//! Operations on a single commit-graph file.use std::{ fmt::{Display, Formatter}, ops::Range, path::PathBuf,};use memmap2::Mmap;pub use self::{commit::Commit, init::Error};mod access;pub mod commit;mod init;pub mod verify;const COMMIT_DATA_ENTRY_SIZE_SANS_HASH: usize = 16;const FAN_LEN: usize = 256;const HEADER_LEN: usize = 8;const SIGNATURE: &[u8] = b"CGPH";type ChunkId = git_chunk::Id;const BASE_GRAPHS_LIST_CHUNK_ID: ChunkId = *b"BASE";const COMMIT_DATA_CHUNK_ID: ChunkId = *b"CDAT";const EXTENDED_EDGES_LIST_CHUNK_ID: ChunkId = *b"EDGE";const OID_FAN_CHUNK_ID: ChunkId = *b"OIDF";const OID_LOOKUP_CHUNK_ID: ChunkId = *b"OIDL";// Note that git's commit-graph-format.txt as of v2.28.0 gives an incorrect value 0x0700_0000 for// NO_PARENT. Fixed in https://github.com/git/git/commit/4d515253afcef985e94400adbfed7044959f9121 .const NO_PARENT: u32 = 0x7000_0000;const EXTENDED_EDGES_MASK: u32 = 0x8000_0000;const LAST_EXTENDED_EDGE_MASK: u32 = 0x8000_0000;/// 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: Mmap, extra_edges_list_range: Option<Range<usize>>, fan: [u32; FAN_LEN], oid_lookup_offset: usize, path: PathBuf, hash_len: usize, object_hash: git_hash::Kind,}/// The position of a given commit within a graph file, starting at 0.////// Commits within a graph file are sorted in lexicographical order by OID; a commit's lexigraphical position/// is its position in this ordering. If a commit graph spans multiple files, each file's commits/// start at lexigraphical position 0, so it is unique across a single file but is not unique across/// the whole commit graph. Each commit also has a graph position ([`graph::Position`][crate::graph::Position]),/// which is unique /// across the whole commit graph. In order to avoid accidentally mixing lexigraphical positions with graph/// positions, distinct types are used for each.#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]pub struct Position(pub u32);impl Display for Position { fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result { self.0.fmt(f) }}
//! Operations on a single commit-graph file.
use std::{
fmt::{Display, Formatter},
ops::Range,
path::PathBuf,
};
use memmap2::Mmap;
pub use self::{commit::Commit, init::Error};
mod access;
pub mod commit;
mod init;
pub mod verify;
const COMMIT_DATA_ENTRY_SIZE_SANS_HASH: usize = 16;
const FAN_LEN: usize = 256;
const HEADER_LEN: usize = 8;
const SIGNATURE: &[u8] = b"CGPH";
type ChunkId = git_chunk::Id;
const BASE_GRAPHS_LIST_CHUNK_ID: ChunkId = *b"BASE";
const COMMIT_DATA_CHUNK_ID: ChunkId = *b"CDAT";
const EXTENDED_EDGES_LIST_CHUNK_ID: ChunkId = *b"EDGE";
const OID_FAN_CHUNK_ID: ChunkId = *b"OIDF";
const OID_LOOKUP_CHUNK_ID: ChunkId = *b"OIDL";
// Note that git's commit-graph-format.txt as of v2.28.0 gives an incorrect value 0x0700_0000 for
// NO_PARENT. Fixed in https://github.com/git/git/commit/4d515253afcef985e94400adbfed7044959f9121 .
const NO_PARENT: u32 = 0x7000_0000;
const EXTENDED_EDGES_MASK: u32 = 0x8000_0000;
const LAST_EXTENDED_EDGE_MASK: u32 = 0x8000_0000;
/// 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: Mmap,
extra_edges_list_range: Option<Range<usize>>,
fan: [u32; FAN_LEN],
oid_lookup_offset: usize,
path: PathBuf,
hash_len: usize,
object_hash: git_hash::Kind,
}
/// The position of a given commit within a graph file, starting at 0.
///
/// Commits within a graph file are sorted in lexicographical order by OID; a commit's lexigraphical position
/// is its position in this ordering. If a commit graph spans multiple files, each file's commits
/// start at lexigraphical position 0, so it is unique across a single file but is not unique across
/// the whole commit graph. Each commit also has a graph position ([`graph::Position`][crate::graph::Position]),
/// which is unique /// across the whole commit graph. In order to avoid accidentally mixing lexigraphical positions with graph
/// positions, distinct types are used for each.
#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
pub struct Position(pub u32);
impl Display for Position {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
self.0.fmt(f)
}
}