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locale_database: Use context manager interface to update source files

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Use context manager interface (with statement) to atomically update source
files. This ensures that all files are properly closed and the temporary
file is removed even in case of errors.

Task-number: QTBUG-83488
Pick-to: 6.2
Change-Id: I18cd96f1d03e467dea6212f6576a41e65f414ce1
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>
This commit is contained in:
Ievgenii Meshcheriakov 2021-07-12 14:11:39 +02:00
parent 424243ab17
commit e9519d207e
3 changed files with 133 additions and 128 deletions
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14
util/locale_database/cldr2qtimezone.py
View File

@ -369,20 +369,14 @@ def main(out, err):
return 1
out.write('Input file parsed, now writing data\n')
try:
writer = ZoneIdWriter(dataFilePath, qtPath)
except IOError as e:
err.write(f'Failed to open files to transcribe: {e}')
return 1
try:
writer.write(version, defaults, winIds)
except Error as e:
writer.cleanup()
err.write(f'\nError in Windows ID data: {e}\n')
with ZoneIdWriter(dataFilePath, qtPath) as writer:
writer.write(version, defaults, winIds)
except Exception as e:
err.write(f'\nError while updating timezone data: {e}\n')
return 1
writer.close()
out.write(f'Data generation completed, please check the new file at {dataFilePath}\n')
return 0

140
util/locale_database/localetools.py
View File

@ -37,6 +37,7 @@ Classes:
SourceFileEditor -- adds standard prelude and tail handling to Transcriber.
"""
from contextlib import ExitStack, contextmanager
from pathlib import Path
from tempfile import NamedTemporaryFile
@ -69,45 +70,98 @@ def wrap_list(lst):
yield head
return ",\n".join(", ".join(x) for x in split(lst, 20))
class Transcriber (object):
"""Helper class to facilitate rewriting source files.
This class takes care of the temporary file manipulation. Derived
classes need to implement transcribing of the content, with
@contextmanager
def AtomicRenameTemporaryFile(originalLocation: Path, *, prefix: str, dir: Path):
"""Context manager for safe file update via a temporary file.
Accepts path to the file to be updated. Yields a temporary file to the user
code, open for writing.
On success closes the temporary file and moves its content to the original
location. On error, removes temporary file, without disturbing the original.
"""
tempFile = NamedTemporaryFile('w', prefix=prefix, dir=dir, delete=False)
try:
yield tempFile
tempFile.close()
# Move the modified file to the original location
Path(tempFile.name).rename(originalLocation)
except Exception:
# delete the temporary file in case of error
tempFile.close()
Path(tempFile.name).unlink()
raise
class Transcriber:
"""Context manager base-class to manage source file rewrites.
Derived classes need to implement transcribing of the content, with
whatever modifications they may want. Members reader and writer
are exposed; use writer.write() to output to the new file; use
reader.readline() or iterate reader to read the original.
Callers should call close() on success or cleanup() on failure (to
clear away the temporary file).
This class is intended to be used as context manager only (inside a
`with` statement).
Reimplement onEnter() to write any preamble the file may have,
onExit() to write any tail. The body of the with statement takes
care of anything in between, using methods provided by derived classes.
The data is written to a temporary file first. The temporary file data
is then moved to the original location if there were no errors. Otherwise
the temporary file is removed and the original is left unchanged.
"""
def __init__(self, path: Path, temp_dir: Path):
# Open the old file
self.reader = open(path)
self.path = path
# Create a temp file to write the new data into
self.writer = NamedTemporaryFile('w', prefix=path.name, dir=temp_dir, delete=False)
self.tempDir = temp_dir
def close(self) -> None:
self.reader.close()
self.writer.close()
def onEnter(self) -> None:
"""
Called before transferring control to user code.
# Move the modified file to the original location
self.path.unlink()
Path(self.writer.name).rename(self.path)
This function can be overridden in derived classes to perform actions
before transferring control to the user code.
self.reader = self.writer = None
The default implementation does nothing.
"""
pass
def cleanup(self) -> None:
if self.reader:
self.reader.close()
self.reader = None
def onExit(self) -> None:
"""
Called after return from user code.
if self.writer:
self.writer.close()
# Remove temp-file:
Path(self.writer.name).unlink(missing_ok=True)
self.writer = None
This function can be overridden in derived classes to perform actions
after successful return from user code.
The default implementation does nothing.
"""
pass
def __enter__(self):
with ExitStack() as resources:
# Create a temp file to write the new data into
self.writer = resources.enter_context(
AtomicRenameTemporaryFile(self.path, prefix=self.path.name, dir=self.tempDir))
# Open the old file
self.reader = resources.enter_context(open(self.path))
self.onEnter()
# Prevent resources from being closed on normal return from this
# method and make them available inside __exit__():
self.__resources = resources.pop_all()
return self
def __exit__(self, exc_type, exc_value, traceback):
if exc_type is None:
with self.__resources:
self.onExit()
else:
self.__resources.__exit__(exc_type, exc_value, traceback)
return False
class SourceFileEditor (Transcriber):
@ -121,41 +175,27 @@ class SourceFileEditor (Transcriber):
the new version to replace it.
This class takes care of transcribing the parts before and after
the generated content; on creation, an instance will copy the
preamble up to the start marker; its close() will skip over the
original's generated content and resume transcribing with the end
marker. Derived classes need only implement the generation of the
content in between.
the generated content; on entering the context, an instance will
copy the preamble up to the start marker; on exit from the context
it will skip over the original's generated content and resume
transcribing with the end marker.
Callers should call close() on success or cleanup() on failure (to
clear away the temporary file); see Transcriber.
This class is only intended to be used as a context manager:
see Transcriber. Derived classes implement suitable methods for use in
the body of the with statement, using self.writer to rewrite the part
of the file between the start and end markers.
"""
def __init__(self, path: Path, temp_dir: Path):
"""Set up the source file editor.
Requires two arguments: the path to the source file to be read
and, on success, replaced with a new version; and the
directory in which to store the temporary file during the
rewrite."""
super().__init__(path, temp_dir)
self.__copyPrelude()
def close(self):
self.__copyTail()
super().close()
# Implementation details:
GENERATED_BLOCK_START = '// GENERATED PART STARTS HERE'
GENERATED_BLOCK_END = '// GENERATED PART ENDS HERE'
def __copyPrelude(self):
def onEnter(self) -> None:
# Copy over the first non-generated section to the new file
for line in self.reader:
self.writer.write(line)
if line.strip() == self.GENERATED_BLOCK_START:
break
def __copyTail(self):
def onExit(self) -> None:
# Skip through the old generated data in the old file
for line in self.reader:
if line.strip() == self.GENERATED_BLOCK_END:

107
util/locale_database/qlocalexml2cpp.py
View File

@ -135,10 +135,14 @@ def currencyIsoCodeData(s):
class LocaleSourceEditor (SourceFileEditor):
def __init__(self, path: Path, temp: Path, version: str):
super().__init__(path, temp)
self.version = version
def onEnter(self) -> None:
super().onEnter()
self.writer.write(f"""
/*
This part of the file was generated on {datetime.date.today()} from the
Common Locale Data Repository v{version}
Common Locale Data Repository v{self.version}
http://www.unicode.org/cldr/
@ -535,89 +539,56 @@ def main(out, err):
locale_keys = sorted(locale_map.keys(), key=LocaleKeySorter(reader.defaultMap()))
try:
writer = LocaleDataWriter(qtsrcdir.joinpath('src/corelib/text/qlocale_data_p.h'),
qtsrcdir, reader.cldrVersion)
except IOError as e:
err.write(f'Failed to open files to transcribe locale data: {e}')
return 1
try:
writer.likelySubtags(reader.likelyMap())
writer.localeIndex(reader.languageIndices(tuple(k[0] for k in locale_map)))
writer.localeData(locale_map, locale_keys)
writer.writer.write('\n')
writer.languageNames(reader.languages)
writer.scriptNames(reader.scripts)
writer.territoryNames(reader.territories)
# TODO: merge the next three into the previous three
writer.languageCodes(reader.languages)
writer.scriptCodes(reader.scripts)
writer.territoryCodes(reader.territories)
except Error as e:
writer.cleanup()
with LocaleDataWriter(qtsrcdir.joinpath('src/corelib/text/qlocale_data_p.h'),
qtsrcdir, reader.cldrVersion) as writer:
writer.likelySubtags(reader.likelyMap())
writer.localeIndex(reader.languageIndices(tuple(k[0] for k in locale_map)))
writer.localeData(locale_map, locale_keys)
writer.writer.write('\n')
writer.languageNames(reader.languages)
writer.scriptNames(reader.scripts)
writer.territoryNames(reader.territories)
# TODO: merge the next three into the previous three
writer.languageCodes(reader.languages)
writer.scriptCodes(reader.scripts)
writer.territoryCodes(reader.territories)
except Exception as e:
err.write(f'\nError updating locale data: {e}\n')
return 1
writer.close()
# Generate calendar data
for calendar, stem in calendars.items():
try:
writer = CalendarDataWriter(
qtsrcdir.joinpath(f'src/corelib/time/q{stem}calendar_data_p.h'),
qtsrcdir, reader.cldrVersion)
except IOError as e:
err.write(f'Failed to open files to transcribe {calendar} data {e}')
return 1
try:
writer.write(calendar, locale_map, locale_keys)
except Error as e:
writer.cleanup()
with CalendarDataWriter(
qtsrcdir.joinpath(f'src/corelib/time/q{stem}calendar_data_p.h'),
qtsrcdir, reader.cldrVersion) as writer:
writer.write(calendar, locale_map, locale_keys)
except Exception as e:
err.write(f'\nError updating {calendar} locale data: {e}\n')
return 1
writer.close()
# qlocale.h
try:
writer = LocaleHeaderWriter(qtsrcdir.joinpath('src/corelib/text/qlocale.h'),
qtsrcdir, reader.dupes)
except IOError as e:
err.write(f'Failed to open files to transcribe qlocale.h: {e}')
return 1
try:
writer.languages(reader.languages)
writer.scripts(reader.scripts)
writer.territories(reader.territories)
except Error as e:
writer.cleanup()
with LocaleHeaderWriter(qtsrcdir.joinpath('src/corelib/text/qlocale.h'),
qtsrcdir, reader.dupes) as writer:
writer.languages(reader.languages)
writer.scripts(reader.scripts)
writer.territories(reader.territories)
except Exception as e:
err.write(f'\nError updating qlocale.h: {e}\n')
return 1
writer.close()
# qlocale.qdoc
try:
writer = Transcriber(qtsrcdir.joinpath('src/corelib/text/qlocale.qdoc'), qtsrcdir)
except IOError as e:
err.write(f'Failed to open files to transcribe qlocale.qdoc: {e}')
with Transcriber(qtsrcdir.joinpath('src/corelib/text/qlocale.qdoc'), qtsrcdir) as qdoc:
DOCSTRING = " QLocale's data is based on Common Locale Data Repository "
for line in qdoc.reader:
if DOCSTRING in line:
qdoc.writer.write(f'{DOCSTRING}v{reader.cldrVersion}.\n')
else:
qdoc.writer.write(line)
except Exception as e:
err.write(f'\nError updating qlocale.h: {e}\n')
return 1
DOCSTRING = " QLocale's data is based on Common Locale Data Repository "
try:
for line in writer.reader:
if DOCSTRING in line:
writer.writer.write(f'{DOCSTRING}v{reader.cldrVersion}.\n')
else:
writer.writer.write(line)
except Error as e:
writer.cleanup()
err.write(f'\nError updating qlocale.qdoc: {e}\n')
return 1
writer.close()
return 0
if __name__ == "__main__":