##// END OF EJS Templates
revlog: addgroup checks if incoming deltas add censored revs, sets flag bit...
revlog: addgroup checks if incoming deltas add censored revs, sets flag bit A censored revision stored in a revlog should have the censored revlog index flag bit set. This implies we must know if a revision is censored before we add it to the revlog. When adding revisions from exchanged deltas, we would prefer to determine this flag without decoding every single full text. This change introduces a heuristic based on assumptions around the Mercurial delta format and filelog metadata. Since deltas which produce a censored revision must be full-replacement deltas, we can read the delta's first bytes to check the filelog metadata. Since "censored" is the alphabetically first filelog metadata key, censored filelog revisions have a well-known prefix we can look for. For more on the design and background of the censorship feature, see: http://mercurial.selenic.com/wiki/CensorPlan

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manifest.py
389 lines | 12.6 KiB | text/x-python | PythonLexer
# 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
import array, struct
class _lazymanifest(dict):
"""This is the pure implementation of lazymanifest.
It has not been optimized *at all* and is not lazy.
"""
def __init__(self, data):
# This init method does a little bit of excessive-looking
# precondition checking. This is so that the behavior of this
# class exactly matches its C counterpart to try and help
# prevent surprise breakage for anyone that develops against
# the pure version.
if data and data[-1] != '\n':
raise ValueError('Manifest did not end in a newline.')
dict.__init__(self)
prev = None
for l in data.splitlines():
if prev is not None and prev > l:
raise ValueError('Manifest lines not in sorted order.')
prev = l
f, n = l.split('\0')
if len(n) > 40:
self[f] = revlog.bin(n[:40]), n[40:]
else:
self[f] = revlog.bin(n), ''
def __setitem__(self, k, v):
node, flag = v
assert node is not None
if len(node) > 21:
node = node[:21] # match c implementation behavior
dict.__setitem__(self, k, (node, flag))
def __iter__(self):
return ((f, e[0], e[1]) for f, e in sorted(self.iteritems()))
def copy(self):
c = _lazymanifest('')
c.update(self)
return c
def diff(self, m2, clean=False):
'''Finds changes between the current manifest and m2.'''
diff = {}
for fn, e1 in self.iteritems():
if fn not in m2:
diff[fn] = e1, (None, '')
else:
e2 = m2[fn]
if e1 != e2:
diff[fn] = e1, e2
elif clean:
diff[fn] = None
for fn, e2 in m2.iteritems():
if fn not in self:
diff[fn] = (None, ''), e2
return diff
def filtercopy(self, filterfn):
c = _lazymanifest('')
for f, n, fl in self:
if filterfn(f):
c[f] = n, fl
return c
def text(self):
"""Get the full data of this manifest as a bytestring."""
fl = sorted(self)
_hex = revlog.hex
# if this is changed to support newlines in filenames,
# be sure to check the templates/ dir again (especially *-raw.tmpl)
return ''.join("%s\0%s%s\n" % (
f, _hex(n[:20]), flag) for f, n, flag in fl)
try:
_lazymanifest = parsers.lazymanifest
except AttributeError:
pass
class manifestdict(object):
def __init__(self, data=''):
self._lm = _lazymanifest(data)
def __getitem__(self, key):
return self._lm[key][0]
def __len__(self):
return len(self._lm)
def __setitem__(self, key, node):
self._lm[key] = node, self.flags(key, '')
def __contains__(self, key):
return key in self._lm
def __delitem__(self, key):
del self._lm[key]
def keys(self):
return [x[0] for x in self._lm]
def iterkeys(self):
return iter(self.keys())
def intersectfiles(self, files):
'''make a new lazymanifest with the intersection of self with files
The algorithm assumes that files is much smaller than self.'''
ret = manifestdict()
lm = self._lm
for fn in files:
if fn in lm:
ret._lm[fn] = self._lm[fn]
return ret
def filesnotin(self, m2):
'''Set of files in this manifest that are not in the other'''
files = set(self.iterkeys())
files.difference_update(m2.iterkeys())
return files
def matches(self, match):
'''generate a new manifest filtered by the match argument'''
if match.always():
return self.copy()
files = match.files()
if (match.matchfn == match.exact or
(not match.anypats() and util.all(fn in self for fn in files))):
return self.intersectfiles(files)
lm = manifestdict('')
lm._lm = self._lm.filtercopy(match)
return lm
def diff(self, m2, clean=False):
'''Finds changes between the current manifest and m2.
Args:
m2: the manifest to which this manifest should be compared.
clean: if true, include files unchanged between these manifests
with a None value in the returned dictionary.
The result is returned as a dict with filename as key and
values of the form ((n1,fl1),(n2,fl2)), where n1/n2 is the
nodeid in the current/other manifest and fl1/fl2 is the flag
in the current/other manifest. Where the file does not exist,
the nodeid will be None and the flags will be the empty
string.
'''
return self._lm.diff(m2._lm, clean)
def setflag(self, key, flag):
self._lm[key] = self[key], flag
def get(self, key, default=None):
try:
return self._lm[key][0]
except KeyError:
return default
def flags(self, key, default=''):
try:
return self._lm[key][1]
except KeyError:
return default
def __iter__(self):
return (x[0] for x in self._lm)
def copy(self):
c = manifestdict('')
c._lm = self._lm.copy()
return c
def iteritems(self):
return (x[:2] for x in self._lm)
def text(self):
return self._lm.text()
def fastdelta(self, base, changes):
"""Given a base manifest text as an array.array and a list of changes
relative to that text, compute a delta that can be used by revlog.
"""
delta = []
dstart = None
dend = None
dline = [""]
start = 0
# zero copy representation of base as a buffer
addbuf = util.buffer(base)
# start with a readonly loop that finds the offset of
# each line and creates the deltas
for f, todelete in changes:
# bs will either be the index of the item or the insert point
start, end = _msearch(addbuf, f, start)
if not todelete:
h, fl = self._lm[f]
l = "%s\0%s%s\n" % (f, revlog.hex(h), fl)
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 base, and get a delta for addrevision
deltatext, arraytext = _addlistdelta(base, delta)
return arraytext, deltatext
def _msearch(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 _checkforbidden(l):
"""Check filenames for illegal characters."""
for f in l:
if '\n' in f or '\r' in f:
raise error.RevlogError(
_("'\\n' and '\\r' disallowed in filenames: %r") % f)
# 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
class manifest(revlog.revlog):
def __init__(self, opener):
# During normal operations, we expect to deal with not more than four
# revs at a time (such as during commit --amend). When rebasing large
# stacks of commits, the number can go up, hence the config knob below.
cachesize = 4
opts = getattr(opener, 'options', None)
if opts is not None:
cachesize = opts.get('manifestcachesize', cachesize)
self._mancache = util.lrucachedict(cachesize)
revlog.revlog.__init__(self, opener, "00manifest.i")
def readdelta(self, node):
r = self.rev(node)
d = mdiff.patchtext(self.revdiff(self.deltaparent(r), r))
return manifestdict(d)
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)
m = manifestdict(text)
self._mancache[node] = (m, arraytext)
return m
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:
m = self._mancache[node][0]
return m.get(f), m.flags(f)
text = self.revision(node)
try:
return manifestdict(text)._lm[f]
except KeyError:
return None, None
def add(self, m, transaction, link, p1, p2, added, removed):
if p1 in self._mancache:
# If our first parent is in the manifest cache, we can
# compute a delta here using properties we know about the
# manifest up-front, which may save time later for the
# revlog layer.
_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()
arraytext, deltatext = m.fastdelta(self._mancache[p1][1], work)
cachedelta = self.rev(p1), deltatext
text = util.buffer(arraytext)
else:
# The first parent manifest isn't already loaded, so we'll
# just encode a fulltext of the manifest and pass that
# through to the revlog layer, and let it handle the delta
# process.
text = m.text()
arraytext = array.array('c', text)
cachedelta = None
n = self.addrevision(text, transaction, link, p1, p2, cachedelta)
self._mancache[n] = (m, arraytext)
return n