use crate::{extension, extension::Signature, util::from_be_u32};
pub(crate) fn header(data: &[u8]) -> (Signature, u32, &[u8]) {
let (signature, data) = data.split_at(4);
let (size, data) = data.split_at(4);
(signature.try_into().unwrap(), from_be_u32(size), data)
}
mod error {
use crate::extension;
#[derive(Debug, thiserror::Error)]
#[allow(missing_docs)]
pub enum Error {
#[error(
"Encountered mandatory extension '{}' which isn't implemented yet",
String::from_utf8_lossy(signature)
)]
MandatoryUnimplemented { signature: extension::Signature },
#[error("Could not parse mandatory link extension")]
Link(#[from] extension::link::decode::Error),
}
}
pub use error::Error;
pub(crate) fn all(
maybe_beginning_of_extensions: &[u8],
object_hash: gix_hash::Kind,
) -> Result<(Outcome, &[u8]), Error> {
let mut ext_iter = match extension::Iter::new_without_checksum(maybe_beginning_of_extensions, object_hash) {
Some(iter) => iter,
None => return Ok((Outcome::default(), maybe_beginning_of_extensions)),
};
let mut ext = Outcome::default();
for (signature, ext_data) in ext_iter.by_ref() {
match signature {
extension::tree::SIGNATURE => {
ext.tree = extension::tree::decode(ext_data, object_hash);
}
extension::resolve_undo::SIGNATURE => {
ext.resolve_undo = extension::resolve_undo::decode(ext_data, object_hash);
}
extension::untracked_cache::SIGNATURE => {
ext.untracked = extension::untracked_cache::decode(ext_data, object_hash);
}
extension::fs_monitor::SIGNATURE => {
ext.fs_monitor = extension::fs_monitor::decode(ext_data);
}
extension::end_of_index_entry::SIGNATURE => {
ext.end_of_index = true;
} extension::index_entry_offset_table::SIGNATURE => {
ext.offset_table = true;
} mandatory if mandatory[0].is_ascii_lowercase() => match mandatory {
extension::link::SIGNATURE => ext.link = extension::link::decode(ext_data, object_hash)?.into(),
extension::sparse::SIGNATURE => {
if !ext_data.is_empty() {
return Err(Error::MandatoryUnimplemented { signature: mandatory });
}
ext.is_sparse = true
}
unknown => return Err(Error::MandatoryUnimplemented { signature: unknown }),
},
_unknown => {} }
}
Ok((ext, &maybe_beginning_of_extensions[ext_iter.consumed..]))
}
#[derive(Default)]
pub(crate) struct Outcome {
pub tree: Option<extension::Tree>,
pub link: Option<extension::Link>,
pub resolve_undo: Option<extension::resolve_undo::Paths>,
pub untracked: Option<extension::UntrackedCache>,
pub fs_monitor: Option<extension::FsMonitor>,
pub is_sparse: bool,
pub offset_table: bool,
pub end_of_index: bool,
}