dirstate: delay writing out to ensure timestamp of each entries explicitly
Even though "dirstate.write()" is invoked explicitly after "normal"
invocations, timestamp field of entries may be still "unset" in the
"dirstate" file itself , because "pack_dirstate" drops it when it is
equal to the timestamp of "dirstate" file itself.
This can avoid overlooking modification of files, which are updated at
same time in the second. But on the other hand, this may hide timing
critical problems.
For example, incorrect "normal"-ing (or lack of "normallookup"-ing on
the already "normal"-ed entry) is visible only when:
- the target file is modified in the working directory at T1, and
- "dirstate" file is written out at T2 (!= T1)
Otherwise, T1 is dropped by "pack_dirstate" in "dirstate.write()"
invocation, and "unset" is stored into "dirstate" file.
It often fails to reproduce problems from incorrect "normal"-ing by
Mercurial testset, because automated actions in the small repository
almost always causes that T1 and T2 are same.
This patch adds the debug feature to delay writing out to ensure
timestamp of each entries explicitly.
This feature is used to make timing critical "dirstate" problems
reproducable in subsequent patches.
# manifest.py - manifest revision class for mercurial
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from i18n import _
import mdiff, parsers, error, revlog, util, dicthelpers
import array, struct
class manifestdict(dict):
def __init__(self, mapping=None, flags=None):
if mapping is None:
mapping = {}
if flags is None:
flags = {}
dict.__init__(self, mapping)
self._flags = flags
def flags(self, f):
return self._flags.get(f, "")
def withflags(self):
return set(self._flags.keys())
def set(self, f, flags):
self._flags[f] = flags
def copy(self):
return manifestdict(self, dict.copy(self._flags))
def intersectfiles(self, files):
'''make a new manifestdict with the intersection of self with files
The algorithm assumes that files is much smaller than self.'''
ret = manifestdict()
for fn in files:
if fn in self:
ret[fn] = self[fn]
flags = self._flags.get(fn, None)
if flags:
ret._flags[fn] = flags
return ret
def flagsdiff(self, d2):
return dicthelpers.diff(self._flags, d2._flags, "")
class manifest(revlog.revlog):
def __init__(self, opener):
# we expect to deal with not more than four revs at a time,
# during a commit --amend
self._mancache = util.lrucachedict(4)
revlog.revlog.__init__(self, opener, "00manifest.i")
def parse(self, lines):
mfdict = manifestdict()
parsers.parse_manifest(mfdict, mfdict._flags, lines)
return mfdict
def readdelta(self, node):
r = self.rev(node)
return self.parse(mdiff.patchtext(self.revdiff(self.deltaparent(r), r)))
def readfast(self, node):
'''use the faster of readdelta or read'''
r = self.rev(node)
deltaparent = self.deltaparent(r)
if deltaparent != revlog.nullrev and deltaparent in self.parentrevs(r):
return self.readdelta(node)
return self.read(node)
def read(self, node):
if node == revlog.nullid:
return manifestdict() # don't upset local cache
if node in self._mancache:
return self._mancache[node][0]
text = self.revision(node)
arraytext = array.array('c', text)
mapping = self.parse(text)
self._mancache[node] = (mapping, arraytext)
return mapping
def _search(self, m, s, lo=0, hi=None):
'''return a tuple (start, end) that says where to find s within m.
If the string is found m[start:end] are the line containing
that string. If start == end the string was not found and
they indicate the proper sorted insertion point.
m should be a buffer or a string
s is a string'''
def advance(i, c):
while i < lenm and m[i] != c:
i += 1
return i
if not s:
return (lo, lo)
lenm = len(m)
if not hi:
hi = lenm
while lo < hi:
mid = (lo + hi) // 2
start = mid
while start > 0 and m[start - 1] != '\n':
start -= 1
end = advance(start, '\0')
if m[start:end] < s:
# we know that after the null there are 40 bytes of sha1
# this translates to the bisect lo = mid + 1
lo = advance(end + 40, '\n') + 1
else:
# this translates to the bisect hi = mid
hi = start
end = advance(lo, '\0')
found = m[lo:end]
if s == found:
# we know that after the null there are 40 bytes of sha1
end = advance(end + 40, '\n')
return (lo, end + 1)
else:
return (lo, lo)
def find(self, node, f):
'''look up entry for a single file efficiently.
return (node, flags) pair if found, (None, None) if not.'''
if node in self._mancache:
mapping = self._mancache[node][0]
return mapping.get(f), mapping.flags(f)
text = self.revision(node)
start, end = self._search(text, f)
if start == end:
return None, None
l = text[start:end]
f, n = l.split('\0')
return revlog.bin(n[:40]), n[40:-1]
def add(self, map, transaction, link, p1=None, p2=None,
changed=None):
# apply the changes collected during the bisect loop to our addlist
# return a delta suitable for addrevision
def addlistdelta(addlist, x):
# for large addlist arrays, building a new array is cheaper
# than repeatedly modifying the existing one
currentposition = 0
newaddlist = array.array('c')
for start, end, content in x:
newaddlist += addlist[currentposition:start]
if content:
newaddlist += array.array('c', content)
currentposition = end
newaddlist += addlist[currentposition:]
deltatext = "".join(struct.pack(">lll", start, end, len(content))
+ content for start, end, content in x)
return deltatext, newaddlist
def checkforbidden(l):
for f in l:
if '\n' in f or '\r' in f:
raise error.RevlogError(
_("'\\n' and '\\r' disallowed in filenames: %r") % f)
# if we're using the cache, make sure it is valid and
# parented by the same node we're diffing against
if not (changed and p1 and (p1 in self._mancache)):
files = sorted(map)
checkforbidden(files)
# if this is changed to support newlines in filenames,
# be sure to check the templates/ dir again (especially *-raw.tmpl)
hex, flags = revlog.hex, map.flags
text = ''.join("%s\0%s%s\n" % (f, hex(map[f]), flags(f))
for f in files)
arraytext = array.array('c', text)
cachedelta = None
else:
added, removed = changed
addlist = self._mancache[p1][1]
checkforbidden(added)
# combine the changed lists into one list for sorting
work = [(x, False) for x in added]
work.extend((x, True) for x in removed)
# this could use heapq.merge() (from Python 2.6+) or equivalent
# since the lists are already sorted
work.sort()
delta = []
dstart = None
dend = None
dline = [""]
start = 0
# zero copy representation of addlist as a buffer
addbuf = util.buffer(addlist)
# start with a readonly loop that finds the offset of
# each line and creates the deltas
for f, todelete in work:
# bs will either be the index of the item or the insert point
start, end = self._search(addbuf, f, start)
if not todelete:
l = "%s\0%s%s\n" % (f, revlog.hex(map[f]), map.flags(f))
else:
if start == end:
# item we want to delete was not found, error out
raise AssertionError(
_("failed to remove %s from manifest") % f)
l = ""
if dstart is not None and dstart <= start and dend >= start:
if dend < end:
dend = end
if l:
dline.append(l)
else:
if dstart is not None:
delta.append([dstart, dend, "".join(dline)])
dstart = start
dend = end
dline = [l]
if dstart is not None:
delta.append([dstart, dend, "".join(dline)])
# apply the delta to the addlist, and get a delta for addrevision
deltatext, addlist = addlistdelta(addlist, delta)
cachedelta = (self.rev(p1), deltatext)
arraytext = addlist
text = util.buffer(arraytext)
n = self.addrevision(text, transaction, link, p1, p2, cachedelta)
self._mancache[n] = (map, arraytext)
return n