mercurial/cffi/osutil.py

rebase: store rebase state after each commit

Before this patch, we stored the rebase state early in the processing
of a node, before we updated the rebase state to indicate that the
node was processed. This meant that we could redo the working copy
merge and run into conflicts. However, this only happened in the
--collapse case if the rebase was interrupted while editing the final
commit message; in the case earlier interruptions, we would instead
detect the in-process revision by finding two dirstate parents.

This patch moves the writing of the rebase state to after we have
completed the revision completely, and, importantly, after we have
updated the rebase state to mark it done. This means we'll realize
that all nodes have been rebased in the case mentioned above of
editing the final commit message of a --collapse. See change to test
case.

I also moved the writing outside of the large if/elif block in
_rebasenode(). This shouldn't matter much, but seems cleaner. One
observable effect is if rebase was interrupted just after ignoring an
obsolete node ("not rebasing ####, already in destination"), we used
to come up with the same decision after --continue too, but after this
patch we'll instead say "already rebased ###". This seems more
consistent, since that's what we would do with obsolete nodes that had
been marked done earlier in the process (not only just before the
interruption).

Differential Revision: https://phab.mercurial-scm.org/D2913

# osutil.py - CFFI version of osutil.c
#
# Copyright 2016 Maciej Fijalkowski <[e-mail]>
#
# 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 os
import stat as statmod

from ..pure.osutil import *

from .. import (
    pycompat,
)

if pycompat.isdarwin:
    from . import _osutil

    ffi = _osutil.ffi
    lib = _osutil.lib

    listdir_batch_size = 4096
    # tweakable number, only affects performance, which chunks
    # of bytes do we get back from getattrlistbulk

    attrkinds = [None] * 20 # we need the max no for enum VXXX, 20 is plenty

    attrkinds[lib.VREG] = statmod.S_IFREG
    attrkinds[lib.VDIR] = statmod.S_IFDIR
    attrkinds[lib.VLNK] = statmod.S_IFLNK
    attrkinds[lib.VBLK] = statmod.S_IFBLK
    attrkinds[lib.VCHR] = statmod.S_IFCHR
    attrkinds[lib.VFIFO] = statmod.S_IFIFO
    attrkinds[lib.VSOCK] = statmod.S_IFSOCK

    class stat_res(object):
        def __init__(self, st_mode, st_mtime, st_size):
            self.st_mode = st_mode
            self.st_mtime = st_mtime
            self.st_size = st_size

    tv_sec_ofs = ffi.offsetof("struct timespec", "tv_sec")
    buf = ffi.new("char[]", listdir_batch_size)

    def listdirinternal(dfd, req, stat, skip):
        ret = []
        while True:
            r = lib.getattrlistbulk(dfd, req, buf, listdir_batch_size, 0)
            if r == 0:
                break
            if r == -1:
                raise OSError(ffi.errno, os.strerror(ffi.errno))
            cur = ffi.cast("val_attrs_t*", buf)
            for i in range(r):
                lgt = cur.length
                assert lgt == ffi.cast('uint32_t*', cur)[0]
                ofs = cur.name_info.attr_dataoffset
                str_lgt = cur.name_info.attr_length
                base_ofs = ffi.offsetof('val_attrs_t', 'name_info')
                name = str(ffi.buffer(ffi.cast("char*", cur) + base_ofs + ofs,
                           str_lgt - 1))
                tp = attrkinds[cur.obj_type]
                if name == "." or name == "..":
                    continue
                if skip == name and tp == statmod.S_ISDIR:
                    return []
                if stat:
                    mtime = cur.mtime.tv_sec
                    mode = (cur.accessmask & ~lib.S_IFMT)| tp
                    ret.append((name, tp, stat_res(st_mode=mode, st_mtime=mtime,
                                st_size=cur.datalength)))
                else:
                    ret.append((name, tp))
                cur = ffi.cast("val_attrs_t*", int(ffi.cast("intptr_t", cur))
                    + lgt)
        return ret

    def listdir(path, stat=False, skip=None):
        req = ffi.new("struct attrlist*")
        req.bitmapcount = lib.ATTR_BIT_MAP_COUNT
        req.commonattr = (lib.ATTR_CMN_RETURNED_ATTRS |
                          lib.ATTR_CMN_NAME |
                          lib.ATTR_CMN_OBJTYPE |
                          lib.ATTR_CMN_ACCESSMASK |
                          lib.ATTR_CMN_MODTIME)
        req.fileattr = lib.ATTR_FILE_DATALENGTH
        dfd = lib.open(path, lib.O_RDONLY, 0)
        if dfd == -1:
            raise OSError(ffi.errno, os.strerror(ffi.errno))

        try:
            ret = listdirinternal(dfd, req, stat, skip)
        finally:
            try:
                lib.close(dfd)
            except BaseException:
                pass # we ignore all the errors from closing, not
                # much we can do about that
        return ret