manifest: split manifestdict into high-level and low-level logic
The low-level logic type (_lazymanifest) matches the behavior of the C
implementation introduced in a5f1bccd. A future patch will use that
when available.
# 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)
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