Files
bench/manager/core/sync.py
T
istos 9d98e2c55a sync: origin/main as the shared board, behind BOARD_SYNC
Team mode's second half. A board-made move already commits itself (18);
now that commit publishes, every board pulls on a beat, and a card two
boards move at once resolves the way git resolves everything else — the
push race is the concurrency control.

- core/sync.py: push is event-driven (a new state.COMMIT_HOOKS registry
  fires it from taskfiles, so taskfiles stays left of everything that
  reacts to it); pull is a beat that fast-forwards, or replays this
  board's own commits on top when the two diverged. A replay that
  conflicts on a task file drops the local move — origin is the
  linearizer — and toasts who took the card.
- The piggyback guard stands in front of every push and every replay:
  each local-ahead commit on main must be `board: `-prefixed, so a
  human's unpushed work is never published as a side effect of a card
  moving. Uncommitted changes, a checkout off main and an unreachable
  origin all stall or degrade rather than risk anything, each narrated
  once instead of once per beat.
- watch.py names the commit author instead of "disk" for moves a pull
  brought, via the arrivals sync files for it; its narration moved out
  of the loop into narrate() so it can be tested directly.
- The board grows a sync chip that appears only when sync stops
  converging, and the SSE stream grows a toast type so the server can
  say something to the person, not just to the ticker.

Gate off (the default) means no fetch, no push, no thread, no change.

Verified with tests/test_boards_sync.py: two real clones of a real bare
upstream race each other through every case above.
2026-07-30 09:47:38 +02:00

449 lines
18 KiB
Python

"""Boards converge through origin/main: push what this board commits, pull
what the other boards published.
Gated on `BOARD_SYNC` (which implies `BOARD_COMMIT_MOVES` — a move that
never commits has nothing to publish). Off, nothing here runs: no fetch,
no push, no thread.
The shape of it:
- **push** is event-driven. `taskfiles` fires `state.task_committed` after
a board-made move commits; the hook installed here publishes it. A
rejected push means another board got there first, so the whole converge
runs and pushes again.
- **pull** is a beat: fetch, then integrate. Purely behind → fast-forward.
Diverged → the board's own commits are rebased on top, never merged
past; a rebase that conflicts on a task file means the local move lost
the race, and it is dropped with a toast naming who took the card.
- **the piggyback guard** stands in front of every push: each local-ahead
commit on main must be `board: `-prefixed. A human's unpushed work is
never published as a side effect of a card moving.
- **offline** is not an error. The first unreachable fetch says so once,
the rest are silent, commits queue on local main and the next reachable
fetch catches up.
Git is the lock server and main the linearizer — that is the whole
concurrency control. Nothing here reacts to synced state beyond narrating
it: replicas render, they do not act.
"""
from __future__ import annotations
import subprocess
import threading
import time
from pathlib import Path
import config
import state
from taskfiles import NUMBER_RE
REMOTE = "origin" # one remote, one branch — by design
BRANCH = "main"
UPSTREAM = f"{REMOTE}/{BRANCH}"
BOARD_COMMIT = "board: " # the prefix taskfiles messages its own commits with
PUSH_TIMEOUT = 120
REBASE_TIMEOUT = 120
ARRIVED_TTL = 60.0 # the watcher polls every 2s; this is generous
_LOCK = threading.Lock() # one git operation on the checkout at a time
_ARRIVED_LOCK = threading.Lock()
ARRIVED: dict[str, tuple[str, float]] = {} # filename -> (author, ts) from the last pull
_NOTES: dict[str, tuple[str, str]] = {} # key -> (summary, level) already narrated
def _git(*args: str, timeout: float = 30) -> subprocess.CompletedProcess:
"""Never raises: a timeout or a missing binary is just a failed run."""
try:
return subprocess.run(["git", "-C", str(config.REPO), *args],
capture_output=True, text=True, timeout=timeout)
except subprocess.TimeoutExpired:
return subprocess.CompletedProcess(args, 128, "", "timed out")
except OSError as exc:
return subprocess.CompletedProcess(args, 128, "", str(exc))
# ── narration ──────────────────────────────────────────────────────────
# Every condition here repeats on every beat, so each one is narrated once
# and then held: the ticker says it, the header chip keeps saying it.
def status() -> dict:
"""What the header shows: ok while converging, otherwise the reason."""
if not config.SYNC:
return {"enabled": False, "state": "off", "detail": ""}
for level in ("offline", "stalled"):
for summary, note_level in _NOTES.values():
if note_level == level:
return {"enabled": True, "state": level, "detail": summary}
return {"enabled": True, "state": "ok", "detail": ""}
def _note(key: str, summary: str, level: str = "stalled") -> None:
if _NOTES.get(key) == (summary, level):
return # same condition as last time: said once is enough
_NOTES[key] = (summary, level)
state.record_board_event({"kind": "sync", "actor": "sync", "summary": summary})
state.broadcast({"type": "board"})
def _clear(key: str, recovery: str = "") -> None:
if _NOTES.pop(key, None) is None:
return
if recovery:
state.record_board_event({"kind": "sync", "actor": "sync", "summary": recovery})
state.broadcast({"type": "board"})
# ── the checkout ───────────────────────────────────────────────────────
def _origin_present() -> bool:
return REMOTE in _git("remote").stdout.split()
def _head() -> str:
return _git("rev-parse", "HEAD").stdout.strip()
def _on_main() -> bool:
return _git("rev-parse", "--abbrev-ref", "HEAD").stdout.strip() == BRANCH
def _clean() -> bool:
"""Tracked files only: an untracked scratch file is nobody's business,
but a modified one is what a fast-forward would run over."""
return not _git("status", "--porcelain", "--untracked-files=no").stdout.strip()
def _count(rng: str) -> int:
out = _git("rev-list", "--count", rng).stdout.strip()
return int(out) if out.isdigit() else 0
def _tasks_prefix() -> str:
try:
return config.TASKS.resolve().relative_to(config.REPO.resolve()).as_posix() + "/"
except ValueError:
return "tasks/"
def _fetch() -> bool:
result = _git("fetch", REMOTE, BRANCH, timeout=config.FETCH_TIMEOUT)
if result.returncode != 0:
if "couldn't find remote ref" in (result.stderr or "").lower():
_note("no-branch", f"sync stalled: {REMOTE} has no {BRANCH} branch — "
f"sync rides {UPSTREAM} and nothing else")
return False
_note("offline",
f"sync is behind: {REMOTE} is unreachable — this board keeps "
f"working locally and catches up when it returns", "offline")
return False
_clear("no-branch")
_clear("offline", f"sync caught up: {REMOTE} is reachable again")
return True
# ── publishing ─────────────────────────────────────────────────────────
def _ahead() -> list[str]:
"""`<short sha> <subject>` for every commit local main has and
origin/main does not — newest first."""
out = _git("log", "--format=%h %s", f"{UPSTREAM}..{BRANCH}").stdout
return [line for line in out.splitlines() if line.strip()]
def _stray(commits: list[str]) -> str:
"""The piggyback hazard: pushing publishes *every* local-ahead commit,
so one that the board did not make is a human's private work and stops
the push. Oldest first — that is the one to deal with."""
for line in reversed(commits):
subject = line.split(" ", 1)[1] if " " in line else ""
if not subject.startswith(BOARD_COMMIT):
return line
return ""
def _publish() -> str:
"""Push local main if — and only if — everything on it is the board's.
ok | nothing | stray | not-on-main | retry | offline | stalled
"""
if not _on_main():
branch = _git("rev-parse", "--abbrev-ref", "HEAD").stdout.strip() or "a detached HEAD"
_note("branch", f"sync paused: this checkout is on '{branch}', not {BRANCH} — "
f"board commits are not landing where sync publishes from")
return "not-on-main"
_clear("branch")
if _git("rev-parse", "--verify", "--quiet", UPSTREAM).returncode != 0:
return "retry" # never fetched: converge first, then publish
commits = _ahead()
stray = _stray(commits)
if stray:
_note("stray", f"not pushing: {stray} is not a board commit — sync will not "
f"publish it for you. Push main yourself, or move that commit "
f"off main, and sync resumes")
return "stray"
_clear("stray") # nothing stray left to refuse, however that happened
if not commits:
return "nothing"
result = _git("push", REMOTE, f"{BRANCH}:{BRANCH}", timeout=PUSH_TIMEOUT)
if result.returncode == 0:
_clear("push")
_clear("offline", f"sync caught up: {REMOTE} is reachable again")
state.record_board_event({
"kind": "sync", "actor": "sync",
"summary": f"pushed {len(commits)} board commit"
f"{'s' if len(commits) > 1 else ''} to {UPSTREAM}"})
return "ok"
stderr = (result.stderr or result.stdout).strip()
if _rejected(stderr):
return "retry"
if _unreachable(stderr):
_note("offline",
f"sync is behind: {REMOTE} is unreachable — this board keeps "
f"working locally and catches up when it returns", "offline")
return "offline"
detail = stderr.splitlines()[-1][:140] if stderr else "git said nothing"
_note("push", f"sync could not push to {UPSTREAM}: {detail}")
return "stalled"
def _rejected(stderr: str) -> bool:
text = stderr.lower()
return "non-fast-forward" in text or "fetch first" in text or "! [rejected]" in text
def _unreachable(stderr: str) -> bool:
text = stderr.lower()
return any(mark in text for mark in (
"could not read from remote", "could not resolve", "unable to access",
"does not appear to be a git repository", "connection", "timed out",
"no such file or directory", "permission denied"))
# ── integrating what arrived ───────────────────────────────────────────
def _conflicted() -> list[str]:
out = _git("diff", "--name-only", "--diff-filter=U").stdout
return [line.strip() for line in out.splitlines() if line.strip()]
def _is_task_file(path: str) -> bool:
return path.startswith(_tasks_prefix()) and path.endswith(".md")
def _author_of(filename: str, rev: str) -> str:
"""Who wrote the newest commit touching this card in `rev` — a range for
what a pull brought, a ref for what origin already holds."""
return _git("log", "-1", "--format=%an", rev, "--",
f"{_tasks_prefix()}*/{filename}").stdout.strip()
def _number(filename: str) -> str:
match = NUMBER_RE.match(filename)
return match.group(1) if match else filename[:-3] if filename.endswith(".md") else filename
def _lost(filename: str) -> None:
"""The local move lost the race. Say who took the card — the file itself
reverts to origin's version when the rebase drops our commit."""
who = _author_of(filename, UPSTREAM) or "someone else"
message = f"{_number(filename)} claimed by {who} — your move was undone"
state.record_board_event({"kind": "sync", "actor": "sync", "file": filename,
"summary": message})
state.broadcast({"type": "toast", "message": message, "error": True})
state.broadcast({"type": "board"})
def _replay() -> str:
"""Rebase this board's commits onto origin/main. Conflicts on a task
file are resolved by dropping our commit: origin is the linearizer, and
a card someone else moved first is theirs. Anything conflicting outside
tasks/ is a real collision — abort and wait for a human.
ok | dirty | stalled
"""
if not _clean():
_note("dirty", "sync paused: main has uncommitted changes — commit or stash "
"them and sync resumes (code work belongs in a worktree)")
return "dirty"
_clear("dirty")
result = _git("rebase", UPSTREAM, timeout=REBASE_TIMEOUT)
for _ in range(50): # bounded: one round per replayed commit
if result.returncode == 0:
_clear("replay")
return "ok"
conflicted = _conflicted()
if not conflicted or not all(_is_task_file(p) for p in conflicted):
_git("rebase", "--abort")
detail = ", ".join(conflicted[:3]) or (result.stderr or result.stdout).strip()[-140:]
_note("replay", f"sync stalled: replaying this board's commits onto {UPSTREAM} "
f"collides outside tasks/ ({detail}) — a human has to settle it")
return "stalled"
for name in dict.fromkeys(Path(p).name for p in conflicted):
_lost(name)
result = _git("rebase", "--skip", timeout=REBASE_TIMEOUT)
_git("rebase", "--abort")
_note("replay", f"sync stalled: replaying onto {UPSTREAM} did not settle — "
f"a human has to settle it")
return "stalled"
def _integrate() -> str:
"""Bring local main to origin/main without ever merging past a
divergence.
up-to-date | pulled | not-on-main | dirty | diverged | stalled
"""
if _count(f"{BRANCH}..{UPSTREAM}") == 0:
return "up-to-date"
if not _on_main():
branch = _git("rev-parse", "--abbrev-ref", "HEAD").stdout.strip() or "a detached HEAD"
_note("branch", f"sync paused: this checkout is on '{branch}', not {BRANCH} — "
f"switch back and the board catches up with {UPSTREAM}")
return "not-on-main"
_clear("branch")
# Diverged. The board's own bookkeeping can be replayed on top of what
# arrived — that is how a lost race resolves. A human's commit cannot,
# and the guard that refuses to push it refuses to rebase it too.
commits = _ahead()
stray = _stray(commits)
if stray:
_note("diverged", f"sync stalled: main and {UPSTREAM} have diverged and "
f"{stray} is not a board commit — pull or rebase it by "
f"hand, and this board starts converging again")
return "diverged"
_clear("diverged")
if commits:
outcome = _replay()
return "pulled" if outcome == "ok" else outcome
if not _clean():
_note("dirty", "sync paused: main has uncommitted changes — commit or stash "
"them and sync resumes (code work belongs in a worktree)")
return "dirty"
_clear("dirty")
result = _git("merge", "--ff-only", UPSTREAM, timeout=REBASE_TIMEOUT)
if result.returncode != 0:
detail = (result.stderr or result.stdout).strip().splitlines()
_note("merge", f"sync stalled: fast-forwarding to {UPSTREAM} failed "
f"({detail[-1][:140] if detail else 'no detail'})")
return "stalled"
_clear("merge")
return "pulled"
def _record_arrivals(before: str) -> None:
"""Attribute what the pull brought: each task file it touched is filed
under the name of whoever committed it, for the watcher to use instead
of "disk" when the move surfaces on the next poll."""
head = _head()
if not before or not head or head == before:
return
rng = f"{before}..{head}"
changed = _git("diff", "--name-only", rng, "--", _tasks_prefix()).stdout.splitlines()
names = sorted({Path(p).name for p in changed if p.strip().endswith(".md")})
if not names:
return
now = time.time()
authors = set()
with _ARRIVED_LOCK:
for name in names:
who = _author_of(name, rng)
if who:
ARRIVED[name] = (who, now)
authors.add(who)
for name in [n for n, (_, ts) in ARRIVED.items() if now - ts > ARRIVED_TTL]:
ARRIVED.pop(name, None)
count = _count(rng)
state.record_board_event({
"kind": "sync", "actor": "sync",
"summary": f"pulled {count} commit{'s' if count != 1 else ''} from {UPSTREAM}"
+ (f" ({', '.join(sorted(authors))})" if authors else "")})
state.broadcast({"type": "board"})
def arrived_actor(filename: str) -> str:
"""Who moved this card, if a pull just brought it. Consumed once — the
watcher asks exactly when it notices the move."""
with _ARRIVED_LOCK:
entry = ARRIVED.pop(filename, None)
if not entry:
return ""
who, ts = entry
return who if time.time() - ts <= ARRIVED_TTL else ""
# ── the two entry points ───────────────────────────────────────────────
def _converge() -> str:
"""One full beat: fetch, integrate what arrived, publish what is ours."""
if not _origin_present():
return "no-origin"
if not _fetch():
return "offline"
before = _head()
outcome = _integrate()
_record_arrivals(before)
if outcome in ("up-to-date", "pulled"):
published = _publish()
if published in ("stray", "offline", "stalled", "not-on-main"):
return published
return outcome
def push_now() -> str:
"""A board commit just landed — publish it. The fast path skips the
fetch; a rejection means another board pushed first, and then the full
converge (fetch, replay, push) runs."""
if not config.SYNC:
return "off"
with _LOCK:
if not _origin_present():
return "no-origin"
outcome = _publish()
if outcome != "retry":
return outcome
return _converge()
def pull_now() -> str:
"""The beat. Also the offline catch-up: a fetch that works again is
followed by the push that could not happen while origin was gone."""
if not config.SYNC:
return "off"
with _LOCK:
return _converge()
def on_commit(filename: str) -> None:
"""The `state.task_committed` hook: publish off the caller's thread, so
a card move never waits on the network."""
if not config.SYNC:
return
threading.Thread(target=push_now, name="sync-push", daemon=True).start()
def install() -> None:
"""Wire the push hook. Called once at startup, only with the gate on."""
if on_commit not in state.COMMIT_HOOKS:
state.COMMIT_HOOKS.append(on_commit)
def beat(interval: float | None = None) -> None:
interval = config.SYNC_INTERVAL if interval is None else interval
while True:
try:
pull_now()
except Exception as exc: # noqa: BLE001 — the beat outlives a bad cycle
state.record_board_event({"kind": "sync", "actor": "sync",
"summary": f"sync cycle failed: {str(exc)[:140]}"})
time.sleep(interval)