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Viewing changes to utilities/script_commands.py

  • Committer: Launchpad Patch Queue Manager
  • Date: 2011-08-04 18:06:38 UTC
  • mfrom: (13588.1.4 induce-latency)
  • Revision ID: launchpad@pqm.canonical.com-20110804180638-e1m4y7fcwlseqrle
[r=jcsackett][bug=821038] Add local-latency script.

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utilities/script_commands.py
 
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import optparse
 
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class UserError(Exception):
 
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    pass
 
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class OptionParser(optparse.OptionParser):
 
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    UNSPECIFIED = object()
 
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    def add_option(self, *args, **kwargs):
 
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        """Add an option, with the default that it not be included."""
 
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        kwargs['default'] = kwargs.get('default', self.UNSPECIFIED)
 
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        optparse.OptionParser.add_option(self, *args, **kwargs)
 
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    def parse_args_dict(self, cmd_args):
 
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        """Return a dict of specified options.
 
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        Unspecified options with no explicit default are not included in the
 
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        dict."""
 
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        options, args = self.parse_args(cmd_args)
 
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        option_dict = dict(
 
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            item for item in options.__dict__.items()
 
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            if item[1] is not self.UNSPECIFIED)
 
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        return args, option_dict
 
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class Command:
 
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    """Base class for subcommands."""
 
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    commands = {}
 
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    @classmethod
 
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    def parse_args(cls, args):
 
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        if len(args) != 0:
 
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            raise UserError('Too many arguments.')
 
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        return {}
 
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    @classmethod
 
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    def run_from_args(cls, cmd_args):
 
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        args, kwargs = cls.get_parser().parse_args_dict(cmd_args)
 
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        kwargs.update(cls.parse_args(args))
 
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        cls.run(**kwargs)
 
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    @classmethod
 
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    def run_subcommand(cls, argv):
 
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        if len(argv) < 1:
 
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            raise UserError('Must supply a command: %s.' %
 
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                            ', '.join(cls.commands.keys()))
 
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        try:
 
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            command = cls.commands[argv[0]]
 
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        except KeyError:
 
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            raise UserError('%s invalid.  Valid commands: %s.' %
 
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                            (argv[0], ', '.join(cls.commands.keys())))
 
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        command.run_from_args(argv[1:])