pym/_emerge/__init__.py

#!/usr/bin/python -O
# Copyright 1999-2006 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id: emerge 5976 2007-02-17 09:14:53Z genone $

import sys
# This block ensures that ^C interrupts are handled quietly.
try:
	import signal

	def exithandler(signum,frame):
		signal.signal(signal.SIGINT, signal.SIG_IGN)
		signal.signal(signal.SIGTERM, signal.SIG_IGN)
		sys.exit(1)
	
	signal.signal(signal.SIGINT, exithandler)
	signal.signal(signal.SIGTERM, exithandler)
	signal.signal(signal.SIGPIPE, signal.SIG_DFL)

except KeyboardInterrupt:
	sys.exit(1)

import array
from collections import deque
import fcntl
import formatter
import fpformat
import logging
import select
import shlex
import shutil
import textwrap
import urlparse
import weakref
import gc
import os, stat
import platform

try:
	import portage
except ImportError:
	from os import path as osp
	sys.path.insert(0, osp.join(osp.dirname(osp.dirname(osp.realpath(__file__))), "pym"))
	import portage

from portage import digraph, portdbapi
from portage.const import NEWS_LIB_PATH, CACHE_PATH, PRIVATE_PATH, USER_CONFIG_PATH, GLOBAL_CONFIG_PATH

import _emerge.help
import portage.xpak, commands, errno, re, socket, time, types
from portage.output import blue, bold, colorize, darkblue, darkgreen, darkred, green, \
	havecolor, nc_len, nocolor, red, teal, turquoise, white, xtermTitle, \
	xtermTitleReset, yellow
from portage.output import create_color_func
good = create_color_func("GOOD")
bad = create_color_func("BAD")
# white looks bad on terminals with white background
from portage.output import bold as white

import portage.elog
import portage.dep
portage.dep._dep_check_strict = True
import portage.util
import portage.locks
import portage.exception
from portage.data import secpass
from portage.elog.messages import eerror
from portage.util import normalize_path as normpath
from portage.util import writemsg, writemsg_level
from portage.sets import load_default_config, SETPREFIX
from portage.sets.base import InternalPackageSet

from itertools import chain, izip
from UserDict import DictMixin

try:
	import cPickle
except ImportError:
	import pickle as cPickle

try:
	import cStringIO as StringIO
except ImportError:
	import StringIO

class stdout_spinner(object):
	scroll_msgs = [
		"Gentoo Rocks ("+platform.system()+")",
		"Thank you for using Gentoo. :)",
		"Are you actually trying to read this?",
		"How many times have you stared at this?",
		"We are generating the cache right now",
		"You are paying too much attention.",
		"A theory is better than its explanation.",
		"Phasers locked on target, Captain.",
		"Thrashing is just virtual crashing.",
		"To be is to program.",
		"Real Users hate Real Programmers.",
		"When all else fails, read the instructions.",
		"Functionality breeds Contempt.",
		"The future lies ahead.",
		"3.1415926535897932384626433832795028841971694",
		"Sometimes insanity is the only alternative.",
		"Inaccuracy saves a world of explanation.",
	]

	twirl_sequence = "/-\\|/-\\|/-\\|/-\\|\\-/|\\-/|\\-/|\\-/|"

	def __init__(self):
		self.spinpos = 0
		self.update = self.update_twirl
		self.scroll_sequence = self.scroll_msgs[
			int(time.time() * 100) % len(self.scroll_msgs)]
		self.last_update = 0
		self.min_display_latency = 0.05

	def _return_early(self):
		"""
		Flushing ouput to the tty too frequently wastes cpu time. Therefore,
		each update* method should return without doing any output when this
		method returns True.
		"""
		cur_time = time.time()
		if cur_time - self.last_update < self.min_display_latency:
			return True
		self.last_update = cur_time
		return False

	def update_basic(self):
		self.spinpos = (self.spinpos + 1) % 500
		if self._return_early():
			return
		if (self.spinpos % 100) == 0:
			if self.spinpos == 0:
				sys.stdout.write(". ")
			else:
				sys.stdout.write(".")
		sys.stdout.flush()

	def update_scroll(self):
		if self._return_early():
			return
		if(self.spinpos >= len(self.scroll_sequence)):
			sys.stdout.write(darkgreen(" \b\b\b" + self.scroll_sequence[
				len(self.scroll_sequence) - 1 - (self.spinpos % len(self.scroll_sequence))]))
		else:
			sys.stdout.write(green("\b " + self.scroll_sequence[self.spinpos]))
		sys.stdout.flush()
		self.spinpos = (self.spinpos + 1) % (2 * len(self.scroll_sequence))

	def update_twirl(self):
		self.spinpos = (self.spinpos + 1) % len(self.twirl_sequence)
		if self._return_early():
			return
		sys.stdout.write("\b\b " + self.twirl_sequence[self.spinpos])
		sys.stdout.flush()

	def update_quiet(self):
		return

def userquery(prompt, responses=None, colours=None):
	"""Displays a prompt and a set of responses, then waits for a response
	which is checked against the responses and the first to match is
	returned.  An empty response will match the first value in responses.  The
	input buffer is *not* cleared prior to the prompt!

	prompt: a String.
	responses: a List of Strings.
	colours: a List of Functions taking and returning a String, used to
	process the responses for display. Typically these will be functions
	like red() but could be e.g. lambda x: "DisplayString".
	If responses is omitted, defaults to ["Yes", "No"], [green, red].
	If only colours is omitted, defaults to [bold, ...].

	Returns a member of the List responses. (If called without optional
	arguments, returns "Yes" or "No".)
	KeyboardInterrupt is converted to SystemExit to avoid tracebacks being
	printed."""
	if responses is None:
		responses = ["Yes", "No"]
		colours = [
			create_color_func("PROMPT_CHOICE_DEFAULT"),
			create_color_func("PROMPT_CHOICE_OTHER")
		]
	elif colours is None:
		colours=[bold]
	colours=(colours*len(responses))[:len(responses)]
	print bold(prompt),
	try:
		while True:
			response=raw_input("["+"/".join([colours[i](responses[i]) for i in range(len(responses))])+"] ")
			for key in responses:
				# An empty response will match the first value in responses.
				if response.upper()==key[:len(response)].upper():
					return key
			print "Sorry, response '%s' not understood." % response,
	except (EOFError, KeyboardInterrupt):
		print "Interrupted."
		sys.exit(1)

actions=[
"clean", "config", "depclean",
"info", "metadata",
"prune", "regen",  "search",
"sync",  "unmerge",
]
options=[
"--ask",          "--alphabetical",
"--buildpkg",     "--buildpkgonly",
"--changelog",    "--columns",
"--complete-graph",
"--debug",        "--deep",
"--digest",
"--emptytree",
"--fetchonly",    "--fetch-all-uri",
"--getbinpkg",    "--getbinpkgonly",
"--help",         "--ignore-default-opts",
"--keep-going",
"--noconfmem",
"--newuse",       "--nocolor",
"--nodeps",       "--noreplace",
"--nospinner",    "--oneshot",
"--onlydeps",     "--pretend",
"--quiet",        "--resume",
"--searchdesc",   "--selective",
"--skipfirst",
"--tree",
"--update",
"--usepkg",       "--usepkgonly",
"--verbose",      "--version"
]

shortmapping={
"1":"--oneshot",
"a":"--ask",
"b":"--buildpkg",  "B":"--buildpkgonly",
"c":"--clean",     "C":"--unmerge",
"d":"--debug",     "D":"--deep",
"e":"--emptytree",
"f":"--fetchonly", "F":"--fetch-all-uri",
"g":"--getbinpkg", "G":"--getbinpkgonly",
"h":"--help",
"k":"--usepkg",    "K":"--usepkgonly",
"l":"--changelog",
"n":"--noreplace", "N":"--newuse",
"o":"--onlydeps",  "O":"--nodeps",
"p":"--pretend",   "P":"--prune",
"q":"--quiet",
"s":"--search",    "S":"--searchdesc",
"t":"--tree",
"u":"--update",
"v":"--verbose",   "V":"--version"
}

def emergelog(xterm_titles, mystr, short_msg=None):
	if xterm_titles and short_msg:
		if "HOSTNAME" in os.environ:
			short_msg = os.environ["HOSTNAME"]+": "+short_msg
		xtermTitle(short_msg)
	try:
		file_path = "/var/log/emerge.log"
		mylogfile = open(file_path, "a")
		portage.util.apply_secpass_permissions(file_path,
			uid=portage.portage_uid, gid=portage.portage_gid,
			mode=0660)
		mylock = None
		try:
			mylock = portage.locks.lockfile(mylogfile)
			# seek because we may have gotten held up by the lock.
			# if so, we may not be positioned at the end of the file.
			mylogfile.seek(0, 2)
			mylogfile.write(str(time.time())[:10]+": "+mystr+"\n")
			mylogfile.flush()
		finally:
			if mylock:
				portage.locks.unlockfile(mylock)
			mylogfile.close()
	except (IOError,OSError,portage.exception.PortageException), e:
		if secpass >= 1:
			print >> sys.stderr, "emergelog():",e

def countdown(secs=5, doing="Starting"):
	if secs:
		print ">>> Waiting",secs,"seconds before starting..."
		print ">>> (Control-C to abort)...\n"+doing+" in: ",
		ticks=range(secs)
		ticks.reverse()
		for sec in ticks:
			sys.stdout.write(colorize("UNMERGE_WARN", str(sec+1)+" "))
			sys.stdout.flush()
			time.sleep(1)
		print

# formats a size given in bytes nicely
def format_size(mysize):
	if type(mysize) not in [types.IntType,types.LongType]:
		return str(mysize)
	if 0 != mysize % 1024:
		# Always round up to the next kB so that it doesn't show 0 kB when
		# some small file still needs to be fetched.
		mysize += 1024 - mysize % 1024
	mystr=str(mysize/1024)
	mycount=len(mystr)
	while (mycount > 3):
		mycount-=3
		mystr=mystr[:mycount]+","+mystr[mycount:]
	return mystr+" kB"


def getgccversion(chost):
	"""
	rtype: C{str}
	return:  the current in-use gcc version
	"""

	gcc_ver_command = 'gcc -dumpversion'
	gcc_ver_prefix = 'gcc-'

	gcc_not_found_error = red(
	"!!! No gcc found. You probably need to 'source /etc/profile'\n" +
	"!!! to update the environment of this terminal and possibly\n" +
	"!!! other terminals also.\n"
	)

	mystatus, myoutput = commands.getstatusoutput("gcc-config -c")
	if mystatus == os.EX_OK and myoutput.startswith(chost + "-"):
		return myoutput.replace(chost + "-", gcc_ver_prefix, 1)

	mystatus, myoutput = commands.getstatusoutput(
		chost + "-" + gcc_ver_command)
	if mystatus == os.EX_OK:
		return gcc_ver_prefix + myoutput

	mystatus, myoutput = commands.getstatusoutput(gcc_ver_command)
	if mystatus == os.EX_OK:
		return gcc_ver_prefix + myoutput

	portage.writemsg(gcc_not_found_error, noiselevel=-1)
	return "[unavailable]"

def getportageversion(portdir, target_root, profile, chost, vardb):
	profilever = "unavailable"
	if profile:
		realpath = os.path.realpath(profile)
		basepath   = os.path.realpath(os.path.join(portdir, "profiles"))
		if realpath.startswith(basepath):
			profilever = realpath[1 + len(basepath):]
		else:
			try:
				profilever = "!" + os.readlink(profile)
			except (OSError):
				pass
		del realpath, basepath

	libcver=[]
	libclist  = vardb.match("virtual/libc")
	libclist += vardb.match("virtual/glibc")
	libclist  = portage.util.unique_array(libclist)
	for x in libclist:
		xs=portage.catpkgsplit(x)
		if libcver:
			libcver+=","+"-".join(xs[1:])
		else:
			libcver="-".join(xs[1:])
	if libcver==[]:
		libcver="unavailable"

	gccver = getgccversion(chost)
	unameout=platform.release()+" "+platform.machine()

	return "Portage " + portage.VERSION +" ("+profilever+", "+gccver+", "+libcver+", "+unameout+")"

def create_depgraph_params(myopts, myaction):
	#configure emerge engine parameters
	#
	# self:      include _this_ package regardless of if it is merged.
	# selective: exclude the package if it is merged
	# recurse:   go into the dependencies
	# deep:      go into the dependencies of already merged packages
	# empty:     pretend nothing is merged
	# complete:  completely account for all known dependencies
	# remove:    build graph for use in removing packages
	myparams = set(["recurse"])

	if myaction == "remove":
		myparams.add("remove")
		myparams.add("complete")
		return myparams

	if "--update" in myopts or \
		"--newuse" in myopts or \
		"--reinstall" in myopts or \
		"--noreplace" in myopts:
		myparams.add("selective")
	if "--emptytree" in myopts:
		myparams.add("empty")
		myparams.discard("selective")
	if "--nodeps" in myopts:
		myparams.discard("recurse")
	if "--deep" in myopts:
		myparams.add("deep")
	if "--complete-graph" in myopts:
		myparams.add("complete")
	return myparams

# search functionality
class search(object):

	#
	# class constants
	#
	VERSION_SHORT=1
	VERSION_RELEASE=2

	#
	# public interface
	#
	def __init__(self, root_config, spinner, searchdesc,
		verbose, usepkg, usepkgonly):
		"""Searches the available and installed packages for the supplied search key.
		The list of available and installed packages is created at object instantiation.
		This makes successive searches faster."""
		self.settings = root_config.settings
		self.vartree = root_config.trees["vartree"]
		self.spinner = spinner
		self.verbose = verbose
		self.searchdesc = searchdesc
		self.root_config = root_config
		self.setconfig = root_config.setconfig

		def fake_portdb():
			pass
		self.portdb = fake_portdb
		for attrib in ("aux_get", "cp_all",
			"xmatch", "findname", "getfetchlist"):
			setattr(fake_portdb, attrib, getattr(self, "_"+attrib))

		self._dbs = []

		portdb = root_config.trees["porttree"].dbapi
		bindb = root_config.trees["bintree"].dbapi
		vardb = root_config.trees["vartree"].dbapi

		if not usepkgonly and portdb._have_root_eclass_dir:
			self._dbs.append(portdb)

		if (usepkg or usepkgonly) and bindb.cp_all():
			self._dbs.append(bindb)

		self._dbs.append(vardb)
		self._portdb = portdb

	def _cp_all(self):
		cp_all = set()
		for db in self._dbs:
			cp_all.update(db.cp_all())
		return list(sorted(cp_all))

	def _aux_get(self, *args, **kwargs):
		for db in self._dbs:
			try:
				return db.aux_get(*args, **kwargs)
			except KeyError:
				pass
		raise

	def _findname(self, *args, **kwargs):
		for db in self._dbs:
			if db is not self._portdb:
				# We don't want findname to return anything
				# unless it's an ebuild in a portage tree.
				# Otherwise, it's already built and we don't
				# care about it.
				continue
			func = getattr(db, "findname", None)
			if func:
				value = func(*args, **kwargs)
				if value:
					return value
		return None

	def _getfetchlist(self, *args, **kwargs):
		for db in self._dbs:
			func = getattr(db, "getfetchlist", None)
			if func:
				value = func(*args, **kwargs)
				if value:
					return value
		return [], []

	def _visible(self, db, cpv, metadata):
		installed = db is self.vartree.dbapi
		built = installed or db is not self._portdb
		pkg_type = "ebuild"
		if installed:
			pkg_type = "installed"
		elif built:
			pkg_type = "binary"
		return visible(self.settings,
			Package(type_name=pkg_type, root_config=self.root_config,
			cpv=cpv, built=built, installed=installed, metadata=metadata))

	def _xmatch(self, level, atom):
		"""
		This method does not expand old-style virtuals because it
		is restricted to returning matches for a single ${CATEGORY}/${PN}
		and old-style virual matches unreliable for that when querying
		multiple package databases. If necessary, old-style virtuals
		can be performed on atoms prior to calling this method.
		"""
		cp = portage.dep_getkey(atom)
		if level == "match-all":
			matches = set()
			for db in self._dbs:
				if hasattr(db, "xmatch"):
					matches.update(db.xmatch(level, atom))
				else:
					matches.update(db.match(atom))
			result = list(x for x in matches if portage.cpv_getkey(x) == cp)
			db._cpv_sort_ascending(result)
		elif level == "match-visible":
			matches = set()
			for db in self._dbs:
				if hasattr(db, "xmatch"):
					matches.update(db.xmatch(level, atom))
				else:
					db_keys = list(db._aux_cache_keys)
					for cpv in db.match(atom):
						metadata = izip(db_keys,
							db.aux_get(cpv, db_keys))
						if not self._visible(db, cpv, metadata):
							continue
						matches.add(cpv)
			result = list(x for x in matches if portage.cpv_getkey(x) == cp)
			db._cpv_sort_ascending(result)
		elif level == "bestmatch-visible":
			result = None
			for db in self._dbs:
				if hasattr(db, "xmatch"):
					cpv = db.xmatch("bestmatch-visible", atom)
					if not cpv or portage.cpv_getkey(cpv) != cp:
						continue
					if not result or cpv == portage.best([cpv, result]):
						result = cpv
				else:
					db_keys = list(db._aux_cache_keys)
					# break out of this loop with highest visible
					# match, checked in descending order
					for cpv in reversed(db.match(atom)):
						if portage.cpv_getkey(cpv) != cp:
							continue
						metadata = izip(db_keys,
							db.aux_get(cpv, db_keys))
						if not self._visible(db, cpv, metadata):
							continue
						if not result or cpv == portage.best([cpv, result]):
							result = cpv
						break
		else:
			raise NotImplementedError(level)
		return result

	def execute(self,searchkey):
		"""Performs the search for the supplied search key"""
		match_category = 0
		self.searchkey=searchkey
		self.packagematches = []
		if self.searchdesc:
			self.searchdesc=1
			self.matches = {"pkg":[], "desc":[], "set":[]}
		else:
			self.searchdesc=0
			self.matches = {"pkg":[], "set":[]}
		print "Searching...   ",

		regexsearch = False
		if self.searchkey.startswith('%'):
			regexsearch = True
			self.searchkey = self.searchkey[1:]
		if self.searchkey.startswith('@'):
			match_category = 1
			self.searchkey = self.searchkey[1:]
		if regexsearch:
			self.searchre=re.compile(self.searchkey,re.I)
		else:
			self.searchre=re.compile(re.escape(self.searchkey), re.I)
		for package in self.portdb.cp_all():
			self.spinner.update()

			if match_category:
				match_string  = package[:]
			else:
				match_string  = package.split("/")[-1]

			masked=0
			if self.searchre.search(match_string):
				if not self.portdb.xmatch("match-visible", package):
					masked=1
				self.matches["pkg"].append([package,masked])
			elif self.searchdesc: # DESCRIPTION searching
				full_package = self.portdb.xmatch("bestmatch-visible", package)
				if not full_package:
					#no match found; we don't want to query description
					full_package = portage.best(
						self.portdb.xmatch("match-all", package))
					if not full_package:
						continue
					else:
						masked=1
				try:
					full_desc = self.portdb.aux_get(
						full_package, ["DESCRIPTION"])[0]
				except KeyError:
					print "emerge: search: aux_get() failed, skipping"
					continue
				if self.searchre.search(full_desc):
					self.matches["desc"].append([full_package,masked])

		self.sdict = self.setconfig.getSets()
		for setname in self.sdict:
			self.spinner.update()
			if match_category:
				match_string = setname
			else:
				match_string = setname.split("/")[-1]
			
			if self.searchre.search(match_string):
				self.matches["set"].append([setname, False])
			elif self.searchdesc:
				if self.searchre.search(
					self.sdict[setname].getMetadata("DESCRIPTION")):
					self.matches["set"].append([setname, False])
			
		self.mlen=0
		for mtype in self.matches:
			self.matches[mtype].sort()
			self.mlen += len(self.matches[mtype])

	def output(self):
		"""Outputs the results of the search."""
		print "\b\b  \n[ Results for search key : "+white(self.searchkey)+" ]"
		print "[ Applications found : "+white(str(self.mlen))+" ]"
		print " "
		vardb = self.vartree.dbapi
		for mtype in self.matches:
			for match,masked in self.matches[mtype]:
				full_package = None
				if mtype == "pkg":
					catpack = match
					full_package = self.portdb.xmatch(
						"bestmatch-visible", match)
					if not full_package:
						#no match found; we don't want to query description
						masked=1
						full_package = portage.best(
							self.portdb.xmatch("match-all",match))
				elif mtype == "desc":
					full_package = match
					match        = portage.cpv_getkey(match)
				elif mtype == "set":
					print green("*")+"  "+white(match)
					print "     ", darkgreen("Description:")+"  ", self.sdict[match].getMetadata("DESCRIPTION")
					print
				if full_package:
					try:
						desc, homepage, license = self.portdb.aux_get(
							full_package, ["DESCRIPTION","HOMEPAGE","LICENSE"])
					except KeyError:
						print "emerge: search: aux_get() failed, skipping"
						continue
					if masked:
						print green("*")+"  "+white(match)+" "+red("[ Masked ]")
					else:
						print green("*")+"  "+white(match)
					myversion = self.getVersion(full_package, search.VERSION_RELEASE)

					mysum = [0,0]
					file_size_str = None
					mycat = match.split("/")[0]
					mypkg = match.split("/")[1]
					mycpv = match + "-" + myversion
					myebuild = self.portdb.findname(mycpv)
					if myebuild:
						pkgdir = os.path.dirname(myebuild)
						from portage import manifest
						mf = manifest.Manifest(
							pkgdir, self.settings["DISTDIR"])
						fetchlist = self.portdb.getfetchlist(mycpv,
							mysettings=self.settings, all=True)[1]
						try:
							mysum[0] = mf.getDistfilesSize(fetchlist)
						except KeyError, e:
							file_size_str = "Unknown (missing digest for %s)" % \
								str(e)

					available = False
					for db in self._dbs:
						if db is not vardb and \
							db.cpv_exists(mycpv):
							available = True
							if not myebuild and hasattr(db, "bintree"):
								myebuild = db.bintree.getname(mycpv)
								try:
									mysum[0] = os.stat(myebuild).st_size
								except OSError:
									myebuild = None
							break

					if myebuild and file_size_str is None:
						mystr = str(mysum[0] / 1024)
						mycount = len(mystr)
						while (mycount > 3):
							mycount -= 3
							mystr = mystr[:mycount] + "," + mystr[mycount:]
						file_size_str = mystr + " kB"

					if self.verbose:
						if available:
							print "     ", darkgreen("Latest version available:"),myversion
						print "     ", self.getInstallationStatus(mycat+'/'+mypkg)
						if myebuild:
							print "      %s %s" % \
								(darkgreen("Size of files:"), file_size_str)
						print "     ", darkgreen("Homepage:")+"     ",homepage
						print "     ", darkgreen("Description:")+"  ",desc
						print "     ", darkgreen("License:")+"      ",license
						print
		print
	#
	# private interface
	#
	def getInstallationStatus(self,package):
		installed_package = self.vartree.dep_bestmatch(package)
		result = ""
		version = self.getVersion(installed_package,search.VERSION_RELEASE)
		if len(version) > 0:
			result = darkgreen("Latest version installed:")+" "+version
		else:
			result = darkgreen("Latest version installed:")+" [ Not Installed ]"
		return result

	def getVersion(self,full_package,detail):
		if len(full_package) > 1:
			package_parts = portage.catpkgsplit(full_package)
			if detail == search.VERSION_RELEASE and package_parts[3] != 'r0':
				result = package_parts[2]+ "-" + package_parts[3]
			else:
				result = package_parts[2]
		else:
			result = ""
		return result

class RootConfig(object):
	"""This is used internally by depgraph to track information about a
	particular $ROOT."""

	pkg_tree_map = {
		"ebuild"    : "porttree",
		"binary"    : "bintree",
		"installed" : "vartree"
	}

	tree_pkg_map = {}
	for k, v in pkg_tree_map.iteritems():
		tree_pkg_map[v] = k

	def __init__(self, settings, trees, setconfig):
		self.trees = trees
		self.settings = settings
		self.iuse_implicit = tuple(sorted(settings._get_implicit_iuse()))
		self.root = self.settings["ROOT"]
		self.setconfig = setconfig
		self.sets = self.setconfig.getSets()
		self.visible_pkgs = PackageVirtualDbapi(self.settings)

def create_world_atom(pkg, args_set, root_config):
	"""Create a new atom for the world file if one does not exist.  If the
	argument atom is precise enough to identify a specific slot then a slot
	atom will be returned. Atoms that are in the system set may also be stored
	in world since system atoms can only match one slot while world atoms can
	be greedy with respect to slots.  Unslotted system packages will not be
	stored in world."""

	arg_atom = args_set.findAtomForPackage(pkg)
	if not arg_atom:
		return None
	cp = portage.dep_getkey(arg_atom)
	new_world_atom = cp
	sets = root_config.sets
	portdb = root_config.trees["porttree"].dbapi
	vardb = root_config.trees["vartree"].dbapi
	available_slots = set(portdb.aux_get(cpv, ["SLOT"])[0] \
		for cpv in portdb.match(cp))
	slotted = len(available_slots) > 1 or \
		(len(available_slots) == 1 and "0" not in available_slots)
	if not slotted:
		# check the vdb in case this is multislot
		available_slots = set(vardb.aux_get(cpv, ["SLOT"])[0] \
			for cpv in vardb.match(cp))
		slotted = len(available_slots) > 1 or \
			(len(available_slots) == 1 and "0" not in available_slots)
	if slotted and arg_atom != cp:
		# If the user gave a specific atom, store it as a
		# slot atom in the world file.
		slot_atom = pkg.slot_atom

		# For USE=multislot, there are a couple of cases to
		# handle here:
		#
		# 1) SLOT="0", but the real SLOT spontaneously changed to some
		#    unknown value, so just record an unslotted atom.
		#
		# 2) SLOT comes from an installed package and there is no
		#    matching SLOT in the portage tree.
		#
		# Make sure that the slot atom is available in either the
		# portdb or the vardb, since otherwise the user certainly
		# doesn't want the SLOT atom recorded in the world file
		# (case 1 above).  If it's only available in the vardb,
		# the user may be trying to prevent a USE=multislot
		# package from being removed by --depclean (case 2 above).

		mydb = portdb
		if not portdb.match(slot_atom):
			# SLOT seems to come from an installed multislot package
			mydb = vardb
		# If there is no installed package matching the SLOT atom,
		# it probably changed SLOT spontaneously due to USE=multislot,
		# so just record an unslotted atom.
		if vardb.match(slot_atom):
			# Now verify that the argument is precise
			# enough to identify a specific slot.
			matches = mydb.match(arg_atom)
			matched_slots = set()
			for cpv in matches:
				matched_slots.add(mydb.aux_get(cpv, ["SLOT"])[0])
			if len(matched_slots) == 1:
				new_world_atom = slot_atom

	if new_world_atom == sets["world"].findAtomForPackage(pkg):
		# Both atoms would be identical, so there's nothing to add.
		return None
	if not slotted:
		# Unlike world atoms, system atoms are not greedy for slots, so they
		# can't be safely excluded from world if they are slotted.
		system_atom = sets["system"].findAtomForPackage(pkg)
		if system_atom:
			if not portage.dep_getkey(system_atom).startswith("virtual/"):
				return None
			# System virtuals aren't safe to exclude from world since they can
			# match multiple old-style virtuals but only one of them will be
			# pulled in by update or depclean.
			providers = portdb.mysettings.getvirtuals().get(
				portage.dep_getkey(system_atom))
			if providers and len(providers) == 1 and providers[0] == cp:
				return None
	return new_world_atom

def filter_iuse_defaults(iuse):
	for flag in iuse:
		if flag.startswith("+") or flag.startswith("-"):
			yield flag[1:]
		else:
			yield flag

class SlotObject(object):
	__slots__ = ("__weakref__",)

	def __init__(self, **kwargs):
		classes = [self.__class__]
		while classes:
			c = classes.pop()
			if c is SlotObject:
				continue
			classes.extend(c.__bases__)
			slots = getattr(c, "__slots__", None)
			if not slots:
				continue
			for myattr in slots:
				myvalue = kwargs.get(myattr, None)
				setattr(self, myattr, myvalue)

	def copy(self):
		"""
		Create a new instance and copy all attributes
		defined from __slots__ (including those from
		inherited classes).
		"""
		obj = self.__class__()

		classes = [self.__class__]
		while classes:
			c = classes.pop()
			if c is SlotObject:
				continue
			classes.extend(c.__bases__)
			slots = getattr(c, "__slots__", None)
			if not slots:
				continue
			for myattr in slots:
				setattr(obj, myattr, getattr(self, myattr))

		return obj

class AbstractDepPriority(SlotObject):
	__slots__ = ("buildtime", "runtime", "runtime_post")

	def __lt__(self, other):
		return self.__int__() < other

	def __le__(self, other):
		return self.__int__() <= other

	def __eq__(self, other):
		return self.__int__() == other

	def __ne__(self, other):
		return self.__int__() != other

	def __gt__(self, other):
		return self.__int__() > other

	def __ge__(self, other):
		return self.__int__() >= other

	def copy(self):
		import copy
		return copy.copy(self)

class DepPriority(AbstractDepPriority):
	"""
		This class generates an integer priority level based of various
		attributes of the dependency relationship.  Attributes can be assigned
		at any time and the new integer value will be generated on calls to the
		__int__() method.  Rich comparison operators are supported.

		The boolean attributes that affect the integer value are "satisfied",
		"buildtime", "runtime", and "system".  Various combinations of
		attributes lead to the following priority levels:

		Combination of properties           Priority  Category

		not satisfied and buildtime            0       HARD
		not satisfied and runtime             -1       MEDIUM
		not satisfied and runtime_post        -2       MEDIUM_SOFT
		satisfied and buildtime and rebuild   -3       SOFT
		satisfied and buildtime               -4       SOFT
		satisfied and runtime                 -5       SOFT
		satisfied and runtime_post            -6       SOFT
		(none of the above)                   -6       SOFT

		Several integer constants are defined for categorization of priority
		levels:

		MEDIUM   The upper boundary for medium dependencies.
		MEDIUM_SOFT   The upper boundary for medium-soft dependencies.
		SOFT     The upper boundary for soft dependencies.
		MIN      The lower boundary for soft dependencies.
	"""
	__slots__ = ("satisfied", "rebuild")
	MEDIUM = -1
	MEDIUM_SOFT = -2
	SOFT   = -3
	MIN    = -6

	def __int__(self):
		if not self.satisfied:
			if self.buildtime:
				return 0
			if self.runtime:
				return -1
			if self.runtime_post:
				return -2
		if self.buildtime:
			if self.rebuild:
				return -3
			return -4
		if self.runtime:
			return -5
		if self.runtime_post:
			return -6
		return -6

	def __str__(self):
		myvalue = self.__int__()
		if myvalue > self.MEDIUM:
			return "hard"
		if myvalue > self.MEDIUM_SOFT:
			return "medium"
		if myvalue > self.SOFT:
			return "medium-soft"
		return "soft"

class BlockerDepPriority(DepPriority):
	__slots__ = ()
	def __int__(self):
		return 0

BlockerDepPriority.instance = BlockerDepPriority()

class UnmergeDepPriority(AbstractDepPriority):
	__slots__ = ("satisfied",)
	"""
	Combination of properties           Priority  Category

	runtime                                0       HARD
	runtime_post                          -1       HARD
	buildtime                             -2       SOFT
	(none of the above)                   -2       SOFT
	"""

	MAX    =  0
	SOFT   = -2
	MIN    = -2

	def __int__(self):
		if self.runtime:
			return 0
		if self.runtime_post:
			return -1
		if self.buildtime:
			return -2
		return -2

	def __str__(self):
		myvalue = self.__int__()
		if myvalue > self.SOFT:
			return "hard"
		return "soft"

class FakeVartree(portage.vartree):
	"""This is implements an in-memory copy of a vartree instance that provides
	all the interfaces required for use by the depgraph.  The vardb is locked
	during the constructor call just long enough to read a copy of the
	installed package information.  This allows the depgraph to do it's
	dependency calculations without holding a lock on the vardb.  It also
	allows things like vardb global updates to be done in memory so that the
	user doesn't necessarily need write access to the vardb in cases where
	global updates are necessary (updates are performed when necessary if there
	is not a matching ebuild in the tree)."""
	def __init__(self, root_config, pkg_cache=None, acquire_lock=1):
		self._root_config = root_config
		if pkg_cache is None:
			pkg_cache = {}
		real_vartree = root_config.trees["vartree"]
		portdb = root_config.trees["porttree"].dbapi
		self.root = real_vartree.root
		self.settings = real_vartree.settings
		mykeys = list(real_vartree.dbapi._aux_cache_keys)
		self._pkg_cache = pkg_cache
		self.dbapi = PackageVirtualDbapi(real_vartree.settings)
		vdb_path = os.path.join(self.root, portage.VDB_PATH)
		try:
			# At least the parent needs to exist for the lock file.
			portage.util.ensure_dirs(vdb_path)
		except portage.exception.PortageException:
			pass
		vdb_lock = None
		try:
			if acquire_lock and os.access(vdb_path, os.W_OK):
				vdb_lock = portage.locks.lockdir(vdb_path)
			real_dbapi = real_vartree.dbapi
			slot_counters = {}
			for cpv in real_dbapi.cpv_all():
				cache_key = ("installed", self.root, cpv, "nomerge")
				pkg = self._pkg_cache.get(cache_key)
				if pkg is not None:
					metadata = pkg.metadata
				else:
					metadata = dict(izip(mykeys, real_dbapi.aux_get(cpv, mykeys)))
				myslot = metadata["SLOT"]
				mycp = portage.dep_getkey(cpv)
				myslot_atom = "%s:%s" % (mycp, myslot)
				try:
					mycounter = long(metadata["COUNTER"])
				except ValueError:
					mycounter = 0
					metadata["COUNTER"] = str(mycounter)
				other_counter = slot_counters.get(myslot_atom, None)
				if other_counter is not None:
					if other_counter > mycounter:
						continue
				slot_counters[myslot_atom] = mycounter
				if pkg is None:
					pkg = Package(built=True, cpv=cpv,
						installed=True, metadata=metadata,
						root_config=root_config, type_name="installed")
				self._pkg_cache[pkg] = pkg
				self.dbapi.cpv_inject(pkg)
			real_dbapi.flush_cache()
		finally:
			if vdb_lock:
				portage.locks.unlockdir(vdb_lock)
		# Populate the old-style virtuals using the cached values.
		if not self.settings.treeVirtuals:
			self.settings.treeVirtuals = portage.util.map_dictlist_vals(
				portage.getCPFromCPV, self.get_all_provides())

		# Intialize variables needed for lazy cache pulls of the live ebuild
		# metadata.  This ensures that the vardb lock is released ASAP, without
		# being delayed in case cache generation is triggered.
		self._aux_get = self.dbapi.aux_get
		self.dbapi.aux_get = self._aux_get_wrapper
		self._match = self.dbapi.match
		self.dbapi.match = self._match_wrapper
		self._aux_get_history = set()
		self._portdb_keys = ["DEPEND", "RDEPEND", "PDEPEND"]
		self._portdb = portdb
		self._global_updates = None

	def _match_wrapper(self, cpv, use_cache=1):
		"""
		Make sure the metadata in Package instances gets updated for any
		cpv that is returned from a match() call, since the metadata can
		be accessed directly from the Package instance instead of via
		aux_get().
		"""
		matches = self._match(cpv, use_cache=use_cache)
		for cpv in matches:
			if cpv in self._aux_get_history:
				continue
			self._aux_get_wrapper(cpv, [])
		return matches

	def _aux_get_wrapper(self, pkg, wants):
		if pkg in self._aux_get_history:
			return self._aux_get(pkg, wants)
		self._aux_get_history.add(pkg)
		try:
			# Use the live ebuild metadata if possible.
			live_metadata = dict(izip(self._portdb_keys,
				self._portdb.aux_get(pkg, self._portdb_keys)))
			self.dbapi.aux_update(pkg, live_metadata)
		except (KeyError, portage.exception.PortageException):
			if self._global_updates is None:
				self._global_updates = \
					grab_global_updates(self._portdb.porttree_root)
			perform_global_updates(
				pkg, self.dbapi, self._global_updates)
		return self._aux_get(pkg, wants)

	def sync(self, acquire_lock=1):
		"""
		Call this method to synchronize state with the real vardb
		after one or more packages may have been installed or
		uninstalled.
		"""
		vdb_path = os.path.join(self.root, portage.VDB_PATH)
		try:
			# At least the parent needs to exist for the lock file.
			portage.util.ensure_dirs(vdb_path)
		except portage.exception.PortageException:
			pass
		vdb_lock = None
		try:
			if acquire_lock and os.access(vdb_path, os.W_OK):
				vdb_lock = portage.locks.lockdir(vdb_path)
			self._sync()
		finally:
			if vdb_lock:
				portage.locks.unlockdir(vdb_lock)

	def _sync(self):

		real_vardb = self._root_config.trees["vartree"].dbapi
		current_cpv_set = frozenset(real_vardb.cpv_all())
		pkg_vardb = self.dbapi
		aux_get_history = self._aux_get_history

		# Remove any packages that have been uninstalled.
		for pkg in list(pkg_vardb):
			if pkg.cpv not in current_cpv_set:
				pkg_vardb.cpv_remove(pkg)
				aux_get_history.discard(pkg.cpv)

		# Validate counters and timestamps.
		slot_counters = {}
		root = self.root
		validation_keys = ["COUNTER", "_mtime_"]
		for cpv in current_cpv_set:

			pkg_hash_key = ("installed", root, cpv, "nomerge")
			pkg = pkg_vardb.get(pkg_hash_key)
			if pkg is not None:
				counter, mtime = real_vardb.aux_get(cpv, validation_keys)

				if counter != pkg.metadata["COUNTER"] or \
					mtime != pkg.mtime:
					pkg_vardb.cpv_remove(pkg)
					aux_get_history.discard(pkg.cpv)
					pkg = None

			if pkg is None:
				pkg = self._pkg(cpv)

			other_counter = slot_counters.get(pkg.slot_atom)
			if other_counter is not None:
				if other_counter > pkg.counter:
					continue

			slot_counters[pkg.slot_atom] = pkg.counter
			pkg_vardb.cpv_inject(pkg)

		real_vardb.flush_cache()

	def _pkg(self, cpv):
		root_config = self._root_config
		real_vardb = root_config.trees["vartree"].dbapi
		db_keys = list(real_vardb._aux_cache_keys)
		pkg = Package(cpv=cpv, installed=True,
			metadata=izip(db_keys, real_vardb.aux_get(cpv, db_keys)),
			root_config=root_config,
			type_name="installed")
		return pkg

def grab_global_updates(portdir):
	from portage.update import grab_updates, parse_updates
	updpath = os.path.join(portdir, "profiles", "updates")
	try:
		rawupdates = grab_updates(updpath)
	except portage.exception.DirectoryNotFound:
		rawupdates = []
	upd_commands = []
	for mykey, mystat, mycontent in rawupdates:
		commands, errors = parse_updates(mycontent)
		upd_commands.extend(commands)
	return upd_commands

def perform_global_updates(mycpv, mydb, mycommands):
	from portage.update import update_dbentries
	aux_keys = ["DEPEND", "RDEPEND", "PDEPEND"]
	aux_dict = dict(izip(aux_keys, mydb.aux_get(mycpv, aux_keys)))
	updates = update_dbentries(mycommands, aux_dict)
	if updates:
		mydb.aux_update(mycpv, updates)

def visible(pkgsettings, pkg):
	"""
	Check if a package is visible. This can raise an InvalidDependString
	exception if LICENSE is invalid.
	TODO: optionally generate a list of masking reasons
	@rtype: Boolean
	@returns: True if the package is visible, False otherwise.
	"""
	if not pkg.metadata["SLOT"]:
		return False
	if pkg.built and not pkg.installed and "CHOST" in pkg.metadata:
		if not pkgsettings._accept_chost(pkg):
			return False
	if not portage.eapi_is_supported(pkg.metadata["EAPI"]):
		return False
	if not pkg.installed and \
		pkgsettings._getMissingKeywords(pkg.cpv, pkg.metadata):
		return False
	if pkgsettings._getMaskAtom(pkg.cpv, pkg.metadata):
		return False
	if pkgsettings._getProfileMaskAtom(pkg.cpv, pkg.metadata):
		return False
	try:
		if pkgsettings._getMissingLicenses(pkg.cpv, pkg.metadata):
			return False
	except portage.exception.InvalidDependString:
		return False
	return True

def get_masking_status(pkg, pkgsettings, root_config):

	mreasons = portage.getmaskingstatus(
		pkg, settings=pkgsettings,
		portdb=root_config.trees["porttree"].dbapi)

	if pkg.built and not pkg.installed and "CHOST" in pkg.metadata:
		if not pkgsettings._accept_chost(pkg):
			mreasons.append("CHOST: %s" % \
				pkg.metadata["CHOST"])

	if not pkg.metadata["SLOT"]:
		mreasons.append("invalid: SLOT is undefined")

	return mreasons

def get_mask_info(root_config, cpv, pkgsettings,
	db, pkg_type, built, installed, db_keys):
	eapi_masked = False
	try:
		metadata = dict(izip(db_keys,
			db.aux_get(cpv, db_keys)))
	except KeyError:
		metadata = None
	if metadata and not built:
		pkgsettings.setcpv(cpv, mydb=metadata)
		metadata["USE"] = pkgsettings["PORTAGE_USE"]
	if metadata is None:
		mreasons = ["corruption"]
	else:
		pkg = Package(type_name=pkg_type, root_config=root_config,
			cpv=cpv, built=built, installed=installed, metadata=metadata)
		mreasons = get_masking_status(pkg, pkgsettings, root_config)
	return metadata, mreasons

def show_masked_packages(masked_packages):
	shown_licenses = set()
	shown_comments = set()
	# Maybe there is both an ebuild and a binary. Only
	# show one of them to avoid redundant appearance.
	shown_cpvs = set()
	have_eapi_mask = False
	for (root_config, pkgsettings, cpv,
		metadata, mreasons) in masked_packages:
		if cpv in shown_cpvs:
			continue
		shown_cpvs.add(cpv)
		comment, filename = None, None
		if "package.mask" in mreasons:
			comment, filename = \
				portage.getmaskingreason(
				cpv, metadata=metadata,
				settings=pkgsettings,
				portdb=root_config.trees["porttree"].dbapi,
				return_location=True)
		missing_licenses = []
		if metadata:
			if not portage.eapi_is_supported(metadata["EAPI"]):
				have_eapi_mask = True
			try:
				missing_licenses = \
					pkgsettings._getMissingLicenses(
						cpv, metadata)
			except portage.exception.InvalidDependString:
				# This will have already been reported
				# above via mreasons.
				pass

		print "- "+cpv+" (masked by: "+", ".join(mreasons)+")"
		if comment and comment not in shown_comments:
			print filename+":"
			print comment
			shown_comments.add(comment)
		portdb = root_config.trees["porttree"].dbapi
		for l in missing_licenses:
			l_path = portdb.findLicensePath(l)
			if l in shown_licenses:
				continue
			msg = ("A copy of the '%s' license" + \
			" is located at '%s'.") % (l, l_path)
			print msg
			print
			shown_licenses.add(l)
	return have_eapi_mask

class Task(SlotObject):
	__slots__ = ("_hash_key", "_hash_value")

	def _get_hash_key(self):
		hash_key = getattr(self, "_hash_key", None)
		if hash_key is None:
			raise NotImplementedError(self)
		return hash_key

	def __eq__(self, other):
		return self._get_hash_key() == other

	def __ne__(self, other):
		return self._get_hash_key() != other

	def __hash__(self):
		hash_value = getattr(self, "_hash_value", None)
		if hash_value is None:
			self._hash_value = hash(self._get_hash_key())
		return self._hash_value

	def __len__(self):
		return len(self._get_hash_key())

	def __getitem__(self, key):
		return self._get_hash_key()[key]

	def __iter__(self):
		return iter(self._get_hash_key())

	def __contains__(self, key):
		return key in self._get_hash_key()

	def __str__(self):
		return str(self._get_hash_key())

class Blocker(Task):

	__hash__ = Task.__hash__
	__slots__ = ("root", "atom", "cp", "satisfied")

	def __init__(self, **kwargs):
		Task.__init__(self, **kwargs)
		self.cp = portage.dep_getkey(self.atom)

	def _get_hash_key(self):
		hash_key = getattr(self, "_hash_key", None)
		if hash_key is None:
			self._hash_key = \
				("blocks", self.root, self.atom)
		return self._hash_key

class Package(Task):

	__hash__ = Task.__hash__
	__slots__ = ("built", "cpv", "depth",
		"installed", "metadata", "onlydeps", "operation",
		"root_config", "type_name",
		"category", "counter", "cp", "cpv_split",
		"inherited", "iuse", "mtime",
		"pf", "pv_split", "root", "slot", "slot_atom", "use")

	metadata_keys = [
		"CHOST", "COUNTER", "DEPEND", "EAPI",
		"INHERITED", "IUSE", "KEYWORDS",
		"LICENSE", "PDEPEND", "PROVIDE", "RDEPEND",
		"repository", "RESTRICT", "SLOT", "USE", "_mtime_"]

	def __init__(self, **kwargs):
		Task.__init__(self, **kwargs)
		self.root = self.root_config.root
		self.metadata = _PackageMetadataWrapper(self, self.metadata)
		self.cp = portage.cpv_getkey(self.cpv)
		self.slot_atom = portage.dep.Atom("%s:%s" % (self.cp, self.slot))
		self.category, self.pf = portage.catsplit(self.cpv)
		self.cpv_split = portage.catpkgsplit(self.cpv)
		self.pv_split = self.cpv_split[1:]

	class _use(object):

		__slots__ = ("__weakref__", "enabled")

		def __init__(self, use):
			self.enabled = frozenset(use)

	class _iuse(object):

		__slots__ = ("__weakref__", "all", "enabled", "disabled", "iuse_implicit", "regex", "tokens")

		def __init__(self, tokens, iuse_implicit):
			self.tokens = tuple(tokens)
			self.iuse_implicit = iuse_implicit
			enabled = []
			disabled = []
			other = []
			for x in tokens:
				prefix = x[:1]
				if prefix == "+":
					enabled.append(x[1:])
				elif prefix == "-":
					disabled.append(x[1:])
				else:
					other.append(x)
			self.enabled = frozenset(enabled)
			self.disabled = frozenset(disabled)
			self.all = frozenset(chain(enabled, disabled, other))

		def __getattribute__(self, name):
			if name == "regex":
				try:
					return object.__getattribute__(self, "regex")
				except AttributeError:
					all = object.__getattribute__(self, "all")
					iuse_implicit = object.__getattribute__(self, "iuse_implicit")
					# Escape anything except ".*" which is supposed
					# to pass through from _get_implicit_iuse()
					regex = (re.escape(x) for x in chain(all, iuse_implicit))
					regex = "^(%s)$" % "|".join(regex)
					regex = regex.replace("\\.\\*", ".*")
					self.regex = re.compile(regex)
			return object.__getattribute__(self, name)

	def _get_hash_key(self):
		hash_key = getattr(self, "_hash_key", None)
		if hash_key is None:
			if self.operation is None:
				self.operation = "merge"
				if self.onlydeps or self.installed:
					self.operation = "nomerge"
			self._hash_key = \
				(self.type_name, self.root, self.cpv, self.operation)
		return self._hash_key

	def __cmp__(self, other):
		if self > other:
			return 1
		elif self < other:
			return -1
		return 0

	def __lt__(self, other):
		if other.cp != self.cp:
			return False
		if portage.pkgcmp(self.pv_split, other.pv_split) < 0:
			return True
		return False

	def __le__(self, other):
		if other.cp != self.cp:
			return False
		if portage.pkgcmp(self.pv_split, other.pv_split) <= 0:
			return True
		return False

	def __gt__(self, other):
		if other.cp != self.cp:
			return False
		if portage.pkgcmp(self.pv_split, other.pv_split) > 0:
			return True
		return False

	def __ge__(self, other):
		if other.cp != self.cp:
			return False
		if portage.pkgcmp(self.pv_split, other.pv_split) >= 0:
			return True
		return False

_all_metadata_keys = set(x for x in portage.auxdbkeys \
	if not x.startswith("UNUSED_"))
_all_metadata_keys.discard("CDEPEND")
_all_metadata_keys.update(Package.metadata_keys)

from portage.cache.mappings import slot_dict_class
_PackageMetadataWrapperBase = slot_dict_class(_all_metadata_keys)

class _PackageMetadataWrapper(_PackageMetadataWrapperBase):
	"""
	Detect metadata updates and synchronize Package attributes.
	"""

	__slots__ = ("_pkg",)
	_wrapped_keys = frozenset(
		["COUNTER", "INHERITED", "IUSE", "SLOT", "USE", "_mtime_"])

	def __init__(self, pkg, metadata):
		_PackageMetadataWrapperBase.__init__(self)
		self._pkg = pkg
		self.update(metadata)

	def __setitem__(self, k, v):
		_PackageMetadataWrapperBase.__setitem__(self, k, v)
		if k in self._wrapped_keys:
			getattr(self, "_set_" + k.lower())(k, v)

	def _set_inherited(self, k, v):
		if isinstance(v, basestring):
			v = frozenset(v.split())
		self._pkg.inherited = v

	def _set_iuse(self, k, v):
		self._pkg.iuse = self._pkg._iuse(
			v.split(), self._pkg.root_config.iuse_implicit)

	def _set_slot(self, k, v):
		self._pkg.slot = v

	def _set_use(self, k, v):
		self._pkg.use = self._pkg._use(v.split())

	def _set_counter(self, k, v):
		if isinstance(v, basestring):
			try:
				v = int(v.strip())
			except ValueError:
				v = 0
		self._pkg.counter = v

	def _set__mtime_(self, k, v):
		if isinstance(v, basestring):
			try:
				v = float(v.strip())
			except ValueError:
				v = 0
		self._pkg.mtime = v

class EbuildFetchPretend(SlotObject):

	__slots__ = ("fetch_all", "pkg", "settings")

	def execute(self):
		portdb = self.pkg.root_config.trees["porttree"].dbapi
		ebuild_path = portdb.findname(self.pkg.cpv)
		debug = self.settings.get("PORTAGE_DEBUG") == "1"

		retval = portage.doebuild(ebuild_path, "fetch",
			self.settings["ROOT"], self.settings, debug=debug,
			listonly=1, fetchonly=1, fetchall=self.fetch_all,
			mydbapi=portdb, tree="porttree")
		return retval

class AsynchronousTask(SlotObject):
	"""
	Subclasses override _wait() and _poll() so that calls
	to public methods can be wrapped for implementing
	hooks such as exit listener notification.

	Sublasses should call self.wait() to notify exit listeners after
	the task is complete and self.returncode has been set.
	"""

	__slots__ = ("background", "cancelled", "returncode") + \
		("_exit_listeners", "_exit_listener_stack", "_start_listeners")

	def start(self):
		"""
		Start an asynchronous task and then return as soon as possible.
		"""
		self._start()
		self._start_hook()

	def _start(self):
		raise NotImplementedError(self)

	def isAlive(self):
		return self.returncode is None

	def poll(self):
		self._wait_hook()
		return self._poll()

	def _poll(self):
		return self.returncode

	def wait(self):
		if self.returncode is None:
			self._wait()
		self._wait_hook()
		return self.returncode

	def _wait(self):
		return self.returncode

	def cancel(self):
		self.cancelled = True
		self.wait()

	def addStartListener(self, f):
		"""
		The function will be called with one argument, a reference to self.
		"""
		if self._start_listeners is None:
			self._start_listeners = []
		self._start_listeners.append(f)

	def removeStartListener(self, f):
		if self._start_listeners is None:
			return
		self._start_listeners.remove(f)

	def _start_hook(self):
		if self._start_listeners is not None:
			start_listeners = self._start_listeners
			self._start_listeners = None

			for f in start_listeners:
				f(self)

	def addExitListener(self, f):
		"""
		The function will be called with one argument, a reference to self.
		"""
		if self._exit_listeners is None:
			self._exit_listeners = []
		self._exit_listeners.append(f)

	def removeExitListener(self, f):
		if self._exit_listeners is None:
			if self._exit_listener_stack is not None:
				self._exit_listener_stack.remove(f)
			return
		self._exit_listeners.remove(f)

	def _wait_hook(self):
		"""
		Call this method after the task completes, just before returning
		the returncode from wait() or poll(). This hook is
		used to trigger exit listeners when the returncode first
		becomes available.
		"""
		if self.returncode is not None and \
			self._exit_listeners is not None:

			# This prevents recursion, in case one of the
			# exit handlers triggers this method again by
			# calling wait(). Use a stack that gives
			# removeExitListener() an opportunity to consume
			# listeners from the stack, before they can get
			# called below. This is necessary because a call
			# to one exit listener may result in a call to
			# removeExitListener() for another listener on
			# the stack. That listener needs to be removed
			# from the stack since it would be inconsistent
			# to call it after it has been been passed into
			# removeExitListener().
			self._exit_listener_stack = self._exit_listeners
			self._exit_listeners = None

			self._exit_listener_stack.reverse()
			while self._exit_listener_stack:
				self._exit_listener_stack.pop()(self)

class PipeReader(AsynchronousTask):

	"""
	Reads output from one or more files and saves it in memory,
	for retrieval via the getvalue() method. This is driven by
	the scheduler's poll() loop, so it runs entirely within the
	current process.
	"""

	__slots__ = ("input_files", "scheduler",) + \
		("pid", "_read_data", "_registered", "_reg_ids")

	_bufsize = 4096

	def _start(self):
		self._reg_ids = set()
		self._read_data = []
		for k, f in self.input_files.iteritems():
			fcntl.fcntl(f.fileno(), fcntl.F_SETFL,
				fcntl.fcntl(f.fileno(), fcntl.F_GETFL) | os.O_NONBLOCK)
			self._reg_ids.add(self.scheduler.register(f.fileno(),
				PollConstants.POLLIN, self._output_handler))
		self._registered = True

	def isAlive(self):
		return self._registered

	def _wait(self):
		if self.returncode is not None:
			return self.returncode

		if self._registered:
			self.scheduler.schedule(self._reg_ids)
			self._unregister()

		self.returncode = os.EX_OK
		return self.returncode

	def getvalue(self):
		"""Retrieve the entire contents"""
		return "".join(self._read_data)

	def close(self):
		"""Free the memory buffer."""
		self._read_data = None

	def _output_handler(self, fd, event):
		files = self.input_files
		for f in files.itervalues():
			if fd == f.fileno():
				break

		buf = array.array('B')
		try:
			buf.fromfile(f, self._bufsize)
		except EOFError:
			pass

		if buf:
			self._read_data.append(buf.tostring())
		else:
			self._unregister()
			self.wait()

		return self._registered

	def _unregister(self):
		"""
		Unregister from the scheduler and close open files.
		"""

		self._registered = False

		if self._reg_ids is not None:
			for reg_id in self._reg_ids:
				self.scheduler.unregister(reg_id)
			self._reg_ids = None

		if self.input_files is not None:
			for f in self.input_files.itervalues():
				f.close()
			self.input_files = None

class CompositeTask(AsynchronousTask):

	__slots__ = ("scheduler",) + ("_current_task",)

	def isAlive(self):
		return self._current_task is not None

	def cancel(self):
		self.cancelled = True
		if self._current_task is not None:
			self._current_task.cancel()

	def _poll(self):
		"""
		This does a loop calling self._current_task.poll()
		repeatedly as long as the value of self._current_task
		keeps changing. It calls poll() a maximum of one time
		for a given self._current_task instance. This is useful
		since calling poll() on a task can trigger advance to
		the next task could eventually lead to the returncode
		being set in cases when polling only a single task would
		not have the same effect.
		"""

		prev = None
		while True:
			task = self._current_task
			if task is None or task is prev:
				# don't poll the same task more than once
				break
			task.poll()
			prev = task

		return self.returncode

	def _wait(self):

		prev = None
		while True:
			task = self._current_task
			if task is None:
				# don't wait for the same task more than once
				break
			if task is prev:
				# Before the task.wait() method returned, an exit
				# listener should have set self._current_task to either
				# a different task or None. Something is wrong.
				raise AssertionError("self._current_task has not " + \
					"changed since calling wait", self, task)
			task.wait()
			prev = task

		return self.returncode

	def _assert_current(self, task):
		"""
		Raises an AssertionError if the given task is not the
		same one as self._current_task. This can be useful
		for detecting bugs.
		"""
		if task is not self._current_task:
			raise AssertionError("Unrecognized task: %s" % (task,))

	def _default_exit(self, task):
		"""
		Calls _assert_current() on the given task and then sets the
		composite returncode attribute if task.returncode != os.EX_OK.
		If the task failed then self._current_task will be set to None.
		Subclasses can use this as a generic task exit callback.

		@rtype: int
		@returns: The task.returncode attribute.
		"""
		self._assert_current(task)
		if task.returncode != os.EX_OK:
			self.returncode = task.returncode
			self._current_task = None
		return task.returncode

	def _final_exit(self, task):
		"""
		Assumes that task is the final task of this composite task.
		Calls _default_exit() and sets self.returncode to the task's
		returncode and sets self._current_task to None.
		"""
		self._default_exit(task)
		self._current_task = None
		self.returncode = task.returncode
		return self.returncode

	def _default_final_exit(self, task):
		"""
		This calls _final_exit() and then wait().

		Subclasses can use this as a generic final task exit callback.

		"""
		self._final_exit(task)
		return self.wait()

	def _start_task(self, task, exit_handler):
		"""
		Register exit handler for the given task, set it
		as self._current_task, and call task.start().

		Subclasses can use this as a generic way to start
		a task.

		"""
		task.addExitListener(exit_handler)
		self._current_task = task
		task.start()

class TaskSequence(CompositeTask):
	"""
	A collection of tasks that executes sequentially. Each task
	must have a addExitListener() method that can be used as
	a means to trigger movement from one task to the next.
	"""

	__slots__ = ("_task_queue",)

	def __init__(self, **kwargs):
		AsynchronousTask.__init__(self, **kwargs)
		self._task_queue = deque()

	def add(self, task):
		self._task_queue.append(task)

	def _start(self):
		self._start_next_task()

	def cancel(self):
		self._task_queue.clear()
		CompositeTask.cancel(self)

	def _start_next_task(self):
		self._start_task(self._task_queue.popleft(),
			self._task_exit_handler)

	def _task_exit_handler(self, task):
		if self._default_exit(task) != os.EX_OK:
			self.wait()
		elif self._task_queue:
			self._start_next_task()
		else:
			self._final_exit(task)
			self.wait()

class SubProcess(AsynchronousTask):

	__slots__ = ("scheduler",) + ("pid", "_files", "_registered", "_reg_id")

	# A file descriptor is required for the scheduler to monitor changes from
	# inside a poll() loop. When logging is not enabled, create a pipe just to
	# serve this purpose alone.
	_dummy_pipe_fd = 9

	def _poll(self):
		if self.returncode is not None:
			return self.returncode
		if self.pid is None:
			return self.returncode
		if self._registered:
			return self.returncode

		try:
			retval = os.waitpid(self.pid, os.WNOHANG)
		except OSError, e:
			if e.errno != errno.ECHILD:
				raise
			del e
			retval = (self.pid, 1)

		if retval == (0, 0):
			return None
		self._set_returncode(retval)
		return self.returncode

	def cancel(self):
		if self.isAlive():
			try:
				os.kill(self.pid, signal.SIGTERM)
			except OSError, e:
				if e.errno != errno.ESRCH:
					raise
				del e

		self.cancelled = True
		if self.pid is not None:
			self.wait()
		return self.returncode

	def isAlive(self):
		return self.pid is not None and \
			self.returncode is None

	def _wait(self):

		if self.returncode is not None:
			return self.returncode

		if self._registered:
			self.scheduler.schedule(self._reg_id)
			self._unregister()
			if self.returncode is not None:
				return self.returncode

		try:
			wait_retval = os.waitpid(self.pid, 0)
		except OSError, e:
			if e.errno != errno.ECHILD:
				raise
			del e
			self._set_returncode((self.pid, 1))
		else:
			self._set_returncode(wait_retval)

		return self.returncode

	def _unregister(self):
		"""
		Unregister from the scheduler and close open files.
		"""

		self._registered = False

		if self._reg_id is not None:
			self.scheduler.unregister(self._reg_id)
			self._reg_id = None

		if self._files is not None:
			for f in self._files.itervalues():
				f.close()
			self._files = None

	def _set_returncode(self, wait_retval):

		retval = wait_retval[1]

		if retval != os.EX_OK:
			if retval & 0xff:
				retval = (retval & 0xff) << 8
			else:
				retval = retval >> 8

		self.returncode = retval

class SpawnProcess(SubProcess):

	"""
	Constructor keyword args are passed into portage.process.spawn().
	The required "args" keyword argument will be passed as the first
	spawn() argument.
	"""

	_spawn_kwarg_names = ("env", "opt_name", "fd_pipes",
		"uid", "gid", "groups", "umask", "logfile",
		"path_lookup", "pre_exec")

	__slots__ = ("args",) + \
		_spawn_kwarg_names

	_file_names = ("log", "process", "stdout")
	_files_dict = slot_dict_class(_file_names, prefix="")
	_bufsize = 4096

	def _start(self):

		if self.cancelled:
			return

		if self.fd_pipes is None:
			self.fd_pipes = {}
		fd_pipes = self.fd_pipes
		fd_pipes.setdefault(0, sys.stdin.fileno())
		fd_pipes.setdefault(1, sys.stdout.fileno())
		fd_pipes.setdefault(2, sys.stderr.fileno())

		# flush any pending output
		for fd in fd_pipes.itervalues():
			if fd == sys.stdout.fileno():
				sys.stdout.flush()
			if fd == sys.stderr.fileno():
				sys.stderr.flush()

		logfile = self.logfile
		self._files = self._files_dict()
		files = self._files

		master_fd, slave_fd = self._pipe(fd_pipes)
		fcntl.fcntl(master_fd, fcntl.F_SETFL,
			fcntl.fcntl(master_fd, fcntl.F_GETFL) | os.O_NONBLOCK)

		null_input = None
		fd_pipes_orig = fd_pipes.copy()
		if self.background:
			# TODO: Use job control functions like tcsetpgrp() to control
			# access to stdin. Until then, use /dev/null so that any
			# attempts to read from stdin will immediately return EOF
			# instead of blocking indefinitely.
			null_input = open('/dev/null', 'rb')
			fd_pipes[0] = null_input.fileno()
		else:
			fd_pipes[0] = fd_pipes_orig[0]

		files.process = os.fdopen(master_fd, 'r')
		if logfile is not None:

			fd_pipes[1] = slave_fd
			fd_pipes[2] = slave_fd

			files.log = open(logfile, "a")
			portage.util.apply_secpass_permissions(logfile,
				uid=portage.portage_uid, gid=portage.portage_gid,
				mode=0660)

			if not self.background:
				files.stdout = os.fdopen(os.dup(fd_pipes_orig[1]), 'w')

			output_handler = self._output_handler

		else:

			# Create a dummy pipe so the scheduler can monitor
			# the process from inside a poll() loop.
			fd_pipes[self._dummy_pipe_fd] = slave_fd
			if self.background:
				fd_pipes[1] = slave_fd
				fd_pipes[2] = slave_fd
			output_handler = self._dummy_handler

		kwargs = {}
		for k in self._spawn_kwarg_names:
			v = getattr(self, k)
			if v is not None:
				kwargs[k] = v

		kwargs["fd_pipes"] = fd_pipes
		kwargs["returnpid"] = True
		kwargs.pop("logfile", None)

		retval = self._spawn(self.args, **kwargs)

		os.close(slave_fd)
		if null_input is not None:
			null_input.close()

		if isinstance(retval, int):
			# spawn failed
			os.close(master_fd)
			for f in self.files.values():
				f.close()
			self.returncode = retval
			self.wait()
			return

		self.pid = retval[0]
		portage.process.spawned_pids.remove(self.pid)

		self._reg_id = self.scheduler.register(files.process.fileno(),
			PollConstants.POLLIN, output_handler)
		self._registered = True

	def _pipe(self, fd_pipes):
		"""
		@type fd_pipes: dict
		@param fd_pipes: pipes from which to copy terminal size if desired.
		"""
		return os.pipe()

	def _spawn(self, args, **kwargs):
		return portage.process.spawn(args, **kwargs)

	def _output_handler(self, fd, event):
		files = self._files
		buf = array.array('B')
		try:
			buf.fromfile(files.process, self._bufsize)
		except EOFError:
			pass
		if buf:
			if not self.background:
				buf.tofile(files.stdout)
				files.stdout.flush()
			buf.tofile(files.log)
			files.log.flush()
		else:
			self._unregister()
			self.wait()
		return self._registered

	def _dummy_handler(self, fd, event):
		"""
		This method is mainly interested in detecting EOF, since
		the only purpose of the pipe is to allow the scheduler to
		monitor the process from inside a poll() loop.
		"""
		files = self._files
		buf = array.array('B')
		try:
			buf.fromfile(files.process, self._bufsize)
		except EOFError:
			pass
		if buf:
			pass
		else:
			self._unregister()
			self.wait()
		return self._registered

class MiscFunctionsProcess(SpawnProcess):
	"""
	Spawns misc-functions.sh with an existing ebuild environment.
	"""

	__slots__ = ("commands", "phase", "pkg", "settings")

	def _start(self):
		settings = self.settings
		portage_bin_path = settings["PORTAGE_BIN_PATH"]
		misc_sh_binary = os.path.join(portage_bin_path,
			os.path.basename(portage.const.MISC_SH_BINARY))

		self.args = [portage._shell_quote(misc_sh_binary)] + self.commands
		self.logfile = settings.get("PORTAGE_LOG_FILE")

		portage._doebuild_exit_status_unlink(
			settings.get("EBUILD_EXIT_STATUS_FILE"))

		SpawnProcess._start(self)

	def _spawn(self, args, **kwargs):
		settings = self.settings
		debug = settings.get("PORTAGE_DEBUG") == "1"
		return portage.spawn(" ".join(args), settings,
			debug=debug, **kwargs)

	def _set_returncode(self, wait_retval):
		SpawnProcess._set_returncode(self, wait_retval)
		self.returncode = portage._doebuild_exit_status_check_and_log(
			self.settings, self.phase, self.returncode)

class EbuildFetcher(SpawnProcess):

	__slots__ = ("fetchonly", "fetchall", "pkg",)

	def _start(self):

		root_config = self.pkg.root_config
		portdb = root_config.trees["porttree"].dbapi
		ebuild_path = portdb.findname(self.pkg.cpv)
		settings = root_config.settings
		phase = "fetch"
		if self.fetchall:
			phase = "fetchall"

		# If any incremental variables have been overridden
		# via the environment, those values need to be passed
		# along here so that they are correctly considered by
		# the config instance in the subproccess.
		fetch_env = os.environ.copy()

		fetch_env["PORTAGE_NICENESS"] = "0"
		if self.fetchonly:
			fetch_env["PORTAGE_PARALLEL_FETCHONLY"] = "1"

		ebuild_binary = os.path.join(
			settings["PORTAGE_BIN_PATH"], "ebuild")

		fetch_args = [ebuild_binary, ebuild_path, phase]
		debug = settings.get("PORTAGE_DEBUG") == "1"
		if debug:
			fetch_args.append("--debug")

		self.args = fetch_args
		self.env = fetch_env
		SpawnProcess._start(self)

class EbuildBuildDir(SlotObject):

	__slots__ = ("dir_path", "pkg", "settings",
		"locked", "_catdir", "_lock_obj")

	def __init__(self, **kwargs):
		SlotObject.__init__(self, **kwargs)
		self.locked = False

	def lock(self):
		"""
		This raises an AlreadyLocked exception if lock() is called
		while a lock is already held. In order to avoid this, call
		unlock() or check whether the "locked" attribute is True
		or False before calling lock().
		"""
		if self._lock_obj is not None:
			raise self.AlreadyLocked((self._lock_obj,))

		dir_path = self.dir_path
		if dir_path is None:
			root_config = self.pkg.root_config
			portdb = root_config.trees["porttree"].dbapi
			ebuild_path = portdb.findname(self.pkg.cpv)
			settings = self.settings
			debug = settings.get("PORTAGE_DEBUG") == "1"
			use_cache = 1 # always true
			portage.doebuild_environment(ebuild_path, "setup", root_config.root,
				self.settings, debug, use_cache, portdb)
			dir_path = self.settings["PORTAGE_BUILDDIR"]

		catdir = os.path.dirname(dir_path)
		self._catdir = catdir

		portage.util.ensure_dirs(os.path.dirname(catdir),
			uid=portage.portage_uid, gid=portage.portage_gid,
			mode=070, mask=0)
		catdir_lock = None
		try:
			catdir_lock = portage.locks.lockdir(catdir)
			portage.util.ensure_dirs(catdir,
				gid=portage.portage_gid,
				mode=070, mask=0)
			self._lock_obj = portage.locks.lockdir(dir_path)
		finally:
			self.locked = self._lock_obj is not None
			if catdir_lock is not None:
				portage.locks.unlockdir(catdir_lock)

	def unlock(self):
		if self._lock_obj is None:
			return

		portage.locks.unlockdir(self._lock_obj)
		self._lock_obj = None
		self.locked = False

		catdir = self._catdir
		catdir_lock = None
		try:
			catdir_lock = portage.locks.lockdir(catdir)
		finally:
			if catdir_lock:
				try:
					os.rmdir(catdir)
				except OSError, e:
					if e.errno not in (errno.ENOENT,
						errno.ENOTEMPTY, errno.EEXIST):
						raise
					del e
				portage.locks.unlockdir(catdir_lock)

	class AlreadyLocked(portage.exception.PortageException):
		pass

class EbuildBuild(CompositeTask):

	__slots__ = ("args_set", "background", "find_blockers",
		"ldpath_mtimes", "logger", "opts", "pkg", "pkg_count",
		"prefetcher", "settings", "world_atom") + \
		("_build_dir", "_buildpkg", "_ebuild_path", "_issyspkg", "_tree")

	def _start(self):

		logger = self.logger
		opts = self.opts
		pkg = self.pkg
		settings = self.settings
		world_atom = self.world_atom
		root_config = pkg.root_config
		tree = "porttree"
		self._tree = tree
		portdb = root_config.trees[tree].dbapi
		settings["EMERGE_FROM"] = pkg.type_name
		settings.backup_changes("EMERGE_FROM")
		settings.reset()
		ebuild_path = portdb.findname(self.pkg.cpv)
		self._ebuild_path = ebuild_path

		prefetcher = self.prefetcher
		if prefetcher is None:
			pass
		elif not prefetcher.isAlive():
			prefetcher.cancel()
		elif prefetcher.poll() is None:

			waiting_msg = "Fetching files " + \
				"in the background. " + \
				"To view fetch progress, run `tail -f " + \
				"/var/log/emerge-fetch.log` in another " + \
				"terminal."
			msg_prefix = colorize("GOOD", " * ")
			from textwrap import wrap
			waiting_msg = "".join("%s%s\n" % (msg_prefix, line) \
				for line in wrap(waiting_msg, 65))
			if not self.background:
				writemsg(waiting_msg, noiselevel=-1)

			self._current_task = prefetcher
			prefetcher.addExitListener(self._prefetch_exit)
			return

		self._prefetch_exit(prefetcher)

	def _prefetch_exit(self, prefetcher):

		opts = self.opts
		pkg = self.pkg
		settings = self.settings

		if opts.fetchonly and opts.pretend:
				fetcher = EbuildFetchPretend(
					fetch_all=opts.fetch_all_uri,
					pkg=pkg, settings=settings)
				retval = fetcher.execute()
				self.returncode = retval
				self.wait()
				return

		fetch_log = None
		if self.background:
			fetch_log = self.scheduler.fetch.log_file

		fetcher = EbuildFetcher(fetchall=opts.fetch_all_uri,
			fetchonly=opts.fetchonly,
			background=self.background, logfile=fetch_log,
			pkg=pkg, scheduler=self.scheduler)

		if self.background:
			fetcher.addExitListener(self._fetch_exit)
			self._current_task = fetcher
			self.scheduler.fetch.schedule(fetcher)
		else:
			self._start_task(fetcher, self._fetch_exit)

	def _fetch_exit(self, fetcher):

		opts = self.opts
		pkg = self.pkg

		if opts.fetchonly:
			if self._final_exit(fetcher) != os.EX_OK:
				if not self.background:
					eerror("Fetch for %s failed, continuing..." % pkg.cpv,
						phase="unpack", key=pkg.cpv)
			self.wait()
			return

		if self._default_exit(fetcher) != os.EX_OK:
			self.wait()
			return

		logger = self.logger
		opts = self.opts
		pkg_count = self.pkg_count
		scheduler = self.scheduler
		settings = self.settings
		features = settings.features
		ebuild_path = self._ebuild_path
		system_set = pkg.root_config.sets["system"]

		self._build_dir = EbuildBuildDir(pkg=pkg, settings=settings)
		self._build_dir.lock()

		# Cleaning is triggered before the setup
		# phase, in portage.doebuild().
		msg = " === (%s of %s) Cleaning (%s::%s)" % \
			(pkg_count.curval, pkg_count.maxval, pkg.cpv, ebuild_path)
		short_msg = "emerge: (%s of %s) %s Clean" % \
			(pkg_count.curval, pkg_count.maxval, pkg.cpv)
		logger.log(msg, short_msg=short_msg)

		#buildsyspkg: Check if we need to _force_ binary package creation
		self._issyspkg = "buildsyspkg" in features and \
				system_set.findAtomForPackage(pkg) and \
				not opts.buildpkg

		if opts.buildpkg or self._issyspkg:

			self._buildpkg = True

			msg = " === (%s of %s) Compiling/Packaging (%s::%s)" % \
				(pkg_count.curval, pkg_count.maxval, pkg.cpv, ebuild_path)
			short_msg = "emerge: (%s of %s) %s Compile" % \
				(pkg_count.curval, pkg_count.maxval, pkg.cpv)
			logger.log(msg, short_msg=short_msg)

		else:
			msg = " === (%s of %s) Compiling/Merging (%s::%s)" % \
				(pkg_count.curval, pkg_count.maxval, pkg.cpv, ebuild_path)
			short_msg = "emerge: (%s of %s) %s Compile" % \
				(pkg_count.curval, pkg_count.maxval, pkg.cpv)
			logger.log(msg, short_msg=short_msg)

		build = EbuildExecuter(background=self.background, pkg=pkg,
			scheduler=scheduler, settings=settings)
		self._start_task(build, self._build_exit)

	def _unlock_builddir(self):
		portage.elog.elog_process(self.pkg.cpv, self.settings)
		self._build_dir.unlock()

	def _build_exit(self, build):
		if self._default_exit(build) != os.EX_OK:
			self._unlock_builddir()
			self.wait()
			return

		opts = self.opts
		buildpkg = self._buildpkg

		if not buildpkg:
			self._final_exit(build)
			self.wait()
			return

		if self._issyspkg:
			msg = ">>> This is a system package, " + \
				"let's pack a rescue tarball.\n"

			log_path = self.settings.get("PORTAGE_LOG_FILE")
			if log_path is not None:
				log_file = open(log_path, 'a')
				try:
					log_file.write(msg)
				finally:
					log_file.close()

			if not self.background:
				portage.writemsg_stdout(msg, noiselevel=-1)

		packager = EbuildBinpkg(background=self.background, pkg=self.pkg,
			scheduler=self.scheduler, settings=self.settings)

		self._start_task(packager, self._buildpkg_exit)

	def _buildpkg_exit(self, packager):
		"""
		Released build dir lock when there is a failure or
		when in buildpkgonly mode. Otherwise, the lock will
		be released when merge() is called.
		"""

		if self._default_exit(packager) == os.EX_OK and \
			self.opts.buildpkgonly:
			# Need to call "clean" phase for buildpkgonly mode
			phase = "clean"
			clean_phase = EbuildPhase(background=self.background,
				pkg=self.pkg, phase=phase,
				scheduler=self.scheduler, settings=self.settings,
				tree=self._tree)
			self._start_task(clean_phase, self._clean_exit)
			return

		if self._final_exit(packager) != os.EX_OK or \
			self.opts.buildpkgonly:
			self._unlock_builddir()
		self.wait()

	def _clean_exit(self, clean_phase):
		if self._final_exit(clean_phase) != os.EX_OK or \
			self.opts.buildpkgonly:
			self._unlock_builddir()
		self.wait()

	def install(self):
		"""
		Install the package and then clean up and release locks.
		Only call this after the build has completed successfully
		and neither fetchonly nor buildpkgonly mode are enabled.
		"""

		find_blockers = self.find_blockers
		ldpath_mtimes = self.ldpath_mtimes
		logger = self.logger
		pkg = self.pkg
		pkg_count = self.pkg_count
		settings = self.settings
		world_atom = self.world_atom
		ebuild_path = self._ebuild_path
		tree = self._tree

		merge = EbuildMerge(find_blockers=self.find_blockers,
			ldpath_mtimes=ldpath_mtimes, logger=logger, pkg=pkg,
			pkg_count=pkg_count, pkg_path=ebuild_path,
			scheduler=self.scheduler,
			settings=settings, tree=tree, world_atom=world_atom)

		msg = " === (%s of %s) Merging (%s::%s)" % \
			(pkg_count.curval, pkg_count.maxval,
			pkg.cpv, ebuild_path)
		short_msg = "emerge: (%s of %s) %s Merge" % \
			(pkg_count.curval, pkg_count.maxval, pkg.cpv)
		logger.log(msg, short_msg=short_msg)

		try:
			rval = merge.execute()
		finally:
			self._unlock_builddir()

		return rval

class EbuildExecuter(CompositeTask):

	__slots__ = ("pkg", "scheduler", "settings") + ("_tree",)

	_phases = ("configure", "compile", "test", "install")

	_live_eclasses = frozenset([
		"cvs",
		"darcs",
		"git",
		"mercurial",
		"subversion"
	])

	def _start(self):
		self._tree = "porttree"
		pkg = self.pkg
		phase = "clean"
		clean_phase = EbuildPhase(background=self.background, pkg=pkg, phase=phase,
			scheduler=self.scheduler, settings=self.settings, tree=self._tree)
		self._start_task(clean_phase, self._clean_phase_exit)

	def _clean_phase_exit(self, clean_phase):

		if self._default_exit(clean_phase) != os.EX_OK:
			self.wait()
			return

		pkg = self.pkg
		scheduler = self.scheduler
		settings = self.settings
		cleanup = 1

		# This initializes PORTAGE_LOG_FILE.
		portage.prepare_build_dirs(pkg.root, settings, cleanup)

		setup_phase = EbuildPhase(background=self.background,
			pkg=pkg, phase="setup", scheduler=scheduler,
			settings=settings, tree=self._tree)

		setup_phase.addExitListener(self._setup_exit)
		self._current_task = setup_phase
		self.scheduler.scheduleSetup(setup_phase)

	def _setup_exit(self, setup_phase):

		if self._default_exit(setup_phase) != os.EX_OK:
			self.wait()
			return

		unpack_phase = EbuildPhase(background=self.background,
			pkg=self.pkg, phase="unpack", scheduler=self.scheduler,
			settings=self.settings, tree=self._tree)

		if self._live_eclasses.intersection(self.pkg.inherited):
			# Serialize $DISTDIR access for live ebuilds since
			# otherwise they can interfere with eachother.

			unpack_phase.addExitListener(self._unpack_exit)
			self._current_task = unpack_phase
			self.scheduler.scheduleUnpack(unpack_phase)

		else:
			self._start_task(unpack_phase, self._unpack_exit)

	def _unpack_exit(self, unpack_phase):