) sprout_anchors_by_height: BTreeMap<block::Height, sprout::tree::Root>,
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/// The Sprout note commitment tree for each anchor.
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/// This is required for interstitial states.
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pub(crate) sprout_trees_by_anchor:
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HashMap<sprout::tree::Root, sprout::tree::NoteCommitmentTree>,
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/// The Sapling anchors created by `blocks`.
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pub(crate) sapling_anchors: MultiSet<sapling::tree::Root>,
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/// The Sapling anchors created by each block in `blocks`.
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pub(crate) sapling_anchors_by_height: BTreeMap<block::Height, sapling::tree::Root>,
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/// The Orchard anchors created by `blocks`.
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pub(crate) orchard_anchors: MultiSet<orchard::tree::Root>,
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/// The Orchard anchors created by each block in `blocks`.
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pub(crate) orchard_anchors_by_height: BTreeMap<block::Height, orchard::tree::Root>,
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/// The Sprout nullifiers revealed by `blocks`.
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pub(super) sprout_nullifiers: HashSet<sprout::Nullifier>,
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/// The Sapling nullifiers revealed by `blocks`.
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pub(super) sapling_nullifiers: HashSet<sapling::Nullifier>,
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/// The Orchard nullifiers revealed by `blocks`.
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pub(super) orchard_nullifiers: HashSet<orchard::Nullifier>,
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/// The cumulative work represented by `blocks`.
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///
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/// Since the best chain is determined by the largest cumulative work,
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/// the work represented by finalized blocks can be ignored,
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/// because they are common to all non-finalized chains.
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pub(super) partial_cumulative_work: PartialCumulativeWork,
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/// The chain value pool balances of the tip of this `Chain`,
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/// including the block value pool changes from all finalized blocks,
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/// and the non-finalized blocks in this chain.
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///
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/// When a new chain is created from the finalized tip,
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/// it is initialized with the finalized tip chain value pool balances.
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pub(crate) chain_value_pools: ValueBalance<NonNegative>,
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}
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impl Chain {
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/// Create a new Chain with the given trees and network.
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pub(crate) fn new(
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network: Network,
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sprout_note_commitment_tree: sprout::tree::NoteCommitmentTree,
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sapling_note_commitment_tree: sapling::tree::NoteCommitmentTree,
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orchard_note_commitment_tree: orchard::tree::NoteCommitmentTree,
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history_tree: HistoryTree,
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finalized_tip_chain_value_pools: ValueBalance<NonNegative>,
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) -> Self {
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Self {
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network,
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blocks: Default::default(),
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height_by_hash: Default::default(),
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tx_by_hash: Default::default(),
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created_utxos: Default::default(),
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sprout_note_commitment_tree,
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sapling_note_commitment_tree,
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orchard_note_commitment_tree,
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spent_utxos: Default::default(),
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sprout_anchors: MultiSet::new(),
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sprout_anchors_by_height: Default::default(),
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sprout_trees_by_anchor: Default::default(),
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sapling_anchors: MultiSet::new(),
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sapling_anchors_by_height: Default::default(),
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orchard_anchors: MultiSet::new(),
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orchard_anchors_by_height: Default::default(),
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sprout_nullifiers: Default::default(),
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sapling_nullifiers: Default::default(),
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orchard_nullifiers: Default::default(),
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partial_cumulative_work: Default::default(),
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history_tree,
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chain_value_pools: finalized_tip_chain_value_pools,
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}
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}
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/// Is the internal state of `self` the same as `other`?
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///
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/// [`Chain`] has custom [`Eq`] and [`Ord`] implementations based on proof of work,
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/// which are used to select the best chain. So we can't derive [`Eq`] for [`Chain`].
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///
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/// Unlike the custom trait impls, this method returns `true` if the entire internal state
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/// of two chains is equal.
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///
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/// If the internal states are different, it returns `false`,
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/// even if the blocks in the two chains are equal.
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#[cfg(test)]
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pub(crate) fn eq_internal_state(&self, other: &Chain) -> bool {
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use zebra_chain::history_tree::NonEmptyHistoryTree;
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// blocks, heights, hashes
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self.blocks == other.blocks &&
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self.height_by_hash == other.height_by_hash &&
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self.tx_by_hash == other.tx_by_hash &&
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// transparent UTXOs
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self.created_utxos == other.created_utxos &&
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self.spent_utxos == other.spent_utxos &&
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// note commitment trees
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self.sprout_note_commitment_tree.root() == other.sprout_note_commitment_tree.root() &&
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self.sprout_trees_by_anchor == other.sprout_trees_by_anchor &&
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self.sapling_note_commitment_tree.root() == other.sapling_note_commitment_tree.root() &&
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self.orchard_note_commitment_tree.root() == other.orchard_note_commitment_tree.root() &&
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// history tree
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self.history_tree.as_ref().map(NonEmptyHistoryTree::hash) == other.history_tree.as_ref().map(NonEmptyHistoryTree::hash) &&
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// anchors
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self.sprout_anchors == other.sprout_anchors &&
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self.sprout_anchors_by_height == other.sprout_anchors_by_height &&
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self.sapling_anchors == other.sapling_anchors &&
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self.sapling_anchors_by_height == other.sapling_anchors_by_height &&
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self.orchard_anchors == other.orchard_anchors &&
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self.orchard_anchors_by_height == other.orchard_anchors_by_height &&
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// nullifiers
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self.sprout_nullifiers == other.sprout_nullifiers &&
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self.sapling_nullifiers == other.sapling_nullifiers &&
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self.orchard_nullifiers == other.orchard_nullifiers &&
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// proof of work
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self.partial_cumulative_work == other.partial_cumulative_work &&
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// chain value pool balances
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self.chain_value_pools == other.chain_value_pools
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}
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/// Push a contextually valid non-finalized block into this chain as the new tip.
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///
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/// If the block is invalid, drop this chain and return an error.
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///
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/// Note: a [`ContextuallyValidBlock`] isn't actually contextually valid until
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/// [`update_chain_state_with`] returns success.
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#[instrument(level = "debug", skip(self, block), fields(block = %block.block))]
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pub fn push(mut self, block: ContextuallyValidBlock) -> Result<Chain, ValidateContextError> {
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// update cumulative data members
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self.update_chain_tip_with(&block)?;
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tracing::debug!(block = %block.block, "adding block to chain");
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self.blocks.insert(block.height, block);
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Ok(self)
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}
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/// Remove the lowest height block of the non-finalized portion of a chain.
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#[instrument(level = "debug", skip(self))]
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pub(crate) fn pop_root(&mut self) -> ContextuallyValidBlock {
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let block_height = self.lowest_height();
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// remove the lowest height block from self.blocks
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let block = self
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.blocks
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.remove(&block_height)
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.expect("only called while blocks is populated");
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// update cumulative data members
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self.revert_chain_with(&block, RevertPosition::Root);
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// return the prepared block
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block
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}
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fn lowest_height(&self) -> block::Height {
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self.blocks
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.keys()
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.next()
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.cloned()
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.expect("only called while blocks is populated")
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}
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/// Fork a chain at the block with the given hash, if it is part of this
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/// chain.
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///
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/// The trees must match the trees of the finalized tip and are used
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/// to rebuild them after the fork.
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pub fn fork(
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&self,
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fork_tip: block::Hash,
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sprout_note_commitment_tree: sprout::tree::NoteCommitmentTree,
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sapling_note_commitment_tree: sapling::tree::NoteCommitmentTree,
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orchard_note_commitment_tree: orchard::tree::NoteCommitmentTree,
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history_tree: HistoryTree,
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) -> Result<Option<Self>, ValidateContextError> {
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if !self.height_by_hash.contains_key(&fork_tip) {
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return Ok(None);
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}
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let mut forked = self.with_trees(
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sprout_note_commitment_tree,
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sapling_note_commitment_tree,
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orchard_note_commitment_tree,
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history_tree,
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);
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while forked.non_finalized_tip_hash() != fork_tip {
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forked.pop_tip();
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}
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// Rebuild the note commitment trees, starting from the finalized tip tree.
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// TODO: change to a more efficient approach by removing nodes
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// from the tree of the original chain (in `pop_tip()`).
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// See https://github.com/ZcashFoundation/zebra/issues/2378
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for block in forked.blocks.values() {
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for transaction in block.block.transactions.iter() {
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for sprout_note_commitment in transaction.sprout_note_commitments() {
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forked
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.sprout_note_commitment_tree
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.append(*sprout_note_commitment)
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.expect("must work since it was already appended before the fork");
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}
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for sapling_note_commitment in transaction.sapling_note_commitments() {
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forked
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.sapling_note_commitment_tree
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.append(*sapling_note_commitment)
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.expect("must work since it was already appended before the fork");
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}
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for orchard_note_commitment in transaction.orchard_note_commitments() {
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forked
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.orchard_note_commitment_tree
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.append(*orchard_note_commitment)
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.expect("must work since it was already appended before the fork");
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}
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}
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// Note that anchors don't need to be recreated since they are already
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// handled in revert_chain_state_with.
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let sapling_root = forked
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.sapling_anchors_by_height
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.get(&block.height)
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.expect("Sapling anchors must exist for pre-fork blocks");
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let orchard_root = forked
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.orchard_anchors_by_height
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.get(&block.height)
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.expect("Orchard anchors must exist for pre-fork blocks");
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forked.history_tree.push(
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self.network,
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block.block.clone(),
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*sapling_root,
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*orchard_root,
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)?;
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}
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Ok(Some(forked))
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}
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pub fn non_finalized_tip_hash(&self) -> block::Hash {
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self.blocks
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.values()
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.next_back()
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.expect("only called while blocks is populated")
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.hash
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}
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/// Remove the highest height block of the non-finalized portion of a chain.
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fn pop_tip(&mut self) {
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let block_height = self.non_finalized_tip_height();
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let block = self
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.blocks
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.remove(&block_height)
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.expect("only called while blocks is populated");
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assert!(
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!self.blocks.is_empty(),
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"Non-finalized chains must have at least one block to be valid"
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);
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self.revert_chain_with(&block, RevertPosition::Tip);
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}
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/// Return the non-finalized tip height for this chain.
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///
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/// # Panics
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///
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/// Panics if called while the chain is empty,
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/// or while the chain is updating its internal state with the first block.
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pub fn non_finalized_tip_height(&self) -> block::Height {
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self.max_block_height()
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.expect("only called while blocks is populated")
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}
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/// Return the non-finalized tip height for this chain,
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/// or `None` if `self.blocks` is empty.
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fn max_block_height(&self) -> Option<block::Height> {
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self.blocks.keys().next_back().cloned()
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}
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pub fn is_empty(&self) -> bool {
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self.blocks.is_empty()
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}
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/// Returns the unspent transaction outputs (UTXOs) in this non-finalized chain.
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///
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/// Callers should also check the finalized state for available UTXOs.
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/// If UTXOs remain unspent when a block is finalized, they are stored in the finalized state,
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/// and removed from the relevant chain(s).
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pub fn unspent_utxos(&self) -> HashMap<transparent::OutPoint, transparent::Utxo> {
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let mut unspent_utxos = self.created_utxos.clone();
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unspent_utxos.retain(|out_point, _utxo| !self.spent_utxos.contains(out_point));
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unspent_utxos
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}
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/// Clone the Chain but not the history and note commitment trees, using
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/// the specified trees instead.
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///
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/// Useful when forking, where the trees are rebuilt anyway.
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fn with_trees(
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&self,
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sprout_note_commitment_tree: sprout::tree::NoteCommitmentTree,
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sapling_note_commitment_tree: sapling::tree::NoteCommitmentTree,
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orchard_note_commitment_tree: orchard::tree::NoteCommitmentTree,
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history_tree: HistoryTree,
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) -> Self {
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Chain {
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network: self.network,
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blocks: self.blocks.clone(),
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height_by_hash: self.height_by_hash.clone(),
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tx_by_hash: self.tx_by_hash.clone(),
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created_utxos: self.created_utxos.clone(),
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spent_utxos: self.spent_utxos.clone(),
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sprout_note_commitment_tree,
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sapling_note_commitment_tree,
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orchard_note_commitment_tree,
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sprout_anchors: self.sprout_anchors.clone(),
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sapling_anchors: self.sapling_anchors.clone(),
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orchard_anchors: self.orchard_anchors.clone(),
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sprout_trees_by_anchor: self.sprout_trees_by_anchor.clone(),
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sprout_anchors_by_height: self.sprout_anchors_by_height.clone(),
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sapling_anchors_by_height: self.sapling_anchors_by_height.clone(),
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orchard_anchors_by_height: self.orchard_anchors_by_height.clone(),
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sprout_nullifiers: self.sprout_nullifiers.clone(),
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sapling_nullifiers: self.sapling_nullifiers.clone(),
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orchard_nullifiers: self.orchard_nullifiers.clone(),
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partial_cumulative_work: self.partial_cumulative_work,
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history_tree,
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chain_value_pools: self.chain_value_pools,
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}
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}
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}
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/// The revert position being performed on a chain.
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#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
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enum RevertPosition {
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/// The chain root is being reverted via [`pop_root`],
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/// when a block is finalized.
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Root,
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/// The chain tip is being reverted via [`pop_tip`],
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/// when a chain is forked.
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Tip,
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}
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|
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/// Helper trait to organize inverse operations done on the `Chain` type.
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///
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/// Used to overload update and revert methods, based on the type of the argument,
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/// and the position of the removed block in the chain.
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///
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/// This trait was motivated by the length of the `push`, `pop_root`, and `pop_tip` functions,
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/// and fear that it would be easy to introduce bugs when updating them,
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/// unless the code was reorganized to keep related operations adjacent to each other.
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trait UpdateWith<T> {
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/// When `T` is added to the chain tip,
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/// update `Chain` cumulative data members to add data that are derived from `T`.
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fn update_chain_tip_with(&mut self, _: &T) -> Result<(), ValidateContextError>;
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/// When `T` is removed from `position` in the chain,
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/// revert `Chain` cumulative data members to remove data that are derived from `T`.
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fn revert_chain_with(&mut self, _: &T, position: RevertPosition);
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}
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impl UpdateWith<ContextuallyValidBlock> for Chain {
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#[instrument(skip(self, contextually_valid), fields(block = %contextually_valid.block))]
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fn update_chain_tip_with(
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&mut self,
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contextually_valid: &ContextuallyValidBlock,
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) -> Result<(), ValidateContextError> {
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let (block, hash, height, new_outputs, transaction_hashes, chain_value_pool_change) = (
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contextually_valid.block.as_ref(),
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contextually_valid.hash,
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contextually_valid.height,
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&contextually_valid.new_outputs,
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&contextually_valid.transaction_hashes,
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&contextually_valid.chain_value_pool_change,
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);
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|
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// add hash to height_by_hash
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|
let prior_height = self.height_by_hash.insert(hash, height);
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assert!(
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prior_height.is_none(),
|
|
"block heights must be unique within a single chain"
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);
|
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|
|
// add work to partial cumulative work
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|
let block_work = block
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.header
|
|
.difficulty_threshold
|
|
.to_work()
|
|
.expect("work has already been validated");
|
|
self.partial_cumulative_work += block_work;
|
|
|
|
// for each transaction in block
|
|
for (transaction_index, (transaction, transaction_hash)) in block
|
|
.transactions
|
|
.iter()
|
|
.zip(transaction_hashes.iter().cloned())
|
|
.enumerate()
|
|
{
|
|
let (
|
|
inputs,
|
|
joinsplit_data,
|
|
sapling_shielded_data_per_spend_anchor,
|
|
sapling_shielded_data_shared_anchor,
|
|
orchard_shielded_data,
|
|
) = match transaction.deref() {
|
|
V4 {
|
|
inputs,
|
|
joinsplit_data,
|
|
sapling_shielded_data,
|
|
..
|
|
} => (inputs, joinsplit_data, sapling_shielded_data, &None, &None),
|
|
V5 {
|
|
inputs,
|
|
sapling_shielded_data,
|
|
orchard_shielded_data,
|
|
..
|
|
} => (
|
|
inputs,
|
|
&None,
|
|
&None,
|
|
sapling_shielded_data,
|
|
orchard_shielded_data,
|
|
),
|
|
V1 { .. } | V2 { .. } | V3 { .. } => unreachable!(
|
|
"older transaction versions only exist in finalized blocks, because of the mandatory canopy checkpoint",
|
|
),
|
|
};
|
|
|
|
// add key `transaction.hash` and value `(height, tx_index)` to `tx_by_hash`
|
|
let prior_pair = self
|
|
.tx_by_hash
|
|
.insert(transaction_hash, (height, transaction_index));
|
|
assert!(
|
|
prior_pair.is_none(),
|
|
"transactions must be unique within a single chain"
|
|
);
|
|
|
|
// add the utxos this produced
|
|
self.update_chain_tip_with(new_outputs)?;
|
|
// add the utxos this consumed
|
|
self.update_chain_tip_with(inputs)?;
|
|
|
|
// add the shielded data
|
|
self.update_chain_tip_with(joinsplit_data)?;
|
|
self.update_chain_tip_with(sapling_shielded_data_per_spend_anchor)?;
|
|
self.update_chain_tip_with(sapling_shielded_data_shared_anchor)?;
|
|
self.update_chain_tip_with(orchard_shielded_data)?;
|
|
}
|
|
|
|
// Having updated all the note commitment trees and nullifier sets in
|
|
// this block, the roots of the note commitment trees as of the last
|
|
// transaction are the treestates of this block.
|
|
let sprout_root = self.sprout_note_commitment_tree.root();
|
|
self.sprout_anchors.insert(sprout_root);
|
|
self.sprout_anchors_by_height.insert(height, sprout_root);
|
|
self.sprout_trees_by_anchor
|
|
.insert(sprout_root, self.sprout_note_commitment_tree.clone());
|
|
let sapling_root = self.sapling_note_commitment_tree.root();
|
|
self.sapling_anchors.insert(sapling_root);
|
|
self.sapling_anchors_by_height.insert(height, sapling_root);
|
|
|
|
let orchard_root = self.orchard_note_commitment_tree.root();
|
|
self.orchard_anchors.insert(orchard_root);
|
|
self.orchard_anchors_by_height.insert(height, orchard_root);
|
|
|
|
self.history_tree.push(
|
|
self.network,
|
|
contextually_valid.block.clone(),
|
|
sapling_root,
|
|
orchard_root,
|
|
)?;
|
|
|
|
// update the chain value pool balances
|
|
self.update_chain_tip_with(chain_value_pool_change)?;
|
|
|
|
Ok(())
|
|
}
|
|
|
|
#[instrument(skip(self, contextually_valid), fields(block = %contextually_valid.block))]
|
|
fn revert_chain_with(
|
|
&mut self,
|
|
contextually_valid: &ContextuallyValidBlock,
|
|
position: RevertPosition,
|
|
) {
|
|
let (block, hash, height, new_outputs, transaction_hashes, chain_value_pool_change) = (
|
|
contextually_valid.block.as_ref(),
|
|
contextually_valid.hash,
|
|
contextually_valid.height,
|
|
&contextually_valid.new_outputs,
|
|
&contextually_valid.transaction_hashes,
|
|
&contextually_valid.chain_value_pool_change,
|
|
);
|
|
|
|
// remove the blocks hash from `height_by_hash`
|
|
assert!(
|
|
self.height_by_hash.remove(&hash).is_some(),
|
|
"hash must be present if block was added to chain"
|
|
);
|
|
|
|
// remove work from partial_cumulative_work
|
|
let block_work = block
|
|
.header
|
|
.difficulty_threshold
|
|
.to_work()
|
|
.expect("work has already been validated");
|
|
self.partial_cumulative_work -= block_work;
|
|
|
|
// Note: the history tree is not modified in this method.
|
|
// This method is called on two scenarios:
|
|
// - When popping the root: the history tree does not change.
|
|
// - When popping the tip: the history tree is rebuilt in fork().
|
|
|
|
// for each transaction in block
|
|
for (transaction, transaction_hash) in
|
|
block.transactions.iter().zip(transaction_hashes.iter())
|
|
{
|
|
let (
|
|
inputs,
|
|
joinsplit_data,
|
|
sapling_shielded_data_per_spend_anchor,
|
|
sapling_shielded_data_shared_anchor,
|
|
orchard_shielded_data,
|
|
) = match transaction.deref() {
|
|
V4 {
|
|
inputs,
|
|
joinsplit_data,
|
|
sapling_shielded_data,
|
|
..
|
|
} => (inputs, joinsplit_data, sapling_shielded_data, &None, &None),
|
|
V5 {
|
|
inputs,
|
|
sapling_shielded_data,
|
|
orchard_shielded_data,
|
|
..
|
|
} => (
|
|
inputs,
|
|
&None,
|
|
&None,
|
|
sapling_shielded_data,
|
|
orchard_shielded_data,
|
|
),
|
|
V1 { .. } | V2 { .. } | V3 { .. } => unreachable!(
|
|
"older transaction versions only exist in finalized blocks, because of the mandatory canopy checkpoint",
|
|
),
|
|
};
|
|
|
|
// remove `transaction.hash` from `tx_by_hash`
|
|
assert!(
|
|
self.tx_by_hash.remove(transaction_hash).is_some(),
|
|
"transactions must be present if block was added to chain"
|
|
);
|
|
|
|
// remove the utxos this produced
|
|
self.revert_chain_with(new_outputs, position);
|
|
// remove the utxos this consumed
|
|
self.revert_chain_with(inputs, position);
|
|
|
|
// remove the shielded data
|
|
self.revert_chain_with(joinsplit_data, position);
|
|
self.revert_chain_with(sapling_shielded_data_per_spend_anchor, position);
|
|
self.revert_chain_with(sapling_shielded_data_shared_anchor, position);
|
|
self.revert_chain_with(orchard_shielded_data, position);
|
|
}
|
|
|
|
let anchor = self
|
|
.sprout_anchors_by_height
|
|
.remove(&height)
|
|
.expect("Sprout anchor must be present if block was added to chain");
|
|
assert!(
|
|
self.sprout_anchors.remove(&anchor),
|
|
"Sprout anchor must be present if block was added to chain"
|
|
);
|
|
if !self.sprout_anchors.contains(&anchor) {
|
|
self.sprout_trees_by_anchor.remove(&anchor);
|
|
}
|
|
|
|
let anchor = self
|
|
.sapling_anchors_by_height
|
|
.remove(&height)
|
|
.expect("Sapling anchor must be present if block was added to chain");
|
|
assert!(
|
|
self.sapling_anchors.remove(&anchor),
|
|
"Sapling anchor must be present if block was added to chain"
|
|
);
|
|
|
|
let anchor = self
|
|
.orchard_anchors_by_height
|
|
.remove(&height)
|
|
.expect("Orchard anchor must be present if block was added to chain");
|
|
assert!(
|
|
self.orchard_anchors.remove(&anchor),
|
|
"Orchard anchor must be present if block was added to chain"
|
|
);
|
|
|
|
// revert the chain value pool balances, if needed
|
|
self.revert_chain_with(chain_value_pool_change, position);
|
|
}
|
|
}
|
|
|
|
impl UpdateWith<HashMap<transparent::OutPoint, transparent::Utxo>> for Chain {
|
|
fn update_chain_tip_with(
|
|
&mut self,
|
|
utxos: &HashMap<transparent::OutPoint, transparent::Utxo>,
|
|
) -> Result<(), ValidateContextError> {
|
|
self.created_utxos
|
|
.extend(utxos.iter().map(|(k, v)| (*k, v.clone())));
|
|
Ok(())
|
|
}
|
|
|
|
fn revert_chain_with(
|
|
&mut self,
|
|
utxos: &HashMap<transparent::OutPoint, transparent::Utxo>,
|
|
_position: RevertPosition,
|
|
) {
|
|
self.created_utxos
|
|
.retain(|outpoint, _| !utxos.contains_key(outpoint));
|
|
}
|
|
}
|
|
|
|
impl UpdateWith<Vec<transparent::Input>> for Chain {
|
|
fn update_chain_tip_with(
|
|
&mut self,
|
|
inputs: &Vec<transparent::Input>,
|
|
) -> Result<(), ValidateContextError> {
|
|
for consumed_utxo in inputs {
|
|
match consumed_utxo {
|
|
transparent::Input::PrevOut { outpoint, .. } => {
|
|
self.spent_utxos.insert(*outpoint);
|
|
}
|
|
transparent::Input::Coinbase { .. } => {}
|
|
}
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
fn revert_chain_with(&mut self, inputs: &Vec<transparent::Input>, _position: RevertPosition) {
|
|
for consumed_utxo in inputs {
|
|
match consumed_utxo {
|
|
transparent::Input::PrevOut { outpoint, .. } => {
|
|
assert!(
|
|
self.spent_utxos.remove(outpoint),
|
|
"spent_utxos must be present if block was added to chain"
|
|
);
|
|
}
|
|
transparent::Input::Coinbase { .. } => {}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
impl UpdateWith<Option<transaction::JoinSplitData<Groth16Proof>>> for Chain {
|
|
#[instrument(skip(self, joinsplit_data))]
|
|
fn update_chain_tip_with(
|
|
&mut self,
|
|
joinsplit_data: &Option<transaction::JoinSplitData<Groth16Proof>>,
|
|
) -> Result<(), ValidateContextError> {
|
|
if let Some(joinsplit_data) = joinsplit_data {
|
|
for cm in joinsplit_data.note_commitments() {
|
|
self.sprout_note_commitment_tree.append(*cm)?;
|
|
}
|
|
|
|
check::nullifier::add_to_non_finalized_chain_unique(
|
|
&mut self.sprout_nullifiers,
|
|
joinsplit_data.nullifiers(),
|
|
)?;
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
/// # Panics
|
|
///
|
|
/// Panics if any nullifier is missing from the chain when we try to remove it.
|
|
///
|
|
/// See [`check::nullifier::remove_from_non_finalized_chain`] for details.
|
|
#[instrument(skip(self, joinsplit_data))]
|
|
fn revert_chain_with(
|
|
&mut self,
|
|
joinsplit_data: &Option<transaction::JoinSplitData<Groth16Proof>>,
|
|
_position: RevertPosition,
|
|
) {
|
|
if let Some(joinsplit_data) = joinsplit_data {
|
|
check::nullifier::remove_from_non_finalized_chain(
|
|
&mut self.sprout_nullifiers,
|
|
joinsplit_data.nullifiers(),
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<AnchorV> UpdateWith<Option<sapling::ShieldedData<AnchorV>>> for Chain
|
|
where
|
|
AnchorV: sapling::AnchorVariant + Clone,
|
|
{
|
|
#[instrument(skip(self, sapling_shielded_data))]
|
|
fn update_chain_tip_with(
|
|
&mut self,
|
|
sapling_shielded_data: &Option<sapling::ShieldedData<AnchorV>>,
|
|
) -> Result<(), ValidateContextError> {
|
|
if let Some(sapling_shielded_data) = sapling_shielded_data {
|
|
// The `_u` here indicates that the Sapling note commitment is
|
|
// specified only by the `u`-coordinate of the Jubjub curve
|
|
// point `(u, v)`.
|
|
for cm_u in sapling_shielded_data.note_commitments() {
|
|
self.sapling_note_commitment_tree.append(*cm_u)?;
|
|
}
|
|
|
|
check::nullifier::add_to_non_finalized_chain_unique(
|
|
&mut self.sapling_nullifiers,
|
|
sapling_shielded_data.nullifiers(),
|
|
)?;
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
/// # Panics
|
|
///
|
|
/// Panics if any nullifier is missing from the chain when we try to remove it.
|
|
///
|
|
/// See [`check::nullifier::remove_from_non_finalized_chain`] for details.
|
|
#[instrument(skip(self, sapling_shielded_data))]
|
|
fn revert_chain_with(
|
|
&mut self,
|
|
sapling_shielded_data: &Option<sapling::ShieldedData<AnchorV>>,
|
|
_position: RevertPosition,
|
|
) {
|
|
if let Some(sapling_shielded_data) = sapling_shielded_data {
|
|
// Note commitments are not removed from the tree here because we
|
|
// don't support that operation yet. Instead, we recreate the tree
|
|
// from the finalized tip in NonFinalizedState.
|
|
|
|
check::nullifier::remove_from_non_finalized_chain(
|
|
&mut self.sapling_nullifiers,
|
|
sapling_shielded_data.nullifiers(),
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
impl UpdateWith<Option<orchard::ShieldedData>> for Chain {
|
|
#[instrument(skip(self, orchard_shielded_data))]
|
|
fn update_chain_tip_with(
|
|
&mut self,
|
|
orchard_shielded_data: &Option<orchard::ShieldedData>,
|
|
) -> Result<(), ValidateContextError> {
|
|
if let Some(orchard_shielded_data) = orchard_shielded_data {
|
|
for cm_x in orchard_shielded_data.note_commitments() {
|
|
self.orchard_note_commitment_tree.append(*cm_x)?;
|
|
}
|
|
|
|
check::nullifier::add_to_non_finalized_chain_unique(
|
|
&mut self.orchard_nullifiers,
|
|
orchard_shielded_data.nullifiers(),
|
|
)?;
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
/// # Panics
|
|
///
|
|
/// Panics if any nullifier is missing from the chain when we try to remove it.
|
|
///
|
|
/// See [`check::nullifier::remove_from_non_finalized_chain`] for details.
|
|
#[instrument(skip(self, orchard_shielded_data))]
|
|
fn revert_chain_with(
|
|
&mut self,
|
|
orchard_shielded_data: &Option<orchard::ShieldedData>,
|
|
_position: RevertPosition,
|
|
) {
|
|
if let Some(orchard_shielded_data) = orchard_shielded_data {
|
|
// Note commitments are not removed from the tree here because we
|
|
// don't support that operation yet. Instead, we recreate the tree
|
|
// from the finalized tip in NonFinalizedState.
|
|
|
|
check::nullifier::remove_from_non_finalized_chain(
|
|
&mut self.orchard_nullifiers,
|
|
orchard_shielded_data.nullifiers(),
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
impl UpdateWith<ValueBalance<NegativeAllowed>> for Chain {
|
|
fn update_chain_tip_with(
|
|
&mut self,
|
|
block_value_pool_change: &ValueBalance<NegativeAllowed>,
|
|
) -> Result<(), ValidateContextError> {
|
|
match self
|
|
.chain_value_pools
|
|
.add_chain_value_pool_change(*block_value_pool_change)
|
|
{
|
|
Ok(chain_value_pools) => self.chain_value_pools = chain_value_pools,
|
|
Err(value_balance_error) => Err(ValidateContextError::AddValuePool {
|
|
value_balance_error,
|
|
chain_value_pools: self.chain_value_pools,
|
|
block_value_pool_change: *block_value_pool_change,
|
|
// assume that the current block is added to `blocks` after `update_chain_tip_with`
|
|
height: self.max_block_height().and_then(|height| height + 1),
|
|
})?,
|
|
};
|
|
|
|
Ok(())
|
|
}
|
|
|
|
/// Revert the chain state using a block chain value pool change.
|
|
///
|
|
/// When forking from the tip, subtract the block's chain value pool change.
|
|
///
|
|
/// When finalizing the root, leave the chain value pool balances unchanged.
|
|
/// [`chain_value_pools`] tracks the chain value pools for all finalized blocks,
|
|
/// and the non-finalized blocks in this chain.
|
|
/// So finalizing the root doesn't change the set of blocks it tracks.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Panics if the chain pool value balance is invalid
|
|
/// after we subtract the block value pool change.
|
|
fn revert_chain_with(
|
|
&mut self,
|
|
block_value_pool_change: &ValueBalance<NegativeAllowed>,
|
|
position: RevertPosition,
|
|
) {
|
|
use std::ops::Neg;
|
|
|
|
if position == RevertPosition::Tip {
|
|
self.chain_value_pools = self
|
|
.chain_value_pools
|
|
.add_chain_value_pool_change(block_value_pool_change.neg())
|
|
.expect("reverting the tip will leave the pools in a previously valid state");
|
|
}
|
|
}
|
|
}
|
|
|
|
impl Ord for Chain {
|
|
/// Chain order for the [`NonFinalizedState`]'s `chain_set`.
|
|
/// Chains with higher cumulative Proof of Work are [`Ordering::Greater`],
|
|
/// breaking ties using the tip block hash.
|
|
///
|
|
/// Despite the consensus rules, Zebra uses the tip block hash as a tie-breaker.
|
|
/// Zebra blocks are downloaded in parallel, so download timestamps may not be unique.
|
|
/// (And Zebra currently doesn't track download times, because [`Block`]s are immutable.)
|
|
///
|
|
/// This departure from the consensus rules may delay network convergence,
|
|
/// for as long as the greater hash belongs to the later mined block.
|
|
/// But Zebra nodes should converge as soon as the tied work is broken.
|
|
///
|
|
/// "At a given point in time, each full validator is aware of a set of candidate blocks.
|
|
/// These form a tree rooted at the genesis block, where each node in the tree
|
|
/// refers to its parent via the hashPrevBlock block header field.
|
|
///
|
|
/// A path from the root toward the leaves of the tree consisting of a sequence
|
|
/// of one or more valid blocks consistent with consensus rules,
|
|
/// is called a valid block chain.
|
|
///
|
|
/// In order to choose the best valid block chain in its view of the overall block tree,
|
|
/// a node sums the work ... of all blocks in each valid block chain,
|
|
/// and considers the valid block chain with greatest total work to be best.
|
|
///
|
|
/// To break ties between leaf blocks, a node will prefer the block that it received first.
|
|
///
|
|
/// The consensus protocol is designed to ensure that for any given block height,
|
|
/// the vast majority of nodes should eventually agree on their best valid block chain
|
|
/// up to that height."
|
|
///
|
|
/// https://zips.z.cash/protocol/protocol.pdf#blockchain
|
|
///
|
|
/// # Correctness
|
|
///
|
|
/// `Chain::cmp` is used in a `BTreeSet`, so the fields accessed by `cmp` must not have
|
|
/// interior mutability.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// If two chains compare equal.
|
|
///
|
|
/// This panic enforces the `NonFinalizedState.chain_set` unique chain invariant.
|
|
///
|
|
/// If the chain set contains duplicate chains, the non-finalized state might
|
|
/// handle new blocks or block finalization incorrectly.
|
|
fn cmp(&self, other: &Self) -> Ordering {
|
|
if self.partial_cumulative_work != other.partial_cumulative_work {
|
|
self.partial_cumulative_work
|
|
.cmp(&other.partial_cumulative_work)
|
|
} else {
|
|
let self_hash = self
|
|
.blocks
|
|
.values()
|
|
.last()
|
|
.expect("always at least 1 element")
|
|
.hash;
|
|
|
|
let other_hash = other
|
|
.blocks
|
|
.values()
|
|
.last()
|
|
.expect("always at least 1 element")
|
|
.hash;
|
|
|
|
// This comparison is a tie-breaker within the local node, so it does not need to
|
|
// be consistent with the ordering on `ExpandedDifficulty` and `block::Hash`.
|
|
match self_hash.0.cmp(&other_hash.0) {
|
|
Ordering::Equal => unreachable!("Chain tip block hashes are always unique"),
|
|
ordering => ordering,
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
impl PartialOrd for Chain {
|
|
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
|
|
Some(self.cmp(other))
|
|
}
|
|
}
|
|
|
|
impl PartialEq for Chain {
|
|
/// Chain equality for the [`NonFinalizedState`]'s `chain_set`,
|
|
/// using proof of work, then the tip block hash as a tie-breaker.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// If two chains compare equal.
|
|
///
|
|
/// See [`Chain::cmp`] for details.
|
|
fn eq(&self, other: &Self) -> bool {
|
|
self.partial_cmp(other) == Some(Ordering::Equal)
|
|
}
|
|
}
|
|
|
|
impl Eq for Chain {}
|