Mercurial > hg
view mercurial/pure/parsers.py @ 33822:42ad7cc645a4
copies: add more details to the documentation of mergecopies()
This documentation is very helpful for any developer to understand what
copytracing is and what the function does. Since this is the main function of
doing copytracing, I have also included bits about copytracing in it.
This additions are picked from a doc by Stash@Fb. So thanks to him.
Differential Revision: https://phab.mercurial-scm.org/D409
author | Pulkit Goyal <7895pulkit@gmail.com> |
---|---|
date | Wed, 16 Aug 2017 00:25:20 +0530 |
parents | df448de7cf3b |
children | 531332502568 |
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# parsers.py - Python implementation of parsers.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 struct import zlib from ..node import nullid from .. import pycompat stringio = pycompat.stringio _pack = struct.pack _unpack = struct.unpack _compress = zlib.compress _decompress = zlib.decompress # Some code below makes tuples directly because it's more convenient. However, # code outside this module should always use dirstatetuple. def dirstatetuple(*x): # x is a tuple return x indexformatng = ">Qiiiiii20s12x" indexfirst = struct.calcsize('Q') sizeint = struct.calcsize('i') indexsize = struct.calcsize(indexformatng) def gettype(q): return int(q & 0xFFFF) def offset_type(offset, type): return int(int(offset) << 16 | type) class BaseIndexObject(object): def __len__(self): return self._lgt + len(self._extra) + 1 def insert(self, i, tup): assert i == -1 self._extra.append(tup) def _fix_index(self, i): if not isinstance(i, int): raise TypeError("expecting int indexes") if i < 0: i = len(self) + i if i < 0 or i >= len(self): raise IndexError return i def __getitem__(self, i): i = self._fix_index(i) if i == len(self) - 1: return (0, 0, 0, -1, -1, -1, -1, nullid) if i >= self._lgt: return self._extra[i - self._lgt] index = self._calculate_index(i) r = struct.unpack(indexformatng, self._data[index:index + indexsize]) if i == 0: e = list(r) type = gettype(e[0]) e[0] = offset_type(0, type) return tuple(e) return r class IndexObject(BaseIndexObject): def __init__(self, data): assert len(data) % indexsize == 0 self._data = data self._lgt = len(data) // indexsize self._extra = [] def _calculate_index(self, i): return i * indexsize def __delitem__(self, i): if not isinstance(i, slice) or not i.stop == -1 or not i.step is None: raise ValueError("deleting slices only supports a:-1 with step 1") i = self._fix_index(i.start) if i < self._lgt: self._data = self._data[:i * indexsize] self._lgt = i self._extra = [] else: self._extra = self._extra[:i - self._lgt] class InlinedIndexObject(BaseIndexObject): def __init__(self, data, inline=0): self._data = data self._lgt = self._inline_scan(None) self._inline_scan(self._lgt) self._extra = [] def _inline_scan(self, lgt): off = 0 if lgt is not None: self._offsets = [0] * lgt count = 0 while off <= len(self._data) - indexsize: s, = struct.unpack('>i', self._data[off + indexfirst:off + sizeint + indexfirst]) if lgt is not None: self._offsets[count] = off count += 1 off += indexsize + s if off != len(self._data): raise ValueError("corrupted data") return count def __delitem__(self, i): if not isinstance(i, slice) or not i.stop == -1 or not i.step is None: raise ValueError("deleting slices only supports a:-1 with step 1") i = self._fix_index(i.start) if i < self._lgt: self._offsets = self._offsets[:i] self._lgt = i self._extra = [] else: self._extra = self._extra[:i - self._lgt] def _calculate_index(self, i): return self._offsets[i] def parse_index2(data, inline): if not inline: return IndexObject(data), None return InlinedIndexObject(data, inline), (0, data) def parse_dirstate(dmap, copymap, st): parents = [st[:20], st[20: 40]] # dereference fields so they will be local in loop format = ">cllll" e_size = struct.calcsize(format) pos1 = 40 l = len(st) # the inner loop while pos1 < l: pos2 = pos1 + e_size e = _unpack(">cllll", st[pos1:pos2]) # a literal here is faster pos1 = pos2 + e[4] f = st[pos2:pos1] if '\0' in f: f, c = f.split('\0') copymap[f] = c dmap[f] = e[:4] return parents def pack_dirstate(dmap, copymap, pl, now): now = int(now) cs = stringio() write = cs.write write("".join(pl)) for f, e in dmap.iteritems(): if e[0] == 'n' and e[3] == now: # The file was last modified "simultaneously" with the current # write to dirstate (i.e. within the same second for file- # systems with a granularity of 1 sec). This commonly happens # for at least a couple of files on 'update'. # The user could change the file without changing its size # within the same second. Invalidate the file's mtime in # dirstate, forcing future 'status' calls to compare the # contents of the file if the size is the same. This prevents # mistakenly treating such files as clean. e = dirstatetuple(e[0], e[1], e[2], -1) dmap[f] = e if f in copymap: f = "%s\0%s" % (f, copymap[f]) e = _pack(">cllll", e[0], e[1], e[2], e[3], len(f)) write(e) write(f) return cs.getvalue()