view mercurial/mdiff.py @ 766:b444a7e053f1

Get addremove to use new walk code.

It is now more verbose than it used to be.  If given file names, it
prints nothing, as before.  But if given patterns or nothing, it prints
the names of the files it is operating on, to remove that air of mystery.

It also now operates at or below the current directory.

# mdiff.py - diff and patch routines for mercurial
#
# Copyright 2005 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.

import difflib, struct, bdiff
from mpatch import *

def unidiff(a, ad, b, bd, fn, r=None):

    if not a and not b: return ""

    if a == None:
        b = b.splitlines(1)
        l1 = "--- %s\t%s\n" % ("/dev/null", ad)
        l2 = "+++ %s\t%s\n" % ("b/" + fn, bd)
        l3 = "@@ -0,0 +1,%d @@\n" % len(b)
        l = [l1, l2, l3] + ["+" + e for e in b]
    elif b == None:
        a = a.splitlines(1)
        l1 = "--- %s\t%s\n" % ("a/" + fn, ad)
        l2 = "+++ %s\t%s\n" % ("/dev/null", bd)
        l3 = "@@ -1,%d +0,0 @@\n" % len(a)
        l = [l1, l2, l3] + ["-" + e for e in a]
    else:
        a = a.splitlines(1)
        b = b.splitlines(1)
        l = list(difflib.unified_diff(a, b, "a/" + fn, "b/" + fn))
        if not l: return ""
        # difflib uses a space, rather than a tab
        l[0] = l[0][:-2] + "\t" + ad + "\n"
        l[1] = l[1][:-2] + "\t" + bd + "\n"

    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)

def sortdiff(a, b):
    la = lb = 0
    lena = len(a)
    lenb = len(b)

    while 1:
        am, bm, = la, lb

        # walk over matching lines
        while lb < lenb and la < lena and a[la] == b[lb] :
            la += 1
            lb += 1

        if la > am:
            yield (am, bm, la - am) # return a match

        # skip mismatched lines from b
        while la < lena and lb < lenb and b[lb] < a[la]:
            lb += 1

        if lb >= lenb:
            break

        # skip mismatched lines from a
        while la < lena and lb < lenb and b[lb] > a[la]:
            la += 1

        if la >= lena:
            break

    yield (lena, lenb, 0)

def diff(a, b, sorted=0):
    if not a:
        s = "".join(b)
        return s and (struct.pack(">lll", 0, 0, len(s)) + s)

    bin = []
    p = [0]
    for i in a: p.append(p[-1] + len(i))

    if sorted:
        try:
            d = sortdiff(a, b)
        except:
            raise
    else:
        d = difflib.SequenceMatcher(None, a, b).get_matching_blocks()
    la = 0
    lb = 0
    for am, bm, size in d:
        s = "".join(b[lb:bm])
        if am > la or s:
            bin.append(struct.pack(">lll", p[la], p[am], len(s)) + s)
        la = am + size
        lb = bm + size

    return "".join(bin)

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 patches(a, [bin])

textdiff = bdiff.bdiff