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helix/helix-vcs/src/git.rs

134 lines
5.0 KiB
Rust

use anyhow::{bail, Context, Result};
use arc_swap::ArcSwap;
use gix::filter::plumbing::driver::apply::Delay;
use std::io::Read;
use std::path::Path;
use std::sync::Arc;
use gix::objs::tree::EntryKind;
use gix::sec::trust::DefaultForLevel;
use gix::{Commit, ObjectId, Repository, ThreadSafeRepository};
use crate::DiffProvider;
#[cfg(test)]
mod test;
pub struct Git;
impl Git {
fn open_repo(path: &Path, ceiling_dir: Option<&Path>) -> Result<ThreadSafeRepository> {
// custom open options
let mut git_open_opts_map = gix::sec::trust::Mapping::<gix::open::Options>::default();
// On windows various configuration options are bundled as part of the installations
// This path depends on the install location of git and therefore requires some overhead to lookup
// This is basically only used on windows and has some overhead hence it's disabled on other platforms.
// `gitoxide` doesn't use this as default
let config = gix::open::permissions::Config {
system: true,
git: true,
user: true,
env: true,
includes: true,
git_binary: cfg!(windows),
};
// change options for config permissions without touching anything else
git_open_opts_map.reduced = git_open_opts_map
.reduced
.permissions(gix::open::Permissions {
config,
..gix::open::Permissions::default_for_level(gix::sec::Trust::Reduced)
});
git_open_opts_map.full = git_open_opts_map.full.permissions(gix::open::Permissions {
config,
..gix::open::Permissions::default_for_level(gix::sec::Trust::Full)
});
let open_options = gix::discover::upwards::Options {
ceiling_dirs: ceiling_dir
.map(|dir| vec![dir.to_owned()])
.unwrap_or_default(),
dot_git_only: true,
..Default::default()
};
let res = ThreadSafeRepository::discover_with_environment_overrides_opts(
path,
open_options,
git_open_opts_map,
)?;
Ok(res)
}
}
impl DiffProvider for Git {
fn get_diff_base(&self, file: &Path) -> Result<Vec<u8>> {
debug_assert!(!file.exists() || file.is_file());
debug_assert!(file.is_absolute());
// TODO cache repository lookup
let repo_dir = file.parent().context("file has no parent directory")?;
let repo = Git::open_repo(repo_dir, None)
.context("failed to open git repo")?
.to_thread_local();
let head = repo.head_commit()?;
let file_oid = find_file_in_commit(&repo, &head, file)?;
let file_object = repo.find_object(file_oid)?;
let data = file_object.detach().data;
// Get the actual data that git would make out of the git object.
// This will apply the user's git config or attributes like crlf conversions.
if let Some(work_dir) = repo.work_dir() {
let rela_path = file.strip_prefix(work_dir)?;
let rela_path = gix::path::try_into_bstr(rela_path)?;
let (mut pipeline, _) = repo.filter_pipeline(None)?;
let mut worktree_outcome =
pipeline.convert_to_worktree(&data, rela_path.as_ref(), Delay::Forbid)?;
let mut buf = Vec::with_capacity(data.len());
worktree_outcome.read_to_end(&mut buf)?;
Ok(buf)
} else {
Ok(data)
}
}
fn get_current_head_name(&self, file: &Path) -> Result<Arc<ArcSwap<Box<str>>>> {
debug_assert!(!file.exists() || file.is_file());
debug_assert!(file.is_absolute());
let repo_dir = file.parent().context("file has no parent directory")?;
let repo = Git::open_repo(repo_dir, None)
.context("failed to open git repo")?
.to_thread_local();
let head_ref = repo.head_ref()?;
let head_commit = repo.head_commit()?;
let name = match head_ref {
Some(reference) => reference.name().shorten().to_string(),
None => head_commit.id.to_hex_with_len(8).to_string(),
};
Ok(Arc::new(ArcSwap::from_pointee(name.into_boxed_str())))
}
}
/// Finds the object that contains the contents of a file at a specific commit.
fn find_file_in_commit(repo: &Repository, commit: &Commit, file: &Path) -> Result<ObjectId> {
let repo_dir = repo.work_dir().context("repo has no worktree")?;
let rel_path = file.strip_prefix(repo_dir)?;
let tree = commit.tree()?;
let tree_entry = tree
.lookup_entry_by_path(rel_path, &mut Vec::new())?
.context("file is untracked")?;
match tree_entry.mode().kind() {
// not a file, everything is new, do not show diff
mode @ (EntryKind::Tree | EntryKind::Commit | EntryKind::Link) => {
bail!("entry at {} is not a file but a {mode:?}", file.display())
}
// found a file
EntryKind::Blob | EntryKind::BlobExecutable => Ok(tree_entry.object_id()),
}
}