761 lines
29 KiB
Rust
761 lines
29 KiB
Rust
use std::{
|
|
cmp::Ordering,
|
|
collections::{BTreeMap, HashMap, HashSet},
|
|
ops::Deref,
|
|
};
|
|
|
|
use multiset::HashMultiSet;
|
|
use tracing::instrument;
|
|
|
|
use zebra_chain::{
|
|
block, orchard, primitives::Groth16Proof, sapling, sprout, transaction,
|
|
transaction::Transaction::*, transparent, work::difficulty::PartialCumulativeWork,
|
|
};
|
|
|
|
use crate::{service::check, ContextuallyValidBlock, PreparedBlock, ValidateContextError};
|
|
|
|
#[derive(Debug, Clone)]
|
|
pub struct Chain {
|
|
/// The contextually valid blocks which form this non-finalized partial chain, in height order.
|
|
pub(crate) blocks: BTreeMap<block::Height, ContextuallyValidBlock>,
|
|
|
|
/// An index of block heights for each block hash in `blocks`.
|
|
pub height_by_hash: HashMap<block::Hash, block::Height>,
|
|
/// An index of block heights and transaction indexes for each transaction hash in `blocks`.
|
|
pub tx_by_hash: HashMap<transaction::Hash, (block::Height, usize)>,
|
|
|
|
/// The [`Utxo`]s created by `blocks`.
|
|
///
|
|
/// Note that these UTXOs may not be unspent.
|
|
/// Outputs can be spent by later transactions or blocks in the chain.
|
|
pub(crate) created_utxos: HashMap<transparent::OutPoint, transparent::Utxo>,
|
|
/// The [`OutPoint`]s spent by `blocks`,
|
|
/// including those created by earlier transactions or blocks in the chain.
|
|
pub(crate) spent_utxos: HashSet<transparent::OutPoint>,
|
|
|
|
/// The Sapling note commitment tree of the tip of this Chain.
|
|
pub(super) sapling_note_commitment_tree: sapling::tree::NoteCommitmentTree,
|
|
/// The Orchard note commitment tree of the tip of this Chain.
|
|
pub(super) orchard_note_commitment_tree: orchard::tree::NoteCommitmentTree,
|
|
|
|
/// The Sapling anchors created by `blocks`.
|
|
pub(super) sapling_anchors: HashMultiSet<sapling::tree::Root>,
|
|
/// The Sapling anchors created by each block in the chain.
|
|
pub(super) sapling_anchors_by_height: BTreeMap<block::Height, sapling::tree::Root>,
|
|
/// The Orchard anchors created by `blocks`.
|
|
pub(super) orchard_anchors: HashMultiSet<orchard::tree::Root>,
|
|
/// The Orchard anchors created by each block in the chain.
|
|
pub(super) orchard_anchors_by_height: BTreeMap<block::Height, orchard::tree::Root>,
|
|
|
|
/// The Sprout nullifiers revealed by `blocks`.
|
|
pub(super) sprout_nullifiers: HashSet<sprout::Nullifier>,
|
|
/// The Sapling nullifiers revealed by `blocks`.
|
|
pub(super) sapling_nullifiers: HashSet<sapling::Nullifier>,
|
|
/// The Orchard nullifiers revealed by `blocks`.
|
|
pub(super) orchard_nullifiers: HashSet<orchard::Nullifier>,
|
|
|
|
/// The cumulative work represented by this partial non-finalized chain.
|
|
pub(super) partial_cumulative_work: PartialCumulativeWork,
|
|
}
|
|
|
|
impl Chain {
|
|
// Create a new Chain with the given note commitment trees.
|
|
pub(crate) fn new(
|
|
sapling_note_commitment_tree: sapling::tree::NoteCommitmentTree,
|
|
orchard_note_commitment_tree: orchard::tree::NoteCommitmentTree,
|
|
) -> Self {
|
|
Self {
|
|
blocks: Default::default(),
|
|
height_by_hash: Default::default(),
|
|
tx_by_hash: Default::default(),
|
|
created_utxos: Default::default(),
|
|
sapling_note_commitment_tree,
|
|
orchard_note_commitment_tree,
|
|
spent_utxos: Default::default(),
|
|
sapling_anchors: HashMultiSet::new(),
|
|
sapling_anchors_by_height: Default::default(),
|
|
orchard_anchors: HashMultiSet::new(),
|
|
orchard_anchors_by_height: Default::default(),
|
|
sprout_nullifiers: Default::default(),
|
|
sapling_nullifiers: Default::default(),
|
|
orchard_nullifiers: Default::default(),
|
|
partial_cumulative_work: Default::default(),
|
|
}
|
|
}
|
|
|
|
/// Is the internal state of `self` the same as `other`?
|
|
///
|
|
/// [`Chain`] has custom [`Eq`] and [`Ord`] implementations based on proof of work,
|
|
/// which are used to select the best chain. So we can't derive [`Eq`] for [`Chain`].
|
|
///
|
|
/// Unlike the custom trait impls, this method returns `true` if the entire internal state
|
|
/// of two chains is equal.
|
|
///
|
|
/// If the internal states are different, it returns `false`,
|
|
/// even if the blocks in the two chains are equal.
|
|
#[cfg(test)]
|
|
pub(crate) fn eq_internal_state(&self, other: &Chain) -> bool {
|
|
// this method must be updated every time a field is added to Chain
|
|
|
|
// blocks, heights, hashes
|
|
self.blocks == other.blocks &&
|
|
self.height_by_hash == other.height_by_hash &&
|
|
self.tx_by_hash == other.tx_by_hash &&
|
|
|
|
// transparent UTXOs
|
|
self.created_utxos == other.created_utxos &&
|
|
self.spent_utxos == other.spent_utxos &&
|
|
|
|
// note commitment trees
|
|
self.sapling_note_commitment_tree.root() == other.sapling_note_commitment_tree.root() &&
|
|
self.orchard_note_commitment_tree.root() == other.orchard_note_commitment_tree.root() &&
|
|
|
|
// anchors
|
|
self.sapling_anchors == other.sapling_anchors &&
|
|
self.sapling_anchors_by_height == other.sapling_anchors_by_height &&
|
|
self.orchard_anchors == other.orchard_anchors &&
|
|
self.orchard_anchors_by_height == other.orchard_anchors_by_height &&
|
|
|
|
// nullifiers
|
|
self.sprout_nullifiers == other.sprout_nullifiers &&
|
|
self.sapling_nullifiers == other.sapling_nullifiers &&
|
|
self.orchard_nullifiers == other.orchard_nullifiers &&
|
|
|
|
// proof of work
|
|
self.partial_cumulative_work == other.partial_cumulative_work
|
|
}
|
|
|
|
/// Push a contextually valid non-finalized block into this chain as the new tip.
|
|
///
|
|
/// If the block is invalid, drop this chain and return an error.
|
|
#[instrument(level = "debug", skip(self, block), fields(block = %block.block))]
|
|
pub fn push(mut self, block: PreparedBlock) -> Result<Chain, ValidateContextError> {
|
|
// the block isn't contextually valid until `update_chain_state_with` returns success
|
|
let block = ContextuallyValidBlock::from(block);
|
|
|
|
// update cumulative data members
|
|
self.update_chain_state_with(&block)?;
|
|
tracing::debug!(block = %block.block, "adding block to chain");
|
|
self.blocks.insert(block.height, block);
|
|
Ok(self)
|
|
}
|
|
|
|
/// Remove the lowest height block of the non-finalized portion of a chain.
|
|
#[instrument(level = "debug", skip(self))]
|
|
pub(crate) fn pop_root(&mut self) -> ContextuallyValidBlock {
|
|
let block_height = self.lowest_height();
|
|
|
|
// remove the lowest height block from self.blocks
|
|
let block = self
|
|
.blocks
|
|
.remove(&block_height)
|
|
.expect("only called while blocks is populated");
|
|
|
|
// update cumulative data members
|
|
self.revert_chain_state_with(&block);
|
|
|
|
// return the prepared block
|
|
block
|
|
}
|
|
|
|
fn lowest_height(&self) -> block::Height {
|
|
self.blocks
|
|
.keys()
|
|
.next()
|
|
.cloned()
|
|
.expect("only called while blocks is populated")
|
|
}
|
|
|
|
/// Fork a chain at the block with the given hash, if it is part of this
|
|
/// chain.
|
|
///
|
|
/// The note commitment trees must be the trees of the finalized tip.
|
|
pub fn fork(
|
|
&self,
|
|
fork_tip: block::Hash,
|
|
sapling_note_commitment_tree: sapling::tree::NoteCommitmentTree,
|
|
orchard_note_commitment_tree: orchard::tree::NoteCommitmentTree,
|
|
) -> Result<Option<Self>, ValidateContextError> {
|
|
if !self.height_by_hash.contains_key(&fork_tip) {
|
|
return Ok(None);
|
|
}
|
|
|
|
let mut forked =
|
|
self.with_trees(sapling_note_commitment_tree, orchard_note_commitment_tree);
|
|
|
|
while forked.non_finalized_tip_hash() != fork_tip {
|
|
forked.pop_tip();
|
|
}
|
|
|
|
// Rebuild the note commitment trees, starting from the finalized tip tree.
|
|
// TODO: change to a more efficient approach by removing nodes
|
|
// from the tree of the original chain (in `pop_tip()`).
|
|
// See https://github.com/ZcashFoundation/zebra/issues/2378
|
|
for block in forked.blocks.values() {
|
|
for transaction in block.block.transactions.iter() {
|
|
for sapling_note_commitment in transaction.sapling_note_commitments() {
|
|
forked
|
|
.sapling_note_commitment_tree
|
|
.append(*sapling_note_commitment)
|
|
.expect("must work since it was already appended before the fork");
|
|
}
|
|
for orchard_note_commitment in transaction.orchard_note_commitments() {
|
|
forked
|
|
.orchard_note_commitment_tree
|
|
.append(*orchard_note_commitment)
|
|
.expect("must work since it was already appended before the fork");
|
|
}
|
|
}
|
|
}
|
|
|
|
Ok(Some(forked))
|
|
}
|
|
|
|
pub fn non_finalized_tip_hash(&self) -> block::Hash {
|
|
self.blocks
|
|
.values()
|
|
.next_back()
|
|
.expect("only called while blocks is populated")
|
|
.hash
|
|
}
|
|
|
|
/// Remove the highest height block of the non-finalized portion of a chain.
|
|
fn pop_tip(&mut self) {
|
|
let block_height = self.non_finalized_tip_height();
|
|
|
|
let block = self
|
|
.blocks
|
|
.remove(&block_height)
|
|
.expect("only called while blocks is populated");
|
|
|
|
assert!(
|
|
!self.blocks.is_empty(),
|
|
"Non-finalized chains must have at least one block to be valid"
|
|
);
|
|
|
|
self.revert_chain_state_with(&block);
|
|
}
|
|
|
|
pub fn non_finalized_tip_height(&self) -> block::Height {
|
|
*self
|
|
.blocks
|
|
.keys()
|
|
.next_back()
|
|
.expect("only called while blocks is populated")
|
|
}
|
|
|
|
pub fn is_empty(&self) -> bool {
|
|
self.blocks.is_empty()
|
|
}
|
|
|
|
/// Returns the unspent transaction outputs (UTXOs) in this non-finalized chain.
|
|
///
|
|
/// Callers should also check the finalized state for available UTXOs.
|
|
/// If UTXOs remain unspent when a block is finalized, they are stored in the finalized state,
|
|
/// and removed from the relevant chain(s).
|
|
pub fn unspent_utxos(&self) -> HashMap<transparent::OutPoint, transparent::Utxo> {
|
|
let mut unspent_utxos = self.created_utxos.clone();
|
|
unspent_utxos.retain(|out_point, _utxo| !self.spent_utxos.contains(out_point));
|
|
unspent_utxos
|
|
}
|
|
|
|
/// Clone the Chain but not the history and note commitment trees, using
|
|
/// the specified trees instead.
|
|
///
|
|
/// Useful when forking, where the trees are rebuilt anyway.
|
|
fn with_trees(
|
|
&self,
|
|
sapling_note_commitment_tree: sapling::tree::NoteCommitmentTree,
|
|
orchard_note_commitment_tree: orchard::tree::NoteCommitmentTree,
|
|
) -> Self {
|
|
Chain {
|
|
blocks: self.blocks.clone(),
|
|
height_by_hash: self.height_by_hash.clone(),
|
|
tx_by_hash: self.tx_by_hash.clone(),
|
|
created_utxos: self.created_utxos.clone(),
|
|
spent_utxos: self.spent_utxos.clone(),
|
|
sapling_note_commitment_tree,
|
|
orchard_note_commitment_tree,
|
|
sapling_anchors: self.sapling_anchors.clone(),
|
|
orchard_anchors: self.orchard_anchors.clone(),
|
|
sapling_anchors_by_height: self.sapling_anchors_by_height.clone(),
|
|
orchard_anchors_by_height: self.orchard_anchors_by_height.clone(),
|
|
sprout_nullifiers: self.sprout_nullifiers.clone(),
|
|
sapling_nullifiers: self.sapling_nullifiers.clone(),
|
|
orchard_nullifiers: self.orchard_nullifiers.clone(),
|
|
partial_cumulative_work: self.partial_cumulative_work,
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Helper trait to organize inverse operations done on the `Chain` type. Used to
|
|
/// overload the `update_chain_state_with` and `revert_chain_state_with` methods
|
|
/// based on the type of the argument.
|
|
///
|
|
/// This trait was motivated by the length of the `push` and `pop_root` functions
|
|
/// and fear that it would be easy to introduce bugs when updating them unless
|
|
/// the code was reorganized to keep related operations adjacent to eachother.
|
|
trait UpdateWith<T> {
|
|
/// Update `Chain` cumulative data members to add data that are derived from
|
|
/// `T`
|
|
fn update_chain_state_with(&mut self, _: &T) -> Result<(), ValidateContextError>;
|
|
|
|
/// Update `Chain` cumulative data members to remove data that are derived
|
|
/// from `T`
|
|
fn revert_chain_state_with(&mut self, _: &T);
|
|
}
|
|
|
|
impl UpdateWith<ContextuallyValidBlock> for Chain {
|
|
#[instrument(skip(self, contextually_valid), fields(block = %contextually_valid.block))]
|
|
fn update_chain_state_with(
|
|
&mut self,
|
|
contextually_valid: &ContextuallyValidBlock,
|
|
) -> Result<(), ValidateContextError> {
|
|
let (block, hash, height, new_outputs, transaction_hashes) = (
|
|
contextually_valid.block.as_ref(),
|
|
contextually_valid.hash,
|
|
contextually_valid.height,
|
|
&contextually_valid.new_outputs,
|
|
&contextually_valid.transaction_hashes,
|
|
);
|
|
|
|
// add hash to height_by_hash
|
|
let prior_height = self.height_by_hash.insert(hash, height);
|
|
assert!(
|
|
prior_height.is_none(),
|
|
"block heights must be unique within a single chain"
|
|
);
|
|
|
|
// add work to partial cumulative work
|
|
let block_work = block
|
|
.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_state_with(new_outputs)?;
|
|
// add the utxos this consumed
|
|
self.update_chain_state_with(inputs)?;
|
|
|
|
// add the shielded data
|
|
self.update_chain_state_with(joinsplit_data)?;
|
|
self.update_chain_state_with(sapling_shielded_data_per_spend_anchor)?;
|
|
self.update_chain_state_with(sapling_shielded_data_shared_anchor)?;
|
|
self.update_chain_state_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 root = self.sapling_note_commitment_tree.root();
|
|
self.sapling_anchors.insert(root);
|
|
self.sapling_anchors_by_height.insert(height, root);
|
|
let root = self.orchard_note_commitment_tree.root();
|
|
self.orchard_anchors.insert(root);
|
|
self.orchard_anchors_by_height.insert(height, root);
|
|
|
|
Ok(())
|
|
}
|
|
|
|
#[instrument(skip(self, contextually_valid), fields(block = %contextually_valid.block))]
|
|
fn revert_chain_state_with(&mut self, contextually_valid: &ContextuallyValidBlock) {
|
|
let (block, hash, height, new_outputs, transaction_hashes) = (
|
|
contextually_valid.block.as_ref(),
|
|
contextually_valid.hash,
|
|
contextually_valid.height,
|
|
&contextually_valid.new_outputs,
|
|
&contextually_valid.transaction_hashes,
|
|
);
|
|
|
|
// 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;
|
|
|
|
// 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_state_with(new_outputs);
|
|
// remove the utxos this consumed
|
|
self.revert_chain_state_with(inputs);
|
|
|
|
// remove the shielded data
|
|
self.revert_chain_state_with(joinsplit_data);
|
|
self.revert_chain_state_with(sapling_shielded_data_per_spend_anchor);
|
|
self.revert_chain_state_with(sapling_shielded_data_shared_anchor);
|
|
self.revert_chain_state_with(orchard_shielded_data);
|
|
}
|
|
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"
|
|
);
|
|
}
|
|
}
|
|
|
|
impl UpdateWith<HashMap<transparent::OutPoint, transparent::Utxo>> for Chain {
|
|
fn update_chain_state_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_state_with(
|
|
&mut self,
|
|
utxos: &HashMap<transparent::OutPoint, transparent::Utxo>,
|
|
) {
|
|
self.created_utxos
|
|
.retain(|outpoint, _| !utxos.contains_key(outpoint));
|
|
}
|
|
}
|
|
|
|
impl UpdateWith<Vec<transparent::Input>> for Chain {
|
|
fn update_chain_state_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_state_with(&mut self, inputs: &Vec<transparent::Input>) {
|
|
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_state_with(
|
|
&mut self,
|
|
joinsplit_data: &Option<transaction::JoinSplitData<Groth16Proof>>,
|
|
) -> Result<(), ValidateContextError> {
|
|
if let Some(joinsplit_data) = joinsplit_data {
|
|
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_state_with(
|
|
&mut self,
|
|
joinsplit_data: &Option<transaction::JoinSplitData<Groth16Proof>>,
|
|
) {
|
|
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_state_with(
|
|
&mut self,
|
|
sapling_shielded_data: &Option<sapling::ShieldedData<AnchorV>>,
|
|
) -> Result<(), ValidateContextError> {
|
|
if let Some(sapling_shielded_data) = sapling_shielded_data {
|
|
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_state_with(
|
|
&mut self,
|
|
sapling_shielded_data: &Option<sapling::ShieldedData<AnchorV>>,
|
|
) {
|
|
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_state_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_state_with(&mut self, orchard_shielded_data: &Option<orchard::ShieldedData>) {
|
|
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 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
|
|
///
|
|
/// # 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 {}
|