/// A trait to model putting objects at a given pack `offset` into a cache, and fetching them.////// It is used to speed up [pack traversals][crate::pack::index::File::traverse()].pub trait DecodeEntry { /// Store a fully decoded object at `offset` of `kind` with `compressed_size` and `data` in the cache. /// /// It is up to the cache implementation whether that actually happens or not. fn put(&mut self, offset: u64, data: &[u8], kind: git_object::Kind, compressed_size: usize); /// Attempt to fetch the object at `offset` and store its decoded bytes in `out`, as previously stored with [`DecodeEntry::put()`], and return /// its (object `kind`, `decompressed_size`) fn get(&mut self, offset: u64, out: &mut Vec<u8>) -> Option<(git_object::Kind, usize)>;}/// A cache that stores nothing and retrieves nothing.#[derive(Default)]pub struct Noop;impl DecodeEntry for Noop { fn put(&mut self, _offset: u64, _data: &[u8], _kind: git_object::Kind, _compressed_size: usize) {} fn get(&mut self, _offset: u64, _out: &mut Vec<u8>) -> Option<(git_object::Kind, usize)> { None }}/// A cache using a least-recently-used implementation capable of storing the 64 most recent objects.struct LRUEntry { offset: u64, data: Vec<u8>, kind: git_object::Kind, compressed_size: usize,}/// A least-recently-used cache to accelerate pack traversal#[derive(Default)]pub struct LRU(uluru::LRUCache<[uluru::Entry<LRUEntry>; 64]>);impl DecodeEntry for LRU { fn put(&mut self, offset: u64, data: &[u8], kind: git_object::Kind, compressed_size: usize) { self.0.insert(LRUEntry { offset, data: Vec::from(data), kind, compressed_size, }) } fn get(&mut self, offset: u64, out: &mut Vec<u8>) -> Option<(git_object::Kind, usize)> { self.0.lookup(|e: &mut LRUEntry| { if e.offset == offset { out.resize(e.data.len(), 0); out.copy_from_slice(&e.data); Some((e.kind, e.compressed_size)) } else { None } }) }}
/// A trait to model putting objects at a given pack `offset` into a cache, and fetching them.
///
/// It is used to speed up [pack traversals][crate::pack::index::File::traverse()].
pub trait DecodeEntry {
/// Store a fully decoded object at `offset` of `kind` with `compressed_size` and `data` in the cache.
///
/// It is up to the cache implementation whether that actually happens or not.
fn put(&mut self, offset: u64, data: &[u8], kind: git_object::Kind, compressed_size: usize);
/// Attempt to fetch the object at `offset` and store its decoded bytes in `out`, as previously stored with [`DecodeEntry::put()`], and return
/// its (object `kind`, `decompressed_size`)
fn get(&mut self, offset: u64, out: &mut Vec<u8>) -> Option<(git_object::Kind, usize)>;
}
/// A cache that stores nothing and retrieves nothing.
#[derive(Default)]
pub struct Noop;
impl DecodeEntry for Noop {
fn put(&mut self, _offset: u64, _data: &[u8], _kind: git_object::Kind, _compressed_size: usize) {}
fn get(&mut self, _offset: u64, _out: &mut Vec<u8>) -> Option<(git_object::Kind, usize)> {
None
}
}
/// A cache using a least-recently-used implementation capable of storing the 64 most recent objects.
struct LRUEntry {
offset: u64,
data: Vec<u8>,
kind: git_object::Kind,
compressed_size: usize,
}
/// A least-recently-used cache to accelerate pack traversal
#[derive(Default)]
pub struct LRU(uluru::LRUCache<[uluru::Entry<LRUEntry>; 64]>);
impl DecodeEntry for LRU {
fn put(&mut self, offset: u64, data: &[u8], kind: git_object::Kind, compressed_size: usize) {
self.0.insert(LRUEntry {
offset,
data: Vec::from(data),
kind,
compressed_size,
})
}
fn get(&mut self, offset: u64, out: &mut Vec<u8>) -> Option<(git_object::Kind, usize)> {
self.0.lookup(|e: &mut LRUEntry| {
if e.offset == offset {
out.resize(e.data.len(), 0);
out.copy_from_slice(&e.data);
Some((e.kind, e.compressed_size))
} else {
None
}
})
}
}