[Zodb-checkins] SVN: ZODB/trunk/src/persistent/wref.py Reverted the indentation and kept the docformat (merge from the 3.8 branch)
Christophe Combelles
ccomb at free.fr
Mon Oct 13 08:54:16 EDT 2008
Log message for revision 92114:
Reverted the indentation and kept the docformat (merge from the 3.8 branch)
Changed:
U ZODB/trunk/src/persistent/wref.py
-=-
Modified: ZODB/trunk/src/persistent/wref.py
===================================================================
--- ZODB/trunk/src/persistent/wref.py 2008-10-13 12:50:56 UTC (rev 92113)
+++ ZODB/trunk/src/persistent/wref.py 2008-10-13 12:54:15 UTC (rev 92114)
@@ -32,72 +32,72 @@
Here's an example. We'll start by creating a persistent object and
a reference to it:
- >>> import persistent.list
- >>> import ZODB.tests.util
- >>> ob = persistent.list.PersistentList()
- >>> ref = WeakRef(ob)
- >>> ref() is ob
- True
+ >>> import persistent.list
+ >>> import ZODB.tests.util
+ >>> ob = persistent.list.PersistentList()
+ >>> ref = WeakRef(ob)
+ >>> ref() is ob
+ True
The hash of the ref if the same as the hash of the referenced object:
- >>> hash(ref) == hash(ob)
- True
+ >>> hash(ref) == hash(ob)
+ True
Two refs to the same object are equal:
- >>> WeakRef(ob) == ref
- True
+ >>> WeakRef(ob) == ref
+ True
- >>> ob2 = persistent.list.PersistentList([1])
- >>> WeakRef(ob2) == ref
- False
+ >>> ob2 = persistent.list.PersistentList([1])
+ >>> WeakRef(ob2) == ref
+ False
Lets save the reference and the referenced object in a database:
- >>> db = ZODB.tests.util.DB()
+ >>> db = ZODB.tests.util.DB()
- >>> conn1 = db.open()
- >>> conn1.root()['ob'] = ob
- >>> conn1.root()['ref'] = ref
- >>> ZODB.tests.util.commit()
+ >>> conn1 = db.open()
+ >>> conn1.root()['ob'] = ob
+ >>> conn1.root()['ref'] = ref
+ >>> ZODB.tests.util.commit()
If we open a new connection, we can use the reference:
- >>> conn2 = db.open()
- >>> conn2.root()['ref']() is conn2.root()['ob']
- True
- >>> hash(conn2.root()['ref']) == hash(conn2.root()['ob'])
- True
+ >>> conn2 = db.open()
+ >>> conn2.root()['ref']() is conn2.root()['ob']
+ True
+ >>> hash(conn2.root()['ref']) == hash(conn2.root()['ob'])
+ True
But if we delete the referenced object and pack:
- >>> del conn2.root()['ob']
- >>> ZODB.tests.util.commit()
- >>> ZODB.tests.util.pack(db)
+ >>> del conn2.root()['ob']
+ >>> ZODB.tests.util.commit()
+ >>> ZODB.tests.util.pack(db)
And then look in a new connection:
- >>> conn3 = db.open()
- >>> conn3.root()['ob']
- Traceback (most recent call last):
- ...
- KeyError: 'ob'
+ >>> conn3 = db.open()
+ >>> conn3.root()['ob']
+ Traceback (most recent call last):
+ ...
+ KeyError: 'ob'
Trying to dereference the reference returns None:
- >>> conn3.root()['ref']()
+ >>> conn3.root()['ref']()
Trying to get a hash, raises a type error:
- >>> hash(conn3.root()['ref'])
- Traceback (most recent call last):
- ...
- TypeError: Weakly-referenced object has gone away
+ >>> hash(conn3.root()['ref'])
+ Traceback (most recent call last):
+ ...
+ TypeError: Weakly-referenced object has gone away
- Always explicitly close databases :) :
+ Always explicitly close databases: :)
- >>> db.close()
+ >>> db.close()
"""
@@ -144,96 +144,96 @@
of items is extremely lazy. See below.
We'll start by creating a PersistentWeakKeyDictionary and adding
- some persistent objects to it:
+ some persistent objects to it.
- >>> d = PersistentWeakKeyDictionary()
- >>> import ZODB.tests.util
- >>> p1 = ZODB.tests.util.P('p1')
- >>> p2 = ZODB.tests.util.P('p2')
- >>> p3 = ZODB.tests.util.P('p3')
- >>> d[p1] = 1
- >>> d[p2] = 2
- >>> d[p3] = 3
+ >>> d = PersistentWeakKeyDictionary()
+ >>> import ZODB.tests.util
+ >>> p1 = ZODB.tests.util.P('p1')
+ >>> p2 = ZODB.tests.util.P('p2')
+ >>> p3 = ZODB.tests.util.P('p3')
+ >>> d[p1] = 1
+ >>> d[p2] = 2
+ >>> d[p3] = 3
We'll create an extra persistent object that's not in the dict:
- >>> p4 = ZODB.tests.util.P('p4')
+ >>> p4 = ZODB.tests.util.P('p4')
Now we'll excercise iteration and item access:
- >>> l = [(str(k), d[k], d.get(k)) for k in d]
- >>> l.sort()
- >>> l
- [('P(p1)', 1, 1), ('P(p2)', 2, 2), ('P(p3)', 3, 3)]
+ >>> l = [(str(k), d[k], d.get(k)) for k in d]
+ >>> l.sort()
+ >>> l
+ [('P(p1)', 1, 1), ('P(p2)', 2, 2), ('P(p3)', 3, 3)]
And the containment operator:
- >>> [p in d for p in [p1, p2, p3, p4]]
- [True, True, True, False]
+ >>> [p in d for p in [p1, p2, p3, p4]]
+ [True, True, True, False]
We can add the dict and the referenced objects to a database:
- >>> db = ZODB.tests.util.DB()
+ >>> db = ZODB.tests.util.DB()
- >>> conn1 = db.open()
- >>> conn1.root()['p1'] = p1
- >>> conn1.root()['d'] = d
- >>> conn1.root()['p2'] = p2
- >>> conn1.root()['p3'] = p3
- >>> ZODB.tests.util.commit()
+ >>> conn1 = db.open()
+ >>> conn1.root()['p1'] = p1
+ >>> conn1.root()['d'] = d
+ >>> conn1.root()['p2'] = p2
+ >>> conn1.root()['p3'] = p3
+ >>> ZODB.tests.util.commit()
And things still work, as before:
- >>> l = [(str(k), d[k], d.get(k)) for k in d]
- >>> l.sort()
- >>> l
- [('P(p1)', 1, 1), ('P(p2)', 2, 2), ('P(p3)', 3, 3)]
- >>> [p in d for p in [p1, p2, p3, p4]]
- [True, True, True, False]
+ >>> l = [(str(k), d[k], d.get(k)) for k in d]
+ >>> l.sort()
+ >>> l
+ [('P(p1)', 1, 1), ('P(p2)', 2, 2), ('P(p3)', 3, 3)]
+ >>> [p in d for p in [p1, p2, p3, p4]]
+ [True, True, True, False]
Likewise, we can read the objects from another connection and
- things still work:
+ things still work.
- >>> conn2 = db.open()
- >>> d = conn2.root()['d']
- >>> p1 = conn2.root()['p1']
- >>> p2 = conn2.root()['p2']
- >>> p3 = conn2.root()['p3']
- >>> l = [(str(k), d[k], d.get(k)) for k in d]
- >>> l.sort()
- >>> l
- [('P(p1)', 1, 1), ('P(p2)', 2, 2), ('P(p3)', 3, 3)]
- >>> [p in d for p in [p1, p2, p3, p4]]
- [True, True, True, False]
+ >>> conn2 = db.open()
+ >>> d = conn2.root()['d']
+ >>> p1 = conn2.root()['p1']
+ >>> p2 = conn2.root()['p2']
+ >>> p3 = conn2.root()['p3']
+ >>> l = [(str(k), d[k], d.get(k)) for k in d]
+ >>> l.sort()
+ >>> l
+ [('P(p1)', 1, 1), ('P(p2)', 2, 2), ('P(p3)', 3, 3)]
+ >>> [p in d for p in [p1, p2, p3, p4]]
+ [True, True, True, False]
Now, we'll delete one of the objects from the database, but *not*
from the dictionary:
- >>> del conn2.root()['p2']
- >>> ZODB.tests.util.commit()
+ >>> del conn2.root()['p2']
+ >>> ZODB.tests.util.commit()
And pack the database, so that the no-longer referenced p2 is
- actually removed from the database:
+ actually removed from the database.
- >>> ZODB.tests.util.pack(db)
+ >>> ZODB.tests.util.pack(db)
Now if we access the dictionary in a new connection, it no longer
has p2:
- >>> conn3 = db.open()
- >>> d = conn3.root()['d']
- >>> l = [(str(k), d[k], d.get(k)) for k in d]
- >>> l.sort()
- >>> l
- [('P(p1)', 1, 1), ('P(p3)', 3, 3)]
+ >>> conn3 = db.open()
+ >>> d = conn3.root()['d']
+ >>> l = [(str(k), d[k], d.get(k)) for k in d]
+ >>> l.sort()
+ >>> l
+ [('P(p1)', 1, 1), ('P(p3)', 3, 3)]
It's worth nothing that that the versions of the dictionary in
conn1 and conn2 still have p2, because p2 is still in the caches
for those connections.
- Always explicitly close databases :) :
+ Always explicitly close databases: :)
- >>> db.close()
+ >>> db.close()
"""
# TODO: It's expensive trying to load dead objects from the database.
@@ -271,17 +271,17 @@
del self.data[WeakRef(key)]
def get(self, key, default=None):
- """D.get(k[, d]) -> D[k] if k in D, else d. :
+ """D.get(k[, d]) -> D[k] if k in D, else d.
- >>> import ZODB.tests.util
- >>> key = ZODB.tests.util.P("key")
- >>> missing = ZODB.tests.util.P("missing")
- >>> d = PersistentWeakKeyDictionary([(key, 1)])
- >>> d.get(key)
- 1
- >>> d.get(missing)
- >>> d.get(missing, 12)
- 12
+ >>> import ZODB.tests.util
+ >>> key = ZODB.tests.util.P("key")
+ >>> missing = ZODB.tests.util.P("missing")
+ >>> d = PersistentWeakKeyDictionary([(key, 1)])
+ >>> d.get(key)
+ 1
+ >>> d.get(missing)
+ >>> d.get(missing, 12)
+ 12
"""
return self.data.get(WeakRef(key), default)
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