Kowlin a555eff2cc
Fixed a bug with the JSON Driver (#1953)
Administrative merge: Travis CI failed due to docs issue, see #1957
2018-07-25 02:18:54 +02:00

57 lines
1.8 KiB
Python

import functools
import json
import os
import asyncio
import logging
from uuid import uuid4
# This is basically our old DataIO, except that it's now threadsafe
# and just a base for much more elaborate classes
from pathlib import Path
log = logging.getLogger("red")
PRETTY = {"indent": 4, "sort_keys": False, "separators": (",", " : ")}
MINIFIED = {"sort_keys": False, "separators": (",", ":")}
class JsonIO:
"""Basic functions for atomic saving / loading of json files"""
def __init__(self, path: Path = Path.cwd()):
"""
:param path: Full path to file.
"""
self._lock = asyncio.Lock()
self.path = path
# noinspection PyUnresolvedReferences
def _save_json(self, data, settings=PRETTY):
log.debug("Saving file {}".format(self.path))
filename = self.path.stem
tmp_file = "{}-{}.tmp".format(filename, uuid4().fields[0])
tmp_path = self.path.parent / tmp_file
with tmp_path.open(encoding="utf-8", mode="w") as f:
json.dump(data, f, **settings)
tmp_path.replace(self.path)
async def _threadsafe_save_json(self, data, settings=PRETTY):
loop = asyncio.get_event_loop()
func = functools.partial(self._save_json, data, settings)
with await self._lock:
await loop.run_in_executor(None, func)
# noinspection PyUnresolvedReferences
def _load_json(self):
log.debug("Reading file {}".format(self.path))
with self.path.open(encoding="utf-8", mode="r") as f:
data = json.load(f)
return data
async def _threadsafe_load_json(self, path):
loop = asyncio.get_event_loop()
func = functools.partial(self._load_json, path)
task = loop.run_in_executor(None, func)
with await self._lock:
return await asyncio.wait_for(task)