gix_traverse/commit/
mod.rs

1//! Provide multiple traversal implementations with different performance envelopes.
2//!
3//! Use [`Simple`] for fast walks that maintain minimal state, or [`Topo`] for a more elaborate traversal.
4use gix_hash::ObjectId;
5use gix_object::FindExt;
6use gix_revwalk::graph::IdMap;
7use gix_revwalk::PriorityQueue;
8use smallvec::SmallVec;
9
10/// A fast iterator over the ancestors of one or more starting commits.
11pub struct Simple<Find, Predicate> {
12    objects: Find,
13    cache: Option<gix_commitgraph::Graph>,
14    predicate: Predicate,
15    state: simple::State,
16    parents: Parents,
17    sorting: simple::Sorting,
18}
19
20/// Simple ancestors traversal, without the need to keep track of graph-state.
21pub mod simple;
22
23/// A commit walker that walks in topographical order, like `git rev-list
24/// --topo-order` or `--date-order` depending on the chosen [`topo::Sorting`].
25///
26/// Instantiate with [`topo::Builder`].
27pub struct Topo<Find, Predicate> {
28    commit_graph: Option<gix_commitgraph::Graph>,
29    find: Find,
30    predicate: Predicate,
31    indegrees: IdMap<i32>,
32    states: IdMap<topo::WalkFlags>,
33    explore_queue: PriorityQueue<topo::iter::GenAndCommitTime, ObjectId>,
34    indegree_queue: PriorityQueue<topo::iter::GenAndCommitTime, ObjectId>,
35    topo_queue: topo::iter::Queue,
36    parents: Parents,
37    min_gen: u32,
38    buf: Vec<u8>,
39}
40
41pub mod topo;
42
43/// Specify how to handle commit parents during traversal.
44#[derive(Default, Copy, Clone)]
45pub enum Parents {
46    /// Traverse all parents, useful for traversing the entire ancestry.
47    #[default]
48    All,
49    /// Only traverse along the first parent, which commonly ignores all branches.
50    First,
51}
52
53/// The collection of parent ids we saw as part of the iteration.
54///
55/// Note that this list is truncated if [`Parents::First`] was used.
56pub type ParentIds = SmallVec<[gix_hash::ObjectId; 1]>;
57
58/// Information about a commit that we obtained naturally as part of the iteration.
59#[derive(Debug, Clone, PartialEq, Eq, Ord, PartialOrd, Hash)]
60pub struct Info {
61    /// The id of the commit.
62    pub id: gix_hash::ObjectId,
63    /// All parent ids we have encountered. Note that these will be at most one if [`Parents::First`] is enabled.
64    pub parent_ids: ParentIds,
65    /// The time at which the commit was created. It will only be `Some(_)` if the chosen traversal was
66    /// taking dates into consideration.
67    pub commit_time: Option<gix_date::SecondsSinceUnixEpoch>,
68}
69
70enum Either<'buf, 'cache> {
71    CommitRefIter(gix_object::CommitRefIter<'buf>),
72    CachedCommit(gix_commitgraph::file::Commit<'cache>),
73}
74
75fn find<'cache, 'buf, Find>(
76    cache: Option<&'cache gix_commitgraph::Graph>,
77    objects: Find,
78    id: &gix_hash::oid,
79    buf: &'buf mut Vec<u8>,
80) -> Result<Either<'buf, 'cache>, gix_object::find::existing_iter::Error>
81where
82    Find: gix_object::Find,
83{
84    match cache.and_then(|cache| cache.commit_by_id(id).map(Either::CachedCommit)) {
85        Some(c) => Ok(c),
86        None => objects.find_commit_iter(id, buf).map(Either::CommitRefIter),
87    }
88}
gix_traverse/commit/mod.rs

gix_traverse/commit/
mod.rs
