use std::path::{Path, PathBuf};
use super::fetch::{check_manifest, ensure_worktree_of_repo, fetch_tip};
use super::git::{failure_message, Git};
use super::location::{worktree_path, LedgerLocation, Repo};
pub const MAX_ATTEMPTS: usize = 5;
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum PushResult {
Pushed { attempts: usize },
AlreadyOnRemote,
}
pub struct PushOutcome {
pub location: LedgerLocation,
pub path: PathBuf,
pub committed: bool,
pub commit: String,
pub result: PushResult,
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct PushStatus {
pub flag: char,
pub summary: String,
}
impl PushStatus {
pub fn rejected(&self) -> bool {
self.flag == '!'
}
}
pub fn push(
repo: &Repo,
state_root: &Path,
message: &str,
on_retry: &mut dyn FnMut(usize, &PushStatus),
) -> Result<PushOutcome, String> {
let location = repo.location(state_root)?;
let path = existing_worktree(repo, state_root)?;
let wt = Git::new(&path);
ensure_worktree_of_repo(&wt, &repo.common_dir)?;
let mut tip = fetch_tip(&wt, &location)?;
check_manifest(&wt, tip.as_deref().unwrap_or("HEAD"), &location)?;
let committed = commit_changes(&wt, message)?;
for attempt in 1..=MAX_ATTEMPTS {
if attempt > 1 {
tip = fetch_tip(&wt, &location)?;
check_manifest(&wt, tip.as_deref().unwrap_or("HEAD"), &location)?;
}
if let Some(remote_tip) = &tip {
if is_ancestor(&wt, "HEAD", remote_tip)? {
return Ok(PushOutcome {
location,
path,
committed,
commit: remote_tip.clone(),
result: PushResult::AlreadyOnRemote,
});
}
if !is_ancestor(&wt, remote_tip, "HEAD")? {
rebase_onto(&wt, remote_tip, &location)?;
}
}
let status = push_head(&wt, &location, tip.as_deref())?;
if !status.rejected() {
let commit = wt.run_line(["rev-parse", "--verify", "HEAD^{commit}"])?;
return Ok(PushOutcome {
location,
path,
committed,
commit,
result: PushResult::Pushed { attempts: attempt },
});
}
if attempt < MAX_ATTEMPTS {
on_retry(attempt, &status);
}
}
Err(format!(
"error: {} on {} rejected the push {} times; it moved between each fetch and push.\n \
The commit stays in {}. Re-run tsk ledger push to try again",
location.ref_name(),
location.label(),
MAX_ATTEMPTS,
path.display()
))
}
fn existing_worktree(repo: &Repo, state_root: &Path) -> Result<PathBuf, String> {
let missing = |what: String| {
format!(
"error: {}. Run tsk ledger fetch first, which creates the ledger worktree",
what
)
};
let clone_id = repo.read_clone_id()?.ok_or_else(|| {
missing(format!(
"this clone has no clone id yet ({} is absent or empty)",
repo.clone_id_file().display()
))
})?;
let path = worktree_path(state_root, &clone_id);
if !path.is_dir() {
return Err(missing(format!("{} does not exist", path.display())));
}
Ok(path)
}
fn commit_changes(wt: &Git, message: &str) -> Result<bool, String> {
wt.run(["add", "-A"])?;
let args = ["diff", "--cached", "--quiet"];
let (args, output) = wt.output(args)?;
match output.status.code() {
Some(0) => Ok(false),
Some(1) => {
wt.run(["commit", "--quiet", "-m", message])?;
Ok(true)
}
_ => Err(failure_message(&args, &output)),
}
}
fn is_ancestor(wt: &Git, ancestor: &str, descendant: &str) -> Result<bool, String> {
let (args, output) = wt.output(["merge-base", "--is-ancestor", ancestor, descendant])?;
match output.status.code() {
Some(0) => Ok(true),
Some(1) => Ok(false),
_ => Err(failure_message(&args, &output)),
}
}
fn rebase_onto(wt: &Git, tip: &str, location: &LedgerLocation) -> Result<(), String> {
let (_, output) = wt.output(["rebase", "--quiet", tip])?;
if output.status.success() {
return Ok(());
}
let _ = wt.output(["rebase", "--abort"])?;
Err(format!(
"error: rebase onto {}'s {} ({}) conflicted; the rebase is aborted.\n \
Resolve it in {}: git rebase {}, fix the conflicts,\n \
git rebase --continue, then re-run tsk ledger push",
location.label(),
location.ref_name(),
tip,
wt.dir().display(),
tip
))
}
fn push_head(
wt: &Git,
location: &LedgerLocation,
expected: Option<&str>,
) -> Result<PushStatus, String> {
let lease = format!(
"--force-with-lease={}:{}",
location.ref_name(),
expected.unwrap_or("")
);
let refspec = format!("HEAD:{}", location.ref_name());
let (args, output) = wt.output([
"push",
"--porcelain",
lease.as_str(),
location.remote(),
refspec.as_str(),
])?;
let stdout = String::from_utf8_lossy(&output.stdout);
let status = parse_push_status(&stdout, location.ref_name())
.ok_or_else(|| failure_message(&args, &output))?;
if !status.rejected() && !output.status.success() {
return Err(failure_message(&args, &output));
}
Ok(status)
}
pub fn parse_push_status(porcelain: &str, ref_name: &str) -> Option<PushStatus> {
porcelain.lines().find_map(|line| {
let mut fields = line.splitn(3, '\t');
let flag_field = fields.next()?;
let refs = fields.next()?;
let summary = fields.next().unwrap_or("");
let mut flag_chars = flag_field.chars();
let flag = flag_chars.next()?;
if flag_chars.next().is_some() {
return None;
}
let (_, to) = refs.split_once(':')?;
if to != ref_name {
return None;
}
Some(PushStatus {
flag,
summary: summary.to_string(),
})
})
}
#[cfg(test)]
mod tests {
use super::*;
const REF: &str = "refs/heads/tsk/ledger";
#[test]
fn parses_a_fast_forward_line() {
let out = "To /tmp/origin.git\n \tHEAD:refs/heads/tsk/ledger\t1111111..2222222\nDone\n";
let status = parse_push_status(out, REF).unwrap();
assert_eq!(status.flag, ' ');
assert_eq!(status.summary, "1111111..2222222");
assert!(!status.rejected());
}
#[test]
fn parses_a_stale_lease_rejection() {
let out =
"To /tmp/origin.git\n!\tHEAD:refs/heads/tsk/ledger\t[rejected] (stale info)\nDone\n";
let status = parse_push_status(out, REF).unwrap();
assert!(status.rejected());
assert_eq!(status.summary, "[rejected] (stale info)");
}
#[test]
fn parses_a_remote_rejection() {
let out = "To /tmp/origin.git\n!\tHEAD:refs/heads/tsk/ledger\t[remote rejected] (cannot lock ref)\nDone\n";
assert!(parse_push_status(out, REF).unwrap().rejected());
}
#[test]
fn parses_an_up_to_date_line() {
let out = "To /tmp/origin.git\n=\tHEAD:refs/heads/tsk/ledger\t[up to date]\nDone\n";
let status = parse_push_status(out, REF).unwrap();
assert_eq!(status.flag, '=');
assert!(!status.rejected());
}
#[test]
fn ignores_lines_for_other_refs() {
let out = "To /tmp/origin.git\n!\tHEAD:refs/tsk/ledger\t[rejected] (stale info)\nDone\n";
assert_eq!(parse_push_status(out, REF), None);
}
#[test]
fn returns_none_without_a_status_line() {
assert_eq!(parse_push_status("", REF), None);
assert_eq!(parse_push_status("To /tmp/origin.git\nDone\n", REF), None);
}
}