gix_pack/
lib.rs

1//! Git stores all of its data as _Objects_, which are data along with a hash over all data. Storing objects efficiently
2//! is what git packs are concerned about.
3//!
4//! Packs consist of [data files][data::File] and [index files][index::File]. The latter can be generated from a data file
5//! and make accessing objects within a pack feasible.
6//!
7//! A [Bundle] conveniently combines a data pack alongside its index to allow [finding][Find] objects or verifying the pack.
8//! Objects returned by `.find(…)` are [objects][gix_object::Data] which know their pack location in order to speed up
9//! various common operations like creating new packs from existing ones.
10//!
11//! When traversing all objects in a pack, a _delta tree acceleration structure_ can be built from pack data or an index
12//! in order to decompress packs in parallel and without any waste.
13//! ## Feature Flags
14#![cfg_attr(
15    all(doc, feature = "document-features"),
16    doc = ::document_features::document_features!()
17)]
18#![cfg_attr(all(doc, feature = "document-features"), feature(doc_cfg, doc_auto_cfg))]
19#![deny(missing_docs, rust_2018_idioms, unsafe_code)]
20
21///
22pub mod bundle;
23/// A bundle of pack data and the corresponding pack index
24pub struct Bundle {
25    /// The pack file corresponding to `index`
26    pub pack: data::File,
27    /// The index file corresponding to `pack`
28    pub index: index::File,
29}
30
31///
32pub mod find;
33
34///
35pub mod cache;
36///
37pub mod data;
38
39mod find_traits;
40pub use find_traits::{Find, FindExt};
41
42///
43pub mod index;
44///
45pub mod multi_index;
46
47///
48pub mod verify;
49
50mod mmap {
51    use std::path::Path;
52
53    pub fn read_only(path: &Path) -> std::io::Result<memmap2::Mmap> {
54        let file = std::fs::File::open(path)?;
55        // SAFETY: we have to take the risk of somebody changing the file underneath. Git never writes into the same file.
56        #[allow(unsafe_code)]
57        unsafe {
58            memmap2::MmapOptions::new().map_copy_read_only(&file)
59        }
60    }
61}
62
63#[inline]
64fn read_u32(b: &[u8]) -> u32 {
65    u32::from_be_bytes(b.try_into().unwrap())
66}
67
68#[inline]
69fn read_u64(b: &[u8]) -> u64 {
70    u64::from_be_bytes(b.try_into().unwrap())
71}
72
73fn exact_vec<T>(capacity: usize) -> Vec<T> {
74    let mut v = Vec::new();
75    v.reserve_exact(capacity);
76    v
77}
gix_pack/lib.rs

gix_pack/
lib.rs
