Files
hermes-agent/utils.py
2026-03-14 02:56:13 -07:00

104 lines
2.9 KiB
Python

"""Shared utility functions for hermes-agent."""
import json
import os
import tempfile
from pathlib import Path
from typing import Any, Union
import yaml
def atomic_json_write(
path: Union[str, Path],
data: Any,
*,
indent: int = 2,
**dump_kwargs: Any,
) -> None:
"""Write JSON data to a file atomically.
Uses temp file + fsync + os.replace to ensure the target file is never
left in a partially-written state. If the process crashes mid-write,
the previous version of the file remains intact.
Args:
path: Target file path (will be created or overwritten).
data: JSON-serializable data to write.
indent: JSON indentation (default 2).
**dump_kwargs: Additional keyword args forwarded to json.dump(), such
as default=str for non-native types.
"""
path = Path(path)
path.parent.mkdir(parents=True, exist_ok=True)
fd, tmp_path = tempfile.mkstemp(
dir=str(path.parent),
prefix=f".{path.stem}_",
suffix=".tmp",
)
try:
with os.fdopen(fd, "w", encoding="utf-8") as f:
json.dump(
data,
f,
indent=indent,
ensure_ascii=False,
**dump_kwargs,
)
f.flush()
os.fsync(f.fileno())
os.replace(tmp_path, path)
except BaseException:
try:
os.unlink(tmp_path)
except OSError:
pass
raise
def atomic_yaml_write(
path: Union[str, Path],
data: Any,
*,
default_flow_style: bool = False,
sort_keys: bool = False,
extra_content: str | None = None,
) -> None:
"""Write YAML data to a file atomically.
Uses temp file + fsync + os.replace to ensure the target file is never
left in a partially-written state. If the process crashes mid-write,
the previous version of the file remains intact.
Args:
path: Target file path (will be created or overwritten).
data: YAML-serializable data to write.
default_flow_style: YAML flow style (default False).
sort_keys: Whether to sort dict keys (default False).
extra_content: Optional string to append after the YAML dump
(e.g. commented-out sections for user reference).
"""
path = Path(path)
path.parent.mkdir(parents=True, exist_ok=True)
fd, tmp_path = tempfile.mkstemp(
dir=str(path.parent),
prefix=f".{path.stem}_",
suffix=".tmp",
)
try:
with os.fdopen(fd, "w", encoding="utf-8") as f:
yaml.dump(data, f, default_flow_style=default_flow_style, sort_keys=sort_keys)
if extra_content:
f.write(extra_content)
f.flush()
os.fsync(f.fileno())
os.replace(tmp_path, path)
except BaseException:
try:
os.unlink(tmp_path)
except OSError:
pass
raise