diff options
Diffstat (limited to 'helix-vcs/src/git.rs')
-rw-r--r-- | helix-vcs/src/git.rs | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/helix-vcs/src/git.rs b/helix-vcs/src/git.rs new file mode 100644 index 00000000..82b2b558 --- /dev/null +++ b/helix-vcs/src/git.rs @@ -0,0 +1,80 @@ +use std::path::Path; + +use git::objs::tree::EntryMode; +use git::sec::trust::DefaultForLevel; +use git::{Commit, ObjectId, Repository, ThreadSafeRepository}; +use git_repository as git; + +use crate::DiffProvider; + +#[cfg(test)] +mod test; + +pub struct Git; + +impl Git { + fn open_repo(path: &Path, ceiling_dir: Option<&Path>) -> Option<ThreadSafeRepository> { + // custom open options + let mut git_open_opts_map = git::sec::trust::Mapping::<git::open::Options>::default(); + + // don't use the global git configs (not needed) + let config = git::permissions::Config { + system: false, + git: false, + user: false, + env: true, + includes: true, + git_binary: false, + }; + // change options for config permissions without touching anything else + git_open_opts_map.reduced = git_open_opts_map.reduced.permissions(git::Permissions { + config, + ..git::Permissions::default_for_level(git::sec::Trust::Reduced) + }); + git_open_opts_map.full = git_open_opts_map.full.permissions(git::Permissions { + config, + ..git::Permissions::default_for_level(git::sec::Trust::Full) + }); + + let mut open_options = git::discover::upwards::Options::default(); + if let Some(ceiling_dir) = ceiling_dir { + open_options.ceiling_dirs = vec![ceiling_dir.to_owned()]; + } + + ThreadSafeRepository::discover_with_environment_overrides_opts( + path, + open_options, + git_open_opts_map, + ) + .ok() + } +} + +impl DiffProvider for Git { + fn get_diff_base(&self, file: &Path) -> Option<Vec<u8>> { + debug_assert!(!file.exists() || file.is_file()); + debug_assert!(file.is_absolute()); + + // TODO cache repository lookup + let repo = Git::open_repo(file.parent()?, None)?.to_thread_local(); + let head = repo.head_commit().ok()?; + let file_oid = find_file_in_commit(&repo, &head, file)?; + + let file_object = repo.find_object(file_oid).ok()?; + Some(file_object.detach().data) + } +} + +/// 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) -> Option<ObjectId> { + let repo_dir = repo.work_dir()?; + let rel_path = file.strip_prefix(repo_dir).ok()?; + let tree = commit.tree().ok()?; + let tree_entry = tree.lookup_entry_by_path(rel_path).ok()??; + match tree_entry.mode() { + // not a file, everything is new, do not show diff + EntryMode::Tree | EntryMode::Commit | EntryMode::Link => None, + // found a file + EntryMode::Blob | EntryMode::BlobExecutable => Some(tree_entry.object_id()), + } +} |