/// An iterator over the ancestors one or more starting commitspub struct Ancestors<Find, Predicate, StateMut> { find: Find, predicate: Predicate, state: StateMut, parents: Parents, sorting: Sorting,} /// Specify how to handle commit parents during traversal.#[derive(Copy, Clone)]pub enum Parents { /// Traverse all parents, useful for traversing the entire ancestry. All, /// Only traverse along the first parent, which commonly ignores all branches. First,} impl Default for Parents { fn default() -> Self { Parents::All }} /// Specify how to sort commits during traversal.#[derive(Copy, Clone)]pub enum Sorting { /// Commits are sorted as they are mentioned in the commit graph. Topological, /// Commits are sorted by their commit time in descending order, that is newest first. /// /// The sorting applies to all currently queued commit ids and thus is full. /// /// # Performance /// /// This mode benefits greatly from having an object_cache in `find()` /// to avoid having to lookup each commit twice. ByCommitTimeNewestFirst,} impl Default for Sorting { fn default() -> Self { Sorting::Topological }} ///pub mod ancestors { use std::borrow::Borrow; use std::{borrow::BorrowMut, collections::VecDeque, iter::FromIterator}; use git_hash::{oid, ObjectId}; use git_object::CommitRefIter; use crate::commit::{Ancestors, Parents, Sorting}; /// The error is part of the item returned by the [Ancestors] iterator. #[derive(Debug, thiserror::Error)] #[allow(missing_docs)] pub enum Error { #[error("The commit {oid} could not be found")] FindExisting { oid: ObjectId, source: Box<dyn std::error::Error + Send + Sync + 'static>, }, #[error(transparent)] ObjectDecode(#[from] git_object::decode::Error), } type TimeInSeconds = u32; /// The state used and potentially shared by multiple graph traversals. #[derive(Default, Clone)] pub struct State { next: VecDeque<(ObjectId, TimeInSeconds)>, buf: Vec<u8>, seen: hash_hasher::HashedSet<ObjectId>, parents_buf: Vec<u8>, } impl State { fn clear(&mut self) { self.next.clear(); self.buf.clear(); self.seen.clear(); } } /// Builder impl<Find, Predicate, StateMut> Ancestors<Find, Predicate, StateMut> { /// Change our commit parent handling mode to the given one. pub fn parents(mut self, mode: Parents) -> Self { self.parents = mode; self } } /// Builder impl<Find, Predicate, StateMut, E> Ancestors<Find, Predicate, StateMut> where Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Result<CommitRefIter<'a>, E>, StateMut: BorrowMut<State>, E: std::error::Error + Send + Sync + 'static, { /// Set the sorting method, either topological or by author date pub fn sorting(mut self, sorting: Sorting) -> Result<Self, Error> { self.sorting = sorting; if !matches!(self.sorting, Sorting::Topological) { let state = self.state.borrow_mut(); for (commit_id, commit_time) in state.next.iter_mut() { let commit_iter = (self.find)(commit_id, &mut state.buf).map_err(|err| Error::FindExisting { oid: *commit_id, source: err.into(), })?; *commit_time = commit_iter.committer()?.time.seconds_since_unix_epoch; } let mut v = Vec::from_iter(std::mem::take(&mut state.next).into_iter()); v.sort_by(|a, b| a.1.cmp(&b.1).reverse()); state.next = v.into(); } Ok(self) } } /// Initialization impl<Find, StateMut, E> Ancestors<Find, fn(&oid) -> bool, StateMut> where Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Result<CommitRefIter<'a>, E>, StateMut: BorrowMut<State>, E: std::error::Error + Send + Sync + 'static, { /// Create a new instance. /// /// * `find` - a way to lookup new object data during traversal by their ObjectId, writing their data into buffer and returning /// an iterator over commit tokens if the object is present and is a commit. Caching should be implemented within this function /// as needed. /// * `state` - all state used for the traversal. If multiple traversals are performed, allocations can be minimized by reusing /// this state. /// * `tips` /// * the starting points of the iteration, usually commits /// * each commit they lead to will only be returned once, including the tip that started it pub fn new(tips: impl IntoIterator<Item = impl Into<ObjectId>>, state: StateMut, find: Find) -> Self { Self::filtered(tips, state, find, |_| true) } } /// Initialization impl<Find, Predicate, StateMut, E> Ancestors<Find, Predicate, StateMut> where Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Result<CommitRefIter<'a>, E>, Predicate: FnMut(&oid) -> bool, StateMut: BorrowMut<State>, E: std::error::Error + Send + Sync + 'static, { /// Create a new instance with commit filtering enabled. /// /// * `find` - a way to lookup new object data during traversal by their ObjectId, writing their data into buffer and returning /// an iterator over commit tokens if the object is present and is a commit. Caching should be implemented within this function /// as needed. /// * `state` - all state used for the traversal. If multiple traversals are performed, allocations can be minimized by reusing /// this state. /// * `tips` /// * the starting points of the iteration, usually commits /// * each commit they lead to will only be returned once, including the tip that started it /// * `predicate` - indicate whether a given commit should be included in the result as well /// as whether its parent commits should be traversed. pub fn filtered( tips: impl IntoIterator<Item = impl Into<ObjectId>>, mut state: StateMut, find: Find, mut predicate: Predicate, ) -> Self { let tips = tips.into_iter(); { let state = state.borrow_mut(); state.clear(); state.next.reserve(tips.size_hint().0); for tip in tips.map(Into::into) { let was_inserted = state.seen.insert(tip); if was_inserted && predicate(&tip) { state.next.push_back((tip, 0)); } } } Self { find, predicate, state, parents: Default::default(), sorting: Default::default(), } } } /// Access impl<Find, Predicate, StateMut> Ancestors<Find, Predicate, StateMut> where StateMut: Borrow<State>, { /// Return an iterator for accessing more of the current commits data. pub fn commit_iter(&self) -> CommitRefIter<'_> { CommitRefIter::from_bytes(&self.state.borrow().buf) } } impl<Find, Predicate, StateMut, E> Iterator for Ancestors<Find, Predicate, StateMut> where Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Result<CommitRefIter<'a>, E>, Predicate: FnMut(&oid) -> bool, StateMut: BorrowMut<State>, E: std::error::Error + Send + Sync + 'static, { type Item = Result<ObjectId, Error>; fn next(&mut self) -> Option<Self::Item> { if matches!(self.parents, Parents::First) { self.next_by_topology() } else { match self.sorting { Sorting::Topological => self.next_by_topology(), Sorting::ByCommitTimeNewestFirst => self.next_by_commit_date(), } } } } /// Utilities impl<Find, Predicate, StateMut, E> Ancestors<Find, Predicate, StateMut> where Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Result<CommitRefIter<'a>, E>, Predicate: FnMut(&oid) -> bool, StateMut: BorrowMut<State>, E: std::error::Error + Send + Sync + 'static, { fn next_by_commit_date(&mut self) -> Option<Result<ObjectId, Error>> { let state = self.state.borrow_mut(); let (oid, _commit_time) = state.next.pop_front()?; match (self.find)(&oid, &mut state.buf) { Ok(commit_iter) => { let mut count = 0; for token in commit_iter { count += 1; let is_first = count == 1; match token { Ok(git_object::commit::ref_iter::Token::Tree { .. }) => continue, Ok(git_object::commit::ref_iter::Token::Parent { id }) => { let was_inserted = state.seen.insert(id); if !(was_inserted && (self.predicate)(&id)) { if is_first && matches!(self.parents, Parents::First) { break; } else { continue; } } let parent = (self.find)(id.as_ref(), &mut state.parents_buf).ok(); let parent_commit_time = parent .and_then(|parent| { parent .committer() .ok() .map(|committer| committer.time.seconds_since_unix_epoch) }) .unwrap_or_default(); match state.next.binary_search_by(|c| c.1.cmp(&parent_commit_time).reverse()) { Ok(_) => state.next.push_back((id, parent_commit_time)), // collision => topo-sort Err(pos) => state.next.insert(pos, (id, parent_commit_time)), // otherwise insert by commit-time } if is_first && matches!(self.parents, Parents::First) { break; } } Ok(_unused_token) => break, Err(err) => return Some(Err(err.into())), } } } Err(err) => { return Some(Err(Error::FindExisting { oid, source: err.into(), })) } } Some(Ok(oid)) } } /// Utilities impl<Find, Predicate, StateMut, E> Ancestors<Find, Predicate, StateMut> where Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Result<CommitRefIter<'a>, E>, Predicate: FnMut(&oid) -> bool, StateMut: BorrowMut<State>, E: std::error::Error + Send + Sync + 'static, { fn next_by_topology(&mut self) -> Option<Result<ObjectId, Error>> { let state = self.state.borrow_mut(); let (oid, _commit_time) = state.next.pop_front()?; match (self.find)(&oid, &mut state.buf) { Ok(commit_iter) => { for token in commit_iter { match token { Ok(git_object::commit::ref_iter::Token::Tree { .. }) => continue, Ok(git_object::commit::ref_iter::Token::Parent { id }) => { let was_inserted = state.seen.insert(id); if was_inserted && (self.predicate)(&id) { state.next.push_back((id, 0)); } if matches!(self.parents, Parents::First) { break; } } Ok(_a_token_past_the_parents) => break, Err(err) => return Some(Err(err.into())), } } } Err(err) => { return Some(Err(Error::FindExisting { oid, source: err.into(), })) } } Some(Ok(oid)) } }}
/// An iterator over the ancestors one or more starting commits
pub struct Ancestors<Find, Predicate, StateMut> {
find: Find,
predicate: Predicate,
state: StateMut,
parents: Parents,
sorting: Sorting,
}
/// Specify how to handle commit parents during traversal.
#[derive(Copy, Clone)]
pub enum Parents {
/// Traverse all parents, useful for traversing the entire ancestry.
All,
/// Only traverse along the first parent, which commonly ignores all branches.
First,
}
impl Default for Parents {
fn default() -> Self {
Parents::All
}
}
/// Specify how to sort commits during traversal.
#[derive(Copy, Clone)]
pub enum Sorting {
/// Commits are sorted as they are mentioned in the commit graph.
Topological,
/// Commits are sorted by their commit time in descending order, that is newest first.
///
/// The sorting applies to all currently queued commit ids and thus is full.
///
/// # Performance
///
/// This mode benefits greatly from having an object_cache in `find()`
/// to avoid having to lookup each commit twice.
ByCommitTimeNewestFirst,
}
impl Default for Sorting {
fn default() -> Self {
Sorting::Topological
}
}
///
pub mod ancestors {
use std::borrow::Borrow;
use std::{borrow::BorrowMut, collections::VecDeque, iter::FromIterator};
use git_hash::{oid, ObjectId};
use git_object::CommitRefIter;
use crate::commit::{Ancestors, Parents, Sorting};
/// The error is part of the item returned by the [Ancestors] iterator.
#[derive(Debug, thiserror::Error)]
#[allow(missing_docs)]
pub enum Error {
#[error("The commit {oid} could not be found")]
FindExisting {
oid: ObjectId,
source: Box<dyn std::error::Error + Send + Sync + 'static>,
},
#[error(transparent)]
ObjectDecode(#[from] git_object::decode::Error),
}
type TimeInSeconds = u32;
/// The state used and potentially shared by multiple graph traversals.
#[derive(Default, Clone)]
pub struct State {
next: VecDeque<(ObjectId, TimeInSeconds)>,
buf: Vec<u8>,
seen: hash_hasher::HashedSet<ObjectId>,
parents_buf: Vec<u8>,
}
impl State {
fn clear(&mut self) {
self.next.clear();
self.buf.clear();
self.seen.clear();
}
}
/// Builder
impl<Find, Predicate, StateMut> Ancestors<Find, Predicate, StateMut> {
/// Change our commit parent handling mode to the given one.
pub fn parents(mut self, mode: Parents) -> Self {
self.parents = mode;
self
}
}
/// Builder
impl<Find, Predicate, StateMut, E> Ancestors<Find, Predicate, StateMut>
where
Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Result<CommitRefIter<'a>, E>,
StateMut: BorrowMut<State>,
E: std::error::Error + Send + Sync + 'static,
{
/// Set the sorting method, either topological or by author date
pub fn sorting(mut self, sorting: Sorting) -> Result<Self, Error> {
self.sorting = sorting;
if !matches!(self.sorting, Sorting::Topological) {
let state = self.state.borrow_mut();
for (commit_id, commit_time) in state.next.iter_mut() {
let commit_iter = (self.find)(commit_id, &mut state.buf).map_err(|err| Error::FindExisting {
oid: *commit_id,
source: err.into(),
})?;
*commit_time = commit_iter.committer()?.time.seconds_since_unix_epoch;
}
let mut v = Vec::from_iter(std::mem::take(&mut state.next).into_iter());
v.sort_by(|a, b| a.1.cmp(&b.1).reverse());
state.next = v.into();
}
Ok(self)
}
}
/// Initialization
impl<Find, StateMut, E> Ancestors<Find, fn(&oid) -> bool, StateMut>
where
Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Result<CommitRefIter<'a>, E>,
StateMut: BorrowMut<State>,
E: std::error::Error + Send + Sync + 'static,
{
/// Create a new instance.
///
/// * `find` - a way to lookup new object data during traversal by their ObjectId, writing their data into buffer and returning
/// an iterator over commit tokens if the object is present and is a commit. Caching should be implemented within this function
/// as needed.
/// * `state` - all state used for the traversal. If multiple traversals are performed, allocations can be minimized by reusing
/// this state.
/// * `tips`
/// * the starting points of the iteration, usually commits
/// * each commit they lead to will only be returned once, including the tip that started it
pub fn new(tips: impl IntoIterator<Item = impl Into<ObjectId>>, state: StateMut, find: Find) -> Self {
Self::filtered(tips, state, find, |_| true)
}
}
/// Initialization
impl<Find, Predicate, StateMut, E> Ancestors<Find, Predicate, StateMut>
where
Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Result<CommitRefIter<'a>, E>,
Predicate: FnMut(&oid) -> bool,
StateMut: BorrowMut<State>,
E: std::error::Error + Send + Sync + 'static,
{
/// Create a new instance with commit filtering enabled.
///
/// * `find` - a way to lookup new object data during traversal by their ObjectId, writing their data into buffer and returning
/// an iterator over commit tokens if the object is present and is a commit. Caching should be implemented within this function
/// as needed.
/// * `state` - all state used for the traversal. If multiple traversals are performed, allocations can be minimized by reusing
/// this state.
/// * `tips`
/// * the starting points of the iteration, usually commits
/// * each commit they lead to will only be returned once, including the tip that started it
/// * `predicate` - indicate whether a given commit should be included in the result as well
/// as whether its parent commits should be traversed.
pub fn filtered(
tips: impl IntoIterator<Item = impl Into<ObjectId>>,
mut state: StateMut,
find: Find,
mut predicate: Predicate,
) -> Self {
let tips = tips.into_iter();
{
let state = state.borrow_mut();
state.clear();
state.next.reserve(tips.size_hint().0);
for tip in tips.map(Into::into) {
let was_inserted = state.seen.insert(tip);
if was_inserted && predicate(&tip) {
state.next.push_back((tip, 0));
}
}
}
Self {
find,
predicate,
state,
parents: Default::default(),
sorting: Default::default(),
}
}
}
/// Access
impl<Find, Predicate, StateMut> Ancestors<Find, Predicate, StateMut>
where
StateMut: Borrow<State>,
{
/// Return an iterator for accessing more of the current commits data.
pub fn commit_iter(&self) -> CommitRefIter<'_> {
CommitRefIter::from_bytes(&self.state.borrow().buf)
}
}
impl<Find, Predicate, StateMut, E> Iterator for Ancestors<Find, Predicate, StateMut>
where
Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Result<CommitRefIter<'a>, E>,
Predicate: FnMut(&oid) -> bool,
StateMut: BorrowMut<State>,
E: std::error::Error + Send + Sync + 'static,
{
type Item = Result<ObjectId, Error>;
fn next(&mut self) -> Option<Self::Item> {
if matches!(self.parents, Parents::First) {
self.next_by_topology()
} else {
match self.sorting {
Sorting::Topological => self.next_by_topology(),
Sorting::ByCommitTimeNewestFirst => self.next_by_commit_date(),
}
}
}
}
/// Utilities
impl<Find, Predicate, StateMut, E> Ancestors<Find, Predicate, StateMut>
where
Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Result<CommitRefIter<'a>, E>,
Predicate: FnMut(&oid) -> bool,
StateMut: BorrowMut<State>,
E: std::error::Error + Send + Sync + 'static,
{
fn next_by_commit_date(&mut self) -> Option<Result<ObjectId, Error>> {
let state = self.state.borrow_mut();
let (oid, _commit_time) = state.next.pop_front()?;
match (self.find)(&oid, &mut state.buf) {
Ok(commit_iter) => {
let mut count = 0;
for token in commit_iter {
count += 1;
let is_first = count == 1;
match token {
Ok(git_object::commit::ref_iter::Token::Tree { .. }) => continue,
Ok(git_object::commit::ref_iter::Token::Parent { id }) => {
let was_inserted = state.seen.insert(id);
if !(was_inserted && (self.predicate)(&id)) {
if is_first && matches!(self.parents, Parents::First) {
break;
} else {
continue;
}
}
let parent = (self.find)(id.as_ref(), &mut state.parents_buf).ok();
let parent_commit_time = parent
.and_then(|parent| {
parent
.committer()
.ok()
.map(|committer| committer.time.seconds_since_unix_epoch)
})
.unwrap_or_default();
match state.next.binary_search_by(|c| c.1.cmp(&parent_commit_time).reverse()) {
Ok(_) => state.next.push_back((id, parent_commit_time)), // collision => topo-sort
Err(pos) => state.next.insert(pos, (id, parent_commit_time)), // otherwise insert by commit-time
}
if is_first && matches!(self.parents, Parents::First) {
break;
}
}
Ok(_unused_token) => break,
Err(err) => return Some(Err(err.into())),
}
}
}
Err(err) => {
return Some(Err(Error::FindExisting {
oid,
source: err.into(),
}))
}
}
Some(Ok(oid))
}
}
/// Utilities
impl<Find, Predicate, StateMut, E> Ancestors<Find, Predicate, StateMut>
where
Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Result<CommitRefIter<'a>, E>,
Predicate: FnMut(&oid) -> bool,
StateMut: BorrowMut<State>,
E: std::error::Error + Send + Sync + 'static,
{
fn next_by_topology(&mut self) -> Option<Result<ObjectId, Error>> {
let state = self.state.borrow_mut();
let (oid, _commit_time) = state.next.pop_front()?;
match (self.find)(&oid, &mut state.buf) {
Ok(commit_iter) => {
for token in commit_iter {
match token {
Ok(git_object::commit::ref_iter::Token::Tree { .. }) => continue,
Ok(git_object::commit::ref_iter::Token::Parent { id }) => {
let was_inserted = state.seen.insert(id);
if was_inserted && (self.predicate)(&id) {
state.next.push_back((id, 0));
}
if matches!(self.parents, Parents::First) {
break;
}
}
Ok(_a_token_past_the_parents) => break,
Err(err) => return Some(Err(err.into())),
}
}
}
Err(err) => {
return Some(Err(Error::FindExisting {
oid,
source: err.into(),
}))
}
}
Some(Ok(oid))
}
}
}