mirror of
https://github.com/home-assistant/core
synced 2024-09-06 10:29:55 +02:00
83 lines
2.3 KiB
Python
83 lines
2.3 KiB
Python
"""File utility functions."""
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from __future__ import annotations
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import logging
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import os
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import tempfile
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from atomicwrites import AtomicWriter
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from homeassistant.exceptions import HomeAssistantError
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_LOGGER = logging.getLogger(__name__)
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class WriteError(HomeAssistantError):
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"""Error writing the data."""
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def write_utf8_file_atomic(
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filename: str,
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utf8_data: str,
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private: bool = False,
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) -> None:
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"""Write a file and rename it into place using atomicwrites.
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Writes all or nothing.
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This function uses fsync under the hood. It should
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only be used to write mission critical files as
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fsync can block for a few seconds or longer is the
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disk is busy.
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Using this function frequently will significantly
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negatively impact performance.
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"""
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try:
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with AtomicWriter(filename, overwrite=True).open() as fdesc:
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if not private:
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os.fchmod(fdesc.fileno(), 0o644)
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fdesc.write(utf8_data)
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except OSError as error:
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_LOGGER.exception("Saving file failed: %s", filename)
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raise WriteError(error) from error
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def write_utf8_file(
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filename: str,
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utf8_data: str,
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private: bool = False,
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) -> None:
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"""Write a file and rename it into place.
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Writes all or nothing.
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"""
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tmp_filename = ""
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try:
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# Modern versions of Python tempfile create this file with mode 0o600
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with tempfile.NamedTemporaryFile(
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mode="w", encoding="utf-8", dir=os.path.dirname(filename), delete=False
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) as fdesc:
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fdesc.write(utf8_data)
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tmp_filename = fdesc.name
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if not private:
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os.fchmod(fdesc.fileno(), 0o644)
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os.replace(tmp_filename, filename)
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except OSError as error:
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_LOGGER.exception("Saving file failed: %s", filename)
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raise WriteError(error) from error
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finally:
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if os.path.exists(tmp_filename):
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try:
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os.remove(tmp_filename)
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except OSError as err:
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# If we are cleaning up then something else went wrong, so
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# we should suppress likely follow-on errors in the cleanup
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_LOGGER.error(
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"File replacement cleanup failed for %s while saving %s: %s",
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tmp_filename,
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filename,
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err,
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)
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