///pub mod ancestors { use git_hash::{oid, ObjectId}; use git_object::immutable; use quick_error::quick_error; use std::{ borrow::BorrowMut, collections::{BTreeSet, VecDeque}, }; quick_error! { /// The error is part of the item returned by the [Ancestors] iterator. #[derive(Debug)] #[allow(missing_docs)] pub enum Error { NotFound{oid: ObjectId} { display("The object {} could not be found", oid) } ObjectDecode(err: immutable::object::decode::Error) { display("An object could not be decoded") source(err) from() } } } /// The state used and potentially shared by multiple graph traversals. #[derive(Default, Clone)] pub struct State { next: VecDeque<ObjectId>, buf: Vec<u8>, seen: BTreeSet<ObjectId>, } impl State { fn clear(&mut self) { self.next.clear(); self.buf.clear(); self.seen.clear(); } } /// An iterator over the ancestors one or more starting commits pub struct Ancestors<Find, StateMut> { find: Find, state: StateMut, } impl<Find, StateMut> Ancestors<Find, StateMut> where Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Option<immutable::CommitIter<'a>>, StateMut: BorrowMut<State>, { /// 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. The return value is `Option<CommitIter>` which degenerates all error information. Not finding a commit should also /// be considered an errors as all objects in the commit graph should be present in the database. Hence [`Error::NotFound`] should /// be escalated into a more specific error if its encountered by the caller. /// * `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>>, mut state: StateMut, find: Find) -> Self { { let state = state.borrow_mut(); state.clear(); state.next.extend(tips.into_iter().map(Into::into)); state.seen.extend(state.next.iter().cloned()); } Ancestors { find, state } } } impl<Find, StateMut> Iterator for Ancestors<Find, StateMut> where Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Option<immutable::CommitIter<'a>>, StateMut: BorrowMut<State>, { type Item = Result<ObjectId, Error>; fn next(&mut self) -> Option<Self::Item> { let state = self.state.borrow_mut(); let res = state.next.pop_front(); if let Some(oid) = res { match (self.find)(&oid, &mut state.buf) { Some(mut commit_iter) => { if let Some(Err(decode_tree_err)) = commit_iter.next() { return Some(Err(decode_tree_err.into())); } for token in commit_iter { match token { Ok(immutable::commit::iter::Token::Parent { id }) => { let was_inserted = state.seen.insert(id); if was_inserted { state.next.push_back(id); } } Ok(_a_token_past_the_parents) => break, Err(err) => return Some(Err(err.into())), } } } None => return Some(Err(Error::NotFound { oid })), } } res.map(Ok) } }}#[doc(inline)]pub use ancestors::Ancestors;
///
pub mod ancestors {
use git_hash::{oid, ObjectId};
use git_object::immutable;
use quick_error::quick_error;
use std::{
borrow::BorrowMut,
collections::{BTreeSet, VecDeque},
};
quick_error! {
/// The error is part of the item returned by the [Ancestors] iterator.
#[derive(Debug)]
#[allow(missing_docs)]
pub enum Error {
NotFound{oid: ObjectId} {
display("The object {} could not be found", oid)
}
ObjectDecode(err: immutable::object::decode::Error) {
display("An object could not be decoded")
source(err)
from()
}
}
}
/// The state used and potentially shared by multiple graph traversals.
#[derive(Default, Clone)]
pub struct State {
next: VecDeque<ObjectId>,
buf: Vec<u8>,
seen: BTreeSet<ObjectId>,
}
impl State {
fn clear(&mut self) {
self.next.clear();
self.buf.clear();
self.seen.clear();
}
}
/// An iterator over the ancestors one or more starting commits
pub struct Ancestors<Find, StateMut> {
find: Find,
state: StateMut,
}
impl<Find, StateMut> Ancestors<Find, StateMut>
where
Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Option<immutable::CommitIter<'a>>,
StateMut: BorrowMut<State>,
{
/// 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. The return value is `Option<CommitIter>` which degenerates all error information. Not finding a commit should also
/// be considered an errors as all objects in the commit graph should be present in the database. Hence [`Error::NotFound`] should
/// be escalated into a more specific error if its encountered by the caller.
/// * `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>>, mut state: StateMut, find: Find) -> Self {
{
let state = state.borrow_mut();
state.clear();
state.next.extend(tips.into_iter().map(Into::into));
state.seen.extend(state.next.iter().cloned());
}
Ancestors { find, state }
}
}
impl<Find, StateMut> Iterator for Ancestors<Find, StateMut>
where
Find: for<'a> FnMut(&oid, &'a mut Vec<u8>) -> Option<immutable::CommitIter<'a>>,
StateMut: BorrowMut<State>,
{
type Item = Result<ObjectId, Error>;
fn next(&mut self) -> Option<Self::Item> {
let state = self.state.borrow_mut();
let res = state.next.pop_front();
if let Some(oid) = res {
match (self.find)(&oid, &mut state.buf) {
Some(mut commit_iter) => {
if let Some(Err(decode_tree_err)) = commit_iter.next() {
return Some(Err(decode_tree_err.into()));
}
for token in commit_iter {
match token {
Ok(immutable::commit::iter::Token::Parent { id }) => {
let was_inserted = state.seen.insert(id);
if was_inserted {
state.next.push_back(id);
}
}
Ok(_a_token_past_the_parents) => break,
Err(err) => return Some(Err(err.into())),
}
}
}
None => return Some(Err(Error::NotFound { oid })),
}
}
res.map(Ok)
}
}
}
#[doc(inline)]
pub use ancestors::Ancestors;