| #!/usr/bin/env python |
| # Copyright (c) 2016 The Chromium Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| """Writes a file that contains a define that approximates the build date. |
| |
| build_type impacts the timestamp generated: |
| - default: the build date is set to the most recent first Sunday of a month at |
| 5:00am. The reason is that it is a time where invalidating the build cache |
| shouldn't have major reprecussions (due to lower load). |
| - official: the build date is set to the current date at 5:00am, or the day |
| before if the current time is before 5:00am. |
| Either way, it is guaranteed to be in the past and always in UTC. |
| |
| It is also possible to explicitly set a build date to be used. |
| """ |
| |
| import argparse |
| import calendar |
| import datetime |
| import doctest |
| import os |
| import sys |
| |
| |
| def GetFirstSundayOfMonth(year, month): |
| """Returns the first sunday of the given month of the given year. |
| |
| >>> GetFirstSundayOfMonth(2016, 2) |
| 7 |
| >>> GetFirstSundayOfMonth(2016, 3) |
| 6 |
| >>> GetFirstSundayOfMonth(2000, 1) |
| 2 |
| """ |
| weeks = calendar.Calendar().monthdays2calendar(year, month) |
| # Return the first day in the first week that is a Sunday. |
| return [date_day[0] for date_day in weeks[0] if date_day[1] == 6][0] |
| |
| |
| def GetBuildDate(build_type, utc_now): |
| """Gets the approximate build date given the specific build type. |
| |
| >>> GetBuildDate('default', datetime.datetime(2016, 2, 6, 1, 2, 3)) |
| 'Jan 03 2016 01:02:03' |
| >>> GetBuildDate('default', datetime.datetime(2016, 2, 7, 5)) |
| 'Feb 07 2016 05:00:00' |
| >>> GetBuildDate('default', datetime.datetime(2016, 2, 8, 5)) |
| 'Feb 07 2016 05:00:00' |
| """ |
| day = utc_now.day |
| month = utc_now.month |
| year = utc_now.year |
| if build_type != 'official': |
| first_sunday = GetFirstSundayOfMonth(year, month) |
| # If our build is after the first Sunday, we've already refreshed our build |
| # cache on a quiet day, so just use that day. |
| # Otherwise, take the first Sunday of the previous month. |
| if day >= first_sunday: |
| day = first_sunday |
| else: |
| month -= 1 |
| if month == 0: |
| month = 12 |
| year -= 1 |
| day = GetFirstSundayOfMonth(year, month) |
| now = datetime.datetime( |
| year, month, day, utc_now.hour, utc_now.minute, utc_now.second) |
| return '{:%b %d %Y %H:%M:%S}'.format(now) |
| |
| |
| def main(): |
| if doctest.testmod()[0]: |
| return 1 |
| argument_parser = argparse.ArgumentParser( |
| description=sys.modules[__name__].__doc__, |
| formatter_class=argparse.RawDescriptionHelpFormatter) |
| argument_parser.add_argument('output_file', help='The file to write to') |
| argument_parser.add_argument( |
| 'build_type', help='The type of build', choices=('official', 'default')) |
| argument_parser.add_argument( |
| 'build_date_override', nargs='?', |
| help='Optional override for the build date. Format must be ' |
| '\'Mmm DD YYYY HH:MM:SS\'') |
| args = argument_parser.parse_args() |
| |
| if args.build_date_override: |
| # Format is expected to be "Mmm DD YYYY HH:MM:SS". |
| build_date = args.build_date_override |
| else: |
| now = datetime.datetime.utcnow() |
| if now.hour < 5: |
| # The time is locked at 5:00 am in UTC to cause the build cache |
| # invalidation to not happen exactly at midnight. Use the same calculation |
| # as the day before. |
| # See //base/build_time.cc. |
| now = now - datetime.timedelta(days=1) |
| now = datetime.datetime(now.year, now.month, now.day, 5, 0, 0) |
| build_date = GetBuildDate(args.build_type, now) |
| |
| output = ('// Generated by //build/write_build_date_header.py\n' |
| '#ifndef BUILD_DATE\n' |
| '#define BUILD_DATE "{}"\n' |
| '#endif // BUILD_DATE\n'.format(build_date)) |
| |
| current_contents = '' |
| if os.path.isfile(args.output_file): |
| with open(args.output_file, 'r') as current_file: |
| current_contents = current_file.read() |
| |
| if current_contents != output: |
| with open(args.output_file, 'w') as output_file: |
| output_file.write(output) |
| return 0 |
| |
| |
| if __name__ == '__main__': |
| sys.exit(main()) |