Mercurial > hg
view mercurial/pure/bdiff.py @ 29925:1619efcde9a4
manifest: make one use of _mancache avoid manifestctxs
In a future patch we will change manifestctx and treemanifestctx to no longer
derive from manifestdict and treemanifest, respectively. This means that
consumers of the _mancache will now need to be aware of the different between
the two, until we get rid of the manifest entirely and the _mancache becomes
only filled with ctxs.
This fixes one case of it that can be fixed by using the other cache. Future
patches will address the others uses using the upcoming manifestctx.read()
function.
author | Durham Goode <durham@fb.com> |
---|---|
date | Mon, 12 Sep 2016 14:29:09 -0700 |
parents | 1ea77b75d266 |
children | d24e03da24b5 |
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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 array import difflib import re import struct from . import policy policynocffi = policy.policynocffi modulepolicy = policy.policy 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 _tostring(c): if type(c) is array.array: # this copy overhead isn't ideal return c.tostring() return str(c) def bdiff(a, b): a = _tostring(a).splitlines(True) b = _tostring(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 if modulepolicy not in policynocffi: try: from _bdiff_cffi import ffi, lib except ImportError: if modulepolicy == 'cffi': # strict cffi import raise else: def blocks(sa, sb): a = ffi.new("struct bdiff_line**") b = ffi.new("struct bdiff_line**") ac = ffi.new("char[]", sa) bc = ffi.new("char[]", sb) l = ffi.new("struct bdiff_hunk*") try: an = lib.bdiff_splitlines(ac, len(sa), a) bn = lib.bdiff_splitlines(bc, len(sb), b) if not a[0] or not b[0]: raise MemoryError count = lib.bdiff_diff(a[0], an, b[0], bn, l) if count < 0: raise MemoryError rl = [None] * count h = l.next i = 0 while h: rl[i] = (h.a1, h.a2, h.b1, h.b2) h = h.next i += 1 finally: lib.free(a[0]) lib.free(b[0]) lib.bdiff_freehunks(l.next) return rl def bdiff(sa, sb): a = ffi.new("struct bdiff_line**") b = ffi.new("struct bdiff_line**") ac = ffi.new("char[]", sa) bc = ffi.new("char[]", sb) l = ffi.new("struct bdiff_hunk*") try: an = lib.bdiff_splitlines(ac, len(sa), a) bn = lib.bdiff_splitlines(bc, len(sb), b) if not a[0] or not b[0]: raise MemoryError count = lib.bdiff_diff(a[0], an, b[0], bn, l) if count < 0: raise MemoryError rl = [] h = l.next la = lb = 0 while h: if h.a1 != la or h.b1 != lb: lgt = (b[0] + h.b1).l - (b[0] + lb).l rl.append(struct.pack(">lll", (a[0] + la).l - a[0].l, (a[0] + h.a1).l - a[0].l, lgt)) rl.append(str(ffi.buffer((b[0] + lb).l, lgt))) la = h.a2 lb = h.b2 h = h.next finally: lib.free(a[0]) lib.free(b[0]) lib.bdiff_freehunks(l.next) return "".join(rl)