# mdiff.py - diff and patch routines for mercurial
#
# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.
from demandload import demandload
import bdiff, mpatch
demandload(globals(), "re struct util")
def splitnewlines(text):
'''like str.splitlines, but only split on newlines.'''
lines = [l + '\n' for l in text.split('\n')]
if lines:
if lines[-1] == '\n':
lines.pop()
else:
lines[-1] = lines[-1][:-1]
return lines
class diffopts(object):
'''context is the number of context lines
text treats all files as text
showfunc enables diff -p output
git enables the git extended patch format
ignorews ignores all whitespace changes in the diff
ignorewsamount ignores changes in the amount of whitespace
ignoreblanklines ignores changes whose lines are all blank'''
defaults = {
'context': 3,
'text': False,
'showfunc': True,
'git': False,
'ignorews': False,
'ignorewsamount': False,
'ignoreblanklines': False,
}
__slots__ = defaults.keys()
def __init__(self, **opts):
for k in self.__slots__:
v = opts.get(k)
if v is None:
v = self.defaults[k]
setattr(self, k, v)
defaultopts = diffopts()
def unidiff(a, ad, b, bd, fn, r=None, opts=defaultopts):
def datetag(date):
return opts.git and '\n' or '\t%s\n' % date
if not a and not b: return ""
epoch = util.datestr((0, 0))
if not opts.text and (util.binary(a) or util.binary(b)):
l = ['Binary file %s has changed\n' % fn]
elif not a:
b = splitnewlines(b)
if a is None:
l1 = '--- /dev/null%s' % datetag(epoch)
else:
l1 = "--- %s%s" % ("a/" + fn, datetag(ad))
l2 = "+++ %s%s" % ("b/" + fn, datetag(bd))
l3 = "@@ -0,0 +1,%d @@\n" % len(b)
l = [l1, l2, l3] + ["+" + e for e in b]
elif not b:
a = splitnewlines(a)
l1 = "--- %s%s" % ("a/" + fn, datetag(ad))
if b is None:
l2 = '+++ /dev/null%s' % datetag(epoch)
else:
l2 = "+++ %s%s" % ("b/" + fn, datetag(bd))
l3 = "@@ -1,%d +0,0 @@\n" % len(a)
l = [l1, l2, l3] + ["-" + e for e in a]
else:
al = splitnewlines(a)
bl = splitnewlines(b)
l = list(bunidiff(a, b, al, bl, "a/" + fn, "b/" + fn, opts=opts))
if not l: return ""
# difflib uses a space, rather than a tab
l[0] = "%s%s" % (l[0][:-2], datetag(ad))
l[1] = "%s%s" % (l[1][:-2], datetag(bd))
for ln in xrange(len(l)):
if l[ln][-1] != '\n':
l[ln] += "\n\ No newline at end of file\n"
if r:
l.insert(0, "diff %s %s\n" %
(' '.join(["-r %s" % rev for rev in r]), fn))
return "".join(l)
# somewhat self contained replacement for difflib.unified_diff
# t1 and t2 are the text to be diffed
# l1 and l2 are the text broken up into lines
# header1 and header2 are the filenames for the diff output
def bunidiff(t1, t2, l1, l2, header1, header2, opts=defaultopts):
def contextend(l, len):
ret = l + opts.context
if ret > len:
ret = len
return ret
def contextstart(l):
ret = l - opts.context
if ret < 0:
return 0
return ret
def yieldhunk(hunk, header):
if header:
for x in header:
yield x
(astart, a2, bstart, b2, delta) = hunk
aend = contextend(a2, len(l1))
alen = aend - astart
blen = b2 - bstart + aend - a2
func = ""
if opts.showfunc:
# walk backwards from the start of the context
# to find a line starting with an alphanumeric char.
for x in xrange(astart, -1, -1):
t = l1[x].rstrip()
if funcre.match(t):
func = ' ' + t[:40]
break
yield "@@ -%d,%d +%d,%d @@%s\n" % (astart + 1, alen,
bstart + 1, blen, func)
for x in delta:
yield x
for x in xrange(a2, aend):
yield ' ' + l1[x]
header = [ "--- %s\t\n" % header1, "+++ %s\t\n" % header2 ]
if opts.showfunc:
funcre = re.compile('\w')
if opts.ignorewsamount:
wsamountre = re.compile('[ \t]+')
wsappendedre = re.compile(' \n')
if opts.ignoreblanklines:
wsblanklinesre = re.compile('\n')
if opts.ignorews:
wsre = re.compile('[ \t]')
# bdiff.blocks gives us the matching sequences in the files. The loop
# below finds the spaces between those matching sequences and translates
# them into diff output.
#
diff = bdiff.blocks(t1, t2)
hunk = None
for i in xrange(len(diff)):
# The first match is special.
# we've either found a match starting at line 0 or a match later
# in the file. If it starts later, old and new below will both be
# empty and we'll continue to the next match.
if i > 0:
s = diff[i-1]
else:
s = [0, 0, 0, 0]
delta = []
s1 = diff[i]
a1 = s[1]
a2 = s1[0]
b1 = s[3]
b2 = s1[2]
old = l1[a1:a2]
new = l2[b1:b2]
# bdiff sometimes gives huge matches past eof, this check eats them,
# and deals with the special first match case described above
if not old and not new:
continue
if opts.ignoreblanklines:
wsold = wsblanklinesre.sub('', "".join(old))
wsnew = wsblanklinesre.sub('', "".join(new))
if wsold == wsnew:
continue
if opts.ignorewsamount:
wsold = wsamountre.sub(' ', "".join(old))
wsold = wsappendedre.sub('\n', wsold)
wsnew = wsamountre.sub(' ', "".join(new))
wsnew = wsappendedre.sub('\n', wsnew)
if wsold == wsnew:
continue
if opts.ignorews:
wsold = wsre.sub('', "".join(old))
wsnew = wsre.sub('', "".join(new))
if wsold == wsnew:
continue
astart = contextstart(a1)
bstart = contextstart(b1)
prev = None
if hunk:
# join with the previous hunk if it falls inside the context
if astart < hunk[1] + opts.context + 1:
prev = hunk
astart = hunk[1]
bstart = hunk[3]
else:
for x in yieldhunk(hunk, header):
yield x
# we only want to yield the header if the files differ, and
# we only want to yield it once.
header = None
if prev:
# we've joined the previous hunk, record the new ending points.
hunk[1] = a2
hunk[3] = b2
delta = hunk[4]
else:
# create a new hunk
hunk = [ astart, a2, bstart, b2, delta ]
delta[len(delta):] = [ ' ' + x for x in l1[astart:a1] ]
delta[len(delta):] = [ '-' + x for x in old ]
delta[len(delta):] = [ '+' + x for x in new ]
if hunk:
for x in yieldhunk(hunk, header):
yield x
def patchtext(bin):
pos = 0
t = []
while pos < len(bin):
p1, p2, l = struct.unpack(">lll", bin[pos:pos + 12])
pos += 12
t.append(bin[pos:pos + l])
pos += l
return "".join(t)
def patch(a, bin):
return mpatch.patches(a, [bin])
patches = mpatch.patches
patchedsize = mpatch.patchedsize
textdiff = bdiff.bdiff