45 lines
963 B
Python
45 lines
963 B
Python
import contextlib
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import json
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import pathlib
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import time
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def lock(name):
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lockfile = pathlib.Path(f'{name}.lock')
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for i in range(5):
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try:
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lockfile.symlink_to('/dev/null')
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return
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except FileExistsError:
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time.sleep(1)
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raise TimeoutError(f'could not lock {name}')
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def unlock(name):
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lockfile = pathlib.Path(f'{name}.lock')
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lockfile.unlink(missing_ok=True)
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@contextlib.contextmanager
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def locked(name):
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lock(name)
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try:
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yield name
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finally:
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unlock(name)
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def read(name):
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with open(f'{name}.json', 'a+', encoding='utf-8') as f:
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f.seek(0)
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return json.loads(f.read() or '{}')
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def write(name, data):
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with open(f'{name}.json', 'w', encoding='utf-8') as f:
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json.dump(data, f, indent=2)
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f.close()
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def load(name):
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with locked(name):
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return read(name)
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def save(name, data):
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with locked(name):
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write(name, data)
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