use crate::store::packed;impl AsRef<[u8]> for packed::Buffer { fn as_ref(&self) -> &[u8] { &self.data.as_ref()[self.offset..] }}impl AsRef<[u8]> for packed::Backing { fn as_ref(&self) -> &[u8] { match self { packed::Backing::InMemory(data) => data, packed::Backing::Mapped(map) => map, } }}///pub mod open { use std::path::PathBuf; use filebuffer::FileBuffer; use crate::store::packed; /// Initialization impl packed::Buffer { /// Open the file at `path` and map it into memory if the file size is larger than `use_memory_map_if_larger_than_bytes`. /// /// In order to allow fast lookups and optimizations, the contents of the packed refs must be sorted. /// If that's not the case, they will be sorted on the fly with the data being written into a memory buffer. pub fn open(path: impl Into<PathBuf>, use_memory_map_if_larger_than_bytes: u64) -> Result<Self, Error> { let path = path.into(); let (backing, offset) = { let backing = if std::fs::metadata(&path)?.len() <= use_memory_map_if_larger_than_bytes { packed::Backing::InMemory(std::fs::read(&path)?) } else { packed::Backing::Mapped(FileBuffer::open(&path)?) }; let (offset, sorted) = { let data = backing.as_ref(); if *data.get(0).unwrap_or(&b' ') == b'#' { let (records, header) = packed::decode::header::<()>(data).map_err(|_| Error::HeaderParsing)?; let offset = records.as_ptr() as usize - data.as_ptr() as usize; (offset, header.sorted) } else { (0, false) } }; if !sorted { // this implementation is likely slower than what git does, but it's less code, too. let mut entries = packed::Iter::new(&backing.as_ref()[offset..])?.collect::<Result<Vec<_>, _>>()?; entries.sort_by_key(|e| e.name.as_bstr()); let mut serialized = Vec::<u8>::new(); for entry in entries { serialized.extend_from_slice(entry.target); serialized.push(b' '); serialized.extend_from_slice(entry.name.as_bstr()); serialized.push(b'\n'); if let Some(object) = entry.object { serialized.push(b'^'); serialized.extend_from_slice(object); serialized.push(b'\n'); } } (Backing::InMemory(serialized), 0) } else { (backing, offset) } }; Ok(packed::Buffer { offset, data: backing, path, }) } } mod error { use quick_error::quick_error; use crate::packed; quick_error! { /// The error returned by [`open()`][super::packed::Buffer::open()]. #[derive(Debug)] #[allow(missing_docs)] pub enum Error { Iter(err: packed::iter::Error) { display("The packed-refs file did not have a header or wasn't sorted and could not be iterated") from() source(err) } HeaderParsing { display("The header could not be parsed, even though first line started with '#'") } Io(err: std::io::Error) { display("The buffer could not be opened or read") from() source(err) } } } } pub use error::Error; use crate::packed::Backing;}
use crate::store::packed;
impl AsRef<[u8]> for packed::Buffer {
fn as_ref(&self) -> &[u8] {
&self.data.as_ref()[self.offset..]
}
}
impl AsRef<[u8]> for packed::Backing {
fn as_ref(&self) -> &[u8] {
match self {
packed::Backing::InMemory(data) => data,
packed::Backing::Mapped(map) => map,
}
}
}
///
pub mod open {
use std::path::PathBuf;
use filebuffer::FileBuffer;
use crate::store::packed;
/// Initialization
impl packed::Buffer {
/// Open the file at `path` and map it into memory if the file size is larger than `use_memory_map_if_larger_than_bytes`.
///
/// In order to allow fast lookups and optimizations, the contents of the packed refs must be sorted.
/// If that's not the case, they will be sorted on the fly with the data being written into a memory buffer.
pub fn open(path: impl Into<PathBuf>, use_memory_map_if_larger_than_bytes: u64) -> Result<Self, Error> {
let path = path.into();
let (backing, offset) = {
let backing = if std::fs::metadata(&path)?.len() <= use_memory_map_if_larger_than_bytes {
packed::Backing::InMemory(std::fs::read(&path)?)
} else {
packed::Backing::Mapped(FileBuffer::open(&path)?)
};
let (offset, sorted) = {
let data = backing.as_ref();
if *data.get(0).unwrap_or(&b' ') == b'#' {
let (records, header) = packed::decode::header::<()>(data).map_err(|_| Error::HeaderParsing)?;
let offset = records.as_ptr() as usize - data.as_ptr() as usize;
(offset, header.sorted)
} else {
(0, false)
}
};
if !sorted {
// this implementation is likely slower than what git does, but it's less code, too.
let mut entries = packed::Iter::new(&backing.as_ref()[offset..])?.collect::<Result<Vec<_>, _>>()?;
entries.sort_by_key(|e| e.name.as_bstr());
let mut serialized = Vec::<u8>::new();
for entry in entries {
serialized.extend_from_slice(entry.target);
serialized.push(b' ');
serialized.extend_from_slice(entry.name.as_bstr());
serialized.push(b'\n');
if let Some(object) = entry.object {
serialized.push(b'^');
serialized.extend_from_slice(object);
serialized.push(b'\n');
}
}
(Backing::InMemory(serialized), 0)
} else {
(backing, offset)
}
};
Ok(packed::Buffer {
offset,
data: backing,
path,
})
}
}
mod error {
use quick_error::quick_error;
use crate::packed;
quick_error! {
/// The error returned by [`open()`][super::packed::Buffer::open()].
#[derive(Debug)]
#[allow(missing_docs)]
pub enum Error {
Iter(err: packed::iter::Error) {
display("The packed-refs file did not have a header or wasn't sorted and could not be iterated")
from()
source(err)
}
HeaderParsing {
display("The header could not be parsed, even though first line started with '#'")
}
Io(err: std::io::Error) {
display("The buffer could not be opened or read")
from()
source(err)
}
}
}
}
pub use error::Error;
use crate::packed::Backing;
}