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extern crate failure;
extern crate git2;
extern crate slog;
pub const MAX_STACK_CONFIG_NAME: &str = "absorb.maxStack";
pub const MAX_STACK: usize = 10;
fn max_stack(repo: &git2::Repository) -> usize {
match repo.config()
.and_then(|config| config.get_i64(MAX_STACK_CONFIG_NAME))
{
Ok(max_stack) if max_stack > 0 => max_stack as usize,
_ => MAX_STACK,
}
}
pub fn working_stack<'repo>(
repo: &'repo git2::Repository,
base: Option<&git2::Commit<'repo>>,
logger: &slog::Logger,
) -> Result<Vec<git2::Commit<'repo>>, failure::Error> {
let head = repo.head()?;
debug!(logger, "head found"; "head" => head.name());
if !head.is_branch() {
return Err(failure::err_msg("HEAD is not a branch"));
}
let mut revwalk = repo.revwalk()?;
revwalk.set_sorting(git2::SORT_TOPOLOGICAL);
revwalk.push_head()?;
debug!(logger, "head pushed"; "head" => head.name());
if let Some(base) = base {
revwalk.hide(base.id())?;
debug!(logger, "commit hidden"; "commit" => base.id().to_string());
} else {
for branch in repo.branches(Some(git2::BranchType::Local))? {
let (branch, _) = branch?;
let branch = branch.get().name();
match branch {
Some(name) if Some(name) != head.name() => {
revwalk.hide_ref(name)?;
debug!(logger, "branch hidden"; "branch" => branch);
}
_ => {
debug!(logger, "branch not hidden"; "branch" => branch);
}
};
}
}
let mut ret = Vec::new();
let sig = repo.signature()?;
for rev in revwalk {
let commit = repo.find_commit(rev?)?;
if commit.parents().len() > 1 {
warn!(logger, "merge commit found"; "commit" => commit.id().to_string());
break;
}
if commit.author().name_bytes() != sig.name_bytes()
|| commit.author().email_bytes() != sig.email_bytes()
{
warn!(logger, "foreign author found"; "commit" => commit.id().to_string());
break;
}
if ret.len() == max_stack(repo) {
warn!(logger, "stack limit reached"; "limit" => ret.len());
break;
}
debug!(logger, "commit pushed onto stack"; "commit" => commit.id().to_string());
ret.push(commit);
}
Ok(ret)
}
#[cfg(test)]
mod tests {
extern crate tempdir;
use super::*;
fn empty_slog() -> slog::Logger {
slog::Logger::root(slog::Discard, o!())
}
fn init_repo() -> (tempdir::TempDir, git2::Repository) {
// the repo will be deleted when the tempdir gets dropped
let dir = tempdir::TempDir::new("git-absorb").unwrap();
// TODO: use in-memory ODB instead (blocked on git2 support)
let repo = git2::Repository::init(&dir).unwrap();
let mut config = repo.config().unwrap();
config.set_str("user.name", "nobody").unwrap();
config.set_str("user.email", "nobody@example.com").unwrap();
(dir, repo)
}
fn empty_commit<'repo>(
repo: &'repo git2::Repository,
update_ref: &str,
message: &str,
parents: &[&git2::Commit],
) -> git2::Commit<'repo> {
let sig = repo.signature().unwrap();
let tree = repo.find_tree(repo.treebuilder(None).unwrap().write().unwrap())
.unwrap();
repo.find_commit(
repo.commit(Some(update_ref), &sig, &sig, message, &tree, parents)
.unwrap(),
).unwrap()
}
fn empty_commit_chain<'repo>(
repo: &'repo git2::Repository,
update_ref: &str,
initial_parents: &[&git2::Commit],
length: usize,
) -> Vec<git2::Commit<'repo>> {
let mut ret = Vec::with_capacity(length);
for idx in 0..length {
let next = if let Some(last) = ret.last() {
// TODO: how to deduplicate the rest of this call if last doesn't live long enough?
empty_commit(repo, update_ref, &idx.to_string(), &[last])
} else {
empty_commit(repo, update_ref, &idx.to_string(), initial_parents)
};
ret.push(next)
}
assert_eq!(ret.len(), length);
ret
}
fn assert_stack_matches_chain(length: usize, stack: &[git2::Commit], chain: &[git2::Commit]) {
assert_eq!(stack.len(), length);
for (chain_commit, stack_commit) in chain.iter().rev().take(length).zip(stack) {
assert_eq!(stack_commit.id(), chain_commit.id());
}
}
#[test]
fn test_stack_hides_other_branches() {
let (_dir, repo) = init_repo();
let commits = empty_commit_chain(&repo, "HEAD", &[], 2);
repo.branch("hide", &commits[0], false).unwrap();
assert_stack_matches_chain(
1,
&working_stack(&repo, None, &empty_slog()).unwrap(),
&commits,
);
}
#[test]
fn test_stack_uses_custom_base() {
let (_dir, repo) = init_repo();
let commits = empty_commit_chain(&repo, "HEAD", &[], 3);
repo.branch("hide", &commits[1], false).unwrap();
assert_stack_matches_chain(
2,
&working_stack(&repo, Some(&commits[0]), &empty_slog()).unwrap(),
&commits,
);
}
#[test]
fn test_stack_stops_at_default_limit() {
let (_dir, repo) = init_repo();
let commits = empty_commit_chain(&repo, "HEAD", &[], MAX_STACK + 1);
assert_stack_matches_chain(
MAX_STACK,
&working_stack(&repo, None, &empty_slog()).unwrap(),
&commits,
);
}
#[test]
fn test_stack_stops_at_configured_limit() {
let (_dir, repo) = init_repo();
let commits = empty_commit_chain(&repo, "HEAD", &[], MAX_STACK + 2);
repo.config()
.unwrap()
.set_i64(MAX_STACK_CONFIG_NAME, (MAX_STACK + 1) as i64)
.unwrap();
assert_stack_matches_chain(
MAX_STACK + 1,
&working_stack(&repo, None, &empty_slog()).unwrap(),
&commits,
);
}
#[test]
fn test_stack_stops_at_foreign_author() {
let (_dir, repo) = init_repo();
let old_commits = empty_commit_chain(&repo, "HEAD", &[], 3);
repo.config()
.unwrap()
.set_str("user.name", "nobody2")
.unwrap();
let new_commits = empty_commit_chain(&repo, "HEAD", &[old_commits.last().unwrap()], 2);
assert_stack_matches_chain(
2,
&working_stack(&repo, None, &empty_slog()).unwrap(),
&new_commits,
);
}
#[test]
fn test_stack_stops_at_merges() {
let (_dir, repo) = init_repo();
let first = empty_commit(&repo, "HEAD", "first", &[]);
// equivalent to checkout --orphan
repo.set_head("refs/heads/new").unwrap();
let second = empty_commit(&repo, "HEAD", "second", &[]);
// the current commit must be the first parent
let merge = empty_commit(&repo, "HEAD", "merge", &
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