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# Copyright 2010-2011 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
__all__ = ['movefile']
import errno
import os as _os
import shutil as _shutil
import stat
import portage
from portage import bsd_chflags, _encodings, _os_overrides, _selinux, \
_unicode_decode, _unicode_func_wrapper, _unicode_module_wrapper
from portage.const import MOVE_BINARY
from portage.localization import _
from portage.process import spawn
from portage.util import writemsg
if hasattr(_os, "getxattr"):
# Python >=3.3
def _copyxattr(src, dest):
for attr in _os.listxattr(src):
_os.setxattr(dest, attr, _os.getxattr(src, attr))
else:
def _copyxattr(src, dest):
pass
# Maybe call getfattr and setfattr executables.
def movefile(src, dest, newmtime=None, sstat=None, mysettings=None,
hardlink_candidates=None, encoding=_encodings['fs']):
"""moves a file from src to dest, preserving all permissions and attributes; mtime will
be preserved even when moving across filesystems. Returns true on success and false on
failure. Move is atomic."""
#print "movefile("+str(src)+","+str(dest)+","+str(newmtime)+","+str(sstat)+")"
if mysettings is None:
mysettings = portage.settings
selinux_enabled = mysettings.selinux_enabled()
if selinux_enabled:
selinux = _unicode_module_wrapper(_selinux, encoding=encoding)
lchown = _unicode_func_wrapper(portage.data.lchown, encoding=encoding)
os = _unicode_module_wrapper(_os,
encoding=encoding, overrides=_os_overrides)
shutil = _unicode_module_wrapper(_shutil, encoding=encoding)
try:
if not sstat:
sstat=os.lstat(src)
except SystemExit as e:
raise
except Exception as e:
print(_("!!! Stating source file failed... movefile()"))
print("!!!",e)
return None
destexists=1
try:
dstat=os.lstat(dest)
except (OSError, IOError):
dstat=os.lstat(os.path.dirname(dest))
destexists=0
if bsd_chflags:
if destexists and dstat.st_flags != 0:
bsd_chflags.lchflags(dest, 0)
# Use normal stat/chflags for the parent since we want to
# follow any symlinks to the real parent directory.
pflags = os.stat(os.path.dirname(dest)).st_flags
if pflags != 0:
bsd_chflags.chflags(os.path.dirname(dest), 0)
if destexists:
if stat.S_ISLNK(dstat[stat.ST_MODE]):
try:
os.unlink(dest)
destexists=0
except SystemExit as e:
raise
except Exception as e:
pass
if stat.S_ISLNK(sstat[stat.ST_MODE]):
try:
target=os.readlink(src)
if mysettings and mysettings["D"]:
if target.find(mysettings["D"])==0:
target=target[len(mysettings["D"]):]
if destexists and not stat.S_ISDIR(dstat[stat.ST_MODE]):
os.unlink(dest)
try:
if selinux_enabled:
selinux.symlink(target, dest, src)
else:
os.symlink(target, dest)
except OSError as e:
# Some programs will create symlinks automatically, so we have
# to tolerate these links being recreated during the merge
# process. In any case, if the link is pointing at the right
# place, we're in good shape.
if e.errno not in (errno.ENOENT, errno.EEXIST) or \
target != os.readlink(dest):
raise
lchown(dest,sstat[stat.ST_UID],sstat[stat.ST_GID])
# utime() only works on the target of a symlink, so it's not
# possible to perserve mtime on symlinks.
return os.lstat(dest)[stat.ST_MTIME]
except SystemExit as e:
raise
except Exception as e:
print(_("!!! failed to properly create symlink:"))
print("!!!",dest,"->",target)
print("!!!",e)
return None
hardlinked = False
# Since identical files might be merged to multiple filesystems,
# so os.link() calls might fail for some paths, so try them all.
# For atomic replacement, first create the link as a temp file
# and them use os.rename() to replace the destination.
if hardlink_candidates:
head, tail = os.path.split(dest)
hardlink_tmp = os.path.join(head, ".%s._portage_merge_.%s" % \
(tail, os.getpid()))
try:
os.unlink(hardlink_tmp)
except OSError as e:
if e.errno != errno.ENOENT:
writemsg(_("!!! Failed to remove hardlink temp file: %s\n") % \
(hardlink_tmp,), noiselevel=-1)
writemsg("!!! %s\n" % (e,), noiselevel=-1)
return None
del e
for hardlink_src in hardlink_candidates:
try:
os.link(hardlink_src, hardlink_tmp)
except OSError:
continue
else:
try:
os.rename(hardlink_tmp, dest)
except OSError as e:
writemsg(_("!!! Failed to rename %s to %s\n") % \
(hardlink_tmp, dest), noiselevel=-1)
writemsg("!!! %s\n" % (e,), noiselevel=-1)
return None
hardlinked = True
break
renamefailed=1
if hardlinked:
renamefailed = False
if not hardlinked and (selinux_enabled or sstat.st_dev == dstat.st_dev):
try:
if selinux_enabled:
selinux.rename(src, dest)
else:
os.rename(src,dest)
renamefailed=0
except OSError as e:
if e.errno != errno.EXDEV:
# Some random error.
print(_("!!! Failed to move %(src)s to %(dest)s") % {"src": src, "dest": dest})
print("!!!",e)
return None
# Invalid cross-device-link 'bind' mounted or actually Cross-Device
if renamefailed:
didcopy=0
if stat.S_ISREG(sstat[stat.ST_MODE]):
try: # For safety copy then move it over.
if selinux_enabled:
selinux.copyfile(src, dest + "#new")
_copyxattr(src, dest + "#new")
selinux.rename(dest + "#new", dest)
else:
shutil.copyfile(src, dest + "#new")
_copyxattr(src, dest + "#new")
os.rename(dest + "#new", dest)
didcopy=1
except SystemExit as e:
raise
except Exception as e:
print(_('!!! copy %(src)s -> %(dest)s failed.') % {"src": src, "dest": dest})
print("!!!",e)
return None
else:
#we don't yet handle special, so we need to fall back to /bin/mv
a = spawn([MOVE_BINARY, '-f', src, dest], env=os.environ)
if a != os.EX_OK:
writemsg(_("!!! Failed to move special file:\n"), noiselevel=-1)
writemsg(_("!!! '%(src)s' to '%(dest)s'\n") % \
{"src": _unicode_decode(src, encoding=encoding),
"dest": _unicode_decode(dest, encoding=encoding)}, noiselevel=-1)
writemsg("!!! %s\n" % a, noiselevel=-1)
return None # failure
try:
if didcopy:
# didcopy is True only if S_ISREG returned True
os.chown(dest,sstat[stat.ST_UID],sstat[stat.ST_GID])
os.chmod(dest, stat.S_IMODE(sstat[stat.ST_MODE])) # Sticky is reset on chown
os.unlink(src)
except SystemExit as e:
raise
except Exception as e:
print(_("!!! Failed to chown/chmod/unlink in movefile()"))
print("!!!",dest)
print("!!!",e)
return None
# Always use stat_obj[stat.ST_MTIME] for the integral timestamp which
# is returned, since the stat_obj.st_mtime float attribute rounds *up*
# if the nanosecond part of the timestamp is 999999881 ns or greater.
try:
if hardlinked:
newmtime = os.stat(dest)[stat.ST_MTIME]
else:
# Note: It is not possible to preserve nanosecond precision
# (supported in POSIX.1-2008 via utimensat) with the IEEE 754
# double precision float which only has a 53 bit significand.
if newmtime is not None:
os.utime(dest, (newmtime, newmtime))
else:
newmtime = sstat[stat.ST_MTIME]
if renamefailed:
# If rename succeeded then timestamps are automatically
# preserved with complete precision because the source
# and destination inode are the same. Otherwise, round
# down to the nearest whole second since python's float
# st_mtime cannot be used to preserve the st_mtim.tv_nsec
# field with complete precision. Note that we have to use
# stat_obj[stat.ST_MTIME] here because the float
# stat_obj.st_mtime rounds *up* sometimes.
os.utime(dest, (newmtime, newmtime))
except OSError:
# The utime can fail here with EPERM even though the move succeeded.
# Instead of failing, use stat to return the mtime if possible.
try:
newmtime = os.stat(dest)[stat.ST_MTIME]
except OSError as e:
writemsg(_("!!! Failed to stat in movefile()\n"), noiselevel=-1)
writemsg("!!! %s\n" % dest, noiselevel=-1)
writemsg("!!! %s\n" % str(e), noiselevel=-1)
return None
if bsd_chflags:
# Restore the flags we saved before moving
if pflags:
bsd_chflags.chflags(os.path.dirname(dest), pflags)
return newmtime
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