Files
hermes-agent/tools/hook_output_spill.py

118 lines
4.8 KiB
Python

"""Spill oversized hook-injected context to disk with a preview placeholder.
Hook ``{"context": ...}`` output rides EVERY subsequent API call, so a large blob
inflates every turn and breaks the prompt-cache prefix. Above
``hooks.output_spill.max_chars`` (default 10000) the text is written under
``hooks.output_spill.directory`` (default ``<HERMES_HOME>/hook_outputs/<session>``)
and the payload becomes a ``preview_head``/``preview_tail`` excerpt plus the path.
``enabled: false`` disables. Never raises: an I/O failure still returns a preview.
"""
from __future__ import annotations
import logging
import os
import uuid
from pathlib import Path
from typing import Any, Dict, Optional
from tools.tool_output_limits import _coerce_int, _coerce_positive_int
logger = logging.getLogger(__name__)
DEFAULT_MAX_CHARS = 10_000
DEFAULT_PREVIEW_HEAD = 500
DEFAULT_PREVIEW_TAIL = 500
DEFAULT_ENABLED = True
def get_spill_config() -> Dict[str, Any]:
"""Return resolved hook output-spill config. Never raises."""
section: Dict[str, Any] = {}
try:
from hermes_cli.config import load_config
cfg = load_config() or {}
hooks = cfg.get("hooks") if isinstance(cfg, dict) else None
if isinstance(hooks, dict) and isinstance(hooks.get("output_spill"), dict):
section = hooks["output_spill"]
except Exception:
section = {}
enabled_raw = section.get("enabled", DEFAULT_ENABLED)
directory = section.get("directory")
return {
"enabled": bool(enabled_raw) if enabled_raw is not None else DEFAULT_ENABLED,
"max_chars": _coerce_positive_int(section.get("max_chars"), DEFAULT_MAX_CHARS),
# head/tail allow zero (empty tail), max_chars must be positive.
"preview_head": _coerce_int(section.get("preview_head"), DEFAULT_PREVIEW_HEAD, 0),
"preview_tail": _coerce_int(section.get("preview_tail"), DEFAULT_PREVIEW_TAIL, 0),
"directory": directory if isinstance(directory, str) else None,
}
def _resolve_spill_dir(directory_override: Optional[str], session_id: Optional[str]) -> Path:
"""Per-session spill directory; session id is sanitised so it can't escape ``base``."""
if directory_override:
base = Path(os.path.expanduser(directory_override))
else:
from hermes_constants import get_hermes_home
base = Path(get_hermes_home()) / "hook_outputs"
session_segment = (session_id or "no-session").replace("/", "_").replace("\\", "_").replace("..", "_")
return base / session_segment
def spill_if_oversized(
text: str, *, session_id: Optional[str] = None, source: str = "hook", config: Optional[Dict[str, Any]] = None,
) -> str:
"""Spill ``text`` to disk if it exceeds the configured cap.
Returns ``text`` unchanged (under cap, disabled, or empty) or a preview
string pointing at the full content. Non-string input is ``str()``-coerced;
``source`` labels the preview header; ``config`` overrides config.yaml.
"""
if text is None:
return ""
if not isinstance(text, str):
try:
text = str(text)
except Exception:
return ""
cfg = config if config is not None else get_spill_config()
if not cfg.get("enabled", True):
return text
if len(text) <= int(cfg.get("max_chars") or DEFAULT_MAX_CHARS):
return text
head = int(cfg.get("preview_head") or 0)
tail = int(cfg.get("preview_tail") or 0)
# A disk failure must never blow up the turn — fall through to a preview
# without a saved path.
saved_path: Optional[str] = None
try:
spill_dir = _resolve_spill_dir(cfg.get("directory"), session_id)
from tools.spill_safety import ensure_spill_dir, write_text_exclusive
# Hook context may embed raw secrets: private perms + exclusive,
# symlink-refusing create (the per-session dir is predictable).
ensure_spill_dir(spill_dir, private=True)
spill_path = spill_dir / f"{uuid.uuid4().hex}.txt"
# Trailing newline so tail readers don't report "missing newline".
write_text_exclusive(spill_path, text if text.endswith("\n") else text + "\n", private=True)
saved_path = str(spill_path)
except Exception as exc:
logger.warning("hook output spill failed: %s", exc)
total = len(text)
parts = [
f"[{source} output truncated — {total:,} chars; full content "
+ (f"saved to {saved_path}]" if saved_path else "unavailable — spill write failed]"),
]
if head > 0 and text[:head]:
parts.extend(["--- head ---", text[:head]])
if tail > 0 and total > head:
parts.extend(["--- tail ---", text[-tail:]])
return "\n".join(parts)
__all__ = ["DEFAULT_MAX_CHARS", "DEFAULT_PREVIEW_HEAD", "DEFAULT_PREVIEW_TAIL", "DEFAULT_ENABLED",
"get_spill_config", "spill_if_oversized"]