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|
use std::{
convert::TryInto,
fmt::{Debug, Formatter},
path::Path,
};
use crate::{
file::{self, commit::Commit, COMMIT_DATA_ENTRY_SIZE_SANS_HASH},
File,
};
/// Access
impl File {
/// The number of base graphs that this file depends on.
pub fn base_graph_count(&self) -> u8 {
self.base_graph_count
}
/// Returns the commit data for the commit located at the given lexigraphical position.
///
/// `pos` must range from 0 to `self.num_commits()`.
///
/// # Panics
///
/// Panics if `pos` is out of bounds.
pub fn commit_at(&self, pos: file::Position) -> Commit<'_> {
Commit::new(self, pos)
}
/// The kind of hash used in this File.
///
/// Note that it is always conforming to the hash used in the owning repository.
pub fn object_hash(&self) -> gix_hash::Kind {
self.object_hash
}
/// Returns an object id at the given index in our list of (sorted) hashes.
/// The position ranges from 0 to `self.num_commits()`
// copied from gix-odb/src/pack/index/ext
pub fn id_at(&self, pos: file::Position) -> &gix_hash::oid {
assert!(
pos.0 < self.num_commits(),
"expected lexigraphical position less than {}, got {}",
self.num_commits(),
pos.0
);
let pos: usize = pos
.0
.try_into()
.expect("an architecture able to hold 32 bits of integer");
let start = self.oid_lookup_offset + (pos * self.hash_len);
gix_hash::oid::from_bytes_unchecked(&self.data[start..][..self.hash_len])
}
/// Return an iterator over all object hashes stored in the base graph.
pub fn iter_base_graph_ids(&self) -> impl Iterator<Item = &gix_hash::oid> {
let start = self.base_graphs_list_offset.unwrap_or(0);
let base_graphs_list = &self.data[start..][..self.hash_len * usize::from(self.base_graph_count)];
base_graphs_list
.chunks(self.hash_len)
.map(gix_hash::oid::from_bytes_unchecked)
}
/// return an iterator over all commits in this file.
pub fn iter_commits(&self) -> impl Iterator<Item = Commit<'_>> {
(0..self.num_commits()).map(move |i| self.commit_at(file::Position(i)))
}
/// Return an iterator over all object hashes stored in this file.
pub fn iter_ids(&self) -> impl Iterator<Item = &gix_hash::oid> {
(0..self.num_commits()).map(move |i| self.id_at(file::Position(i)))
}
/// Translate the given object hash to its position within this file, if present.
// copied from gix-odb/src/pack/index/ext
pub fn lookup(&self, id: impl AsRef<gix_hash::oid>) -> Option<file::Position> {
self.lookup_inner(id.as_ref())
}
fn lookup_inner(&self, id: &gix_hash::oid) -> Option<file::Position> {
let first_byte = usize::from(id.first_byte());
let mut upper_bound = self.fan[first_byte];
let mut lower_bound = if first_byte != 0 { self.fan[first_byte - 1] } else { 0 };
while lower_bound < upper_bound {
let mid = (lower_bound + upper_bound) / 2;
let mid_sha = self.id_at(file::Position(mid));
use std::cmp::Ordering::*;
match id.cmp(mid_sha) {
Less => upper_bound = mid,
Equal => return Some(file::Position(mid)),
Greater => lower_bound = mid + 1,
}
}
None
}
/// Returns the number of commits in this graph file.
///
/// The maximum valid `file::Position` that can be used with this file is one less than
/// `num_commits()`.
pub fn num_commits(&self) -> u32 {
self.fan[255]
}
/// Returns the path to this file.
pub fn path(&self) -> &Path {
&self.path
}
}
impl File {
/// Returns the byte slice for the given commit in this file's Commit Data (CDAT) chunk.
pub(crate) fn commit_data_bytes(&self, pos: file::Position) -> &[u8] {
assert!(
pos.0 < self.num_commits(),
"expected lexigraphical position less than {}, got {}",
self.num_commits(),
pos.0
);
let pos: usize = pos
.0
.try_into()
.expect("an architecture able to hold 32 bits of integer");
let entry_size = self.hash_len + COMMIT_DATA_ENTRY_SIZE_SANS_HASH;
let start = self.commit_data_offset + (pos * entry_size);
&self.data[start..][..entry_size]
}
/// Returns the byte slice for this file's entire Extra Edge List (EDGE) chunk.
pub(crate) fn extra_edges_data(&self) -> Option<&[u8]> {
Some(&self.data[self.extra_edges_list_range.clone()?])
}
}
impl Debug for File {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
write!(f, r#"File("{:?}")"#, self.path.display())
}
}
|
