Merging upstream version 1.72.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 77 insertions, 0 deletions

diff --git a/vendor/gix-commitgraph/src/lib.rs b/vendor/gix-commitgraph/src/lib.rs
new file mode 100644
index 000000000..231c11c6f
--- /dev/null
+++ b/vendor/gix-commitgraph/src/lib.rs
@@ -0,0 +1,77 @@
+//! Read, verify, and traverse git commit graphs.
+//!
+//! A [commit graph][Graph] is an index of commits in the git commit history.
+//! The [Graph] stores commit data in a way that accelerates lookups considerably compared to
+//! traversing the git history by usual means.
+//!
+//! As generating the full commit graph from scratch can take some time, git may write new commits
+//! to separate [files][File] instead of overwriting the original file.
+//! Eventually, git will merge these files together as the number of files grows.
+//! ## Feature Flags
+#![cfg_attr(
+    feature = "document-features",
+    cfg_attr(doc, doc = ::document_features::document_features!())
+)]
+#![cfg_attr(docsrs, feature(doc_cfg, doc_auto_cfg))]
+#![deny(missing_docs, rust_2018_idioms, unsafe_code)]
+
+use std::path::Path;
+
+/// A single commit-graph file.
+///
+/// All operations on a `File` are local to that graph file. Since a commit graph can span multiple
+/// files, all interesting graph operations belong on [`Graph`][crate::Graph].
+pub struct File {
+    base_graph_count: u8,
+    base_graphs_list_offset: Option<usize>,
+    commit_data_offset: usize,
+    data: memmap2::Mmap,
+    extra_edges_list_range: Option<std::ops::Range<usize>>,
+    fan: [u32; file::FAN_LEN],
+    oid_lookup_offset: usize,
+    path: std::path::PathBuf,
+    hash_len: usize,
+    object_hash: gix_hash::Kind,
+}
+
+/// A complete commit graph.
+///
+/// The data in the commit graph may come from a monolithic `objects/info/commit-graph` file, or it
+/// may come from one or more `objects/info/commit-graphs/graph-*.graph` files. These files are
+/// generated via `git commit-graph write ...` commands.
+pub struct Graph {
+    files: Vec<File>,
+}
+
+/// Instantiate a commit graph from an `.git/objects/info` directory, or one of the various commit-graph files.
+pub fn at(path: impl AsRef<Path>) -> Result<Graph, init::Error> {
+    Graph::at(path)
+}
+
+mod access;
+pub mod file;
+///
+pub mod init;
+pub mod verify;
+
+/// The number of generations that are considered 'infinite' commit history.
+pub const GENERATION_NUMBER_INFINITY: u32 = 0xffff_ffff;
+/// The largest valid generation number.
+///
+/// If a commit's real generation number is larger than this, the commit graph will cap the value to
+/// this number.
+/// The largest distinct generation number is `GENERATION_NUMBER_MAX - 1`.
+pub const GENERATION_NUMBER_MAX: u32 = 0x3fff_ffff;
+
+/// The maximum number of commits that can be stored in a commit graph.
+pub const MAX_COMMITS: u32 = (1 << 30) + (1 << 29) + (1 << 28) - 1;
+
+/// A generalized position for use in [`Graph`].
+#[derive(Clone, Copy, Debug, Eq, Ord, PartialEq, PartialOrd, Hash)]
+pub struct Position(pub u32);
+
+impl std::fmt::Display for Position {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.0.fmt(f)
+    }
+}