diff options
Diffstat (limited to 'Tools/scripts/ndiff.py')
| -rwxr-xr-x | Tools/scripts/ndiff.py | 248 |
1 files changed, 88 insertions, 160 deletions
diff --git a/Tools/scripts/ndiff.py b/Tools/scripts/ndiff.py index 4767d1f..3f453af 100755 --- a/Tools/scripts/ndiff.py +++ b/Tools/scripts/ndiff.py @@ -1,16 +1,50 @@ #! /usr/bin/env python -# Released to the public domain $JustDate: 3/16/98 $, -# by Tim Peters (email tim_one@email.msn.com). +# Module ndiff version 1.3.0 +# Released to the public domain 26-Mar-1999, +# by Tim Peters (tim_one@email.msn.com). -# ndiff file1 file2 -- a human-friendly file differencer. +# Provided as-is; use at your own risk; no warranty; no promises; enjoy! -# $Revision$ +"""ndiff [-q] file1 file2 + +Print a human-friendly file difference report to stdout. Both inter- +and intra-line differences are noted. + +If -q ("quiet") is not specified, the first two lines of output are + +-: file1 ++: file2 + +Each remaining line begins with a two-letter code: + + "- " line unique to file1 + "+ " line unique to file2 + " " line common to both files + "? " line not present in either input file + +Lines beginning with "? " attempt to guide the eye to intraline +differences, and were not present in either input file. + +The first file can be recovered by retaining only lines that begin with +" " or "- ", and deleting those 2-character prefixes. + +The second file can be recovered similarly, but by retaining only " " +and "+ " lines. On Unix, the second file can be recovered by piping the +output through + sed -n '/^[+ ] /s/^..//p' +Modifications to recover the first file are left as an exercise for +the reader. + +See module comments for details and programmatic interface. +""" + +__version__ = 1, 3, 0 # SequenceMatcher tries to compute a "human-friendly diff" between # two sequences (chiefly picturing a file as a sequence of lines, -# and a line as a sequence of characters, here). Unlike UNIX(tm) diff, -# e.g., the fundamental notion is the longest *contiguous* & junk-free +# and a line as a sequence of characters, here). Unlike e.g. UNIX(tm) +# diff, the fundamental notion is the longest *contiguous* & junk-free # matching subsequence. That's what catches peoples' eyes. The # Windows(tm) windiff has another interesting notion, pairing up elements # that appear uniquely in each sequence. That, and the method here, @@ -26,11 +60,11 @@ # apart. Restricting synch points to contiguous matches preserves some # notion of locality, at the occasional cost of producing a longer diff. # -# With respect to junk, an earlier verion of ndiff simply refused to +# With respect to junk, an earlier version of ndiff simply refused to # *start* a match with a junk element. The result was cases like this: # before: private Thread currentThread; # after: private volatile Thread currentThread; -# If you consider whitespace to be junk, the longest continguous match +# If you consider whitespace to be junk, the longest contiguous match # not starting with junk is "e Thread currentThread". So ndiff reported # that "e volatil" was inserted between the 't' and the 'e' in "private". # While an accurate view, to people that's absurd. The current version @@ -40,23 +74,9 @@ # preceding blank; then "private" is matched, and extended to suck up the # following blank; then "Thread" is matched; and finally ndiff reports # that "volatile " was inserted before "Thread". The only quibble -# remaining is that perhaps it was really the case that " volative" +# remaining is that perhaps it was really the case that " volatile" # was inserted after "private". I can live with that <wink>. # -# NOTE on the output: From an ndiff report, -# 1) The first file can be recovered by retaining only lines that begin -# with " " or "- ", and deleting those 2-character prefixes. -# 2) The second file can be recovered similarly, but by retaining only -# " " and "+ " lines. -# 3) Lines beginning with "? " attempt to guide the eye to intraline -# differences, and were not present in either input file. -# -# COROLLARY: -# On Unix, the second file can be recovered by piping the output through -# sed -n '/^[+ ] /s/^..//p' -# Modifications to recover the first file are left as an exercise for -# the reader. -# # NOTE on junk: the module-level names # IS_LINE_JUNK # IS_CHARACTER_JUNK @@ -70,8 +90,8 @@ # # After setting those, you can call fcompare(f1name, f2name) with the # names of the files you want to compare. The difference report -# is sent to stdout. Or you can call main(), which expects to find -# (exactly) the two file names in sys.argv. +# is sent to stdout. Or you can call main(args), passing what would +# have been in sys.argv[1:] had the cmd-line form been used. import string TRACE = 0 @@ -148,7 +168,7 @@ class SequenceMatcher: self.fullbcount = None self.__chain_b() - # for each element x in b, set b2j[x] to a list of the indices in + # For each element x in b, set b2j[x] to a list of the indices in # b where x appears; the indices are in increasing order; note that # the number of times x appears in b is len(b2j[x]) ... # when self.isjunk is defined, junk elements don't show up in this @@ -173,7 +193,7 @@ class SequenceMatcher: b = self.b self.b2j = b2j = {} self.b2jhas = b2jhas = b2j.has_key - for i in xrange(0, len(b)): + for i in xrange(len(b)): elt = b[i] if b2jhas(elt): b2j[elt].append(i) @@ -210,9 +230,9 @@ class SequenceMatcher: k >= k' i <= i' and if i == i', j <= j' - In other words, of all maximal matching blocks, returns one + In other words, of all maximal matching blocks, return one that starts earliest in a, and of all those maximal matching - blocks that start earliest in a, returns the one that starts + blocks that start earliest in a, return the one that starts earliest in b. If isjunk is defined, first the longest matching block is @@ -223,7 +243,7 @@ class SequenceMatcher: as identical junk happens to be adjacent to an "interesting" match. - If no blocks match, returns (alo, blo, 0). + If no blocks match, return (alo, blo, 0). """ # CAUTION: stripping common prefix or suffix would be incorrect. @@ -238,40 +258,28 @@ class SequenceMatcher: # Windiff ends up at the same place as diff, but by pairing up # the unique 'b's and then matching the first two 'a's. - # find longest junk-free match a, b, b2j, isbjunk = self.a, self.b, self.b2j, self.isbjunk besti, bestj, bestsize = alo, blo, 0 + # find longest junk-free match + # during an iteration of the loop, j2len[j] = length of longest + # junk-free match ending with a[i-1] and b[j] + j2len = {} + nothing = [] for i in xrange(alo, ahi): - # check for longest match starting at a[i] - if i + bestsize >= ahi: - # we're too far right to get a new best - break # look at all instances of a[i] in b; note that because # b2j has no junk keys, the loop is skipped if a[i] is junk - for j in b2j.get(a[i], []): + j2lenget = j2len.get + newj2len = {} + for j in b2j.get(a[i], nothing): # a[i] matches b[j] if j < blo: continue - if j + bestsize >= bhi: - # we're too far right to get a new best, here or - # anywhere to the right + if j >= bhi: break - if a[i + bestsize] != b[j + bestsize]: - # can't be longer match; this test is not necessary - # for correctness, but is a huge win for efficiency - continue - # set k to length of match - k = 1 # a[i] == b[j] already known - while i + k < ahi and j + k < bhi and \ - a[i+k] == b[j+k] and not isbjunk(b[j+k]): - k = k + 1 + k = newj2len[j] = j2lenget(j-1, 0) + 1 if k > bestsize: - besti, bestj, bestsize = i, j, k - if i + bestsize >= ahi: - # only time in my life I really wanted a - # labelled break <wink> -- we're done with - # both loops now - break + besti, bestj, bestsize = i-k+1, j-k+1, k + j2len = newj2len # Now that we have a wholly interesting match (albeit possibly # empty!), we may as well suck up the matching junk on each @@ -294,101 +302,6 @@ class SequenceMatcher: print " returns", besti, bestj, bestsize return besti, bestj, bestsize -# A different implementation, using a binary doubling technique that -# does far fewer element compares (trades 'em for integer compares), -# and has n*lg n worst-case behavior. Alas, the code is much harder -# to follow (the details are tricky!), and in most cases I've seen, -# it takes at least 50% longer than the "clever dumb" method above; -# probably due to creating layers of small dicts. -# NOTE: this no longer matches the version above wrt junk; remains -# too unpromising to update it; someday, though ... - -# def find_longest_match(self, alo, ahi, blo, bhi): -# """Find longest matching block in a[alo:ahi] and b[blo:bhi]. -# -# Return (i,j,k) such that a[i:i+k] is equal to b[j:j+k], where -# alo <= i <= i+k <= ahi -# blo <= j <= j+k <= bhi -# and for all (i',j',k') meeting those conditions, -# k >= k' -# i <= i' -# and if i == i', j <= j' -# In other words, of all maximal matching blocks, returns one -# that starts earliest in a, and of all those maximal matching -# blocks that start earliest in a, returns the one that starts -# earliest in b. -# -# If no blocks match, returns (alo, blo, 0). -# """ -# -# a, b2j = self.a, self.b2j -# # alljs[size][i] is a set of all j's s.t. a[i:i+len] matches -# # b[j:j+len] -# alljs = {} -# alljs[1] = js = {} -# ahits = {} -# for i in xrange(alo, ahi): -# elt = a[i] -# if ahits.has_key(elt): -# js[i] = ahits[elt] -# continue -# if b2j.has_key(elt): -# in_range = {} -# for j in b2j[elt]: -# if j >= blo: -# if j >= bhi: -# break -# in_range[j] = 1 -# if in_range: -# ahits[elt] = js[i] = in_range -# del ahits -# size = 1 -# while js: -# oldsize = size -# size = size + size -# oldjs = js -# alljs[size] = js = {} -# for i in oldjs.keys(): -# # i has matches of size oldsize -# if not oldjs.has_key(i + oldsize): -# # can't double it -# continue -# second_js = oldjs[i + oldsize] -# answer = {} -# for j in oldjs[i].keys(): -# if second_js.has_key(j + oldsize): -# answer[j] = 1 -# if answer: -# js[i] = answer -# del alljs[size] -# size = size >> 1 # max power of 2 with a match -# if not size: -# return alo, blo, 0 -# besti, bestj, bestsize = alo, blo, 0 -# fatis = alljs[size].keys() -# fatis.sort() -# for i in fatis: -# # figure out longest match starting at a[i] -# totalsize = halfsize = size -# # i has matches of len totalsize at the indices in js -# js = alljs[size][i].keys() -# while halfsize > 1: -# halfsize = halfsize >> 1 -# # is there a match of len halfsize starting at -# # i + totalsize? -# newjs = [] -# if alljs[halfsize].has_key(i + totalsize): -# second_js = alljs[halfsize][i + totalsize] -# for j in js: -# if second_js.has_key(j + totalsize): -# newjs.append(j) -# if newjs: -# totalsize = totalsize + halfsize -# js = newjs -# if totalsize > bestsize: -# besti, bestj, bestsize = i, min(js), totalsize -# return besti, bestj, bestsize - def get_matching_blocks(self): if self.matching_blocks is not None: return self.matching_blocks @@ -621,7 +534,7 @@ def fopen(fname): try: return open(fname, 'r') except IOError, detail: - print "couldn't open " + fname + ": " + `detail` + print "couldn't open " + fname + ": " + str(detail) return 0 # open two files & spray the diff to stdout; return false iff a problem @@ -649,24 +562,39 @@ def fcompare(f1name, f2name): return 1 -# get file names from argv & compare; return false iff a problem -def main(): - from sys import argv - if len(argv) != 3: +# crack args (sys.argv[1:] is normal) & compare; +# return false iff a problem + +def main(args): + import getopt + try: + opts, args = getopt.getopt(args, "q") + except getopt.error, detail: + print str(detail) + print __doc__ + return 0 + noisy = 1 + for opt, val in opts: + if opt == "-q": + noisy = 0 + if len(args) != 2: print 'need 2 args' + print __doc__ return 0 - [f1name, f2name] = argv[1:3] - print '-:', f1name - print '+:', f2name + f1name, f2name = args + if noisy: + print '-:', f1name + print '+:', f2name return fcompare(f1name, f2name) if __name__ == '__main__': + import sys + args = sys.argv[1:] if 1: - main() + main(args) else: import profile, pstats statf = "ndiff.pro" - profile.run("main()", statf) + profile.run("main(args)", statf) stats = pstats.Stats(statf) stats.strip_dirs().sort_stats('time').print_stats() - |