Re-License to "MIT OR Apache-2.0" — radicle-git

The main dependant of radicle-git, and its crates, is heartwood. It is licensed under MIT or Apache-2.0, which has been incompatible with the GPL-3.0 license. Since the intellectual property of this code base is with the Better Internet Foundation, it was decided to re-license code in this repository to make the upstream repository compatible.

The changes required were:

Remove the license headers (and instructions to add them)
Add MIT and Apache-2.0 licenses
Remove the GPL-3.0 license
Change the license declarations in the Cargo.toml files

 The crowd at `src-d` have a [wonderful guide][fixing-dco] on how to remedy this
 situation.
 ## License Header
 As part of our license, we must include a license header at the top of each
 source file. The template for this header can be found [here][header-template].
 If you are creating a new file in the repository you will have to add this
 header to the file.
 [dco]: ./DCO
 [fixing-dco]: https://github.com/src-d/guide/blob/master/developer-community/fix-DCO.md
 [header-template]: ./.license-header

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 MIT License
 Copyright (c) 2021 The Radicle Foundation
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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 The above copyright notice and this permission notice shall be included in all
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 [package]
 name = "git-commit"
 version = "0.3.0"
 license = "MIT OR Apache-2.0"
 edition = "2021"
 authors = [
   "Alexis Sellier <alexis@radicle.xyz>",
   "Fintan Halpenny <fintan.halpenny@gmail.com>",
 ]
 description = "A small library for parsing, displaying and creating a git commit"
 keywords = ["git", "git-commit", "git-trailers", "radicle"]
 [dependencies]
 thiserror = "1"
 [dependencies.git2]
 version = "0.16.1"
 default-features = false
 features = ["vendored-libgit2"]

 use std::{
     fmt,
     num::ParseIntError,
     str::{self, FromStr},
 };
 use thiserror::Error;
 /// The data for indicating authorship of an action within a
 /// [`super::Commit`].
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct Author {
     /// Name corresponding to `user.name` in the git config.
     ///
     /// Note: this must not contain `<` or `>`.
     pub name: String,
     /// Email corresponding to `user.email` in the git config.
     ///
     /// Note: this must not contain `<` or `>`.
     pub email: String,
     /// The time of this author's action.
     pub time: Time,
 }
 /// The time of a [`Author`]'s action.
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub struct Time {
     seconds: i64,
     offset: i32,
 }
 impl Time {
     pub fn new(seconds: i64, offset: i32) -> Self {
         Self { seconds, offset }
     }
     /// Return the time, in seconds, since the epoch.
     pub fn seconds(&self) -> i64 {
         self.seconds
     }
     /// Return the timezone offset, in minutes.
     pub fn offset(&self) -> i32 {
         self.offset
     }
 }
 impl From<Time> for git2::Time {
     fn from(t: Time) -> Self {
         Self::new(t.seconds, t.offset)
     }
 }
 impl From<git2::Time> for Time {
     fn from(t: git2::Time) -> Self {
         Self::new(t.seconds(), t.offset_minutes())
     }
 }
 impl fmt::Display for Time {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let sign = if self.offset.is_negative() { '-' } else { '+' };
         write!(f, "{} {}{:0>4}", self.seconds, sign, self.offset.abs())
     }
 }
 impl fmt::Display for Author {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "{} <{}> {}", self.name, self.email, self.time,)
     }
 }
 impl TryFrom<&Author> for git2::Signature<'_> {
     type Error = git2::Error;
     fn try_from(person: &Author) -> Result<Self, Self::Error> {
         let time = git2::Time::new(person.time.seconds, person.time.offset);
         git2::Signature::new(&person.name, &person.email, &time)
     }
 }
 impl<'a> TryFrom<&git2::Signature<'a>> for Author {
     type Error = str::Utf8Error;
     fn try_from(value: &git2::Signature<'a>) -> Result<Self, Self::Error> {
         Ok(Self {
             name: str::from_utf8(value.name_bytes())?.to_string(),
             email: str::from_utf8(value.email_bytes())?.to_string(),
             time: value.when().into(),
         })
     }
 }
 #[derive(Debug, Error)]
 pub enum ParseError {
     #[error("missing '{0}' while parsing person signature")]
     Missing(&'static str),
     #[error("offset was incorrect format while parsing person signature")]
     Offset(#[source] ParseIntError),
     #[error("time was incorrect format while parsing person signature")]
     Time(#[source] ParseIntError),
     #[error("time offset is expected to be '+'/'-' for a person siganture")]
     UnknownOffset,
 }
 impl FromStr for Author {
     type Err = ParseError;
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         let mut components = s.split(' ');
         let offset = match components.next_back() {
             None => return Err(ParseError::Missing("offset")),
             Some(offset) => offset.parse::<i32>().map_err(ParseError::Offset)?,
         };
         let time = match components.next_back() {
             None => return Err(ParseError::Missing("time")),
             Some(time) => time.parse::<i64>().map_err(ParseError::Time)?,
         };
         let time = Time::new(time, offset);
         let email = components
             .next_back()
             .ok_or(ParseError::Missing("email"))?
             .trim_matches(|c| c == '<' || c == '>')
             .to_owned();
         let name = components.collect::<Vec<_>>().join(" ");
         Ok(Self { name, email, time })
     }
 }

 radicle-git
 Copyright © 2019-2021 The Radicle Foundation <hello@radicle.foundation>
 Copyright © 2021-2022 The Radicle Link Contributors
 <https://github.com/radicle-dev/radicle-link/graphs/contributors>
 Copyright © 2022 The Radicle Git Contributors
 <https://github.com/radicle-dev/radicle-git/graphs/contributors>
 radicle-link is licensed under version 3 of the GNU General Public License
 (GPLv3). Any contribution to radicle-link must be made subject to the
 Developer Certificate of Origin (DCO).
 By making your contribution, you are making the declaration set out in the
 Linux Foundation’s Developer Certificate of Origin version 1.1, in which
 the “open source licence indicated in the file” is GPLv3. A copy of the
 DCO can be found in the file named “DCO”.
 --------------------------------------------------------------------------
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 . Additional Terms.
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 Additional permissions that are applicable to the entire Program shall
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   When you convey a copy of a covered work, you may at your option
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   All other non-permissive additional terms are considered "further
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 reinstated, you do not qualify to receive new licenses for the same
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 . Acceptance Not Required for Having Copies.
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 occurring solely as a consequence of using peer-to-peer transmission
 to receive a copy likewise does not require acceptance.  However,
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 modify any covered work.  These actions infringe copyright if you do
 not accept this License.  Therefore, by modifying or propagating a
 covered work, you indicate your acceptance of this License to do so.
 . Automatic Licensing of Downstream Recipients.
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 . No Surrender of Others' Freedom.
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 . Use with the GNU Affero General Public License.
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 . Revised Versions of this License.
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 . Interpretation of Sections 15 and 16.
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                      END OF TERMS AND CONDITIONS

 use std::borrow::Cow;
 const BEGIN_SSH: &str = "-----BEGIN SSH SIGNATURE-----\n";
 const BEGIN_PGP: &str = "-----BEGIN PGP SIGNATURE-----\n";
 /// A collection of headers stored in a [`super::Commit`].
 ///
 /// Note: these do not include `tree`, `parent`, `author`, and `committer`.
 #[derive(Clone, Debug, Default)]
 pub struct Headers(pub(super) Vec<(String, String)>);
 /// A `gpgsig` signature stored in a [`super::Commit`].
 pub enum Signature<'a> {
     /// A PGP signature, i.e. starts with `-----BEGIN PGP SIGNATURE-----`.
     Pgp(Cow<'a, str>),
     /// A SSH signature, i.e. starts with `-----BEGIN SSH SIGNATURE-----`.
     Ssh(Cow<'a, str>),
 }
 impl<'a> Signature<'a> {
     fn from_str(s: &'a str) -> Result<Self, UnknownScheme> {
         if s.starts_with(BEGIN_SSH) {
             Ok(Signature::Ssh(Cow::Borrowed(s)))
         } else if s.starts_with(BEGIN_PGP) {
             Ok(Signature::Pgp(Cow::Borrowed(s)))
         } else {
             Err(UnknownScheme)
         }
     }
 }
 pub struct UnknownScheme;
 impl<'a> ToString for Signature<'a> {
     fn to_string(&self) -> String {
         match self {
             Signature::Pgp(pgp) => pgp.to_string(),
             Signature::Ssh(ssh) => ssh.to_string(),
         }
     }
 }
 impl Headers {
     pub fn new() -> Self {
         Headers(Vec::new())
     }
     pub fn iter(&self) -> impl Iterator<Item = (&str, &str)> {
         self.0.iter().map(|(k, v)| (k.as_str(), v.as_str()))
     }
     pub fn values<'a>(&'a self, name: &'a str) -> impl Iterator<Item = &'a str> + '_ {
         self.iter()
             .filter_map(move |(k, v)| (k == name).then_some(v))
     }
     pub fn signatures(&self) -> impl Iterator<Item = Signature> + '_ {
         self.0.iter().filter_map(|(k, v)| {
             if k == "gpgsig" {
                 Signature::from_str(v).ok()
             } else {
                 None
             }
         })
     }
     /// Push a header to the end of the headers section.
     pub fn push(&mut self, name: &str, value: &str) {
         self.0.push((name.to_owned(), value.trim().to_owned()));
     }
 }

 //! The `git-commit` crate provides parsing a displaying of a [git
 //! commit][git-commit].
 //!
 //! The [`Commit`] data can be constructed using the `FromStr`
 //! implementation, or by converting from a `git2::Buf`.
 //!
 //! The [`Headers`] can be accessed via [`Commit::headers`]. If the
 //! signatures of the commit are of particular interest, the
 //! [`Commit::signatures`] method can be used, which returns a series of
 //! [`Signature`]s.
 //!
 //! [git-commit]: https://git-scm.com/book/en/v2/Git-Internals-Git-Objects
 use std::{
     fmt::Write as _,
     str::{self, FromStr},
 };
 use git2::{ObjectType, Oid};
 pub mod author;
 pub use author::Author;
 pub mod headers;
 pub use headers::{Headers, Signature};
 pub mod trailers;
 pub use trailers::{OwnedTrailer, Trailer, Trailers};
 /// A git commit in its object description form, i.e. the output of
 /// `git cat-file` for a commit object.
 #[derive(Debug)]
 pub struct Commit {
     tree: Oid,
     parents: Vec<Oid>,
     author: Author,
     committer: Author,
     headers: Headers,
     message: String,
     trailers: Vec<OwnedTrailer>,
 }
 impl Commit {
     pub fn new<I, T>(
         tree: Oid,
         parents: Vec<Oid>,
         author: Author,
         committer: Author,
         headers: Headers,
         message: String,
         trailers: I,
     ) -> Self
     where
         I: IntoIterator<Item = T>,
         OwnedTrailer: From<T>,
     {
         let trailers = trailers.into_iter().map(OwnedTrailer::from).collect();
         Self {
             tree,
             parents,
             author,
             committer,
             headers,
             message,
             trailers,
         }
     }
     /// Read the [`Commit`] from the `repo` that is expected to be found at
     /// `oid`.
     pub fn read(repo: &git2::Repository, oid: Oid) -> Result<Self, error::Read> {
         let odb = repo.odb()?;
         let object = odb.read(oid)?;
         Ok(Commit::try_from(object.data())?)
     }
     /// Write the given [`Commit`] to the `repo`. The resulting `Oid`
     /// is the identifier for this commit.
     pub fn write(&self, repo: &git2::Repository) -> Result<Oid, git2::Error> {
         let odb = repo.odb()?;
         odb.write(ObjectType::Commit, self.to_string().as_bytes())
     }
     /// The tree [`Oid`] this commit points to.
     pub fn tree(&self) -> Oid {
         self.tree
     }
     /// The parent [`Oid`]s of this commit.
     pub fn parents(&self) -> impl Iterator<Item = Oid> + '_ {
         self.parents.iter().copied()
     }
     /// The author of this commit, i.e. the header corresponding to `author`.
     pub fn author(&self) -> &Author {
         &self.author
     }
     /// The committer of this commit, i.e. the header corresponding to
     /// `committer`.
     pub fn committer(&self) -> &Author {
         &self.committer
     }
     /// The message body of this commit.
     pub fn message(&self) -> &str {
         &self.message
     }
     /// The [`Signature`]s found in this commit, i.e. the headers corresponding
     /// to `gpgsig`.
     pub fn signatures(&self) -> impl Iterator<Item = Signature> + '_ {
         self.headers.signatures()
     }
     /// The [`Headers`] found in this commit.
     ///
     /// Note: these do not include `tree`, `parent`, `author`, and `committer`.
     pub fn headers(&self) -> impl Iterator<Item = (&str, &str)> {
         self.headers.iter()
     }
     /// Iterate over the [`Headers`] values that match the provided `name`.
     pub fn values<'a>(&'a self, name: &'a str) -> impl Iterator<Item = &'a str> + '_ {
         self.headers.values(name)
     }
     /// Push a header to the end of the headers section.
     pub fn push_header(&mut self, name: &str, value: &str) {
         self.headers.push(name, value.trim());
     }
     pub fn trailers(&self) -> impl Iterator<Item = &OwnedTrailer> {
         self.trailers.iter()
     }
 }
 pub mod error {
     use std::str;
     use thiserror::Error;
     use super::author;
     #[derive(Debug, Error)]
     pub enum Read {
         #[error(transparent)]
         Git(#[from] git2::Error),
         #[error(transparent)]
         Parse(#[from] Parse),
     }
     #[derive(Debug, Error)]
     pub enum Parse {
         #[error(transparent)]
         Author(#[from] author::ParseError),
         #[error("invalid '{header}'")]
         InvalidHeader {
             header: &'static str,
             #[source]
             err: git2::Error,
         },
         #[error("invalid git commit object format")]
         InvalidFormat,
         #[error("missing '{0}' while parsing commit")]
         Missing(&'static str),
         #[error("error occurred while checking for git-trailers: {0}")]
         Trailers(#[source] git2::Error),
         #[error(transparent)]
         Utf8(#[from] str::Utf8Error),
     }
 }
 impl TryFrom<git2::Buf> for Commit {
     type Error = error::Parse;
     fn try_from(value: git2::Buf) -> Result<Self, Self::Error> {
         value.as_str().ok_or(error::Parse::InvalidFormat)?.parse()
     }
 }
 impl TryFrom<&[u8]> for Commit {
     type Error = error::Parse;
     fn try_from(data: &[u8]) -> Result<Self, Self::Error> {
         Commit::from_str(str::from_utf8(data)?)
     }
 }
 impl FromStr for Commit {
     type Err = error::Parse;
     fn from_str(buffer: &str) -> Result<Self, Self::Err> {
         let (header, message) = buffer
             .split_once("\n\n")
             .ok_or(error::Parse::InvalidFormat)?;
         let mut lines = header.lines();
         let tree = match lines.next() {
             Some(tree) => tree
                 .strip_prefix("tree ")
                 .map(git2::Oid::from_str)
                 .transpose()
                 .map_err(|err| error::Parse::InvalidHeader {
                     header: "tree",
                     err,
                 })?
                 .ok_or(error::Parse::Missing("tree"))?,
             None => return Err(error::Parse::Missing("tree")),
         };
         let mut parents = Vec::new();
         let mut author: Option<Author> = None;
         let mut committer: Option<Author> = None;
         let mut headers = Headers::new();
         for line in lines {
             // Check if a signature is still being parsed
             if let Some(rest) = line.strip_prefix(' ') {
                 let value: &mut String = headers
                     .0
                     .last_mut()
                     .map(|(_, v)| v)
                     .ok_or(error::Parse::InvalidFormat)?;
                 value.push('\n');
                 value.push_str(rest);
                 continue;
             }
             if let Some((name, value)) = line.split_once(' ') {
                 match name {
                     "parent" => parents.push(git2::Oid::from_str(value).map_err(|err| {
                         error::Parse::InvalidHeader {
                             header: "parent",
                             err,
                         }
                     })?),
                     "author" => author = Some(value.parse::<Author>()?),
                     "committer" => committer = Some(value.parse::<Author>()?),
                     _ => headers.push(name, value),
                 }
                 continue;
             }
         }
         let trailers = trailers::Trailers::parse(message).map_err(error::Parse::Trailers)?;
         let message = message
             .strip_suffix(&trailers.to_string(": "))
             .unwrap_or(message)
             .to_string();
         let trailers = trailers.iter().map(OwnedTrailer::from).collect();
         Ok(Self {
             tree,
             parents,
             author: author.ok_or(error::Parse::Missing("author"))?,
             committer: committer.ok_or(error::Parse::Missing("committer"))?,
             headers,
             message,
             trailers,
         })
     }
 }
 impl ToString for Commit {
     fn to_string(&self) -> String {
         let mut buf = String::new();
         writeln!(buf, "tree {}", self.tree).ok();
         for parent in &self.parents {
             writeln!(buf, "parent {parent}").ok();
         }
         writeln!(buf, "author {}", self.author).ok();
         writeln!(buf, "committer {}", self.committer).ok();
         for (name, value) in self.headers.iter() {
             writeln!(buf, "{name} {}", value.replace('\n', "\n ")).ok();
         }
         writeln!(buf).ok();
         write!(buf, "{}", self.message.trim()).ok();
         writeln!(buf).ok();
         if !self.trailers.is_empty() {
             writeln!(buf).ok();
         }
         for trailer in self.trailers.iter() {
             writeln!(buf, "{}", Trailer::from(trailer).display(": ")).ok();
         }
         buf
     }
 }

 use std::{borrow::Cow, fmt, fmt::Write, ops::Deref, str::FromStr};
 use git2::{MessageTrailersStrs, MessageTrailersStrsIterator};
 /// A Git commit's set of trailers that are left in the commit's
 /// message.
 ///
 /// Trailers are key/value pairs in the last paragraph of a message,
 /// not including any patches or conflicts that may be present.
 ///
 /// # Usage
 ///
 /// To construct `Trailers`, you can use [`Trailers::parse`] or its
 /// `FromStr` implementation.
 ///
 /// To iterate over the trailers, you can use [`Trailers::iter`].
 ///
 /// To render the trailers to a `String`, you can use
 /// [`Trailers::to_string`] or its `Display` implementation (note that
 /// it will default to using `": "` as the separator.
 ///
 /// # Examples
 ///
 /// ```text
 /// Add new functionality
 ///
 /// Making code better with new functionality.
 ///
 /// X-Signed-Off-By: Alex Sellier
 /// X-Co-Authored-By: Fintan Halpenny
 /// ```
 ///
 /// The trailers in the above example are:
 ///
 /// ```text
 /// X-Signed-Off-By: Alex Sellier
 /// X-Co-Authored-By: Fintan Halpenny
 /// ```
 pub struct Trailers {
     inner: MessageTrailersStrs,
 }
 impl Trailers {
     pub fn parse(message: &str) -> Result<Self, git2::Error> {
         Ok(Self {
             inner: git2::message_trailers_strs(message)?,
         })
     }
     pub fn iter(&self) -> Iter<'_> {
         Iter {
             inner: self.inner.iter(),
         }
     }
     pub fn to_string<'a, S>(&self, sep: S) -> String
     where
         S: Separator<'a>,
     {
         let mut buf = String::new();
         for (i, trailer) in self.iter().enumerate() {
             if i > 0 {
                 writeln!(buf).ok();
             }
             write!(buf, "{}", trailer.display(sep.sep_for(&trailer.token))).ok();
         }
         writeln!(buf).ok();
         buf
     }
 }
 impl fmt::Display for Trailers {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.write_str(&self.to_string(": "))
     }
 }
 pub trait Separator<'a> {
     fn sep_for(&self, token: &Token) -> &'a str;
 }
 impl<'a> Separator<'a> for &'a str {
     fn sep_for(&self, _: &Token) -> &'a str {
         self
     }
 }
 impl<'a, F> Separator<'a> for F
 where
     F: Fn(&Token) -> &'a str,
 {
     fn sep_for(&self, token: &Token) -> &'a str {
         self(token)
     }
 }
 impl FromStr for Trailers {
     type Err = git2::Error;
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         Self::parse(s)
     }
 }
 pub struct Iter<'a> {
     inner: MessageTrailersStrsIterator<'a>,
 }
 impl<'a> Iterator for Iter<'a> {
     type Item = Trailer<'a>;
     fn next(&mut self) -> Option<Self::Item> {
         let (token, value) = self.inner.next()?;
         Some(Trailer {
             token: Token(token),
             value: Cow::Borrowed(value),
         })
     }
 }
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct Token<'a>(&'a str);
 impl Deref for Token<'_> {
     type Target = str;
     fn deref(&self) -> &Self::Target {
         self.0
     }
 }
 pub struct Display<'a> {
     trailer: &'a Trailer<'a>,
     separator: &'a str,
 }
 impl<'a> fmt::Display for Display<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(
             f,
             "{}{}{}",
             self.trailer.token.deref(),
             self.separator,
             self.trailer.value,
         )
     }
 }
 /// A trailer is a key/value pair found in the last paragraph of a Git
 /// commit message, not including any patches or conflicts that may be
 /// present.
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct Trailer<'a> {
     pub token: Token<'a>,
     pub value: Cow<'a, str>,
 }
 impl<'a> Trailer<'a> {
     pub fn display(&'a self, separator: &'a str) -> Display<'a> {
         Display {
             trailer: self,
             separator,
         }
     }
     pub fn to_owned(&self) -> OwnedTrailer {
         OwnedTrailer::from(self)
     }
 }
 /// A version of the [`Trailer`] which owns its token and
 /// value. Useful for when you need to carry trailers around in a long
 /// lived data structure.
 #[derive(Debug)]
 pub struct OwnedTrailer {
     pub token: OwnedToken,
     pub value: String,
 }
 #[derive(Debug)]
 pub struct OwnedToken(String);
 impl Deref for OwnedToken {
     type Target = str;
     fn deref(&self) -> &Self::Target {
         &self.0
     }
 }
 impl<'a> From<&Trailer<'a>> for OwnedTrailer {
     fn from(t: &Trailer<'a>) -> Self {
         OwnedTrailer {
             token: OwnedToken(t.token.0.to_string()),
             value: t.value.to_string(),
         }
     }
 }
 impl<'a> From<Trailer<'a>> for OwnedTrailer {
     fn from(t: Trailer<'a>) -> Self {
         (&t).into()
     }
 }
 impl<'a> From<&'a OwnedTrailer> for Trailer<'a> {
     fn from(t: &'a OwnedTrailer) -> Self {
         Trailer {
             token: Token(t.token.0.as_str()),
             value: Cow::from(&t.value),
         }
     }
 }

 [package]
 name = "git-commit-test"
 version = "0.1.0"
 license = "MIT OR Apache-2.0"
 edition = "2021"
 publish = false
 [lib]
 doctest = false
 test = true
 doc = false
 [features]
 test = []
 [dev-dependencies.git-commit]
 path = ".."
 [dev-dependencies.git2]
 version = "0.16.1"
 default-features = false
 features = ["vendored-libgit2"]
 [dev-dependencies.test-helpers]
 path = "../../test/test-helpers"
 \ No newline at end of file

 use std::str::FromStr as _;
 use git_commit::Commit;
 const NO_TRAILER: &str = "\
 tree 50d6ef440728217febf9e35716d8b0296608d7f8
 parent 0ad95dbdfe9fdf81938ca419cf740469173e2022
 parent a4ec9e07e1b2e6f37f7119651ae3bb63b79988b6
 author Fintan Halpenny <fintan.halpenny@gmail.com> 1669292989 +0000
 committer Fintan Halpenny <fintan.halpenny@gmail.com> 1669292989 +0000
 Merge remote-tracking branch 'origin/surf/organise-tests'
 * origin/surf/organise-tests:
   radicle-surf: organise tests
 ";
 const SINGLE_TRAILER: &str = "\
 tree 50d6ef440728217febf9e35716d8b0296608d7f8
 parent 0ad95dbdfe9fdf81938ca419cf740469173e2022
 parent a4ec9e07e1b2e6f37f7119651ae3bb63b79988b6
 author Fintan Halpenny <fintan.halpenny@gmail.com> 1669292989 +0000
 committer Fintan Halpenny <fintan.halpenny@gmail.com> 1669292989 +0000
 Merge remote-tracking branch 'origin/surf/organise-tests'
 * origin/surf/organise-tests:
   radicle-surf: organise tests
 Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
 ";
 const UNSIGNED: &str = "\
 tree c66cc435f83ed0fba90ed4500e9b4b96e9bd001b
 parent af06ad645133f580a87895353508053c5de60716
 author Alexis Sellier <alexis@radicle.xyz> 1664467633 +0200
 committer Alexis Sellier <alexis@radicle.xyz> 1664786099 -0200
 Add SSH functionality with new `radicle-ssh`
 We borrow code from `thrussh`, refactored to be runtime-less.
 X-Signed-Off-By: Alex Sellier
 X-Co-Authored-By: Fintan Halpenny
 ";
 const SSH_SIGNATURE: &str = "\
 -----BEGIN SSH SIGNATURE-----
 U1NIU0lHAAAAAQAAADMAAAALc3NoLWVkMjU1MTkAAAAgvjrQogRxxLjzzWns8+mKJAGzEX
 fm2ALoN7pyvD2ttQAAAADZ2l0AAAAAAAAAAZzaGE1MTIAAABTAAAAC3NzaC1lZDI1NTE5
 AAAAQIQvhIewOgGfnXLgR5Qe1ZEr2vjekYXTdOfNWICi6ZiosgfZnIqV0enCPC4arVqQg+
 GPp0HqxaB911OnSAr6bwU=
 -----END SSH SIGNATURE-----";
 const PGP_SIGNATURE: &str = "\
 -----BEGIN PGP SIGNATURE-----
 iQIzBAABCAAdFiEEHe7BWIo9taTY6TIiJVL7b2QGbLcFAmNcDhsACgkQJVL7b2QG
 bLcc9Q//RgKf5N4enta9AuszGJZvdFhMPfIDUdw+WAZA6Z8zDPb/aAXZrPP/KIOM
 zmX08FTqjP9B9YeWrEcFuAtxsRNqbDKrfpko9Y6bTsdrAJg3WIypBb9F8YDKJ6BO
 CORJJqWOsLW129jW+mJDhcE0YTvPlcMiMI2qjVXKhU6Ag11W8IRZyTb9tvEaDjBR
 YUnkPvgubv61K9BeUKexE2MakPBldaQtl0MF1Dk7/zo5btLd+KP0SOUKEhuMEu5b
 LATHHdiYjt/2Xz7q8EcrFxXUaipxZe89dfTdi2ooJQw3ZDqjDHsGTHpDeBuzuSaJ
 fKVRwFz/78onfHPhmU4wfUhh+Fcl90p5/T+4dt2K6cr+7rq078e+aJYxkX2d0MG
 PG0xGP0RN4g+X92K1kGuzoe4870xAnRTNh5nUB+X9snO8tVqQZTb0M2yI+sTsKrv
 w/f+uiqL6e9DgIxlO5dgiNHCVoCs1QJ900jUGisrlzS4+n6GzMsG6s3c01X4yY9G
 Ou/kGkMsn7tqejqC9RufygcchCFZqYwaHQwPkiYhfYGMarMpoCFvll0h8tSparpS
 nnpAQXVdu8m3v1YdPUuTg5ksxSOe9HCIlVXGFhxy3iqCVRn+51FRnUI63rMTOm9/
 LBqzvji02lDUPGqPgXfcCS0ty8FM2flBIXnwb8TDzCaPYhf53+U=
 =6dw2
 -----END PGP SIGNATURE-----";
 const SIGNED: &str = "\
 tree c66cc435f83ed0fba90ed4500e9b4b96e9bd001b
 parent af06ad645133f580a87895353508053c5de60716
 author Alexis Sellier <alexis@radicle.xyz> 1664467633 +0200
 committer Alexis Sellier <alexis@radicle.xyz> 1664786099 -0200
 other e6fe3c97619deb8ab4198620f9a7eb79d98363dd
 gpgsig -----BEGIN SSH SIGNATURE-----
  U1NIU0lHAAAAAQAAADMAAAALc3NoLWVkMjU1MTkAAAAgvjrQogRxxLjzzWns8+mKJAGzEX
 fm2ALoN7pyvD2ttQAAAADZ2l0AAAAAAAAAAZzaGE1MTIAAABTAAAAC3NzaC1lZDI1NTE5
  AAAAQIQvhIewOgGfnXLgR5Qe1ZEr2vjekYXTdOfNWICi6ZiosgfZnIqV0enCPC4arVqQg+
  GPp0HqxaB911OnSAr6bwU=
  -----END SSH SIGNATURE-----
 gpgsig -----BEGIN PGP SIGNATURE-----
  iQIzBAABCAAdFiEEHe7BWIo9taTY6TIiJVL7b2QGbLcFAmNcDhsACgkQJVL7b2QG
  bLcc9Q//RgKf5N4enta9AuszGJZvdFhMPfIDUdw+WAZA6Z8zDPb/aAXZrPP/KIOM
  zmX08FTqjP9B9YeWrEcFuAtxsRNqbDKrfpko9Y6bTsdrAJg3WIypBb9F8YDKJ6BO
  CORJJqWOsLW129jW+mJDhcE0YTvPlcMiMI2qjVXKhU6Ag11W8IRZyTb9tvEaDjBR
  YUnkPvgubv61K9BeUKexE2MakPBldaQtl0MF1Dk7/zo5btLd+KP0SOUKEhuMEu5b
  LATHHdiYjt/2Xz7q8EcrFxXUaipxZe89dfTdi2ooJQw3ZDqjDHsGTHpDeBuzuSaJ
 fKVRwFz/78onfHPhmU4wfUhh+Fcl90p5/T+4dt2K6cr+7rq078e+aJYxkX2d0MG
  PG0xGP0RN4g+X92K1kGuzoe4870xAnRTNh5nUB+X9snO8tVqQZTb0M2yI+sTsKrv
  w/f+uiqL6e9DgIxlO5dgiNHCVoCs1QJ900jUGisrlzS4+n6GzMsG6s3c01X4yY9G
  Ou/kGkMsn7tqejqC9RufygcchCFZqYwaHQwPkiYhfYGMarMpoCFvll0h8tSparpS
  nnpAQXVdu8m3v1YdPUuTg5ksxSOe9HCIlVXGFhxy3iqCVRn+51FRnUI63rMTOm9/
  LBqzvji02lDUPGqPgXfcCS0ty8FM2flBIXnwb8TDzCaPYhf53+U=
  =6dw2
  -----END PGP SIGNATURE-----
 Add SSH functionality with new `radicle-ssh`
 We borrow code from `thrussh`, refactored to be runtime-less.
 X-Signed-Off-By: Alex Sellier
 X-Co-Authored-By: Fintan Halpenny
 ";
 #[test]
 fn test_push_header() {
     let mut commit = Commit::from_str(UNSIGNED).unwrap();
     commit.push_header("other", "e6fe3c97619deb8ab4198620f9a7eb79d98363dd");
     commit.push_header("gpgsig", SSH_SIGNATURE);
     commit.push_header("gpgsig", PGP_SIGNATURE);
     assert_eq!(commit.to_string(), SIGNED);
 }
 #[test]
 fn test_get_header() {
     let commit = Commit::from_str(SIGNED).unwrap();
     assert_eq!(
         commit
             .signatures()
             .map(|sig| sig.to_string())
             .collect::<Vec<_>>(),
         vec![SSH_SIGNATURE.to_owned(), PGP_SIGNATURE.to_owned()]
     );
     assert_eq!(
         commit.values("other").collect::<Vec<_>>(),
         vec![String::from("e6fe3c97619deb8ab4198620f9a7eb79d98363dd")],
     );
     assert!(commit.values("unknown").next().is_none());
 }
 #[test]
 fn test_conversion() {
     assert_eq!(
         Commit::from_str(NO_TRAILER).unwrap().to_string(),
         NO_TRAILER
     );
     assert_eq!(
         Commit::from_str(SINGLE_TRAILER).unwrap().to_string(),
         SINGLE_TRAILER
     );
     assert_eq!(Commit::from_str(SIGNED).unwrap().to_string(), SIGNED);
     assert_eq!(Commit::from_str(UNSIGNED).unwrap().to_string(), UNSIGNED);
 }

 use std::io;
 use git_commit::Commit;
 use test_helpers::tempdir::WithTmpDir;
 #[test]
 fn valid_commits() {
     let radicle_git = format!(
         "file://{}",
         git2::Repository::discover(".").unwrap().path().display()
     );
     let repo = WithTmpDir::new(|path| {
         let repo = git2::Repository::clone(&radicle_git, path)
             .map_err(|err| io::Error::new(io::ErrorKind::Other, err))?;
         Ok::<_, io::Error>(repo)
     })
     .unwrap();
     let mut walk = repo.revwalk().unwrap();
     walk.push_head().unwrap();
     // take the first 20 commits and make sure we can parse them
     for oid in walk.take(20) {
         let oid = oid.unwrap();
         let commit = Commit::read(&repo, oid);
         assert!(commit.is_ok(), "Oid: {oid}, Error: {commit:?}")
     }
 }

 #[cfg(test)]
 mod commit;
 #[cfg(test)]
 mod integration;

 [package]
 name = "git-trailers"
 version = "0.1.0"
 authors = [
   "Nuno Alexandre <hi@nunoalexandre.com>",
   "Kim Altintop <kim@eagain.st>",
   "Fintan Halpenny <fintan.halpenny@gmail.com>",
 ]
 edition = "2018"
 license = "GPL-3.0-or-later"
 description = "Library to support parsing and display git trailers <https://git-scm.com/docs/git-interpret-trailers>"
 keywords = ["git"]
 [lib]
 doctest = false
 test = false
 [dependencies]
 nom = "7.1"
 thiserror = "1.0"

 // Copyright © 2019-2020 The Radicle Foundation <hello@radicle.foundation>
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use std::{borrow::Cow, convert::TryFrom as _, ops::Deref as _};
 use assert_matches::assert_matches;
 use git_trailers::{display, parse, Error, Token, Trailer};
 use pretty_assertions::assert_eq;
 #[test]
 fn parse_message_with_valid_trailers() {
     let msg = r#"Subject
 A multiline
 description.
 Co-authored-by: John Doe <john.doe@test.com>
 Ticket: #42
 Tested-by:
     John <john@test.com>
     Jane <jane@test.com>
 Just-a-token:
 "#;
     assert_eq!(
         parse(msg, ":").unwrap(),
         vec![
             new_trailer("Co-authored-by", &["John Doe <john.doe@test.com>"]),
             new_trailer("Ticket", &["#42"]),
             new_trailer(
                 "Tested-by",
                 &["John <john@test.com>", "Jane <jane@test.com>"]
             ),
             new_trailer("Just-a-token", &[]),
         ]
     )
 }
 #[test]
 fn parse_message_trailers_with_custom_separators() {
     let separators = ":=$";
     let msg = r#"Subject
 A multiline
 description.
 Co-authored-by: John Doe <john.doe@test.com>
 Ticket = #42
 Tested-by $User <user@test.com>
     John <john@test.com>
     Jane <jane@test.com>
 "#;
     assert_eq!(
         parse(msg, separators).unwrap(),
         vec![
             new_trailer("Co-authored-by", &["John Doe <john.doe@test.com>"]),
             new_trailer("Ticket", &["#42"]),
             new_trailer(
                 "Tested-by",
                 &[
                     "User <user@test.com>",
                     "John <john@test.com>",
                     "Jane <jane@test.com>"
                 ]
             ),
         ]
     )
 }
 #[test]
 fn parse_message_trailers_with_missing_token() {
     let msg = r#"Subject
 Good-trailer: true
 John Doe <john.doe@test.com> # Unparsable token due to missing token"#;
     assert_matches!(
         parse(msg, ":"),
         Err(Error::Trailing(s))
             if s == "John Doe <john.doe@test.com> # Unparsable token due to missing token"
     )
 }
 #[test]
 fn parse_message_trailers_with_invalid_token() {
     let msg = r#"Subject
 Good-trailer: true
 &!#: John Doe <john.doe@test.com> # Unparsable token due to invalid token"#;
     assert_matches!(
         parse(msg, ":"),
         Err(Error::Trailing(s))
             if s == "&!#: John Doe <john.doe@test.com> # Unparsable token due to invalid token"
     )
 }
 #[test]
 fn parse_message_with_only_trailers() {
     let msg = r#"Co-authored-by: John Doe <john.doe@test.com>
 Ticket: #42
 Tested-by: Tester <tester@test.com>
 "#;
     assert_eq!(
         parse(msg, ":").unwrap(),
         vec![
             new_trailer("Co-authored-by", &["John Doe <john.doe@test.com>"]),
             new_trailer("Ticket", &["#42"]),
             new_trailer("Tested-by", &["Tester <tester@test.com>"]),
         ]
     )
 }
 #[test]
 fn parse_empty_message() {
     let msg = "";
     assert_matches!(parse(msg, ":"), Err(Error::MissingParagraph))
 }
 #[test]
 fn display_static() {
     let msg = r#"Tested-by: Alice
   Bob
   Carol
   Dylan
 Acked-by: Eve"#;
     let parsed = parse(msg, ":").unwrap();
     let rendered = format!("{}", display(": ", &parsed));
     assert_eq!(&rendered, msg);
 }
 #[test]
 fn display_dynamic() {
     let msg = r#"Co-authored-by: John Doe <john.doe@test.com>
 Tested-by: Tester <tester@test.com>
 Fixes #42"#;
     let parsed = parse(msg, ":#").unwrap();
     let rendered = format!(
         "{}",
         display(
             |t: &Token| if t.deref() == "Fixes" { " #" } else { ": " },
             &parsed
         )
     );
     assert_eq!(rendered, msg)
 }
 fn new_trailer<'a>(token: &'a str, values: &[&'a str]) -> Trailer<'a> {
     Trailer {
         token: Token::try_from(token).unwrap(),
         values: values.iter().map(|s| Cow::from(*s)).collect(),
     }
 }

-	`#[cfg(test)]`
-	`mod tests;`

 [package]
 name = "link-git"
 version = "0.1.0"
 authors = ["Kim Altintop <kim@eagain.st>"]
 edition = "2018"
 license = "GPL-3.0-or-later"
 description = "Core git types and functionality"
 [lib]
 doctest = false
 test = false
 [dependencies]
 arc-swap = "1.4.0"
 async-process = "1.1.0"
 async-trait = "0.1"
 blocking = "1.0.2"
 bstr = "0.2"
 futures-lite = "1.12.0"
 futures-util = "0.3.15"
 lazy_static = "1.4.0"
 im = "15.0.0"
 once_cell = "1.10"
 parking_lot = "0.12"
 pin-project = "1.0.7"
 regex = "1.5.4"
 rustc-hash = "1.1.0"
 tempfile = "3.4"
 thiserror = "1.0.30"
 tracing = "0.1"
 versions = "3.0.2"
 # gitoxide
 git-actor = "^0.6.0"
 git-hash = "^0.8.0"
 git-lock = "^1.0.1"
 git-object = "^0.15.1"
 git-odb = "^0.24.0"
 git-ref = "^0.9.0"
 git-traverse = "^0.10.0"
 [dependencies.git-features]
 version = "^0.17.0"
 features = ["progress", "parallel", "zlib-ng-compat"]
 [dependencies.git-pack]
 version = "^0.14.0"
 features = ["object-cache-dynamic", "pack-cache-lru-static", "pack-cache-lru-dynamic"]
 [dependencies.git-packetline]
 version = "^0.12.0"
 features = ["async-io"]
 [dependencies.git-protocol]
 version = "^0.12.0"
 features = ["async-client"]
 # compat
 [dependencies.git2]
 version = "0.16.1"
 default-features = false
 features = ["vendored-libgit2"]
 optional = true

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 #[macro_use]
 extern crate async_trait;
 pub mod odb;
 pub mod protocol;
 pub mod refs;
 pub use refs::db as refdb;
 #[cfg(feature = "git2")]
 pub mod service;
 pub use git_actor as actor;
 pub use git_hash as hash;
 pub use git_lock as lock;
 pub use git_object as object;
 pub use git_traverse as traverse;

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use git_hash::oid;
 use thiserror::Error;
 pub mod backend;
 pub mod index;
 pub mod pack;
 pub mod window;
 pub use git_pack::{cache, data::Object};
 #[derive(Debug, Error)]
 pub enum Error {
     #[error(transparent)]
     Packed(#[from] index::error::Lookup<pack::error::Data>),
     #[error(transparent)]
     Loose(#[from] git_odb::loose::find::Error),
 }
 pub struct Odb<I, D> {
     pub loose: backend::Loose,
     pub packed: backend::Packed<I, D>,
 }
 impl<I, D> Odb<I, D>
 where
     I: index::Index,
     D: window::Cache,
 {
     pub fn contains(&self, id: impl AsRef<oid>) -> bool {
         self.packed.contains(id.as_ref()) || self.loose.contains(id)
     }
     pub fn find<'a>(
         &self,
         id: impl AsRef<oid>,
         buf: &'a mut Vec<u8>,
         cache: &mut impl cache::DecodeEntry,
     ) -> Result<Option<Object<'a>>, Error> {
         let id = id.as_ref();
         if self.packed.contains(id) {
             return self.packed.find(id, buf, cache).map_err(Into::into);
         }
         self.loose.try_find(id, buf).map_err(Into::into)
     }
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use git_hash::oid;
 use git_pack::{cache::DecodeEntry, data::Object};
 use super::{index, pack, window};
 pub type Loose = git_odb::loose::Store;
 pub struct Packed<I, D> {
     pub index: I,
     pub data: D,
 }
 impl<I, D> Packed<I, D>
 where
     I: index::Index,
     D: window::Cache,
 {
     pub fn contains(&self, id: impl AsRef<oid>) -> bool {
         self.index.contains(id)
     }
     pub fn find<'a>(
         &self,
         id: impl AsRef<oid>,
         buf: &'a mut Vec<u8>,
         cache: &mut impl DecodeEntry,
     ) -> Result<Option<Object<'a>>, index::error::Lookup<pack::error::Data>> {
         self.index
             .lookup(|info| self.data.get(info), id, buf, cache)
     }
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use std::{
     fs,
     io,
     path::{Path, PathBuf},
     sync::Arc,
 };
 use arc_swap::ArcSwap;
 use git_hash::oid;
 use git_pack::{
     cache::DecodeEntry,
     data::{Object, ResolvedBase},
 };
 use parking_lot::Mutex;
 use tracing::trace;
 use super::pack;
 pub use git_pack::index::File as IndexFile;
 mod metrics;
 pub use metrics::{Metrics, Stats, StatsView};
 pub mod error {
     use super::*;
     use thiserror::Error;
     #[derive(Debug, Error)]
     pub enum Discover {
         #[error(transparent)]
         Index(#[from] pack::error::Index),
         #[error(transparent)]
         Io(#[from] io::Error),
     }
     #[derive(Debug, Error)]
     pub enum Lookup<E> {
         #[error(transparent)]
         Lookup(E),
         #[error(transparent)]
         Reload(#[from] Discover),
         #[error(transparent)]
         Decode(#[from] git_pack::data::decode_entry::Error),
     }
 }
 pub trait Index {
     fn contains(&self, id: impl AsRef<oid>) -> bool;
     fn lookup<'a, F, E>(
         &self,
         pack_cache: F,
         id: impl AsRef<oid>,
         buf: &'a mut Vec<u8>,
         cache: &mut impl DecodeEntry,
     ) -> Result<Option<Object<'a>>, error::Lookup<E>>
     where
         F: FnOnce(&pack::Info) -> Result<Arc<pack::Data>, E>;
 }
 /// An [`Index`] which can be shared between threads.
 ///
 /// [`Shared`] assumes that:
 ///
 /// * newer packs are likely to contain recent objects
 /// * lookups tend to favour recent objects
 /// * lookups tend to expect the object to be found (the object id is either
 ///   pointed to by a ref, or linked to by an existing object)
 ///
 /// Thus, it:
 ///
 /// * orders indices found in `GIT_DIR/objects/pack` by modification time, and
 ///   queries the more recent ones first
 /// * attempts to rescan `GIT_DIR/objects/pack` when an object id was _not_
 ///   found (assuming that this is due to a compaction)
 ///
 /// Unless a reload occurs, lookups are lock-free and mostly wait-free. Writes
 /// ([`Shared::push`], [`Shared::reload`]) are guarded by a [`Mutex`].
 // TODO: consecutive lookups also tend to resolve to the same pack, so we could
 // remember the index into the `im::Vector` where we found a match and look
 // there first. This is what libgit2 does, but the heuristic is not necessarily
 // true when `Shared` is shared across multiple concurrent link replication
 // tasks; per-namespace packs are independent pre-compaction.
 pub struct Shared<M> {
     pack_dir: PathBuf,
     indices: ArcSwap<im::Vector<Arc<pack::Index>>>,
     write: Mutex<()>,
     stats: M,
 }
 impl Shared<()> {
     pub fn open(git_dir: impl AsRef<Path>) -> Result<Self, error::Discover> {
         let pack_dir = git_dir.as_ref().join("objects").join("pack");
         let indices = discover(&pack_dir)?;
         Ok(Self {
             pack_dir,
             indices: ArcSwap::new(Arc::new(indices)),
             write: Mutex::new(()),
             stats: (),
         })
     }
 }
 impl<M> Shared<M>
 where
     M: Metrics,
 {
     pub fn with_stats(self) -> Shared<Stats> {
         self.with_metrics(Stats::default())
     }
     pub fn with_metrics<N: Metrics>(self, m: N) -> Shared<N> {
         Shared {
             pack_dir: self.pack_dir,
             indices: self.indices,
             write: self.write,
             stats: m,
         }
     }
     pub fn stats(&self) -> M::Snapshot {
         self.stats.snapshot(self.len())
     }
     /// Add a newly discovered [`pack::Index`].
     ///
     /// This index will be considered first by subsequent lookups. Note that it
     /// is only guaranteed that the index will be visible to readers if it
     /// resides in the `git_dir` this [`Shared`] was initialised with.
     pub fn push(&self, idx: pack::Index) {
         let lock = self.write.lock();
         let mut new = self.indices.load_full();
         Arc::make_mut(&mut new).push_front(Arc::new(idx));
         self.indices.store(new);
         drop(lock);
         self.stats.record_push()
     }
     /// Re-scan the packs directory and replace the in-memory indices with the
     /// result.
     ///
     /// If the application can intercept compaction events, this method can be
     /// used to release memory early. Otherwise it is not required to call this
     /// method, as [`Shared`] manages reloads automatically.
     pub fn reload(&self) -> Result<(), error::Discover> {
         let lock = self.write.lock();
         let indices = discover(&self.pack_dir)?;
         self.indices.store(Arc::new(indices));
         drop(lock);
         self.stats.record_reload();
         Ok(())
     }
     pub fn is_empty(&self) -> bool {
         self.indices.load().is_empty()
     }
     pub fn len(&self) -> usize {
         self.indices.load().len()
     }
     fn contains(&self, id: impl AsRef<oid>) -> bool {
         for i in 0..2 {
             for idx in self.indices.load().iter() {
                 if idx.contains(&id) {
                     self.stats.record_hit();
                     return true;
                 }
             }
             if i == 0 && self.reload().is_err() {
                 self.stats.record_miss();
                 return false;
             }
         }
         self.stats.record_miss();
         false
     }
     fn lookup<'a, F, E>(
         &self,
         pack_cache: F,
         id: impl AsRef<oid>,
         buf: &'a mut Vec<u8>,
         cache: &mut impl DecodeEntry,
     ) -> Result<Option<Object<'a>>, error::Lookup<E>>
     where
         F: FnOnce(&pack::Info) -> Result<Arc<pack::Data>, E>,
     {
         for i in 0..2 {
             for idx in self.indices.load().iter() {
                 if let Some(ofs) = idx.ofs(&id) {
                     self.stats.record_hit();
                     return load_obj(ofs, idx, pack_cache, buf, cache).map(Some);
                 }
             }
             if i == 0 {
                 self.reload()?;
             }
         }
         self.stats.record_miss();
         Ok(None)
     }
 }
 fn load_obj<'a, F, E>(
     ofs: u64,
     idx: &pack::Index,
     pack_cache: F,
     buf: &'a mut Vec<u8>,
     cache: &mut impl DecodeEntry,
 ) -> Result<Object<'a>, error::Lookup<E>>
 where
     F: FnOnce(&pack::Info) -> Result<Arc<pack::Data>, E>,
 {
     let data = pack_cache(&idx.info).map_err(error::Lookup::Lookup)?;
     let pack = data.file();
     let entry = pack.entry(ofs);
     let obj = pack
         .decode_entry(
             entry,
             buf,
             |id, _| idx.ofs(id).map(|ofs| ResolvedBase::InPack(pack.entry(ofs))),
             cache,
         )
         .map(move |out| Object {
             kind: out.kind,
             data: buf.as_slice(),
             pack_location: None,
         })?;
     Ok(obj)
 }
 fn discover(pack_dir: impl AsRef<Path>) -> Result<im::Vector<Arc<pack::Index>>, error::Discover> {
     let pack_dir = pack_dir.as_ref();
     let pack_dir_disp = pack_dir.display();
     trace!("discovering packs at {}", pack_dir_disp);
     match fs::read_dir(pack_dir) {
         Ok(iter) => {
             let mut paths = Vec::new();
             for entry in iter {
                 let entry = entry?;
                 let path = entry.path();
                 trace!("{}", path.display());
                 let meta = entry.metadata()?;
                 if meta.file_type().is_file() && path.extension().unwrap_or_default() == "idx" {
                     let mtime = meta.modified()?;
                     paths.push((path, mtime));
                 }
             }
             paths.sort_by(|(_, mtime_a), (_, mtime_b)| mtime_a.cmp(mtime_b));
             let indices = paths
                 .into_iter()
                 .rev()
                 .map(|(path, _)| Ok(pack::Index::open(path).map(Arc::new)?))
                 .collect::<Result<_, error::Discover>>()?;
             Ok(indices)
         },
         // It's not an error if the directory doesn't exist, the repository
         // could contain only loose objects
         Err(e) if e.kind() == io::ErrorKind::NotFound => {
             trace!("not a directory: {}", pack_dir_disp);
             Ok(im::Vector::new())
         },
         Err(e) => Err(e.into()),
     }
 }
 impl<M> Index for Shared<M>
 where
     M: Metrics,
 {
     fn contains(&self, id: impl AsRef<oid>) -> bool {
         self.contains(id)
     }
     fn lookup<'a, F, E>(
         &self,
         pack_cache: F,
         id: impl AsRef<oid>,
         buf: &'a mut Vec<u8>,
         cache: &mut impl DecodeEntry,
     ) -> Result<Option<Object<'a>>, error::Lookup<E>>
     where
         F: FnOnce(&pack::Info) -> Result<Arc<pack::Data>, E>,
     {
         self.lookup(pack_cache, id, buf, cache)
     }
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use std::sync::atomic::{AtomicUsize, Ordering};
 pub struct StatsView {
     /// Total number of times a lookup was successful.
     pub hits: usize,
     /// Total number of times a lookup was unsuccessful.
     pub misses: usize,
     /// Total number of times an index was added explicitly via
     /// [`super::Shared::push`].
     pub pushes: usize,
     /// Total number of reloads via [`super::Shared::reload`].
     pub reloads: usize,
     /// Number of [`crate::odb::pack::Index`]es currently held.
     pub indices: usize,
 }
 #[derive(Default)]
 pub struct Stats {
     hits: AtomicUsize,
     misses: AtomicUsize,
     pushes: AtomicUsize,
     reloads: AtomicUsize,
 }
 pub trait Metrics {
     type Snapshot;
     fn record_hit(&self);
     fn record_miss(&self);
     fn record_push(&self);
     fn record_reload(&self);
     fn snapshot(&self, indices: usize) -> Self::Snapshot;
 }
 impl Metrics for Stats {
     type Snapshot = StatsView;
     fn record_hit(&self) {
         self.hits.fetch_add(1, Ordering::Relaxed);
     }
     fn record_miss(&self) {
         self.misses.fetch_add(1, Ordering::Relaxed);
     }
     fn record_push(&self) {
         self.pushes.fetch_add(1, Ordering::Relaxed);
     }
     fn record_reload(&self) {
         self.reloads.fetch_add(1, Ordering::Relaxed);
     }
     fn snapshot(&self, indices: usize) -> Self::Snapshot {
         StatsView {
             hits: self.hits.load(Ordering::Relaxed),
             misses: self.misses.load(Ordering::Relaxed),
             pushes: self.pushes.load(Ordering::Relaxed),
             reloads: self.reloads.load(Ordering::Relaxed),
             indices,
         }
     }
 }
 impl Metrics for () {
     type Snapshot = ();
     fn record_hit(&self) {}
     fn record_miss(&self) {}
     fn record_push(&self) {}
     fn record_reload(&self) {}
     fn snapshot(&self, _: usize) -> Self::Snapshot {}
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use std::{
     path::{Path, PathBuf},
     sync::atomic::{AtomicUsize, Ordering},
 };
 use git_hash::{oid, ObjectId};
 use git_pack::{data, index};
 use rustc_hash::FxHasher;
 use tracing::warn;
 pub mod error {
     use super::*;
     use thiserror::Error;
     #[derive(Debug, Error)]
     #[error("failed to load pack data from {path:?}")]
     pub struct Data {
         pub path: PathBuf,
         pub source: data::header::decode::Error,
     }
     #[derive(Debug, Error)]
     #[error("failed to load pack index from {path:?}")]
     pub struct Index {
         pub path: PathBuf,
         pub source: index::init::Error,
     }
 }
 pub struct Data {
     pub hash: u64,
     hits: AtomicUsize,
     file: data::File,
 }
 impl Data {
     pub fn hit(&self) {
         self.hits.fetch_add(1, Ordering::Relaxed);
     }
     pub fn hits(&self) -> usize {
         self.hits.load(Ordering::Relaxed)
     }
     pub fn file(&self) -> &data::File {
         &self.file
     }
 }
 impl AsRef<data::File> for Data {
     fn as_ref(&self) -> &data::File {
         self.file()
     }
 }
 #[derive(Clone, PartialEq, Eq)]
 pub struct Info {
     pub(super) hash: u64,
     pub data_path: PathBuf,
 }
 impl Info {
     pub fn data(&self) -> Result<Data, error::Data> {
         let file = data::File::at(&self.data_path).map_err(|source| error::Data {
             path: self.data_path.clone(),
             source,
         })?;
         Ok(Data {
             hash: self.hash,
             hits: AtomicUsize::new(0),
             file,
         })
     }
 }
 pub struct Index {
     pub info: Info,
     file: index::File,
 }
 impl Index {
     pub fn open(path: impl AsRef<Path>) -> Result<Self, error::Index> {
         let path = path.as_ref();
         let file = index::File::at(path).map_err(|source| error::Index {
             path: path.to_path_buf(),
             source,
         })?;
         let data_path = path.with_extension("pack");
         let hash = {
             let file_name = path
                 .file_name()
                 .expect("must have a file name, we opened it")
                 .to_string_lossy();
             // XXX: inexplicably, gitoxide omits the "pack-" prefix
             let sha_hex = file_name.strip_prefix("pack-").unwrap_or(&file_name);
             match ObjectId::from_hex(&sha_hex.as_bytes()[..40]) {
                 Err(e) => {
                     warn!(
                         "unconventional pack name {:?}, falling back to fxhash: {}",
                         path, e
                     );
                     hash(path)
                 },
                 Ok(oid) => {
                     let mut buf = [0u8; 8];
                     buf.copy_from_slice(&oid.sha1()[..8]);
                     u64::from_be_bytes(buf)
                 },
             }
         };
         let info = Info { hash, data_path };
         Ok(Self { file, info })
     }
     pub fn contains(&self, id: impl AsRef<oid>) -> bool {
         self.file.lookup(id).is_some()
     }
     pub fn ofs(&self, id: impl AsRef<oid>) -> Option<u64> {
         self.file
             .lookup(id)
             .map(|idx| self.file.pack_offset_at_index(idx))
     }
 }
 fn hash(p: &Path) -> u64 {
     use std::hash::{Hash as _, Hasher as _};
     let mut hasher = FxHasher::default();
     p.hash(&mut hasher);
     hasher.finish()
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use std::sync::Arc;
 use arc_swap::{ArcSwap, Guard};
 use parking_lot::Mutex;
 use super::pack;
 mod metrics;
 pub use metrics::{Metrics, Stats, StatsView};
 /// A threadsafe, shareable cache of packfiles.
 pub trait Cache {
     type Stats;
     fn stats(&self) -> Self::Stats;
     fn get(&self, info: &pack::Info) -> Result<Arc<pack::Data>, pack::error::Data>;
 }
 impl<M, const B: usize, const S: usize> Cache for Fixed<M, B, S>
 where
     M: Metrics,
 {
     type Stats = M::Snapshot;
     fn stats(&self) -> Self::Stats {
         self.stats()
     }
     fn get(&self, info: &pack::Info) -> Result<Arc<pack::Data>, pack::error::Data> {
         self.get(info)
     }
 }
 /// 128 open files
 pub type Small<S> = Fixed<S, 16, 8>;
 /// 512 open files
 pub type Medium<S> = Fixed<S, 32, 16>;
 /// 1024 open files
 pub type Large<S> = Fixed<S, 64, 16>;
 /// 2048 open files
 pub type XLarge<S> = Fixed<S, 128, 16>;
 /// A fixed-size [`Cache`].
 ///
 /// [`Fixed`] is essentially a very simple, fixed-capacity hashtable. When a
 /// pack (data-) file is requested via [`Cache::get`], the file is loaded
 /// (typically `mmap`ed) from disk if it is not already in the cache. Otherwise,
 /// a pointer to the already loaded file is returned. Old entries are replaced
 /// on an approximate LRU basis when the cache becomes full (this means that old
 /// entries are **not** evicted when there is still space).
 ///
 /// The implementation is a somewhat dumbed-down version of JGit's
 /// `WindowCache`. The main differences are that the table buckets are of fixed
 /// size (`SLOTS`), instead of a linked list. This means that the cache does not
 /// allow to (temporarily) commit more entries than its nominal capacity.
 ///
 /// Reading cached values is lock-free and mostly wait-free. Modifications are
 /// guarded by locks on individual buckets; if a cache miss occurs, multiple
 /// threads requesting the same entry will be blocked until one of them
 /// succeeded loading the data and updating the cache. Writers will _not_,
 /// however, contend with readers (unlike `RwLock`).
 ///
 /// This favours usage patterns where different threads tend to request disjoint
 /// sets of packfiles, and of course their hashes colliding relatively
 /// infrequently.
 pub struct Fixed<M, const BUCKETS: usize, const SLOTS: usize> {
     entries: [ArcSwap<[Option<Arc<pack::Data>>; SLOTS]>; BUCKETS],
     locks: [Mutex<()>; BUCKETS],
     stats: M,
 }
 trait AssertSendSync: Send + Sync {}
 impl<M, const B: usize, const S: usize> AssertSendSync for Fixed<M, B, S> where M: Send + Sync {}
 impl<M, const B: usize, const S: usize> AsRef<Fixed<M, B, S>> for Fixed<M, B, S> {
     fn as_ref(&self) -> &Fixed<M, B, S> {
         self
     }
 }
 impl<const B: usize, const S: usize> Default for Fixed<(), B, S> {
     fn default() -> Self {
         Self {
             entries: [(); B].map(|_| ArcSwap::new(Arc::new([(); S].map(|_| None)))),
             locks: [(); B].map(|_| Mutex::new(())),
             stats: (),
         }
     }
 }
 impl<M, const B: usize, const S: usize> Fixed<M, B, S>
 where
     M: Metrics,
 {
     pub fn with_stats(self) -> Fixed<Stats, B, S> {
         self.with_metrics(Stats::default())
     }
     pub fn with_metrics<N: Metrics>(self, m: N) -> Fixed<N, B, S> {
         Fixed {
             entries: self.entries,
             locks: self.locks,
             stats: m,
         }
     }
     pub fn stats(&self) -> M::Snapshot {
         let open_files = self
             .entries
             .iter()
             .map(|bucket| bucket.load().iter().flatten().count())
             .sum();
         self.stats.snapshot(open_files)
     }
     pub fn get(&self, info: &pack::Info) -> Result<Arc<pack::Data>, pack::error::Data> {
         let idx = info.hash as usize % self.entries.len();
         let bucket = self.entries[idx].load();
         for entry in bucket.iter().flatten() {
             if entry.hash == info.hash {
                 self.stats.record_hit();
                 entry.hit();
                 return Ok(Arc::clone(entry));
             }
         }
         drop(bucket);
         self.stats.record_miss();
         // Cache miss, try to load the data file
         let lock = self.locks[idx].lock();
         // Did someone else win the race for the lock?
         let bucket = self.entries[idx].load();
         for entry in bucket.iter().flatten() {
             if entry.hash == info.hash {
                 self.stats.record_hit();
                 entry.hit();
                 return Ok(Arc::clone(entry));
             }
         }
         // No, proceed
         self.stats.record_load();
         let data = Arc::new(info.data()?);
         // Find an empty slot, or swap with the least popular
         let mut access = usize::MAX;
         let mut evict = 0;
         for (i, e) in bucket.iter().enumerate() {
             match e {
                 Some(entry) => {
                     let hits = entry.hits();
                     if hits < access {
                         access = hits;
                         evict = i;
                     }
                 },
                 None => {
                     evict = i;
                     break;
                 },
             }
         }
         let mut entries = Guard::into_inner(bucket);
         {
             // This costs `SLOTS` refcount increments if the slot is currently
             // borrowed.
             let mutti = Arc::make_mut(&mut entries);
             mutti[evict] = Some(Arc::clone(&data));
         }
         self.entries[idx].store(entries);
         drop(lock);
         data.hit();
         Ok(data)
     }
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use std::sync::atomic::{AtomicUsize, Ordering};
 use tracing::trace;
 pub struct StatsView {
     /// Total number of times the requested data was found in the cache.
     pub cache_hits: usize,
     /// Total number of times the requested data was not found in the cache.
     ///
     /// Note that a cache hit can occur after a miss if another thread was
     /// faster to fill in the missing entry. Thus, `cache_hits + cache_misses`
     /// does not necessarily sum up to the number of cache accesses.
     pub cache_misses: usize,
     /// Total number of times a pack file was attempted to be loaded from disk
     /// (incl. failed attempts).
     pub file_loads: usize,
     /// Total number of pack files the cache holds on to.
     pub open_files: usize,
 }
 #[derive(Default)]
 pub struct Stats {
     hits: AtomicUsize,
     miss: AtomicUsize,
     load: AtomicUsize,
 }
 pub trait Metrics {
     type Snapshot;
     fn record_hit(&self);
     fn record_miss(&self);
     fn record_load(&self);
     fn snapshot(&self, open_files: usize) -> Self::Snapshot;
 }
 impl Metrics for Stats {
     type Snapshot = StatsView;
     fn record_hit(&self) {
         trace!("cache hit");
         self.hits.fetch_add(1, Ordering::Relaxed);
     }
     fn record_miss(&self) {
         trace!("cache miss");
         self.miss.fetch_add(1, Ordering::Relaxed);
     }
     fn record_load(&self) {
         trace!("pack load");
         self.load.fetch_add(1, Ordering::Relaxed);
     }
     fn snapshot(&self, open_files: usize) -> Self::Snapshot {
         StatsView {
             cache_hits: self.hits.load(Ordering::Relaxed),
             cache_misses: self.miss.load(Ordering::Relaxed),
             file_loads: self.load.load(Ordering::Relaxed),
             open_files,
         }
     }
 }
 impl Metrics for () {
     type Snapshot = ();
     fn record_hit(&self) {}
     fn record_miss(&self) {}
     fn record_load(&self) {}
     fn snapshot(&self, _: usize) -> Self::Snapshot {}
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use bstr::ByteSlice as _;
 use git_protocol::transport::client;
 use versions::Version;
 pub mod fetch;
 pub mod ls;
 pub mod packwriter;
 pub mod take;
 pub mod transport;
 pub mod upload_pack;
 pub use fetch::{fetch, Ref};
 pub use ls::ls_refs;
 pub use packwriter::PackWriter;
 pub use upload_pack::upload_pack;
 pub use git_hash::{oid, ObjectId};
 fn remote_git_version(caps: &client::Capabilities) -> Option<Version> {
     let agent = caps.capability("agent").and_then(|cap| {
         cap.value()
             .and_then(|bs| bs.to_str().map(|s| s.to_owned()).ok())
     })?;
     Version::new(agent.strip_prefix("git/")?)
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use std::{
     future::Future,
     io,
     mem,
     pin::Pin,
     sync::{
         atomic::{AtomicBool, Ordering},
         Arc,
     },
     task::{Context, Poll},
 };
 use bstr::{BString, ByteSlice as _};
 use futures_lite::{
     future,
     io::{AsyncBufRead, AsyncRead, AsyncWrite},
 };
 use git_features::progress::{self, Progress};
 use git_protocol::{
     fetch::{response, Action, Arguments, Delegate, DelegateBlocking, LsRefsAction, Response},
     transport::client,
 };
 use once_cell::sync::Lazy;
 use pin_project::{pin_project, pinned_drop};
 use versions::Version;
 pub use git_hash::ObjectId;
 pub use git_protocol::fetch::Ref;
 use super::{packwriter::PackWriter, remote_git_version, transport};
 // Work around `git-upload-pack` not handling namespaces properly,
 //
 // cf. https://lore.kernel.org/git/CD2XNXHACAXS.13J6JTWZPO1JA@schmidt/
 // Fixed in `git.git` 1ab13eb, which should land in 2.34
 //
 // Based on testing with git 2.25.1 in Ubuntu 20.04, this workaround is
 // not needed. Hence the checked version is lowered to 2.25.0.
 fn must_namespace_want_ref(caps: &client::Capabilities) -> bool {
     static FIXED_AFTER: Lazy<Version> = Lazy::new(|| Version::new("2.25.0").unwrap());
     remote_git_version(caps)
         .map(|version| version <= *FIXED_AFTER)
         .unwrap_or(false)
 }
 #[derive(Debug)]
 pub struct Options {
     /// The remote (logical) repository to fetch from.
     ///
     /// Normally, this is the path to a repo on the remote side (eg.
     /// `/git.git`). `radicle-link` serves only a single namespaced repo, so
     /// this value should be the name of a namespace.
     pub repo: BString,
     /// [Extra Parameters][extra] to send with the initial transport header.
     ///
     /// [extra]: https://git.kernel.org/pub/scm/git/git.git/tree/Documentation/technical/pack-protocol.txt#n52
     pub extra_params: Vec<(String, Option<String>)>,
     /// [`ObjectId`]s to send as `want` lines.
     pub wants: Vec<ObjectId>,
     /// [`ObjectId`]s to send as `have` lines.
     pub haves: Vec<ObjectId>,
     /// Known refs to ask the server to include in the packfile.
     pub want_refs: Vec<BString>,
 }
 /// Result of a succesful [`fetch`].
 #[derive(Debug)]
 pub struct Outputs<T> {
     /// The `wanted-refs` as acknowledged by the server.
     pub wanted_refs: Vec<Ref>,
     /// If a packfile was received successfully, some info about it.
     pub pack: Option<T>,
 }
 impl<T> Default for Outputs<T> {
     fn default() -> Self {
         Self {
             wanted_refs: Vec::new(),
             pack: None,
         }
     }
 }
 /// [`Delegate`] driving the fetch end of the [pack protocol].
 ///
 /// [pack protocol]: https://git.kernel.org/pub/scm/git/git.git/tree/Documentation/technical/pack-protocol.txt
 pub struct Fetch<P, O> {
     opt: Options,
     pack_writer: P,
     out: Outputs<O>,
     need_namespaced_want_ref: bool,
 }
 impl<P, O> Fetch<P, O> {
     pub fn new(opt: Options, pack_writer: P) -> Self {
         Self {
             opt,
             pack_writer,
             out: Outputs::default(),
             need_namespaced_want_ref: false,
         }
     }
     pub fn outputs(&self) -> &Outputs<O> {
         &self.out
     }
     pub fn take_outputs(&mut self) -> Outputs<O> {
         mem::take(&mut self.out)
     }
 }
 impl<P: PackWriter> DelegateBlocking for Fetch<P, P::Output> {
     fn handshake_extra_parameters(&self) -> Vec<(String, Option<String>)> {
         self.opt.extra_params.clone()
     }
     fn prepare_ls_refs(
         &mut self,
         _: &client::Capabilities,
         _: &mut Vec<BString>,
         _: &mut Vec<(&str, Option<&str>)>,
     ) -> io::Result<LsRefsAction> {
         Ok(LsRefsAction::Skip)
     }
     fn prepare_fetch(
         &mut self,
         _: git_protocol::transport::Protocol,
         caps: &client::Capabilities,
         _: &mut Vec<(&str, Option<&str>)>,
         _: &[Ref],
     ) -> io::Result<Action> {
         if !self.opt.want_refs.is_empty() && !remote_supports_ref_in_want(caps) {
             return Err(io::Error::new(
                 io::ErrorKind::Unsupported,
                 "`want-ref`s given, but server does not support `ref-in-want`",
             ));
         }
         if self.opt.wants.is_empty() && self.opt.want_refs.is_empty() {
             return Err(io::Error::new(
                 io::ErrorKind::InvalidData,
                 "`fetch` is empty",
             ));
         }
         self.need_namespaced_want_ref = must_namespace_want_ref(caps);
         Ok(Action::Continue)
     }
     fn negotiate(
         &mut self,
         _: &[Ref],
         args: &mut Arguments,
         _: Option<&Response>,
     ) -> io::Result<Action> {
         for oid in &self.opt.wants {
             args.want(oid);
         }
         for oid in &self.opt.haves {
             args.have(oid)
         }
         for name in &self.opt.want_refs {
             if self.need_namespaced_want_ref {
                 let want_ref = format!("refs/namespaces/{}/{}", self.opt.repo, name);
                 args.want_ref(BString::from(want_ref).as_bstr());
             } else {
                 args.want_ref(name.as_bstr());
             }
         }
         // send done, as we don't bother with further negotiation
         Ok(Action::Cancel)
     }
 }
 #[async_trait(?Send)]
 impl<P: PackWriter> Delegate for Fetch<P, P::Output> {
     async fn receive_pack(
         &mut self,
         pack: impl AsyncBufRead + Unpin + 'async_trait,
         prog: impl Progress,
         _: &[Ref],
         resp: &Response,
     ) -> io::Result<()> {
         // Strip any namespaces leaked by the other end due to workarounds
         let namespace = format!("refs/namespaces/{}/", self.opt.repo);
         self.out.wanted_refs.extend(resp.wanted_refs().iter().map(
             |response::WantedRef { id, path }| {
                 Ref::Direct {
                     path: path
                         .strip_prefix(namespace.as_bytes())
                         .map(BString::from)
                         .unwrap_or_else(|| path.clone()),
                     object: *id,
                 }
             },
         ));
         let out = self.pack_writer.write_pack(pack, prog)?;
         self.out.pack = Some(out);
         Ok(())
     }
 }
 /// Future created by the [`fetch`] function.
 ///
 /// Ensures that a running inner [`PackWriter`] is cancelled when the
 /// [`Fetching`] future is dropped without also dropping the [`AsyncRead`] data
 /// source.
 #[pin_project(PinnedDrop)]
 struct Fetching<T> {
     stop: Arc<AtomicBool>,
     #[pin]
     task: T,
 }
 #[pinned_drop]
 impl<T> PinnedDrop for Fetching<T> {
     fn drop(self: Pin<&mut Self>) {
         self.stop.store(true, Ordering::Release)
     }
 }
 impl<T> Future for Fetching<T>
 where
     T: Future,
 {
     type Output = T::Output;
     fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
         self.project().task.poll(cx)
     }
 }
 pub fn fetch<B, P, R, W>(
     opt: Options,
     build_pack_writer: B,
     recv: R,
     send: W,
 ) -> impl Future<Output = io::Result<Outputs<P::Output>>>
 where
     B: FnOnce(Arc<AtomicBool>) -> P,
     P: PackWriter + Send + 'static,
     P::Output: Send + 'static,
     R: AsyncRead + Unpin + Send + 'static,
     W: AsyncWrite + Unpin + Send + 'static,
 {
     let stop = Arc::new(AtomicBool::new(false));
     let task = blocking::unblock({
         let mut conn = transport::Stateless::new(opt.repo.clone(), recv, send);
         let pack_writer = build_pack_writer(Arc::clone(&stop));
         move || {
             let mut delegate = Fetch::new(opt, pack_writer);
             future::block_on(git_protocol::fetch(
                 &mut conn,
                 &mut delegate,
                 |_| unreachable!("credentials helper requested"),
                 progress::Discard,
                 git_protocol::FetchConnection::AllowReuse,
             ))
             .map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;
             Ok(delegate.out)
         }
     });
     Fetching { stop, task }
 }
 fn remote_supports_ref_in_want(caps: &client::Capabilities) -> bool {
     caps.capability("fetch")
         .and_then(|cap| cap.supports("ref-in-want"))
         .unwrap_or(false)
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use std::{
     io,
     path::{Path, PathBuf},
     sync::{
         atomic::{AtomicBool, Ordering},
         Arc,
     },
 };
 use futures_lite::io::{AsyncBufRead, BlockOn};
 use git_features::progress::Progress;
 use git_hash::ObjectId;
 use git_odb::{self as odb, pack};
 use super::take::TryTake;
 #[cfg(feature = "git2")]
 pub use libgit::Libgit;
 /// What to do with the `packfile` response.
 ///
 /// _This is mostly the same as [`git_protocol::fetch::Delegate`], but without
 /// incurring the [`git_protocol::fetch::DelegateBlocking`] super-trait
 /// constraint. We can simply make [`crate::protocol::fetch::Fetch`] parametric
 /// over the packfile sink._
 pub trait PackWriter {
     type Output;
     fn write_pack(
         &self,
         pack: impl AsyncBufRead + Unpin,
         progress: impl Progress,
     ) -> io::Result<Self::Output>;
 }
 #[derive(Clone, Copy, Debug)]
 pub struct Options {
     /// How many threads the packfile indexer is allowed to spawn. `None` means
     /// unlimited.
     pub max_indexer_threads: Option<usize>,
     /// The maximum size in bytes of the packfile.
     ///
     /// If the remote sends a larger file, the transfer will be aborted.
     pub max_pack_bytes: u64,
 }
 impl Default for Options {
     fn default() -> Self {
         Self {
             max_indexer_threads: Some(1),
             max_pack_bytes: u64::MAX,
         }
     }
 }
 #[cfg(feature = "git2")]
 pub mod libgit {
     use super::*;
     #[derive(Clone, Copy, Debug)]
     pub struct PackReceived {
         pub objects: usize,
         pub local_objects: usize,
         pub deltas: usize,
     }
     impl From<git2::Progress<'_>> for PackReceived {
         fn from(p: git2::Progress<'_>) -> Self {
             Self {
                 objects: p.indexed_objects(),
                 local_objects: p.local_objects(),
                 deltas: p.indexed_deltas(),
             }
         }
     }
     pub struct Libgit {
         opt: Options,
         repo: git2::Repository,
         stop: Arc<AtomicBool>,
     }
     impl Libgit {
         pub fn new(opt: Options, repo: git2::Repository, stop: Arc<AtomicBool>) -> Self {
             Self { opt, repo, stop }
         }
         fn guard_cancelled(&self) -> io::Result<()> {
             if self.stop.load(Ordering::Acquire) {
                 Err(io::Error::new(io::ErrorKind::Interrupted, "cancelled"))
             } else {
                 Ok(())
             }
         }
     }
     impl PackWriter for Libgit {
         type Output = Option<PackReceived>;
         fn write_pack(
             &self,
             pack: impl AsyncBufRead + Unpin,
             _: impl Progress,
         ) -> io::Result<Self::Output> {
             let mut out = None;
             let odb = self.repo.odb().map_err(io_error)?;
             let mut writer = odb.packwriter().map_err(io_error)?;
             self.guard_cancelled()?;
             io::copy(
                 &mut BlockOn::new(TryTake::new(pack, self.opt.max_pack_bytes)),
                 &mut writer,
             )?;
             self.guard_cancelled()?;
             writer
                 .progress(|p| {
                     out = Some(p.to_owned());
                     true
                 })
                 .commit()
                 .map(|_| ())
                 .map_err(io_error)?;
             // Convince borrowchk that `out` can not possibly be borrowed anymore
             drop(writer);
             Ok(out.map(Into::into))
         }
     }
     fn io_error(e: git2::Error) -> io::Error {
         io::Error::new(io::ErrorKind::Other, e)
     }
 }
 pub type PackReceived = pack::bundle::write::Outcome;
 /// A lookup function to help "thicken" thin packs by finding missing base
 /// objects.
 ///
 /// The impl provided for [`odb::linked::Store`] does not use any pack caching.
 pub trait Thickener {
     fn find_object<'a>(&self, id: ObjectId, buf: &'a mut Vec<u8>)
         -> Option<pack::data::Object<'a>>;
 }
 impl Thickener for odb::linked::Store {
     fn find_object<'a>(
         &self,
         id: ObjectId,
         buf: &'a mut Vec<u8>,
     ) -> Option<pack::data::Object<'a>> {
         use git_odb::FindExt as _;
         self.find(id, buf, &mut pack::cache::Never).ok()
     }
 }
 /// A factory spewing out new [`Thickener`]s with static lifetimes.
 ///
 /// `gitoxide` doesn't currently allow us to initialise thickening lazily (the
 /// pack file may not be thin after all), but requires a static lookup function.
 /// Instead of initialising a new [`odb::linked::Store`] for every pack stream,
 /// users may share a pre-initialised object database provided appropriate
 /// thread safety measures.
 pub trait BuildThickener {
     type Error: std::error::Error + Send + Sync + 'static;
     type Thick: Thickener + 'static;
     fn build_thickener(&self) -> Result<Self::Thick, Self::Error>;
 }
 pub struct StandardThickener {
     git_dir: PathBuf,
 }
 impl StandardThickener {
     pub fn new(git_dir: impl Into<PathBuf>) -> Self {
         let git_dir = git_dir.into();
         Self { git_dir }
     }
 }
 impl BuildThickener for StandardThickener {
     type Error = odb::linked::init::Error;
     type Thick = odb::linked::Store;
     fn build_thickener(&self) -> Result<Self::Thick, Self::Error> {
         odb::linked::Store::at(self.git_dir.join("objects"))
     }
 }
 /// The default [`PackWriter`].
 ///
 /// Writes the packfile into the given output directory, along with a v2
 /// index. The packfile is verified.
 pub struct Standard<F> {
     git_dir: PathBuf,
     opt: Options,
     thick: F,
     stop: Arc<AtomicBool>,
 }
 impl<F> Standard<F> {
     pub fn new(git_dir: impl AsRef<Path>, opt: Options, thick: F, stop: Arc<AtomicBool>) -> Self {
         Self {
             git_dir: git_dir.as_ref().to_owned(),
             opt,
             thick,
             stop,
         }
     }
 }
 impl<F> Drop for Standard<F> {
     fn drop(&mut self) {
         self.stop.store(true, Ordering::Release);
     }
 }
 impl<F: BuildThickener> PackWriter for Standard<F> {
     type Output = PackReceived;
     fn write_pack(
         &self,
         pack: impl AsyncBufRead + Unpin,
         prog: impl Progress,
     ) -> io::Result<Self::Output> {
         use pack::{bundle::write::Options, data::input::Mode, index::Version, Bundle};
         let opts = Options {
             thread_limit: self.opt.max_indexer_threads,
             index_kind: Version::V2,
             iteration_mode: Mode::Verify,
         };
         let thickener = self
             .thick
             .build_thickener()
             .map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;
         Bundle::write_to_directory(
             BlockOn::new(TryTake::new(pack, self.opt.max_pack_bytes)),
             Some(self.git_dir.join("objects").join("pack")),
             prog,
             &self.stop,
             Some(Box::new(move |oid, buf| thickener.find_object(oid, buf))),
             opts,
         )
         .map_err(|e| io::Error::new(io::ErrorKind::Other, e))
     }
 }
 /// No-op [`PackWriter`] which just drains the input.
 pub struct Discard;
 impl PackWriter for Discard {
     type Output = u64;
     fn write_pack(
         &self,
         pack: impl AsyncBufRead + Unpin,
         _: impl Progress,
     ) -> io::Result<Self::Output> {
         io::copy(&mut BlockOn::new(pack), &mut io::sink())
     }
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use std::{
     io,
     pin::Pin,
     task::{Context, Poll},
 };
 use futures_lite::io::{AsyncBufRead, AsyncRead};
 /// Like [`futures_lite::io::Take`], but returns an error if and when the
 /// `limit` is exceeded.
 ///
 /// Note that, unlike [`futures_lite::io::Take`], if a single poll reads past
 /// the limit, the excess bytes are _not_ discarded. Instead, an error is
 /// returned on the next poll.
 pub struct TryTake<R> {
     limit: u64,
     inner: R,
 }
 impl<R> TryTake<R> {
     pub fn new(inner: R, limit: u64) -> Self {
         Self { limit, inner }
     }
 }
 impl<R> AsyncRead for TryTake<R>
 where
     R: AsyncRead + Unpin,
 {
     fn poll_read(
         self: Pin<&mut Self>,
         cx: &mut Context,
         buf: &mut [u8],
     ) -> Poll<Result<usize, io::Error>> {
         if self.limit == 0 {
             return Poll::Ready(Err(io::Error::new(
                 io::ErrorKind::Other,
                 "max input size exceeded",
             )));
         }
         let this = self.get_mut();
         Pin::new(&mut this.inner).poll_read(cx, buf).map(|ready| {
             if let Ok(siz) = ready {
                 this.limit = this.limit.saturating_sub(siz as u64);
             }
             ready
         })
     }
 }
 impl<R> AsyncBufRead for TryTake<R>
 where
     R: AsyncBufRead + Unpin,
 {
     fn poll_fill_buf(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<&[u8], io::Error>> {
         if self.limit == 0 {
             return Poll::Ready(Err(io::Error::new(
                 io::ErrorKind::Other,
                 "max input size exceeded",
             )));
         }
         Pin::new(&mut self.get_mut().inner).poll_fill_buf(cx)
     }
     fn consume(self: Pin<&mut Self>, amt: usize) {
         Pin::new(&mut self.get_mut().inner).consume(amt)
     }
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use bstr::BString;
 use futures_lite::io::{AsyncRead, AsyncWrite};
 use git_protocol::transport::{
     client::{
         self,
         git::{ConnectMode, Connection},
         SetServiceResponse,
         Transport,
         TransportWithoutIO,
     },
     Protocol,
     Service,
 };
 pub struct Stateless<R, W> {
     inner: Connection<R, W>,
 }
 impl<R, W> Stateless<R, W>
 where
     R: AsyncRead + Unpin,
     W: AsyncWrite + Unpin,
 {
     pub fn new(repo: BString, recv: R, send: W) -> Self {
         let url = format!("rad://{repo}");
         let inner = Connection::new(
             recv,
             send,
             Protocol::V2,
             repo,
             None::<(String, Option<u16>)>,
             ConnectMode::Daemon,
         )
         .custom_url(Some(url));
         Self { inner }
     }
 }
 impl<R, W> TransportWithoutIO for Stateless<R, W>
 where
     R: AsyncRead + Unpin,
     W: AsyncWrite + Unpin,
 {
     fn request(
         &mut self,
         write_mode: client::WriteMode,
         on_into_read: client::MessageKind,
     ) -> Result<client::RequestWriter<'_>, client::Error> {
         self.inner.request(write_mode, on_into_read)
     }
     fn to_url(&self) -> String {
         self.inner.to_url()
     }
     fn supported_protocol_versions(&self) -> &[Protocol] {
         &[Protocol::V2]
     }
     fn connection_persists_across_multiple_requests(&self) -> bool {
         false
     }
 }
 #[async_trait(?Send)]
 impl<R, W> Transport for Stateless<R, W>
 where
     R: AsyncRead + Unpin,
     W: AsyncWrite + Unpin,
 {
     async fn handshake<'a>(
         &mut self,
         service: Service,
         extra_parameters: &'a [(&'a str, Option<&'a str>)],
     ) -> Result<SetServiceResponse<'_>, client::Error> {
         self.inner.handshake(service, extra_parameters).await
     }
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use std::{future::Future, io, path::Path, process::ExitStatus, str::FromStr};
 use async_process::{Command, Stdio};
 use futures_lite::io::{copy, AsyncBufReadExt as _, AsyncRead, AsyncWrite, BufReader};
 use futures_util::try_join;
 use git_packetline::{self as packetline, PacketLineRef};
 use once_cell::sync::Lazy;
 use versions::Version;
 mod legacy;
 #[derive(Debug, PartialEq, Eq)]
 pub struct Header {
     pub path: String,
     pub host: Option<(String, Option<u16>)>,
     pub extra: Vec<(String, Option<String>)>,
 }
 impl FromStr for Header {
     type Err = &'static str;
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         let mut parts = s
             .strip_prefix("git-upload-pack ")
             .ok_or("unsupported service")?
             .split_terminator('\0');
         let path = parts.next().ok_or("missing path").and_then(|path| {
             if path.is_empty() {
                 Err("empty path")
             } else {
                 Ok(path.to_owned())
             }
         })?;
         let host = match parts.next() {
             None | Some("") => None,
             Some(host) => match host.strip_prefix("host=") {
                 None => return Err("invalid host"),
                 Some(host) => match host.split_once(':') {
                     None => Some((host.to_owned(), None)),
                     Some((host, port)) => {
                         let port = port.parse::<u16>().or(Err("invalid port"))?;
                         Some((host.to_owned(), Some(port)))
                     },
                 },
             },
         };
         let extra = parts
             .skip_while(|part| part.is_empty())
             .map(|part| match part.split_once('=') {
                 None => (part.to_owned(), None),
                 Some((k, v)) => (k.to_owned(), Some(v.to_owned())),
             })
             .collect();
         Ok(Self { path, host, extra })
     }
 }
 pub async fn upload_pack<R, W>(
     git_dir: impl AsRef<Path>,
     recv: R,
     mut send: W,
 ) -> io::Result<(Header, impl Future<Output = io::Result<ExitStatus>>)>
 where
     R: AsyncRead + Unpin,
     W: AsyncWrite + Unpin,
 {
     let mut recv = BufReader::new(recv);
     let header: Header = match recv.fill_buf().await?.first() {
         // legacy clients don't send a proper pktline header :(
         Some(b'g') => {
             let mut buf = String::with_capacity(256);
             recv.read_line(&mut buf).await?;
             buf.parse().map_err(invalid_data)?
         },
         Some(_) => {
             let mut pktline = packetline::StreamingPeekableIter::new(recv, &[]);
             let pkt = pktline
                 .read_line()
                 .await
                 .ok_or_else(|| invalid_data("missing header"))?
                 .map_err(invalid_data)?
                 .map_err(invalid_data)?;
             let hdr = match pkt {
                 PacketLineRef::Data(data) => std::str::from_utf8(data)
                     .map_err(invalid_data)?
                     .parse()
                     .map_err(invalid_data),
                 _ => Err(invalid_data("not a header packet")),
             }?;
             recv = pktline.into_inner();
             hdr
         },
         None => {
             return Err(io::Error::new(
                 io::ErrorKind::UnexpectedEof,
                 "expected header",
             ))
         },
     };
     let namespace = header
         .path
         // legacy clients redundantly send a full URN
         .strip_prefix("rad:git:")
         .map(ToOwned::to_owned)
         .unwrap_or_else(|| header.path.clone());
     let protocol_version = header
         .extra
         .iter()
         .find_map(|kv| match kv {
             (ref k, Some(v)) if k == "version" => {
                 let version = match v.as_str() {
                     "2" => 2,
                     "1" => 1,
                     _ => 0,
                 };
                 Some(version)
             },
             _ => None,
         })
         .unwrap_or(0);
     // legacy
     let stateless_ls = header.extra.iter().any(|(k, _)| k == "ls");
     let fut = async move {
         if protocol_version < 2 {
             if stateless_ls {
                 return legacy::advertise_refs(git_dir, &namespace, recv, send).await;
             }
         } else {
             advertise_capabilities(&mut send).await?;
         }
         let mut child = {
             let mut cmd = Command::new("git");
             cmd.current_dir(git_dir)
                 .env_clear()
                 .envs(
                     std::env::vars()
                         .filter(|(key, _)| key == "PATH" || key.starts_with("GIT_TRACE")),
                 )
                 .env("GIT_PROTOCOL", format!("version={protocol_version}"))
                 .env("GIT_NAMESPACE", namespace)
                 .args([
                     "-c",
                     "uploadpack.allowanysha1inwant=true",
                     "-c",
                     "uploadpack.allowrefinwant=true",
                     "-c",
                     "lsrefs.unborn=ignore",
                     "upload-pack",
                     "--strict",
                     "--stateless-rpc",
                     ".",
                 ])
                 .stdout(Stdio::piped())
                 .stdin(Stdio::piped())
                 .stderr(Stdio::inherit())
                 .kill_on_drop(true)
                 .reap_on_drop(true)
                 .spawn()?
         };
         let mut stdin = child.stdin.take().unwrap();
         let mut stdout = child.stdout.take().unwrap();
         try_join!(
             copy(&mut recv, &mut stdin),
             copy(&mut stdout, &mut send),
             child.status(),
         )
         .map(|(_, _, status)| status)
     };
     Ok((header, fut))
 }
 async fn advertise_capabilities<W>(mut send: W) -> io::Result<()>
 where
     W: AsyncWrite + Unpin,
 {
     // Thou shallt not upgrade your `git` installation while a link instance is
     // running!
     static GIT_VERSION: Lazy<Version> = Lazy::new(|| git_version().unwrap());
     static AGENT: Lazy<Vec<u8>> = Lazy::new(|| format!("agent=git/{}", *GIT_VERSION).into_bytes());
     static CAPABILITIES: Lazy<[&[u8]; 4]> = Lazy::new(|| {
         [
             b"version 2",
             AGENT.as_slice(),
             b"object-format=sha1",
             b"fetch=ref-in-want",
         ]
     });
     for cap in *CAPABILITIES {
         packetline::encode::text_to_write(cap, &mut send).await?;
     }
     packetline::encode::flush_to_write(&mut send).await?;
     Ok(())
 }
 fn git_version() -> io::Result<Version> {
     let out = std::process::Command::new("git")
         .arg("--version")
         .output()?;
     if !out.status.success() {
         return Err(io::Error::new(
             io::ErrorKind::Other,
             "failed to read `git` version",
         ));
     }
     // parse: git version 2.30.1 <other optional tokens>
     out.stdout
         .split(|x| x == &b' ')
         .nth(2)
         .and_then(|s| {
             let s = std::str::from_utf8(s).ok()?;
             Version::new(s.trim())
         })
         .ok_or_else(|| io::Error::new(io::ErrorKind::Other, "failed to parse `git` version"))
 }
 fn invalid_data<E>(inner: E) -> io::Error
 where
     E: Into<Box<dyn std::error::Error + Sync + Send>>,
 {
     io::Error::new(io::ErrorKind::InvalidData, inner)
 }

 // Copyright © 2019-2020 The Radicle Foundation <hello@radicle.foundation>
 // Copyright © 2021      The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use std::{io, path::Path, process::ExitStatus};
 use async_process::{Command, Stdio};
 use futures_lite::io::{copy, AsyncRead, AsyncReadExt as _, AsyncWrite, AsyncWriteExt as _};
 use futures_util::try_join;
 use git_ref::{
     file::{Store as Refdb, WriteReflog},
     FullName,
     Reference,
 };
 pub(super) async fn advertise_refs<R, W>(
     git_dir: impl AsRef<Path>,
     namespace: &str,
     mut recv: R,
     mut send: W,
 ) -> io::Result<ExitStatus>
 where
     R: AsyncRead + Unpin,
     W: AsyncWrite + Unpin,
 {
     let unhide = blocking::unblock({
         let git_dir = git_dir.as_ref().to_path_buf();
         let prefix = Path::new("refs")
             .join("namespaces")
             .join(namespace)
             .join("refs");
         move || -> io::Result<Vec<FullName>> {
             let refdb = Refdb::at(git_dir, WriteReflog::Disable);
             let packed = refdb
                 .packed_buffer()
                 .map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;
             let refs = refdb
                 .iter_prefixed(packed.as_ref(), prefix)?
                 .filter_map(|r| r.ok().map(|Reference { name, .. }| name))
                 .filter(|name| {
                     const PATTERN: &[u8] = b"rad/ids/any";
                     const SEPARAT: u8 = b'/';
                     name.as_bstr()
                         .rsplit(|b| b == &SEPARAT)
                         .zip(PATTERN.rsplit(|b| b == &SEPARAT))
                         .skip(1)
                         .all(|(a, b)| a == b)
                 })
                 .collect::<Vec<_>>();
             Ok(refs)
         }
     })
     .await?;
     let mut child = {
         let mut cmd = Command::new("git");
         cmd.current_dir(git_dir)
             .env_clear()
             .envs(std::env::vars().filter(|(key, _)| key == "PATH" || key.starts_with("GIT_TRACE")))
             .arg("-c")
             .arg("uploadpack.hiderefs=refs/")
             .arg("-c")
             .arg(format!("uploadpack.hiderefs=!refs/namespaces/{namespace}",));
         for r in unhide {
             cmd.arg("-c")
                 .arg(format!("uploadpack.hiderefs=!{}", r.as_bstr()));
         }
         cmd.args([
             "upload-pack",
             "--strict",
             "--timeout=5",
             "--stateless-rpc",
             "--advertise-refs",
             ".",
         ])
         .stdout(Stdio::piped())
         .stderr(Stdio::inherit())
         .kill_on_drop(true)
         .reap_on_drop(true)
         .spawn()?
     };
     let mut stdout = child.stdout.take().unwrap();
     const HEADER: &[u8] = b"001e# service=git-upload-pack\n0000";
     send.write_all(HEADER).await?;
     let status = try_join!(copy(&mut stdout, &mut send), child.status()).map(|x| x.1);
     // Read one byte off the read stream to ensure it is driven to completion
     // (we expect EOF immediately). Failure to do so may cause resource leaks.
     //
     // Cf. 900b6cf6 (replication: Ensure git stream is closed, 2021-04-26)
     let mut buf = [0; 1];
     recv.read(&mut buf).await?;
     status
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use std::{
     collections::BTreeSet,
     convert::TryInto,
     io,
     path::{Path, PathBuf},
     sync::Arc,
     time::{Duration, SystemTime},
 };
 use git_ref::{
     file::{self, iter::LooseThenPacked, Transaction, WriteReflog},
     packed,
     FullName,
     PartialNameRef,
     Reference,
     Target,
 };
 use parking_lot::RwLock;
 pub mod error {
     use super::*;
     use thiserror::Error;
     #[derive(Debug, Error)]
     pub enum Open {
         #[error("failed to take a snapshot of packed-refs")]
         Snapshot(#[from] Snapshot),
         #[error(transparent)]
         Io(#[from] io::Error),
     }
     #[derive(Debug, Error)]
     pub enum Snapshot {
         #[error("failed to lock packed-refs")]
         Lock(#[from] git_lock::acquire::Error),
         #[error("failed to open packed-refs")]
         Open(#[from] packed::buffer::open::Error),
         #[error(transparent)]
         Io(#[from] io::Error),
     }
     #[derive(Debug, Error)]
     pub enum Follow {
         #[error("cyclic symref: {0:?}")]
         Cycle(FullName),
         #[error("reference {0:?} not found")]
         NotFound(FullName),
         #[error("max symref depth {0} exceeded")]
         DepthLimitExceeded(usize),
         #[error(transparent)]
         Find(#[from] file::find::Error),
     }
 }
 /// Threadsafe refdb with shareable `packed-refs` memory buffer.
 ///
 /// Packed refs are a delicate business: they are written by an external
 /// process, [`git-pack-refs`], _or_ when a packed ref is deleted. It may also
 /// be that no `packed-refs` currently exist.
 ///
 /// The only way we can be certain to operate on a consistent view of what is
 /// committed to disk is to check if the `packed-refs` file has changed since we
 /// last read it. This would be quite expensive to do for small operations.
 /// Thus, the caller is responsible for determining just how much they can
 /// afford to see possibly out-of-date data: the [`Refdb::snapshot`] method
 /// checks if the previously loaded `packed-refs` appear to be out-of-date, and
 /// reloads them if necessary. The resulting [`Snapshot`] contains a pointer to
 /// an immutable memory buffer of the packed refs which can be shared between
 /// threads, or cloned.
 ///
 /// [`git-pack-refs`]: https://git-scm.com/docs/git-pack-refs
 #[derive(Clone)]
 pub struct Refdb {
     store: file::Store,
     packed: Arc<RwLock<Option<Packed>>>,
 }
 impl Refdb {
     pub fn open(git_dir: impl Into<PathBuf>) -> Result<Self, error::Open> {
         let store = file::Store::at(git_dir, WriteReflog::Normal);
         let packed = Arc::new(RwLock::new(Packed::open(store.packed_refs_path())?));
         Ok(Self { store, packed })
     }
     pub fn snapshot(&self) -> Result<Snapshot, error::Snapshot> {
         let read = self.packed.read();
         match &*read {
             None => {
                 drop(read);
                 // always modified, because it was None and now is Some
                 self.reload(|_| true)
             },
             Some(packed) => {
                 if packed.is_modified()? {
                     let mtime = packed.mtime;
                     drop(read);
                     // we don't care what the mtime is, only that we have a
                     // different value than before
                     self.reload(|packed1| packed1.mtime != mtime)
                 } else {
                     Ok(Snapshot {
                         store: self.store.clone(),
                         packed: Some(packed.buf.clone()),
                     })
                 }
             },
         }
     }
     fn reload<F>(&self, modified_while_blocked: F) -> Result<Snapshot, error::Snapshot>
     where
         F: FnOnce(&Packed) -> bool,
     {
         let mut write = self.packed.write();
         if let Some(packed) = &*write {
             if modified_while_blocked(packed) {
                 return Ok(Snapshot {
                     store: self.store.clone(),
                     packed: Some(packed.buf.clone()),
                 });
             }
         }
         match Packed::open(self.store.packed_refs_path())? {
             Some(packed) => {
                 let buf = packed.buf.clone();
                 *write = Some(packed);
                 Ok(Snapshot {
                     store: self.store.clone(),
                     packed: Some(buf),
                 })
             },
             None => {
                 *write = None;
                 Ok(Snapshot {
                     store: self.store.clone(),
                     packed: None,
                 })
             },
         }
     }
 }
 #[derive(Clone)]
 pub struct Snapshot {
     store: file::Store,
     packed: Option<Arc<packed::Buffer>>,
 }
 impl Snapshot {
     pub fn find<'a, N, E>(&self, name: N) -> Result<Option<Reference>, file::find::Error>
     where
         N: TryInto<PartialNameRef<'a>, Error = E>,
         file::find::Error: From<E>,
     {
         self.store.try_find(name, self.packed.as_deref())
     }
     pub fn transaction(&self) -> Transaction {
         self.store.transaction()
     }
     pub fn iter(&self, prefix: Option<impl AsRef<Path>>) -> io::Result<LooseThenPacked> {
         let packed = self.packed.as_deref();
         match prefix {
             None => self.store.iter(packed),
             Some(p) => self.store.iter_prefixed(packed, p),
         }
     }
     /// Follow a symbolic reference until a direct reference is found.
     ///
     /// If `symref` is a direct reference, a copy of it is returned. No more
     /// than five symbolic references will be followed, and cyclic
     /// references are detected. Both result in an error to be returned.
     ///
     /// Note that following is not the same as "peeling": no access to the
     /// object database is made, and thus no assumptions about the kind of
     /// object the reference ultimately points to can be made.
     pub fn follow(&self, symref: &Reference) -> Result<Reference, error::Follow> {
         match &symref.target {
             Target::Peeled(_) => Ok(symref.clone()),
             Target::Symbolic(name) => {
                 let mut seen = BTreeSet::new();
                 seen.insert(symref.name.clone());
                 let mut next = self
                     .find(name.to_partial())?
                     .ok_or_else(|| error::Follow::NotFound(name.clone()))?;
                 seen.insert(name.clone());
                 const MAX_DEPTH: usize = 5;
                 loop {
                     match next.target {
                         Target::Peeled(_) => return Ok(next),
                         Target::Symbolic(sym) => {
                             if seen.len() + 1 > MAX_DEPTH {
                                 return Err(error::Follow::DepthLimitExceeded(MAX_DEPTH));
                             }
                             if seen.contains(&sym) {
                                 return Err(error::Follow::Cycle(sym));
                             }
                             next = self
                                 .find(sym.to_partial())?
                                 .ok_or_else(|| error::Follow::NotFound(sym.clone()))?;
                             seen.insert(sym);
                         },
                     }
                 }
             },
         }
     }
 }
 struct Packed {
     buf: Arc<packed::Buffer>,
     path: PathBuf,
     mtime: SystemTime,
 }
 impl Packed {
     fn open(path: PathBuf) -> Result<Option<Self>, error::Snapshot> {
         use git_lock::{acquire, Marker};
         let _lock = Marker::acquire_to_hold_resource(
             &path,
             acquire::Fail::AfterDurationWithBackoff(Duration::from_millis(500)),
             None,
         )?;
         match path.metadata() {
             // `git-lock` will happily lock a non-existent file
             Err(e) if e.kind() == io::ErrorKind::NotFound => Ok(None),
             Err(e) => Err(e.into()),
             Ok(meta) => {
                 let mtime = meta.modified()?;
                 let buf = Arc::new(packed::Buffer::open(&path, 32 * 1024)?);
                 Ok(Some(Self { buf, path, mtime }))
             },
         }
     }
     fn is_modified(&self) -> io::Result<bool> {
         match self.path.metadata() {
             // it existed before, so gone is modified
             Err(e) if e.kind() == io::ErrorKind::NotFound => Ok(true),
             Err(e) => Err(e),
             Ok(meta) => {
                 let mtime = meta.modified()?;
                 Ok(self.mtime == mtime)
             },
         }
     }
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use std::{fmt::Debug, ops::Deref, str::FromStr};
 use git2::transport::Service as GitService;
 use lazy_static::lazy_static;
 lazy_static! {
     static ref SERVICE_REGEX: regex::Regex = regex::Regex::new(r"(\S+) '/?(.+)'").unwrap();
 }
 #[derive(Clone, Copy, PartialEq)]
 pub struct Service(pub GitService);
 /// A service and URN as passed to the exec_request of an SSH server by git when
 /// talking to an SSH remote. The `FromStr` implementation for this type expects
 /// a string of the form:
 ///
 /// `<request type> /<path>`
 ///
 /// Where the request type is either `upload-pack` or `receive-pack`, the
 /// leading slash before the urn is optional, and the `path` is whatever the
 /// `FromStr` of `Path` provides.
 #[derive(Debug, Clone)]
 pub struct SshService<Path> {
     pub service: Service,
     pub path: Path,
 }
 impl<Path> SshService<Path> {
     pub fn is_upload(&self) -> bool {
         match self.service.0 {
             GitService::UploadPackLs | GitService::UploadPack => true,
             GitService::ReceivePackLs | GitService::ReceivePack => false,
         }
     }
     pub fn is_receive(&self) -> bool {
         !self.is_upload()
     }
 }
 impl From<GitService> for Service {
     fn from(g: GitService) -> Self {
         Service(g)
     }
 }
 impl From<Service> for GitService {
     fn from(s: Service) -> Self {
         s.0
     }
 }
 #[derive(thiserror::Error, Debug)]
 pub enum ParseService {
     #[error("the exec str must be in the form <service> <urn>")]
     Format,
     #[error(transparent)]
     Namespace(Box<dyn std::error::Error + Send + Sync + 'static>),
     #[error("unknown service {0}")]
     UnknownService(String),
 }
 impl Debug for Service {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         f.debug_tuple("Service")
             .field(match self.0 {
                 GitService::UploadPackLs => &"UploadPackLs",
                 GitService::UploadPack => &"UploadPack",
                 GitService::ReceivePackLs => &"ReceivePackLs",
                 GitService::ReceivePack => &"ReceivePack",
             })
             .finish()
     }
 }
 impl std::fmt::Display for Service {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self.0 {
             GitService::UploadPack => write!(f, "upload-pack"),
             GitService::UploadPackLs => write!(f, "upload-pack-ls"),
             GitService::ReceivePack => write!(f, "receive-pack"),
             GitService::ReceivePackLs => write!(f, "receive-pack-ls"),
         }
     }
 }
 impl Deref for Service {
     type Target = GitService;
     fn deref(&self) -> &Self::Target {
         &self.0
     }
 }
 impl<Path> FromStr for SshService<Path>
 where
     Path: FromStr,
     Path::Err: std::error::Error + Send + Sync + 'static,
 {
     type Err = ParseService;
     fn from_str(exec_str: &str) -> Result<Self, Self::Err> {
         let cap = SERVICE_REGEX
             .captures_iter(exec_str)
             .next()
             .ok_or(ParseService::Format)?;
         debug_assert!(cap.len() == 3);
         let service_str: &str = &cap[1];
         let urn_str = &cap[2];
         let path = urn_str
             .parse()
             .map_err(|err| ParseService::Namespace(Box::new(err)))?;
         let service = match service_str {
             "git-upload-pack" => Ok(Service(GitService::UploadPack)),
             "git-receive-pack" => Ok(Service(GitService::ReceivePack)),
             other => Err(ParseService::UnknownService(other.to_string())),
         }?;
         Ok(Self { service, path })
     }
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use std::{
     collections::BTreeSet,
     io,
     path::Path,
     sync::{atomic::AtomicBool, Arc},
 };
 use bstr::ByteSlice as _;
 use futures::{AsyncReadExt as _, TryFutureExt as _};
 use link_git::protocol::{fetch, ls, packwriter, upload_pack, ObjectId, PackWriter, Ref};
 use tempfile::{tempdir, TempDir};
 fn upstream() -> TempDir {
     let tmp = tempdir().unwrap();
     let repo = git2::Repository::init_bare(&tmp).unwrap();
     let auth = git2::Signature::now("apollo", "apollo@cree.de").unwrap();
     let tree = {
         let empty = repo.treebuilder(None).unwrap();
         let oid = empty.write().unwrap();
         repo.find_tree(oid).unwrap()
     };
     let base = {
         let oid = repo
             .commit(
                 Some("refs/namespaces/foo/refs/heads/main"),
                 &auth,
                 &auth,
                 "initial",
                 &tree,
                 &[],
             )
             .unwrap();
         repo.find_commit(oid).unwrap()
     };
     let next = repo
         .commit(
             Some("refs/namespaces/foo/refs/heads/next"),
             &auth,
             &auth,
             "ng",
             &tree,
             &[&base],
         )
         .unwrap();
     repo.reference(
         "refs/namespaces/foo/refs/pulls/1/head",
         next,
         true,
         "pee arrr",
     )
     .unwrap();
     tmp
 }
 fn collect_refs(repo: &git2::Repository) -> Result<Vec<(String, git2::Oid)>, git2::Error> {
     repo.references()?
         .map(|x| x.map(|r| (r.name().unwrap().to_owned(), r.target().unwrap())))
         .collect()
 }
 fn update_tips<'a, T>(repo: &git2::Repository, tips: T) -> Result<(), anyhow::Error>
 where
     T: IntoIterator<Item = &'a Ref>,
 {
     for r in tips {
         match r {
             Ref::Direct { path, object } => {
                 repo.reference(
                     path.to_str()?,
                     git2::Oid::from_bytes(object.as_slice())?,
                     true,
                     "",
                 )?;
             },
             x => anyhow::bail!("unexpected ref variant: {:?}", x),
         }
     }
     Ok(())
 }
 fn collect_history(repo: &git2::Repository, tip: &str) -> Result<Vec<git2::Oid>, git2::Error> {
     let mut revwalk = repo.revwalk()?;
     revwalk.push_ref(tip)?;
     revwalk.collect()
 }
 fn run_ls_refs<R: AsRef<Path>>(remote: R, opt: ls::Options) -> io::Result<Vec<Ref>> {
     let (client, server) = futures_ringbuf::Endpoint::pair(256, 256);
     let client = async move {
         let (recv, send) = client.split();
         ls::ls_refs(opt, recv, send).await
     };
     let server = {
         let (recv, send) = server.split();
         upload_pack::upload_pack(&remote, recv, send).and_then(|(_hdr, run)| run)
     };
     let (client_out, server_out) =
         futures::executor::block_on(futures::future::try_join(client, server))?;
     assert!(server_out.success());
     Ok(client_out)
 }
 fn run_fetch<R, B, P>(
     remote: R,
     opt: fetch::Options,
     build_pack_writer: B,
 ) -> io::Result<fetch::Outputs<P::Output>>
 where
     R: AsRef<Path>,
     B: FnOnce(Arc<AtomicBool>) -> P,
     P: PackWriter + Send + 'static,
     P::Output: Send + 'static,
 {
     let (client, server) = futures_ringbuf::Endpoint::pair(256, 256);
     let client = async move {
         let (recv, send) = client.split();
         fetch::fetch(opt, build_pack_writer, recv, send).await
     };
     let server = {
         let (recv, send) = server.split();
         upload_pack::upload_pack(&remote, recv, send).and_then(|(_hdr, run)| run)
     };
     let (client_out, server_out) =
         futures::executor::block_on(futures::future::try_join(client, server))?;
     assert!(server_out.success());
     Ok(client_out)
 }
 #[test]
 fn smoke() {
     let remote = upstream();
     let refs = run_ls_refs(
         &remote,
         ls::Options {
             repo: "foo".into(),
             extra_params: vec![],
             ref_prefixes: vec!["refs/heads/".into(), "refs/pulls/".into()],
         },
     )
     .unwrap();
     assert_eq!(
         refs.iter().map(|r| r.unpack().0).collect::<BTreeSet<_>>(),
         [
             "refs/heads/main".into(),
             "refs/heads/next".into(),
             "refs/pulls/1/head".into()
         ]
         .iter()
         .collect::<BTreeSet<_>>()
     );
     let out = run_fetch(
         &remote,
         fetch::Options {
             repo: "foo".into(),
             extra_params: vec![],
             haves: vec![],
             wants: vec![],
             want_refs: refs.iter().map(|r| r.unpack().0.clone()).collect(),
         },
         |_| packwriter::Discard,
     )
     .unwrap();
     assert!(out.pack.is_some());
 }
 #[test]
 fn want_ref() {
     let remote = upstream();
     let out = run_fetch(
         &remote,
         fetch::Options {
             repo: "foo".into(),
             extra_params: vec![],
             haves: vec![],
             wants: vec![],
             want_refs: vec!["refs/heads/main".into(), "refs/pulls/1/head".into()],
         },
         |_| packwriter::Discard,
     )
     .unwrap();
     assert!(out.pack.is_some());
     assert_eq!(
         out.wanted_refs
             .iter()
             .map(|r| r.unpack().0)
             .collect::<BTreeSet<_>>(),
         ["refs/heads/main".into(), "refs/pulls/1/head".into(),]
             .iter()
             .collect::<BTreeSet<_>>()
     )
 }
 #[test]
 #[should_panic(expected = "`fetch` is empty")]
 fn empty_fetch() {
     let remote = upstream();
     run_fetch(
         &remote,
         fetch::Options {
             repo: "foo".into(),
             extra_params: vec![],
             haves: vec![],
             wants: vec![],
             want_refs: vec![],
         },
         |_| packwriter::Discard,
     )
     .unwrap();
 }
 fn clone_with<R, L, B, P>(remote: R, local: L, build_pack_writer: B)
 where
     R: AsRef<Path>,
     L: AsRef<Path>,
     B: FnOnce(Arc<AtomicBool>) -> P,
     P: PackWriter + Send + 'static,
     P::Output: Send + 'static,
 {
     let refs = run_ls_refs(
         &remote,
         ls::Options {
             repo: "foo".into(),
             extra_params: vec![],
             ref_prefixes: vec!["refs/heads/".into(), "refs/pulls/".into()],
         },
     )
     .unwrap();
     let out = run_fetch(
         &remote,
         fetch::Options {
             repo: "foo".into(),
             extra_params: vec![],
             haves: vec![],
             wants: vec![],
             want_refs: refs.iter().map(|r| r.unpack().0.clone()).collect(),
         },
         build_pack_writer,
     )
     .unwrap();
     assert!(out.pack.is_some());
     let remote_repo = git2::Repository::open(remote).unwrap();
     remote_repo.set_namespace("foo").unwrap();
     let local_repo = git2::Repository::open(&local).unwrap();
     update_tips(&local_repo, &out.wanted_refs).unwrap();
     let mut remote_refs = collect_refs(&remote_repo).unwrap();
     let mut local_refs = collect_refs(&local_repo).unwrap();
     remote_refs.sort();
     local_refs.sort();
     assert_eq!(remote_refs, local_refs);
 }
 #[test]
 fn clone_libgit() {
     let remote = upstream();
     let local = tempdir().unwrap();
     let local_repo = git2::Repository::init(&local).unwrap();
     clone_with(&remote, &local, move |stop| {
         packwriter::Libgit::new(packwriter::Options::default(), local_repo, stop)
     })
 }
 #[test]
 fn clone_gitoxide() {
     let remote = upstream();
     let local = tempdir().unwrap();
     let local_repo = git2::Repository::init(&local).unwrap();
     clone_with(&remote, &local, move |stop| {
         packwriter::Standard::new(
             local_repo.path(),
             packwriter::Options::default(),
             packwriter::StandardThickener::new(local_repo.path()),
             stop,
         )
     })
 }
 fn thin_pack_with<R, L, B, P>(remote: R, local: L, build_pack_writer: B)
 where
     R: AsRef<Path>,
     L: AsRef<Path>,
     B: Fn(Arc<AtomicBool>) -> P,
     P: PackWriter + Send + 'static,
     P::Output: Send + 'static,
 {
     // Clone main only
     {
         let out = run_fetch(
             &remote,
             fetch::Options {
                 repo: "foo".into(),
                 extra_params: vec![],
                 haves: vec![],
                 wants: vec![],
                 want_refs: vec!["refs/heads/main".into()],
             },
             &build_pack_writer,
         )
         .unwrap();
         assert!(out.pack.is_some());
     }
     let remote_repo = git2::Repository::open(&remote).unwrap();
     remote_repo.set_namespace("foo").unwrap();
     let local_repo = git2::Repository::open(&local).unwrap();
     // Fetch next, which is ahead of main
     {
         let head = remote_repo.refname_to_id("refs/heads/main").unwrap();
         let out = run_fetch(
             &remote,
             fetch::Options {
                 repo: "foo".into(),
                 extra_params: vec![],
                 haves: vec![ObjectId::from_20_bytes(head.as_bytes())],
                 wants: vec![],
                 want_refs: vec!["refs/heads/next".into()],
             },
             build_pack_writer,
         )
         .unwrap();
         assert!(out.pack.is_some());
         update_tips(&local_repo, &out.wanted_refs).unwrap();
     }
     let remote_history = collect_history(&remote_repo, "refs/heads/next").unwrap();
     let local_history = collect_history(&local_repo, "refs/heads/next").unwrap();
     assert!(!remote_history.is_empty());
     assert_eq!(remote_history, local_history)
 }
 #[test]
 #[ignore]
 fn thin_pack_libgit() {
     let remote = upstream();
     let local = tempdir().unwrap();
     thin_pack_with(&remote, &local, |stop| {
         let local_repo = git2::Repository::init(&local).unwrap();
         packwriter::Libgit::new(packwriter::Options::default(), local_repo, stop)
     })
 }
 #[test]
 fn thin_pack_gitoxide() {
     let remote = upstream();
     let local = tempdir().unwrap();
     let local_repo = git2::Repository::init(&local).unwrap();
     let git_dir = local_repo.path().to_owned();
     thin_pack_with(&remote, &local, move |stop| {
         packwriter::Standard::new(
             &git_dir,
             packwriter::Options::default(),
             packwriter::StandardThickener::new(&git_dir),
             stop,
         )
     })
 }

 // Copyright © 2021 The Radicle Link Contributors
 //
 // This file is part of radicle-link, distributed under the GPLv3 with Radicle
 // Linking Exception. For full terms see the included LICENSE file.
 use futures::{executor::block_on, io::Cursor, AsyncReadExt as _};
 use link_git::protocol::take::TryTake;
 use std::io;
 #[test]
 fn when_within_limit() {
     let input = b"the world is everything that is the case";
     let output = block_on(async move {
         let mut buf = Vec::with_capacity(input.len());
         TryTake::new(Cursor::new(input), input.len() as u64 + 1)
             .read_to_end(&mut buf)
             .await?;
         Ok::<_, io::Error>(buf)
     })
     .unwrap();
     assert_eq!(input, output.as_slice())
 }
 #[test]
 fn when_limit_exceeded() {
     let input = b"what is the case, the fact, is the existence of atomic facts";
     let output =
         block_on(TryTake::new(Cursor::new(input), 10).read_to_end(&mut Vec::new())).unwrap_err();
     assert_eq!(output.to_string(), "max input size exceeded")
 }
 #[test]
 fn excess_bytes_remain() {
     let input = b"whereof one cannot speak, thereof one must be silent";
     let output = block_on(async move {
         let mut buf = Vec::with_capacity(input.len());
         let res = TryTake::new(Cursor::new(input), input.len() as u64)
             .read_to_end(&mut buf)
             .await;
         assert!(res.is_err());
         buf
     });
     assert_eq!(input, output.as_slice())
 }