summaryrefslogtreecommitdiffstats
path: root/pym/portage/util/_dyn_libs/PreservedLibsRegistry.py
blob: f05028fa9e866927dad5ec682d2dc37bda534ad3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
# Copyright 1998-2010 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2

import errno
import logging

try:
	import cPickle as pickle
except ImportError:
	import pickle

from portage import os
from portage import _encodings
from portage import _os_merge
from portage import _unicode_encode
from portage.exception import PermissionDenied
from portage.localization import _
from portage.util import atomic_ofstream
from portage.util import writemsg_level
from portage.versions import cpv_getkey

class PreservedLibsRegistry(object):
	""" This class handles the tracking of preserved library objects """
	def __init__(self, eroot, filename, autocommit=True):
		""" 
			@param eroot: root used to check existence of paths in pruneNonExisting
		    @type eroot: String
			@param filename: absolute path for saving the preserved libs records
		    @type filename: String
			@param autocommit: determines if the file is written after every update
			@type autocommit: Boolean
		"""
		self._eroot = eroot
		self._filename = filename
		self._autocommit = autocommit
		self.load()
		self.pruneNonExisting()

	def load(self):
		""" Reload the registry data from file """
		self._data = None
		try:
			self._data = pickle.load(
				open(_unicode_encode(self._filename,
					encoding=_encodings['fs'], errors='strict'), 'rb'))
		except (ValueError, pickle.UnpicklingError) as e:
			writemsg_level(_("!!! Error loading '%s': %s\n") % \
				(self._filename, e), level=logging.ERROR, noiselevel=-1)
		except (EOFError, IOError) as e:
			if isinstance(e, EOFError) or e.errno == errno.ENOENT:
				pass
			elif e.errno == PermissionDenied.errno:
				raise PermissionDenied(self._filename)
			else:
				raise
		if self._data is None:
			self._data = {}
		self._data_orig = self._data.copy()
	def store(self):
		""" Store the registry data to file. No need to call this if autocommit
		    was enabled.
		"""
		if os.environ.get("SANDBOX_ON") == "1" or \
			self._data == self._data_orig:
			return
		try:
			f = atomic_ofstream(self._filename, 'wb')
			pickle.dump(self._data, f, protocol=2)
			f.close()
		except EnvironmentError as e:
			if e.errno != PermissionDenied.errno:
				writemsg_level("!!! %s %s\n" % (e, self._filename),
					level=logging.ERROR, noiselevel=-1)
		else:
			self._data_orig = self._data.copy()

	def register(self, cpv, slot, counter, paths):
		""" Register new objects in the registry. If there is a record with the
			same packagename (internally derived from cpv) and slot it is 
			overwritten with the new data.
			@param cpv: package instance that owns the objects
			@type cpv: CPV (as String)
			@param slot: the value of SLOT of the given package instance
			@type slot: String
			@param counter: vdb counter value for the package instace
			@type counter: Integer
			@param paths: absolute paths of objects that got preserved during an update
			@type paths: List
		"""
		cp = cpv_getkey(cpv)
		cps = cp+":"+slot
		if len(paths) == 0 and cps in self._data \
				and self._data[cps][0] == cpv and int(self._data[cps][1]) == int(counter):
			del self._data[cps]
		elif len(paths) > 0:
			self._data[cps] = (cpv, counter, paths)
		if self._autocommit:
			self.store()
	
	def unregister(self, cpv, slot, counter):
		""" Remove a previous registration of preserved objects for the given package.
			@param cpv: package instance whose records should be removed
			@type cpv: CPV (as String)
			@param slot: the value of SLOT of the given package instance
			@type slot: String
		"""
		self.register(cpv, slot, counter, [])
	
	def pruneNonExisting(self):
		""" Remove all records for objects that no longer exist on the filesystem. """

		os = _os_merge

		for cps in list(self._data):
			cpv, counter, paths = self._data[cps]
			paths = [f for f in paths \
				if os.path.exists(os.path.join(self._eroot, f.lstrip(os.sep)))]
			if len(paths) > 0:
				self._data[cps] = (cpv, counter, paths)
			else:
				del self._data[cps]
		if self._autocommit:
			self.store()
	
	def hasEntries(self):
		""" Check if this registry contains any records. """
		return len(self._data) > 0
	
	def getPreservedLibs(self):
		""" Return a mapping of packages->preserved objects.
			@returns mapping of package instances to preserved objects
			@rtype Dict cpv->list-of-paths
		"""
		rValue = {}
		for cps in self._data:
			rValue[self._data[cps][0]] = self._data[cps][2]
		return rValue