ubuntu-dev-tools/404main

#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# Copyright 2006-2007 (C) Pete Savage <petesavage@ubuntu.com>
# Copyright 2007 (C) Siegfried-A. Gevatter <rainct@ubuntu.com>
# Copyright 2009 (C) Canonical Ltd. (by Colin Watson <cjwatson@ubuntu.com>)
#
# ##################################################################
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
# 
# This program 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 General Public License for more details.
#
# See file /usr/share/common-licenses/GPL for more details.
#
# ##################################################################
#
# This script is used to check if a package and all its build
# dependencies are in main or not.

import subprocess
import sys

import apt_pkg
import apt

def process_deps(cache, deps):
	"""Takes a list of (build) dependencies and processes it."""
	
	for basedep in [d.or_dependencies[0] for d in deps]:
		if not packages.has_key(basedep.name) and basedep.name != '':
			# Check the (build) dependencies recursively
			find_main(cache, basedep.name)


def get_package_version(cache, distro, pack):
	if pack not in cache:
		return None
	for version in (cache[pack].candidate, cache[pack].installed):
		if not version:
			continue
		for origin in version.origins:
			if origin.archive == distro:
				return version
	return None


# Cache::CompTypeDeb isn't exposed via python-apt
def comp_type_deb(op):
	ops = ("", "<=", ">=", "<<", ">>", "=", "!=")
	if (op & 15) < 7:
		return ops[op & 15]
	return ""


def find_main(cache, pack):
	"""Searches the dependencies and build dependencies of a package recursively
	to determine if they are all in the 'main' component or not."""
	
	global packages
	
	if pack in packages:
		return

	# Retrieve information about the package
	version = get_package_version(cache, distro, pack)
	
	if not version:
		packages[pack] = False
		return
	elif [origin for origin in version.origins if origin.component == 'main']:
		packages[pack] = True
		return
	else:
		if not packages.has_key(pack):
			packages[pack] = False
		
		# Retrieve package dependencies
		process_deps(cache, version.dependencies)
		
		# Retrieve package build dependencies. There's no handy
		# attribute on version for this, so unfortunately we have to
		# do a lot of messing about with apt.
		deps = []
		src_records = apt_pkg.GetPkgSrcRecords()
		got_src = False
		while src_records.Lookup(version.source_name):
			if pack in src_records.Binaries:
				got_src = True
				break
		if got_src:
			base_deps = []
			for (name, ver, op, deptype) in src_records.BuildDepends:
				base_deps.append(apt.package.BaseDependency(name, comp_type_deb(op), ver, False))
				if (op & 16) != 16:
					deps.append(apt.package.Dependency(base_deps))
					base_deps = []
		
		process_deps(cache, deps)


def main():
	
	global packages, distro
	
	# Check if the amount of arguments is correct
	if len(sys.argv) < 2 or len(sys.argv) > 3 or sys.argv[1] in ('help', '-h', '--help'):
		print 'Usage: %s <package name> [<distribution>]' % sys.argv[0]
		sys.exit(1)
	
        cache = apt.cache.Cache()

	if len(sys.argv) == 3 and sys.argv[2]:
		distro = sys.argv[2]
		if not get_package_version(cache, distro, 'bash'):
			print '«%s» is not a valid distribution.' % distro
			print 'Remember that for 404main to work with a certain distribution it must be in your /etc/apt/sources.list file.'
			sys.exit(1)
	else:
		distro = subprocess.Popen('lsb_release -cs', shell=True, stdout=subprocess.PIPE).stdout.read().strip('\n')
	
	if not get_package_version(cache, distro, sys.argv[1]):
		print 'Can\'t find package «%s» in distribution «%s».' % (sys.argv[1], distro)
		sys.exit(1)
	
	print 'Checking package «%s» in distribution «%s»...' % (sys.argv[1], distro)
	
	find_main(cache, sys.argv[1])
	
	# True if everything checked until the point is in main
	all_in_main = True
	
	for package in packages:
		if not packages[package]:
			if all_in_main:
				print 'The following packages aren\'t in main:'
				all_in_main = False
			print '  ', package
	
	if all_in_main:
		print 'Package «%s» and all its dependencies and build dependencies are in main.' % sys.argv[1]

if __name__ == '__main__':
	
	# Global variable to hold the status of all packages
	packages = {}
	
	# Global variable to hold the target distribution
	distro = ''
	
	try:
		main()
	except KeyboardInterrupt:
		print 'Aborted.'
		sys.exit(1)