patchbomb: extract 'makeintro' closure into its own function
Keep marching toward the promised land of simplification!
# Copyright (C) 2004, 2005 Canonical Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, see <http://www.gnu.org/licenses/>.
# mbp: "you know that thing where cvs gives you conflict markers?"
# s: "i hate that."
from i18n import _
import scmutil, util, mdiff
import sys, os
class CantReprocessAndShowBase(Exception):
pass
def intersect(ra, rb):
"""Given two ranges return the range where they intersect or None.
>>> intersect((0, 10), (0, 6))
(0, 6)
>>> intersect((0, 10), (5, 15))
(5, 10)
>>> intersect((0, 10), (10, 15))
>>> intersect((0, 9), (10, 15))
>>> intersect((0, 9), (7, 15))
(7, 9)
"""
assert ra[0] <= ra[1]
assert rb[0] <= rb[1]
sa = max(ra[0], rb[0])
sb = min(ra[1], rb[1])
if sa < sb:
return sa, sb
else:
return None
def compare_range(a, astart, aend, b, bstart, bend):
"""Compare a[astart:aend] == b[bstart:bend], without slicing.
"""
if (aend - astart) != (bend - bstart):
return False
for ia, ib in zip(xrange(astart, aend), xrange(bstart, bend)):
if a[ia] != b[ib]:
return False
else:
return True
class Merge3Text(object):
"""3-way merge of texts.
Given strings BASE, OTHER, THIS, tries to produce a combined text
incorporating the changes from both BASE->OTHER and BASE->THIS."""
def __init__(self, basetext, atext, btext, base=None, a=None, b=None):
self.basetext = basetext
self.atext = atext
self.btext = btext
if base is None:
base = mdiff.splitnewlines(basetext)
if a is None:
a = mdiff.splitnewlines(atext)
if b is None:
b = mdiff.splitnewlines(btext)
self.base = base
self.a = a
self.b = b
def merge_lines(self,
name_a=None,
name_b=None,
name_base=None,
start_marker='<<<<<<<',
mid_marker='=======',
end_marker='>>>>>>>',
base_marker=None):
"""Return merge in cvs-like form.
"""
self.conflicts = False
newline = '\n'
if len(self.a) > 0:
if self.a[0].endswith('\r\n'):
newline = '\r\n'
elif self.a[0].endswith('\r'):
newline = '\r'
if name_a:
start_marker = start_marker + ' ' + name_a
if name_b:
end_marker = end_marker + ' ' + name_b
if name_base and base_marker:
base_marker = base_marker + ' ' + name_base
merge_regions = self.merge_regions()
for t in merge_regions:
what = t[0]
if what == 'unchanged':
for i in range(t[1], t[2]):
yield self.base[i]
elif what == 'a' or what == 'same':
for i in range(t[1], t[2]):
yield self.a[i]
elif what == 'b':
for i in range(t[1], t[2]):
yield self.b[i]
elif what == 'conflict':
self.conflicts = True
yield start_marker + newline
for i in range(t[3], t[4]):
yield self.a[i]
if base_marker is not None:
yield base_marker + newline
for i in range(t[1], t[2]):
yield self.base[i]
yield mid_marker + newline
for i in range(t[5], t[6]):
yield self.b[i]
yield end_marker + newline
else:
raise ValueError(what)
def merge_groups(self):
"""Yield sequence of line groups. Each one is a tuple:
'unchanged', lines
Lines unchanged from base
'a', lines
Lines taken from a
'same', lines
Lines taken from a (and equal to b)
'b', lines
Lines taken from b
'conflict', base_lines, a_lines, b_lines
Lines from base were changed to either a or b and conflict.
"""
for t in self.merge_regions():
what = t[0]
if what == 'unchanged':
yield what, self.base[t[1]:t[2]]
elif what == 'a' or what == 'same':
yield what, self.a[t[1]:t[2]]
elif what == 'b':
yield what, self.b[t[1]:t[2]]
elif what == 'conflict':
yield (what,
self.base[t[1]:t[2]],
self.a[t[3]:t[4]],
self.b[t[5]:t[6]])
else:
raise ValueError(what)
def merge_regions(self):
"""Return sequences of matching and conflicting regions.
This returns tuples, where the first value says what kind we
have:
'unchanged', start, end
Take a region of base[start:end]
'same', astart, aend
b and a are different from base but give the same result
'a', start, end
Non-clashing insertion from a[start:end]
Method is as follows:
The two sequences align only on regions which match the base
and both descendants. These are found by doing a two-way diff
of each one against the base, and then finding the
intersections between those regions. These "sync regions"
are by definition unchanged in both and easily dealt with.
The regions in between can be in any of three cases:
conflicted, or changed on only one side.
"""
# section a[0:ia] has been disposed of, etc
iz = ia = ib = 0
for region in self.find_sync_regions():
zmatch, zend, amatch, aend, bmatch, bend = region
#print 'match base [%d:%d]' % (zmatch, zend)
matchlen = zend - zmatch
assert matchlen >= 0
assert matchlen == (aend - amatch)
assert matchlen == (bend - bmatch)
len_a = amatch - ia
len_b = bmatch - ib
len_base = zmatch - iz
assert len_a >= 0
assert len_b >= 0
assert len_base >= 0
#print 'unmatched a=%d, b=%d' % (len_a, len_b)
if len_a or len_b:
# try to avoid actually slicing the lists
equal_a = compare_range(self.a, ia, amatch,
self.base, iz, zmatch)
equal_b = compare_range(self.b, ib, bmatch,
self.base, iz, zmatch)
same = compare_range(self.a, ia, amatch,
self.b, ib, bmatch)
if same:
yield 'same', ia, amatch
elif equal_a and not equal_b:
yield 'b', ib, bmatch
elif equal_b and not equal_a:
yield 'a', ia, amatch
elif not equal_a and not equal_b:
yield 'conflict', iz, zmatch, ia, amatch, ib, bmatch
else:
raise AssertionError("can't handle a=b=base but unmatched")
ia = amatch
ib = bmatch
iz = zmatch
# if the same part of the base was deleted on both sides
# that's OK, we can just skip it.
if matchlen > 0:
assert ia == amatch
assert ib == bmatch
assert iz == zmatch
yield 'unchanged', zmatch, zend
iz = zend
ia = aend
ib = bend
def find_sync_regions(self):
"""Return a list of sync regions, where both descendants match the base.
Generates a list of (base1, base2, a1, a2, b1, b2). There is
always a zero-length sync region at the end of all the files.
"""
ia = ib = 0
amatches = mdiff.get_matching_blocks(self.basetext, self.atext)
bmatches = mdiff.get_matching_blocks(self.basetext, self.btext)
len_a = len(amatches)
len_b = len(bmatches)
sl = []
while ia < len_a and ib < len_b:
abase, amatch, alen = amatches[ia]
bbase, bmatch, blen = bmatches[ib]
# there is an unconflicted block at i; how long does it
# extend? until whichever one ends earlier.
i = intersect((abase, abase + alen), (bbase, bbase + blen))
if i:
intbase = i[0]
intend = i[1]
intlen = intend - intbase
# found a match of base[i[0], i[1]]; this may be less than
# the region that matches in either one
assert intlen <= alen
assert intlen <= blen
assert abase <= intbase
assert bbase <= intbase
asub = amatch + (intbase - abase)
bsub = bmatch + (intbase - bbase)
aend = asub + intlen
bend = bsub + intlen
assert self.base[intbase:intend] == self.a[asub:aend], \
(self.base[intbase:intend], self.a[asub:aend])
assert self.base[intbase:intend] == self.b[bsub:bend]
sl.append((intbase, intend,
asub, aend,
bsub, bend))
# advance whichever one ends first in the base text
if (abase + alen) < (bbase + blen):
ia += 1
else:
ib += 1
intbase = len(self.base)
abase = len(self.a)
bbase = len(self.b)
sl.append((intbase, intbase, abase, abase, bbase, bbase))
return sl
def find_unconflicted(self):
"""Return a list of ranges in base that are not conflicted."""
am = mdiff.get_matching_blocks(self.basetext, self.atext)
bm = mdiff.get_matching_blocks(self.basetext, self.btext)
unc = []
while am and bm:
# there is an unconflicted block at i; how long does it
# extend? until whichever one ends earlier.
a1 = am[0][0]
a2 = a1 + am[0][2]
b1 = bm[0][0]
b2 = b1 + bm[0][2]
i = intersect((a1, a2), (b1, b2))
if i:
unc.append(i)
if a2 < b2:
del am[0]
else:
del bm[0]
return unc
def simplemerge(ui, local, base, other, **opts):
def readfile(filename):
f = open(filename, "rb")
text = f.read()
f.close()
if util.binary(text):
msg = _("%s looks like a binary file.") % filename
if not opts.get('quiet'):
ui.warn(_('warning: %s\n') % msg)
if not opts.get('text'):
raise util.Abort(msg)
return text
name_a = local
name_b = other
name_base = None
labels = opts.get('label', [])
if len(labels) > 0:
name_a = labels[0]
if len(labels) > 1:
name_b = labels[1]
if len(labels) > 2:
name_base = labels[2]
if len(labels) > 3:
raise util.Abort(_("can only specify three labels."))
try:
localtext = readfile(local)
basetext = readfile(base)
othertext = readfile(other)
except util.Abort:
return 1
local = os.path.realpath(local)
if not opts.get('print'):
opener = scmutil.opener(os.path.dirname(local))
out = opener(os.path.basename(local), "w", atomictemp=True)
else:
out = sys.stdout
m3 = Merge3Text(basetext, localtext, othertext)
extrakwargs = {}
if name_base is not None:
extrakwargs['base_marker'] = '|||||||'
extrakwargs['name_base'] = name_base
for line in m3.merge_lines(name_a=name_a, name_b=name_b, **extrakwargs):
out.write(line)
if not opts.get('print'):
out.close()
if m3.conflicts:
if not opts.get('quiet'):
ui.warn(_("warning: conflicts during merge.\n"))
return 1