Files
hermes-agent/tools/approval_gateway_wait.py

207 lines
10 KiB
Python

"""Blocking gateway approval wait for :mod:`tools.approval`.
Mirrors the CLI's synchronous ``input()`` flow: the agent thread enqueues a
pending approval, the gateway notifies the user, and the thread blocks until
``/approve`` / ``/deny`` resolves it or the approval timeout elapses. Multiple
threads (parallel subagents, execute_code RPC handlers) can block concurrently
— each gets its own ``threading.Event``; ``/approve`` resolves the oldest,
``/approve all`` every pending entry. Queue state (``_gateway_queues``,
``_lock``) is owned by ``tools.approval`` and reached through that module at
call time.
"""
import logging
import threading
import time
import uuid
from tools.interrupt import get_interrupt_reason, is_interrupted
from tools import approval_context as _ctx
from tools.approval_human_wait import activity_heartbeat, human_wait_window
logger = logging.getLogger("tools.approval")
class _ApprovalEntry:
"""One pending dangerous-command approval inside a gateway session."""
__slots__ = ("event", "data", "result", "reason", "acknowledged", "settle", "cancelled")
def __init__(self, data: dict):
self.event = threading.Event()
self.data = dict(data)
self.data.setdefault("request_id", uuid.uuid4().hex)
self.acknowledged = False
# Surface hook run once when the wait ends by ANY path (answer, timeout, interrupt, /approve from
# another client): the tui_gateway withdraws its open server→client request through it.
self.settle = None
self.result: str | None = None # "once"|"session"|"always"|"deny"
# Free-text reason from ``/deny <reason>`` so the agent can adapt, not just hear "denied".
self.reason: str | None = None
# Why the prompt was withdrawn with nobody answering (interrupt cause, session teardown);
# followers and teardown read it so a withdrawn prompt never renders as a user deny.
self.cancelled: str | None = None
def _poll_event(event: threading.Event, session_key: str, *, interrupt_log: str) -> str:
"""Wait on *event* until it fires, the turn is interrupted, or approvals.timeout
elapses; returns ``"set"`` | ``"interrupted"`` | ``"timeout"``. Polls in ~1s
slices so activity heartbeats reach the agent's inactivity tracker every ~10s —
otherwise the gateway watchdog kills the agent while the user is still
responding (mirrors ``_wait_for_process()`` cadence). The loop is recorded as
human-wait time so the concurrent batch deadline excludes it.
Any interrupt (/stop, inactivity timeout, delegation teardown) ends the wait
fail-closed: the command does not run. Who caused it is read from the
per-thread interrupt-cause channel (``get_interrupt_reason()``, a trusted fixed
category), never inferred from message text, so the caller can report a
withdrawn prompt without inventing a user refusal."""
deadline = time.monotonic() + max(_ctx._get_approval_timeout(), 0)
heartbeat = activity_heartbeat("waiting for user approval")
with human_wait_window(session_key):
while True:
# The poll loop below is verifiably blocked on a human answer (the user tapping approve/deny on
# the gateway surface), bounded by the approval timeout. Record it as human-wait time so the
# concurrent batch deadline excludes it (#79719).
if is_interrupted():
logger.info(interrupt_log, session_key)
return "interrupted"
remaining = deadline - time.monotonic()
if remaining <= 0:
return "timeout"
if event.wait(timeout=min(1.0, remaining)):
return "set"
heartbeat()
def _cancel_cause(state: str, entry) -> str | None:
"""Why the wait ended with nobody answering: the turn was interrupted (cause from the
per-thread channel — a user /stop or a parent's delegation teardown), the entry was
withdrawn with a stamped cause (leader interrupted, session torn down), or the turn ended
under the prompt (notifier unregistered, result never set). ``None`` for a real answer
or a plain timeout."""
if state == "interrupted":
return get_interrupt_reason() or "turn interrupted"
if state == "set" and entry.result is None:
return entry.cancelled or "the turn ended before the prompt was answered"
return None
def _finish(payload: dict, resolved: bool, choice: str | None, reason, **extra) -> dict:
"""Fire the post hook and build the decision dict. Unresolved (timeout) and
a None choice both mean the user never answered; ``cancelled`` carries the
cause when the prompt was withdrawn rather than answered."""
if extra.get("cancelled"):
hook_choice = "cancelled"
else:
hook_choice = "timeout" if not resolved else (choice or "timeout")
_ctx._fire_approval_hook("post_approval_response", **payload, choice=hook_choice, **extra)
return {"resolved": resolved, "choice": choice, "reason": reason, **extra}
def _await_coalesced_leader(session_key: str, leader, payload: dict):
"""Wait on an already-pending identical approval instead of re-prompting.
Adopts the leader's decision: ``session``/``always`` → approval (same dict
shape as a direct resolution; persistence stays the caller's and is
idempotent across leader and followers); ``deny`` → denial carrying the
leader's reason; leader timeout / our own deadline → unresolved. ``once``
returns ``None``: single-use consent covers only the leader's execution,
so the caller must issue a fresh prompt. Hooks fire with ``coalesced=True``
so observers see the follower's lifecycle without a duplicate prompt."""
_ctx._fire_approval_hook("pre_approval_request", **payload, coalesced=True)
state = _poll_event(leader.event, session_key,
interrupt_log="Coalesced approval wait interrupted — "
"returning deny for session %s")
cancelled = _cancel_cause(state, leader)
if state == "interrupted":
# Deny only OUR follower; the leader thread handles its own signal.
choice, resolved = "deny", True
elif state == "timeout":
choice, resolved = None, False
else:
choice = leader.result
resolved = choice is not None
if choice == "once":
# The post hook fires for the fresh prompt's own lifecycle, not here.
return None
extra = {"cancelled": cancelled} if cancelled else {}
return _finish(payload, resolved, choice, getattr(leader, "reason", None), coalesced=True, **extra)
def _await_gateway_decision(session_key: str, notify_cb, approval_data: dict, *, surface: str = "gateway") -> dict:
"""Enqueue *approval_data*, notify the user, and block until resolved or timed
out. Shared by the terminal command guard, the execute_code guard, the plugin
escalation gate, and MCP elicitation. Returns ``{"resolved", "choice",
"reason"}`` or ``{"resolved": False, "choice": None, "notify_failed": True}``
when the notify callback raised. Persisting the choice and building the
tool-facing result stay with the caller.
Identical concurrent approvals (same command text + pattern-key set) are
coalesced: parallel tool calls would otherwise fire N identical prompts
the user must /approve N times while the agent sits wedged. Followers adopt
the leader's ``session``/``always``/``deny``/timeout; a ``once`` covers only
the leader, so the follower falls through to a fresh prompt."""
from tools import approval as _approval
from agent.terminal_approval_batch import approval_published, preparing_terminal_approval, register_prepared_approval
primary_key = approval_data.get("pattern_key", "")
payload = {
"command": approval_data.get("command", ""),
"description": approval_data.get("description", ""),
"pattern_key": primary_key,
"pattern_keys": list(approval_data.get("pattern_keys", [primary_key])),
"session_key": session_key, "surface": surface,
}
keys = list(approval_data.get("pattern_keys") or [])
with _approval._lock:
leader = next((e for e in _approval._gateway_queues.get(session_key, [])
if e.data.get("command") == approval_data.get("command")
and list(e.data.get("pattern_keys") or []) == keys), None)
if leader is not None and not preparing_terminal_approval():
adopted = _await_coalesced_leader(session_key, leader, payload)
if adopted is not None:
return adopted
entry = _ApprovalEntry(approval_data)
with _approval._lock:
register_prepared_approval(session_key, entry)
_approval._gateway_queues.setdefault(session_key, []).append(entry)
def _drop_entry(reason: str) -> None:
with _approval._lock:
queue = _approval._gateway_queues.get(session_key, [])
if entry in queue:
queue.remove(entry)
if not queue:
_approval._gateway_queues.pop(session_key, None)
settle, entry.settle = entry.settle, None
if settle is not None:
try:
settle(reason)
except Exception:
logger.debug("approval settle hook failed", exc_info=True)
# Plugins hear about the request before the gateway does (real-time observers).
_ctx._fire_approval_hook("pre_approval_request", **payload)
# Bridges sync agent thread → async gateway.
try:
notify_cb(dict(entry.data))
approval_published()
except Exception as exc:
logger.warning("Gateway approval notify failed: %s", exc)
_drop_entry("notify_failed")
_ctx._fire_approval_hook("post_approval_response", **payload, choice="notify_failed")
return {"resolved": False, "choice": None, "notify_failed": True}
state = _poll_event(entry.event, session_key,
interrupt_log="Approval wait interrupted — returning deny for session %s")
cancelled = _cancel_cause(state, entry)
choice = entry.result
if state == "interrupted":
# Our own decision stays a fail-closed deny; coalesced followers wake with the
# cause instead of a deny nobody issued.
choice, entry.cancelled = "deny", cancelled
entry.event.set()
_drop_entry("answered" if state == "set" else state)
extra = {"cancelled": cancelled} if cancelled else {}
return _finish(payload, state != "timeout", choice, entry.reason, **extra)