use crate::pack::index::{self, Kind, FAN_LEN, V2_SIGNATURE};use byteorder::{BigEndian, ByteOrder};use filebuffer::FileBuffer;use git_object::SHA1_SIZE;use quick_error::quick_error;use std::{convert::TryFrom, mem::size_of, path::Path}; quick_error! { #[derive(Debug)] pub enum Error { Io(err: std::io::Error, path: std::path::PathBuf) { display("Could not open pack index file at '{}'", path.display()) source(err) } Corrupt(msg: String) { display("{}", msg) } UnsupportedVersion(version: u32) { display("Unsupported index version: {}", version) } }} const N32_SIZE: usize = size_of::<u32>();const FOOTER_SIZE: usize = SHA1_SIZE * 2; /// Instantiationimpl index::File { pub fn at(path: impl AsRef<Path>) -> Result<index::File, Error> { Self::try_from(path.as_ref()) }} impl TryFrom<&Path> for index::File { type Error = Error; fn try_from(path: &Path) -> Result<Self, Self::Error> { let data = FileBuffer::open(&path).map_err(|e| Error::Io(e, path.to_owned()))?; let idx_len = data.len(); if idx_len < FAN_LEN * N32_SIZE + FOOTER_SIZE { return Err(Error::Corrupt(format!( "Pack index of size {} is too small for even an empty index", idx_len ))); } let (kind, version, fan, num_objects) = { let (kind, d) = { let (sig, d) = data.split_at(V2_SIGNATURE.len()); if sig == V2_SIGNATURE { (Kind::V2, d) } else { (Kind::V1, &data[..]) } }; let (version, d) = { let (mut v, mut d) = (1, d); if let Kind::V2 = kind { let (vd, dr) = d.split_at(N32_SIZE); d = dr; v = BigEndian::read_u32(vd); if v != Kind::V2 as u32 { return Err(Error::UnsupportedVersion(v)); } } (v, d) }; let (fan, bytes_read) = read_fan(d); let (_, _d) = d.split_at(bytes_read); let num_objects = fan[FAN_LEN - 1]; (kind, version, fan, num_objects) }; Ok(index::File { data, path: path.to_owned(), kind, num_objects, version, fan, }) }} fn read_fan(d: &[u8]) -> ([u32; FAN_LEN], usize) { let mut fan = [0; FAN_LEN]; for (c, f) in d.chunks(N32_SIZE).zip(fan.iter_mut()) { *f = BigEndian::read_u32(c); } (fan, FAN_LEN * N32_SIZE)}
use crate::pack::index::{self, Kind, FAN_LEN, V2_SIGNATURE};
use byteorder::{BigEndian, ByteOrder};
use filebuffer::FileBuffer;
use git_object::SHA1_SIZE;
use quick_error::quick_error;
use std::{convert::TryFrom, mem::size_of, path::Path};
quick_error! {
#[derive(Debug)]
pub enum Error {
Io(err: std::io::Error, path: std::path::PathBuf) {
display("Could not open pack index file at '{}'", path.display())
source(err)
}
Corrupt(msg: String) {
display("{}", msg)
}
UnsupportedVersion(version: u32) {
display("Unsupported index version: {}", version)
}
}
}
const N32_SIZE: usize = size_of::<u32>();
const FOOTER_SIZE: usize = SHA1_SIZE * 2;
/// Instantiation
impl index::File {
pub fn at(path: impl AsRef<Path>) -> Result<index::File, Error> {
Self::try_from(path.as_ref())
}
}
impl TryFrom<&Path> for index::File {
type Error = Error;
fn try_from(path: &Path) -> Result<Self, Self::Error> {
let data = FileBuffer::open(&path).map_err(|e| Error::Io(e, path.to_owned()))?;
let idx_len = data.len();
if idx_len < FAN_LEN * N32_SIZE + FOOTER_SIZE {
return Err(Error::Corrupt(format!(
"Pack index of size {} is too small for even an empty index",
idx_len
)));
}
let (kind, version, fan, num_objects) = {
let (kind, d) = {
let (sig, d) = data.split_at(V2_SIGNATURE.len());
if sig == V2_SIGNATURE {
(Kind::V2, d)
} else {
(Kind::V1, &data[..])
}
};
let (version, d) = {
let (mut v, mut d) = (1, d);
if let Kind::V2 = kind {
let (vd, dr) = d.split_at(N32_SIZE);
d = dr;
v = BigEndian::read_u32(vd);
if v != Kind::V2 as u32 {
return Err(Error::UnsupportedVersion(v));
}
}
(v, d)
};
let (fan, bytes_read) = read_fan(d);
let (_, _d) = d.split_at(bytes_read);
let num_objects = fan[FAN_LEN - 1];
(kind, version, fan, num_objects)
};
Ok(index::File {
data,
path: path.to_owned(),
kind,
num_objects,
version,
fan,
})
}
}
fn read_fan(d: &[u8]) -> ([u32; FAN_LEN], usize) {
let mut fan = [0; FAN_LEN];
for (c, f) in d.chunks(N32_SIZE).zip(fan.iter_mut()) {
*f = BigEndian::read_u32(c);
}
(fan, FAN_LEN * N32_SIZE)
}