Switch to a dense representation for clock::Global
Co-Authored-By: Nathan Sobo <nathan@zed.dev>
This commit is contained in:
parent
447f710570
commit
b25c3eb740
3 changed files with 124 additions and 74 deletions
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@ -1,9 +1,8 @@
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use smallvec::SmallVec;
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use std::{
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cmp::{self, Ordering},
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fmt,
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fmt, iter,
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ops::{Add, AddAssign},
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slice,
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};
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pub type ReplicaId = u16;
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@ -59,7 +58,7 @@ impl<'a> AddAssign<&'a Local> for Local {
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}
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#[derive(Clone, Default, Hash, Eq, PartialEq)]
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pub struct Global(SmallVec<[Local; 3]>);
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pub struct Global(SmallVec<[u32; 8]>);
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impl From<Vec<rpc::proto::VectorClockEntry>> for Global {
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fn from(message: Vec<rpc::proto::VectorClockEntry>) -> Self {
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@ -98,75 +97,119 @@ impl Global {
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}
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pub fn get(&self, replica_id: ReplicaId) -> Seq {
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self.0
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.iter()
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.find(|t| t.replica_id == replica_id)
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.map_or(0, |t| t.value)
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self.0.get(replica_id as usize).copied().unwrap_or(0) as Seq
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}
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pub fn observe(&mut self, timestamp: Local) {
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if let Some(entry) = self
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.0
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.iter_mut()
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.find(|t| t.replica_id == timestamp.replica_id)
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{
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entry.value = cmp::max(entry.value, timestamp.value);
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} else {
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self.0.push(timestamp);
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if timestamp.value > 0 {
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let new_len = timestamp.replica_id as usize + 1;
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if new_len > self.0.len() {
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self.0.resize(new_len, 0);
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}
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let entry = &mut self.0[timestamp.replica_id as usize];
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*entry = cmp::max(*entry, timestamp.value);
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}
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}
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pub fn join(&mut self, other: &Self) {
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for timestamp in other.0.iter() {
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self.observe(*timestamp);
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if other.0.len() > self.0.len() {
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self.0.resize(other.0.len(), 0);
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}
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for (left, right) in self.0.iter_mut().zip(&other.0) {
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*left = cmp::max(*left, *right);
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}
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}
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pub fn meet(&mut self, other: &Self) {
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for timestamp in other.0.iter() {
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if let Some(entry) = self
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.0
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.iter_mut()
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.find(|t| t.replica_id == timestamp.replica_id)
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{
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entry.value = cmp::min(entry.value, timestamp.value);
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} else {
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self.0.push(*timestamp);
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if other.0.len() > self.0.len() {
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self.0.resize(other.0.len(), 0);
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}
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let mut new_len = 0;
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for (ix, (left, right)) in self
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.0
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.iter_mut()
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.zip(other.0.iter().chain(iter::repeat(&0)))
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.enumerate()
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{
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if *left == 0 {
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*left = *right;
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} else if *right > 0 {
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*left = cmp::min(*left, *right);
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}
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if *left != 0 {
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new_len = ix + 1;
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}
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}
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self.0.resize(new_len, 0);
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}
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pub fn observed(&self, timestamp: Local) -> bool {
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self.get(timestamp.replica_id) >= timestamp.value
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}
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pub fn changed_since(&self, other: &Self) -> bool {
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self.0.iter().any(|t| t.value > other.get(t.replica_id))
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}
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pub fn iter(&self) -> slice::Iter<Local> {
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self.0.iter()
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}
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}
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impl PartialOrd for Global {
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fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
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let mut global_ordering = Ordering::Equal;
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for timestamp in self.0.iter().chain(other.0.iter()) {
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let ordering = self
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.get(timestamp.replica_id)
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.cmp(&other.get(timestamp.replica_id));
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if ordering != Ordering::Equal {
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if global_ordering == Ordering::Equal {
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global_ordering = ordering;
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} else if ordering != global_ordering {
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return None;
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pub fn observed_any(&self, other: &Self) -> bool {
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let mut lhs = self.0.iter();
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let mut rhs = other.0.iter();
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loop {
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if let Some(left) = lhs.next() {
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if let Some(right) = rhs.next() {
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if *right > 0 && left >= right {
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return true;
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}
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} else {
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return false;
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}
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} else {
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return false;
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}
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}
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}
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Some(global_ordering)
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pub fn ge(&self, other: &Self) -> bool {
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let mut lhs = self.0.iter();
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let mut rhs = other.0.iter();
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loop {
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if let Some(left) = lhs.next() {
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if let Some(right) = rhs.next() {
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if left < right {
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return false;
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}
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} else {
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return true;
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}
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} else {
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return rhs.next().is_none();
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}
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}
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}
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pub fn gt(&self, other: &Self) -> bool {
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let mut lhs = self.0.iter();
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let mut rhs = other.0.iter();
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loop {
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if let Some(left) = lhs.next() {
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if let Some(right) = rhs.next() {
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if left <= right {
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return false;
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}
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} else {
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return true;
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}
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} else {
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return rhs.next().is_none();
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}
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}
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}
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pub fn iter<'a>(&'a self) -> impl 'a + Iterator<Item = Local> {
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self.0.iter().enumerate().map(|(replica_id, seq)| Local {
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replica_id: replica_id as ReplicaId,
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value: *seq,
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})
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}
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}
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@ -219,11 +262,11 @@ impl fmt::Debug for Lamport {
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impl fmt::Debug for Global {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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write!(f, "Global {{")?;
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for (i, element) in self.0.iter().enumerate() {
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if i > 0 {
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for timestamp in self.iter() {
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if timestamp.replica_id > 0 {
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write!(f, ", ")?;
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}
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write!(f, "{}: {}", element.replica_id, element.value)?;
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write!(f, "{}: {}", timestamp.replica_id, timestamp.value)?;
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}
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write!(f, "}}")
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}
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