From e23d579d8bc849408745c196a2794e145743f7d1 Mon Sep 17 00:00:00 2001 From: drebs Date: Thu, 29 Nov 2012 10:56:49 -0200 Subject: add u1db code (not as submodule) --- u1db/commandline/command.py | 80 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 u1db/commandline/command.py (limited to 'u1db/commandline/command.py') diff --git a/u1db/commandline/command.py b/u1db/commandline/command.py new file mode 100644 index 00000000..eace0560 --- /dev/null +++ b/u1db/commandline/command.py @@ -0,0 +1,80 @@ +# Copyright 2011 Canonical Ltd. +# +# This file is part of u1db. +# +# u1db is free software: you can redistribute it and/or modify +# it under the terms of the GNU Lesser General Public License version 3 +# as published by the Free Software Foundation. +# +# u1db is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with u1db. If not, see . + +"""Command infrastructure for u1db""" + +import argparse +import inspect + + +class CommandGroup(object): + """A collection of commands.""" + + def __init__(self, description=None): + self.commands = {} + self.description = description + + def register(self, cmd): + """Register a new command to be incorporated with this group.""" + self.commands[cmd.name] = cmd + + def make_argparser(self): + """Create an argparse.ArgumentParser""" + parser = argparse.ArgumentParser(description=self.description) + subs = parser.add_subparsers(title='commands') + for name, cmd in sorted(self.commands.iteritems()): + sub = subs.add_parser(name, help=cmd.__doc__) + sub.set_defaults(subcommand=cmd) + cmd._populate_subparser(sub) + return parser + + def run_argv(self, argv, stdin, stdout, stderr): + """Run a command, from a sys.argv[1:] style input.""" + parser = self.make_argparser() + args = parser.parse_args(argv) + cmd = args.subcommand(stdin, stdout, stderr) + params, _, _, _ = inspect.getargspec(cmd.run) + vals = [] + for param in params[1:]: + vals.append(getattr(args, param)) + return cmd.run(*vals) + + +class Command(object): + """Definition of a Command that can be run. + + :cvar name: The name of the command, so that you can run + 'u1db-client '. + """ + + name = None + + def __init__(self, stdin, stdout, stderr): + self.stdin = stdin + self.stdout = stdout + self.stderr = stderr + + @classmethod + def _populate_subparser(cls, parser): + """Child classes should override this to provide their arguments.""" + raise NotImplementedError(cls._populate_subparser) + + def run(self, *args): + """This is where the magic happens. + + Subclasses should implement this, requesting their specific arguments. + """ + raise NotImplementedError(self.run) -- cgit v1.2.3