Mercurial > hg
view mercurial/pure/bdiff.py @ 47509:80dc1d452993
dirstate-entry: introduce dedicated accessors for v1 serialization
In the spirit of changing the content and storage of the dirstate entry, we add
new method that the code doing v1 serialisation can use.
Adding such method to the C object is quite trivial.
Differential Revision: https://phab.mercurial-scm.org/D10951
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
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date | Sat, 03 Jul 2021 04:01:17 +0200 |
parents | d4ba4d51f85f |
children | 6000f5b25c9b |
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# bdiff.py - Python implementation of bdiff.c # # Copyright 2009 Olivia Mackall <olivia@selenic.com> and others # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import difflib import re import struct def splitnewlines(text): '''like str.splitlines, but only split on newlines.''' lines = [l + b'\n' for l in text.split(b'\n')] if lines: if lines[-1] == b'\n': lines.pop() else: lines[-1] = lines[-1][:-1] return lines def _normalizeblocks(a, b, blocks): prev = None r = [] for curr in blocks: if prev is None: prev = curr continue shift = 0 a1, b1, l1 = prev a1end = a1 + l1 b1end = b1 + l1 a2, b2, l2 = curr a2end = a2 + l2 b2end = b2 + l2 if a1end == a2: while ( a1end + shift < a2end and a[a1end + shift] == b[b1end + shift] ): shift += 1 elif b1end == b2: while ( b1end + shift < b2end and a[a1end + shift] == b[b1end + shift] ): shift += 1 r.append((a1, b1, l1 + shift)) prev = a2 + shift, b2 + shift, l2 - shift if prev is not None: r.append(prev) return r def bdiff(a, b): a = bytes(a).splitlines(True) b = bytes(b).splitlines(True) if not a: s = b"".join(b) return s and (struct.pack(b">lll", 0, 0, len(s)) + s) bin = [] p = [0] for i in a: p.append(p[-1] + len(i)) d = difflib.SequenceMatcher(None, a, b).get_matching_blocks() d = _normalizeblocks(a, b, d) la = 0 lb = 0 for am, bm, size in d: s = b"".join(b[lb:bm]) if am > la or s: bin.append(struct.pack(b">lll", p[la], p[am], len(s)) + s) la = am + size lb = bm + size return b"".join(bin) def blocks(a, b): an = splitnewlines(a) bn = splitnewlines(b) d = difflib.SequenceMatcher(None, an, bn).get_matching_blocks() d = _normalizeblocks(an, bn, d) return [(i, i + n, j, j + n) for (i, j, n) in d] def fixws(text, allws): if allws: text = re.sub(b'[ \t\r]+', b'', text) else: text = re.sub(b'[ \t\r]+', b' ', text) text = text.replace(b' \n', b'\n') return text