Mercurial > hg
view mercurial/pure/bdiff.py @ 36958:644a02f6b34f
util: prefer "bytesio" to "stringio"
The io.BytesIO and io.StringIO types enforce the type of
data being operated on. On Python 2, we use cStringIO.StringIO(),
which is lax about mixing types. On Python 3, we actually use
io.BytesIO. Ideally, we'd use io.BytesIO on Python 2. But I believe
its performance is poor compared to cString.StringIO().
Anyway, we canonically define our pycompat type as "stringio."
That name is misleading, especially on Python 3.
This commit renames the canonical symbols to "bytesio."
"stringio" is preserved as an alias for API compatibility. There
are a lot of callers in the repo and I hesitate to take away the
old name. I also don't feel like changing everything at this time.
But at least new callers can use a "proper" name.
Differential Revision: https://phab.mercurial-scm.org/D2868
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Wed, 14 Mar 2018 11:52:35 -0700 |
parents | 29dd37a418aa |
children | 8b7973d40a01 |
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# bdiff.py - Python implementation of bdiff.c # # Copyright 2009 Matt Mackall <mpm@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 + '\n' for l in text.split('\n')] if lines: if lines[-1] == '\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 r.append(prev) return r def bdiff(a, b): a = bytes(a).splitlines(True) b = bytes(b).splitlines(True) 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)) 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 = "".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 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('[ \t\r]+', '', text) else: text = re.sub('[ \t\r]+', ' ', text) text = text.replace(' \n', '\n') return text def splitnewlines(text): '''like str.splitlines, but only split on newlines.''' lines = [l + '\n' for l in text.split('\n')] if lines: if lines[-1] == '\n': lines.pop() else: lines[-1] = lines[-1][:-1] return lines