comparison mercurial/mdiff.py @ 1637:3b1b44b917f4

Add new bdiff based unidiff generation.
author mason@suse.com
date Tue, 24 Jan 2006 15:02:10 +1300
parents 8ca9f5b17257
children fde8fb2cbede
comparison
equal deleted inserted replaced
1636:7da32bb3d1d3 1637:3b1b44b917f4
3 # Copyright 2005 Matt Mackall <mpm@selenic.com> 3 # Copyright 2005 Matt Mackall <mpm@selenic.com>
4 # 4 #
5 # This software may be used and distributed according to the terms 5 # This software may be used and distributed according to the terms
6 # of the GNU General Public License, incorporated herein by reference. 6 # of the GNU General Public License, incorporated herein by reference.
7 7
8 import difflib, struct, bdiff, util, mpatch 8 from demandload import demandload
9 import struct, bdiff, util, mpatch
10 demandload(globals(), "re")
9 11
10 def unidiff(a, ad, b, bd, fn, r=None, text=False): 12
13 def unidiff(a, ad, b, bd, fn, r=None, text=False,
14 showfunc=False, ignorews=False):
11 15
12 if not a and not b: return "" 16 if not a and not b: return ""
13 epoch = util.datestr((0, 0)) 17 epoch = util.datestr((0, 0))
14 18
15 if not text and (util.binary(a) or util.binary(b)): 19 if not text and (util.binary(a) or util.binary(b)):
25 l1 = "--- %s\t%s\n" % ("a/" + fn, ad) 29 l1 = "--- %s\t%s\n" % ("a/" + fn, ad)
26 l2 = "+++ %s\t%s\n" % ("/dev/null", epoch) 30 l2 = "+++ %s\t%s\n" % ("/dev/null", epoch)
27 l3 = "@@ -1,%d +0,0 @@\n" % len(a) 31 l3 = "@@ -1,%d +0,0 @@\n" % len(a)
28 l = [l1, l2, l3] + ["-" + e for e in a] 32 l = [l1, l2, l3] + ["-" + e for e in a]
29 else: 33 else:
30 a = a.splitlines(1) 34 al = a.splitlines(1)
31 b = b.splitlines(1) 35 bl = b.splitlines(1)
32 l = list(difflib.unified_diff(a, b, "a/" + fn, "b/" + fn)) 36 l = list(bunidiff(a, b, al, bl, "a/" + fn, "b/" + fn,
37 showfunc=showfunc, ignorews=ignorews))
33 if not l: return "" 38 if not l: return ""
34 # difflib uses a space, rather than a tab 39 # difflib uses a space, rather than a tab
35 l[0] = "%s\t%s\n" % (l[0][:-2], ad) 40 l[0] = "%s\t%s\n" % (l[0][:-2], ad)
36 l[1] = "%s\t%s\n" % (l[1][:-2], bd) 41 l[1] = "%s\t%s\n" % (l[1][:-2], bd)
37 42
42 if r: 47 if r:
43 l.insert(0, "diff %s %s\n" % 48 l.insert(0, "diff %s %s\n" %
44 (' '.join(["-r %s" % rev for rev in r]), fn)) 49 (' '.join(["-r %s" % rev for rev in r]), fn))
45 50
46 return "".join(l) 51 return "".join(l)
52
53 # somewhat self contained replacement for difflib.unified_diff
54 # t1 and t2 are the text to be diffed
55 # l1 and l2 are the text broken up into lines
56 # header1 and header2 are the filenames for the diff output
57 # context is the number of context lines
58 # showfunc enables diff -p output
59 # ignorews ignores all whitespace changes in the diff
60 def bunidiff(t1, t2, l1, l2, header1, header2, context=3, showfunc=False,
61 ignorews=False):
62 def contextend(l, len):
63 ret = l + context
64 if ret > len:
65 ret = len
66 return ret
67
68 def contextstart(l):
69 ret = l - context
70 if ret < 0:
71 return 0
72 return ret
73
74 def yieldhunk(hunk, header):
75 if header:
76 for x in header:
77 yield x
78 (astart, a2, bstart, b2, delta) = hunk
79 aend = contextend(a2, len(l1))
80 alen = aend - astart
81 blen = b2 - bstart + aend - a2
82
83 func = ""
84 if showfunc:
85 # walk backwards from the start of the context
86 # to find a line starting with an alphanumeric char.
87 for x in xrange(astart, -1, -1):
88 t = l1[x].rstrip()
89 if funcre.match(t):
90 func = ' ' + t[:40]
91 break
92
93 yield "@@ -%d,%d +%d,%d @@%s\n" % (astart + 1, alen,
94 bstart + 1, blen, func)
95 for x in delta:
96 yield x
97 for x in xrange(a2, aend):
98 yield ' ' + l1[x]
99
100 header = [ "--- %s\t\n" % header1, "+++ %s\t\n" % header2 ]
101
102 if showfunc:
103 funcre = re.compile('\w')
104 if ignorews:
105 wsre = re.compile('[ \t]')
106
107 # bdiff.blocks gives us the matching sequences in the files. The loop
108 # below finds the spaces between those matching sequences and translates
109 # them into diff output.
110 #
111 diff = bdiff.blocks(t1, t2)
112 hunk = None
113 for i in xrange(len(diff)):
114 # The first match is special.
115 # we've either found a match starting at line 0 or a match later
116 # in the file. If it starts later, old and new below will both be
117 # empty and we'll continue to the next match.
118 if i > 0:
119 s = diff[i-1]
120 else:
121 s = [0, 0, 0, 0]
122 delta = []
123 s1 = diff[i]
124 a1 = s[1]
125 a2 = s1[0]
126 b1 = s[3]
127 b2 = s1[2]
128
129 old = l1[a1:a2]
130 new = l2[b1:b2]
131
132 # bdiff sometimes gives huge matches past eof, this check eats them,
133 # and deals with the special first match case described above
134 if not old and not new:
135 continue
136
137 if ignorews:
138 wsold = wsre.sub('', "".join(old))
139 wsnew = wsre.sub('', "".join(new))
140 if wsold == wsnew:
141 continue
142
143 astart = contextstart(a1)
144 bstart = contextstart(b1)
145 prev = None
146 if hunk:
147 # join with the previous hunk if it falls inside the context
148 if astart < hunk[1] + context + 1:
149 prev = hunk
150 astart = hunk[1]
151 bstart = hunk[3]
152 else:
153 for x in yieldhunk(hunk, header):
154 yield x
155 # we only want to yield the header if the files differ, and
156 # we only want to yield it once.
157 header = None
158 if prev:
159 # we've joined the previous hunk, record the new ending points.
160 hunk[1] = a2
161 hunk[3] = b2
162 delta = hunk[4]
163 else:
164 # create a new hunk
165 hunk = [ astart, a2, bstart, b2, delta ]
166
167 delta[len(delta):] = [ ' ' + x for x in l1[astart:a1] ]
168 delta[len(delta):] = [ '-' + x for x in old ]
169 delta[len(delta):] = [ '+' + x for x in new ]
170
171 if hunk:
172 for x in yieldhunk(hunk, header):
173 yield x
47 174
48 def patchtext(bin): 175 def patchtext(bin):
49 pos = 0 176 pos = 0
50 t = [] 177 t = []
51 while pos < len(bin): 178 while pos < len(bin):