/usr/lib/python2.7/dist-packages/persistent/picklecache.py is in python-persistent 4.0.8-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 | ##############################################################################
#
# Copyright (c) 2009 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
import gc
import weakref
from zope.interface import implementer
from persistent.interfaces import CHANGED
from persistent.interfaces import GHOST
from persistent.interfaces import IPickleCache
from persistent.interfaces import STICKY
from persistent.interfaces import OID_TYPE
class RingNode(object):
# 32 byte fixed size wrapper.
__slots__ = ('object', 'next', 'prev')
def __init__(self, object, next=None, prev=None):
self.object = object
self.next = next
self.prev = prev
@implementer(IPickleCache)
class PickleCache(object):
def __init__(self, jar, target_size=0, cache_size_bytes=0):
# TODO: forward-port Dieter's bytes stuff
self.jar = jar
self.target_size = target_size
self.drain_resistance = 0
self.non_ghost_count = 0
self.persistent_classes = {}
self.data = weakref.WeakValueDictionary()
self.ring = RingNode(None)
self.ring.next = self.ring.prev = self.ring
# IPickleCache API
def __len__(self):
""" See IPickleCache.
"""
return (len(self.persistent_classes) +
len(self.data))
def __getitem__(self, oid):
""" See IPickleCache.
"""
value = self.data.get(oid)
if value is not None:
return value
return self.persistent_classes[oid]
def __setitem__(self, oid, value):
""" See IPickleCache.
"""
if not isinstance(oid, OID_TYPE): # XXX bytes
raise ValueError('OID must be %s: %s' % (OID_TYPE, oid))
# XXX
if oid in self.persistent_classes or oid in self.data:
if self.data[oid] is not value:
raise KeyError('Duplicate OID: %s' % oid)
if type(value) is type:
self.persistent_classes[oid] = value
else:
self.data[oid] = value
if value._p_state != GHOST:
self.non_ghost_count += 1
mru = self.ring.prev
self.ring.prev = node = RingNode(value, self.ring, mru)
mru.next = node
def __delitem__(self, oid):
""" See IPickleCache.
"""
if not isinstance(oid, OID_TYPE):
raise ValueError('OID must be %s: %s' % (OID_TYPE, oid))
if oid in self.persistent_classes:
del self.persistent_classes[oid]
else:
value = self.data.pop(oid)
node = self.ring.next
while node is not self.ring:
if node.object is value:
node.prev.next, node.next.prev = node.next, node.prev
self.non_ghost_count -= 1
break
node = node.next
def get(self, oid, default=None):
""" See IPickleCache.
"""
value = self.data.get(oid, self)
if value is not self:
return value
return self.persistent_classes.get(oid, default)
def mru(self, oid):
""" See IPickleCache.
"""
node = self.ring.next
while node is not self.ring and node.object._p_oid != oid:
node = node.next
if node is self.ring:
value = self.data[oid]
if value._p_state != GHOST:
self.non_ghost_count += 1
mru = self.ring.prev
self.ring.prev = node = RingNode(value, self.ring, mru)
mru.next = node
else:
# remove from old location
node.prev.next, node.next.prev = node.next, node.prev
# splice into new
self.ring.prev.next, node.prev = node, self.ring.prev
self.ring.prev, node.next = node, self.ring
def ringlen(self):
""" See IPickleCache.
"""
result = 0
node = self.ring.next
while node is not self.ring:
result += 1
node = node.next
return result
def items(self):
""" See IPickleCache.
"""
return self.data.items()
def lru_items(self):
""" See IPickleCache.
"""
result = []
node = self.ring.next
while node is not self.ring:
result.append((node.object._p_oid, node.object))
node = node.next
return result
def klass_items(self):
""" See IPickleCache.
"""
return self.persistent_classes.items()
def incrgc(self, ignored=None):
""" See IPickleCache.
"""
target = self.target_size
if self.drain_resistance >= 1:
size = self.non_ghost_count
target2 = size - 1 - (size / self.drain_resistance)
if target2 < target:
target = target2
self._sweep(target)
def full_sweep(self, target=None):
""" See IPickleCache.
"""
self._sweep(0)
minimize = full_sweep
def new_ghost(self, oid, obj):
""" See IPickleCache.
"""
if obj._p_oid is not None:
raise ValueError('Object already has oid')
if obj._p_jar is not None:
raise ValueError('Object already has jar')
if oid in self.persistent_classes or oid in self.data:
raise KeyError('Duplicate OID: %s' % oid)
obj._p_oid = oid
obj._p_jar = self.jar
if type(obj) is not type:
if obj._p_state != GHOST:
obj._p_invalidate()
self[oid] = obj
def reify(self, to_reify):
""" See IPickleCache.
"""
if isinstance(to_reify, OID_TYPE): #bytes
to_reify = [to_reify]
for oid in to_reify:
value = self[oid]
if value._p_state == GHOST:
value._p_activate()
self.non_ghost_count += 1
mru = self.ring.prev
self.ring.prev = node = RingNode(value, self.ring, mru)
mru.next = node
def invalidate(self, to_invalidate):
""" See IPickleCache.
"""
if isinstance(to_invalidate, OID_TYPE):
self._invalidate(to_invalidate)
else:
for oid in to_invalidate:
self._invalidate(oid)
def debug_info(self):
result = []
for oid, klass in self.persistent_classes.items():
result.append((oid,
len(gc.get_referents(klass)),
type(klass).__name__,
klass._p_state,
))
for oid, value in self.data.items():
result.append((oid,
len(gc.get_referents(value)),
type(value).__name__,
value._p_state,
))
return result
def update_object_size_estimation(self, oid, new_size):
""" See IPickleCache.
"""
pass #pragma NO COVER
cache_size = property(lambda self: self.target_size)
cache_drain_resistance = property(lambda self: self.drain_resistance)
cache_non_ghost_count = property(lambda self: self.non_ghost_count)
cache_data = property(lambda self: dict(self.data.items()))
cache_klass_count = property(lambda self: len(self.persistent_classes))
# Helpers
def _sweep(self, target):
# lock
node = self.ring.next
while node is not self.ring and self.non_ghost_count > target:
if node.object._p_state not in (STICKY, CHANGED):
node.prev.next, node.next.prev = node.next, node.prev
node.object = None
self.non_ghost_count -= 1
node = node.next
def _invalidate(self, oid):
value = self.data.get(oid)
if value is not None and value._p_state != GHOST:
value._p_invalidate()
node = self.ring.next
while node is not self.ring:
if node.object is value:
node.prev.next, node.next.prev = node.next, node.prev
break
node = node.next
elif oid in self.persistent_classes:
del self.persistent_classes[oid]
|