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use std::io::Write;
use crate::Kind;
/// Writing of objects to a `Write` implementation
pub trait WriteTo {
/// Write a representation of this instance to `out`.
fn write_to(&self, out: &mut dyn std::io::Write) -> std::io::Result<()>;
/// Returns the type of this object.
fn kind(&self) -> Kind;
/// Returns the size of this object's representation (the amount
/// of data which would be written by [`write_to`](Self::write_to)).
///
/// [`size`](Self::size)'s value has no bearing on the validity of
/// the object, as such it's possible for [`size`](Self::size) to
/// return a sensible value but [`write_to`](Self::write_to) to
/// fail because the object was not actually valid in some way.
fn size(&self) -> u64;
/// Returns a loose object header based on the object's data
fn loose_header(&self) -> smallvec::SmallVec<[u8; 28]> {
crate::encode::loose_header(self.kind(), self.size())
}
}
impl<T> WriteTo for &T
where
T: WriteTo,
{
fn write_to(&self, out: &mut dyn Write) -> std::io::Result<()> {
<T as WriteTo>::write_to(self, out)
}
fn kind(&self) -> Kind {
<T as WriteTo>::kind(self)
}
fn size(&self) -> u64 {
<T as WriteTo>::size(self)
}
}
mod find {
use crate::find;
/// Check if an object is present in an object store.
pub trait Exists {
/// Returns `true` if the object exists in the database.
fn exists(&self, id: &gix_hash::oid) -> bool;
}
/// Find an object in the object store.
///
/// ## Notes
///
/// Find effectively needs [generic associated types][issue] to allow a trait for the returned object type.
/// Until then, we will have to make due with explicit types and give them the potentially added features we want.
///
/// [issue]: https://github.com/rust-lang/rust/issues/44265
pub trait Find {
/// Find an object matching `id` in the database while placing its raw, possibly encoded data into `buffer`.
///
/// Returns `Some` object if it was present in the database, or the error that occurred during lookup or object
/// retrieval.
fn try_find<'a>(
&self,
id: &gix_hash::oid,
buffer: &'a mut Vec<u8>,
) -> Result<Option<crate::Data<'a>>, find::Error>;
}
/// Find the header of an object in the object store.
pub trait Header {
/// Find the header of the object matching `id` in the database.
///
/// Returns `Some` header if it was present, or the error that occurred during lookup.
fn try_header(&self, id: &gix_hash::oid) -> Result<Option<crate::Header>, find::Error>;
}
/// A combination of [`Find`] and [`Header`] traits to help with `dyn` trait objects.
pub trait FindObjectOrHeader: Find + Header {}
mod _impls {
use std::{ops::Deref, rc::Rc, sync::Arc};
use gix_hash::oid;
use crate::Data;
impl<T> crate::Exists for &T
where
T: crate::Exists,
{
fn exists(&self, id: &oid) -> bool {
(*self).exists(id)
}
}
impl<T> crate::FindObjectOrHeader for T where T: crate::Find + crate::FindHeader {}
impl<T> crate::Find for &T
where
T: crate::Find,
{
fn try_find<'a>(&self, id: &oid, buffer: &'a mut Vec<u8>) -> Result<Option<Data<'a>>, crate::find::Error> {
(*self).try_find(id, buffer)
}
}
impl<T> crate::FindHeader for &T
where
T: crate::FindHeader,
{
fn try_header(&self, id: &gix_hash::oid) -> Result<Option<crate::Header>, crate::find::Error> {
(*self).try_header(id)
}
}
impl<T> crate::Exists for Box<T>
where
T: crate::Exists,
{
fn exists(&self, id: &oid) -> bool {
self.deref().exists(id)
}
}
impl<T> crate::Exists for Rc<T>
where
T: crate::Exists,
{
fn exists(&self, id: &oid) -> bool {
self.deref().exists(id)
}
}
impl<T> crate::Find for Rc<T>
where
T: crate::Find,
{
fn try_find<'a>(&self, id: &oid, buffer: &'a mut Vec<u8>) -> Result<Option<Data<'a>>, crate::find::Error> {
self.deref().try_find(id, buffer)
}
}
impl<T> crate::FindHeader for Rc<T>
where
T: crate::FindHeader,
{
fn try_header(&self, id: &gix_hash::oid) -> Result<Option<crate::Header>, crate::find::Error> {
self.deref().try_header(id)
}
}
impl<T> crate::Find for Box<T>
where
T: crate::Find,
{
fn try_find<'a>(&self, id: &oid, buffer: &'a mut Vec<u8>) -> Result<Option<Data<'a>>, crate::find::Error> {
self.deref().try_find(id, buffer)
}
}
impl<T> crate::FindHeader for Box<T>
where
T: crate::FindHeader,
{
fn try_header(&self, id: &gix_hash::oid) -> Result<Option<crate::Header>, crate::find::Error> {
self.deref().try_header(id)
}
}
impl<T> crate::Exists for Arc<T>
where
T: crate::Exists,
{
fn exists(&self, id: &oid) -> bool {
self.deref().exists(id)
}
}
impl<T> crate::Find for Arc<T>
where
T: crate::Find,
{
fn try_find<'a>(&self, id: &oid, buffer: &'a mut Vec<u8>) -> Result<Option<Data<'a>>, crate::find::Error> {
self.deref().try_find(id, buffer)
}
}
impl<T> crate::FindHeader for Arc<T>
where
T: crate::FindHeader,
{
fn try_header(&self, id: &gix_hash::oid) -> Result<Option<crate::Header>, crate::find::Error> {
self.deref().try_header(id)
}
}
}
mod ext {
use crate::{
find, BlobRef, CommitRef, CommitRefIter, Kind, ObjectRef, TagRef, TagRefIter, TreeRef, TreeRefIter,
};
macro_rules! make_obj_lookup {
($method:ident, $object_variant:path, $object_kind:path, $object_type:ty) => {
/// Like [`find(…)`][Self::find()], but flattens the `Result<Option<_>>` into a single `Result` making a non-existing object an error
/// while returning the desired object type.
fn $method<'a>(
&self,
id: &gix_hash::oid,
buffer: &'a mut Vec<u8>,
) -> Result<$object_type, find::existing_object::Error> {
self.try_find(id, buffer)
.map_err(find::existing_object::Error::Find)?
.ok_or_else(|| find::existing_object::Error::NotFound {
oid: id.as_ref().to_owned(),
})
.and_then(|o| {
o.decode()
.map_err(|err| find::existing_object::Error::Decode {
source: err,
oid: id.as_ref().to_owned(),
})
})
.and_then(|o| match o {
$object_variant(o) => return Ok(o),
o => Err(find::existing_object::Error::ObjectKind {
oid: id.as_ref().to_owned(),
actual: o.kind(),
expected: $object_kind,
}),
})
}
};
}
macro_rules! make_iter_lookup {
($method:ident, $object_kind:path, $object_type:ty, $into_iter:tt) => {
/// Like [`find(…)`][Self::find()], but flattens the `Result<Option<_>>` into a single `Result` making a non-existing object an error
/// while returning the desired iterator type.
fn $method<'a>(
&self,
id: &gix_hash::oid,
buffer: &'a mut Vec<u8>,
) -> Result<$object_type, find::existing_iter::Error> {
self.try_find(id, buffer)
.map_err(find::existing_iter::Error::Find)?
.ok_or_else(|| find::existing_iter::Error::NotFound {
oid: id.as_ref().to_owned(),
})
.and_then(|o| {
o.$into_iter()
.ok_or_else(|| find::existing_iter::Error::ObjectKind {
oid: id.as_ref().to_owned(),
actual: o.kind,
expected: $object_kind,
})
})
}
};
}
/// An extension trait with convenience functions.
pub trait HeaderExt: super::Header {
/// Like [`try_header(…)`](super::Header::try_header()), but flattens the `Result<Option<_>>` into a single `Result` making a non-existing header an error.
fn header(&self, id: &gix_hash::oid) -> Result<crate::Header, find::existing::Error> {
self.try_header(id)
.map_err(find::existing::Error::Find)?
.ok_or_else(|| find::existing::Error::NotFound { oid: id.to_owned() })
}
}
/// An extension trait with convenience functions.
pub trait FindExt: super::Find {
/// Like [`try_find(…)`](super::Find::try_find()), but flattens the `Result<Option<_>>` into a single `Result` making a non-existing object an error.
fn find<'a>(
&self,
id: &gix_hash::oid,
buffer: &'a mut Vec<u8>,
) -> Result<crate::Data<'a>, find::existing::Error> {
self.try_find(id, buffer)
.map_err(find::existing::Error::Find)?
.ok_or_else(|| find::existing::Error::NotFound { oid: id.to_owned() })
}
make_obj_lookup!(find_commit, ObjectRef::Commit, Kind::Commit, CommitRef<'a>);
make_obj_lookup!(find_tree, ObjectRef::Tree, Kind::Tree, TreeRef<'a>);
make_obj_lookup!(find_tag, ObjectRef::Tag, Kind::Tag, TagRef<'a>);
make_obj_lookup!(find_blob, ObjectRef::Blob, Kind::Blob, BlobRef<'a>);
make_iter_lookup!(find_commit_iter, Kind::Commit, CommitRefIter<'a>, try_into_commit_iter);
make_iter_lookup!(find_tree_iter, Kind::Tree, TreeRefIter<'a>, try_into_tree_iter);
make_iter_lookup!(find_tag_iter, Kind::Tag, TagRefIter<'a>, try_into_tag_iter);
}
impl<T: super::Find + ?Sized> FindExt for T {}
}
pub use ext::{FindExt, HeaderExt};
}
pub use find::*;