Commit 7f1f6deb authored by Tim Peters's avatar Tim Peters

Collector 1822.

Make undo{Log,Info} arguments act like Python slice indices when
both are non-negative.  The code used to do that before ZODB 3.4a9,
but changed to match ZODB's UML documentation.  Alas, some
(untested) code in Zope relied on the actual behavior (see the
collector report).  Changed code, docs, and tests to bless the
old behavior in these cases.

DemoStorage.UndoLog:  this was wrong in several ways.  I'm still
unsure about why it skips "packed" transactions.  That doesn't seem
right, but I don't have time to wonder about that now.
parent fb20b66e
What's new in ZODB3 3.4.1a2? What's new in ZODB3 3.4.1a3?
============================ ============================
Release date: DD-MMM-2005 Release date: DD-MMM-2005
Following are dates of internal releases (to support ongoing Zope 2 Following are dates of internal releases (to support ongoing Zope 2
development) since ZODB 3.4's last public release: development) since ZODB 3.4's last public release:
- 3.4.1a2 29-Jun-2005
- 3.4.1a1 27-Jun-2005 - 3.4.1a1 27-Jun-2005
Savepoints Savepoints
...@@ -18,11 +19,21 @@ Savepoints ...@@ -18,11 +19,21 @@ Savepoints
could cause spurious errors if a transaction with a pending savepoint could cause spurious errors if a transaction with a pending savepoint
needed to fetch an older revision of some object. needed to fetch an older revision of some object.
FileStorage.UndoSearch FileStorage
---------------------- -----------
- (3.4.1a1) The ``_readnext()`` method now returns the transaction size as - (3.4.1a2) Collector #1822. The ``undoLog()`` and ``undoInfo()`` methods
the value of the "size" key. Thanks to Dieter Maurer for the patch, from were changed in 3.4a9 to return the documented results. Alas, some pieces
of (non-ZODB) code relied on the actual behavior. When the `first` and
`last` arguments are both >= 0, these methods now treat them as if they
were Python slice indices, including the `first` index but excluding the
`last` index. This matches former behavior, although it contradicts older
ZODB UML documentation. The documentation in
``ZODB.interfaces.IStorageUndoable`` was changed to match the new intent.
- (3.4.1a1) The ``UndoSearch._readnext()`` method now returns the transaction
size as the value of the "size" key. Thanks to Dieter Maurer for the
patch, from
http://mail.zope.org/pipermail/zodb-dev/2003-October/006157.html. "This is http://mail.zope.org/pipermail/zodb-dev/2003-October/006157.html. "This is
very valuable when you want to spot strange transaction sizes via Zope's very valuable when you want to spot strange transaction sizes via Zope's
'Undo' tab". 'Undo' tab".
...@@ -39,6 +50,11 @@ ThreadedAsync.LoopCallback ...@@ -39,6 +50,11 @@ ThreadedAsync.LoopCallback
example, debugging prints added to Python's ``asyncore.loop`` won't be example, debugging prints added to Python's ``asyncore.loop`` won't be
lost anymore). lost anymore).
DemoStorage
-----------
- The implementation of ``undoLog()`` was wrong in several ways; repaired.
What's new in ZODB3 3.4? What's new in ZODB3 3.4?
======================== ========================
......
...@@ -337,21 +337,19 @@ class DemoStorage(BaseStorage): ...@@ -337,21 +337,19 @@ class DemoStorage(BaseStorage):
self._ltid = self._tid self._ltid = self._tid
def undoLog(self, first, last, filter=None): def undoLog(self, first, last, filter=None):
if last < 0: if last < 0: # abs(last) is an upper bound on the # to return
last = first - last + 1 last = first - last
self._lock_acquire() self._lock_acquire()
try: try:
# Unsure: shouldn we sort this?
transactions = self._data.items() transactions = self._data.items()
pos = len(transactions) pos = len(transactions)
r = [] r = []
i = 0 i = 0
while i < last and pos: while i < last and pos:
pos = pos - 1 pos -= 1
if i < first:
i = i + 1
continue
tid, (p, u, d, e, t) = transactions[pos] tid, (p, u, d, e, t) = transactions[pos]
# Bug alert: why do we skip this if the transaction
# has been packed?
if p: if p:
continue continue
d = {'id': base64.encodestring(tid)[:-1], d = {'id': base64.encodestring(tid)[:-1],
...@@ -359,10 +357,10 @@ class DemoStorage(BaseStorage): ...@@ -359,10 +357,10 @@ class DemoStorage(BaseStorage):
'user_name': u, 'description': d} 'user_name': u, 'description': d}
if e: if e:
d.update(loads(e)) d.update(loads(e))
if filter is None or filter(d): if filter is None or filter(d):
r.append(d) if i >= first:
i = i + 1 r.append(d)
i += 1
return r return r
finally: finally:
self._lock_release() self._lock_release()
......
...@@ -1070,11 +1070,11 @@ class FileStorage(BaseStorage.BaseStorage, ...@@ -1070,11 +1070,11 @@ class FileStorage(BaseStorage.BaseStorage,
def undoLog(self, first=0, last=-20, filter=None): def undoLog(self, first=0, last=-20, filter=None):
if last < 0: if last < 0:
# -last is supposed to be the max # of transactions. Convert to # -last is supposed to be the max # of transactions. Convert to
# a positive index. Should have x - first + 1 = -last, which # a positive index. Should have x - first = -last, which
# means x = first - last - 1. This is spelled out here because # means x = first - last. This is spelled out here because
# the normalization code was incorrect for years (used +1 # the normalization code was incorrect for years (used +1
# instead -- off by 2), until ZODB 3.4. # instead -- off by 1), until ZODB 3.4.
last = first - last - 1 last = first - last
self._lock_acquire() self._lock_acquire()
try: try:
if self._pack_is_in_progress: if self._pack_is_in_progress:
...@@ -2043,7 +2043,7 @@ class UndoSearch: ...@@ -2043,7 +2043,7 @@ class UndoSearch:
self.filter = filter self.filter = filter
# self.i is the index of the transaction we're _going_ to find # self.i is the index of the transaction we're _going_ to find
# next. When it reaches self.first, we should start appending # next. When it reaches self.first, we should start appending
# to self.results. When it reaches self.last + 1, we're done # to self.results. When it reaches self.last, we're done
# (although we may finish earlier). # (although we may finish earlier).
self.i = 0 self.i = 0
self.results = [] self.results = []
...@@ -2052,7 +2052,7 @@ class UndoSearch: ...@@ -2052,7 +2052,7 @@ class UndoSearch:
def finished(self): def finished(self):
"""Return True if UndoSearch has found enough records.""" """Return True if UndoSearch has found enough records."""
# BAW: Why 39 please? This makes no sense (see also below). # BAW: Why 39 please? This makes no sense (see also below).
return self.i > self.last or self.pos < 39 or self.stop return self.i >= self.last or self.pos < 39 or self.stop
def search(self): def search(self):
"""Search for another record.""" """Search for another record."""
......
...@@ -18,12 +18,20 @@ class UndoLogCompatible: ...@@ -18,12 +18,20 @@ class UndoLogCompatible:
def undoInfo(self, first=0, last=-20, specification=None): def undoInfo(self, first=0, last=-20, specification=None):
if specification: if specification:
# filter(desc) returns true iff `desc` is a "superdict"
# of `specification`, meaning that `desc` contains the same
# (key, value) pairs as `specification`, and possibly additional
# (key, value) pairs. Another way to do this might be
# d = desc.copy()
# d.update(specification)
# return d == desc
def filter(desc, spec=specification.items()): def filter(desc, spec=specification.items()):
get=desc.get get = desc.get
for k, v in spec: for k, v in spec:
if get(k, None) != v: if get(k, None) != v:
return 0 return 0
return 1 return 1
else: filter=None else:
filter = None
return self.undoLog(first, last, filter) return self.undoLog(first, last, filter)
...@@ -490,13 +490,15 @@ class IStorageUndoable(IStorage): ...@@ -490,13 +490,15 @@ class IStorageUndoable(IStorage):
`first`: This is the index of the first transaction description `first`: This is the index of the first transaction description
in the slice. It must be >= 0. in the slice. It must be >= 0.
`last`: If >= 0, this is the index of the last transaction `last`: If >= 0, first:last acts like a Python slice, selecting
description in the slice, and `last` should be at least the descriptions at indices `first`, first+1, ..., up to
as large as `first` in this case. If `last` is less than but not including index `last`. At most last-first
0, then abs(last) is taken to be the maximum number descriptions are in the slice, and `last` should be at
of descriptions in the slice (which still begins at least as large as `first` in this case. If `last` is
index `first`). When `last` < 0, the same effect could less than 0, then abs(last) is taken to be the maximum
be gotten by passing the positive first-last-1 for number of descriptions in the slice (which still begins
at index `first`). When `last` < 0, the same effect
could be gotten by passing the positive first-last for
`last` instead. `last` instead.
""" """
......
...@@ -755,7 +755,7 @@ class TransactionalUndoStorage: ...@@ -755,7 +755,7 @@ class TransactionalUndoStorage:
self.assertEqual(default, allofem[:20]) self.assertEqual(default, allofem[:20])
# If we ask for only one, we should get only the most recent. # If we ask for only one, we should get only the most recent.
fresh = info_func(last=0) fresh = info_func(last=1)
self.assertEqual(len(fresh), 1) self.assertEqual(len(fresh), 1)
self.assertEqual(fresh[0], allofem[0]) self.assertEqual(fresh[0], allofem[0])
...@@ -765,11 +765,11 @@ class TransactionalUndoStorage: ...@@ -765,11 +765,11 @@ class TransactionalUndoStorage:
# Try a slice that doesn't start at 0. # Try a slice that doesn't start at 0.
oddball = info_func(first=11, last=17) oddball = info_func(first=11, last=17)
self.assertEqual(len(oddball), 17-11+1) self.assertEqual(len(oddball), 17-11)
self.assertEqual(oddball, allofem[11 : 11+len(oddball)]) self.assertEqual(oddball, allofem[11 : 11+len(oddball)])
# And another way to spell the same thing. # And another way to spell the same thing.
redundant = info_func(first=11, last=-7) redundant = info_func(first=11, last=-6)
self.assertEqual(oddball, redundant) self.assertEqual(oddball, redundant)
cn.close() cn.close()
......
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