2013-10-16 23:03 Mike Frysinger napisał(a): > Rather than each module implementing its own shim around the various > methods for accessing extended attributes, start a dedicated module > that exports a consistent API.
Some things are incompatible with Python 3.
See other comments below.
> ---
> bin/xattr-helper.py | 11 +--
> pym/portage/util/_xattr.py | 189
> +++++++++++++++++++++++++++++++++++++++++++
> pym/portage/util/movefile.py | 99 ++++++-----------------
> 3 files changed, 213 insertions(+), 86 deletions(-)
> create mode 100644 pym/portage/util/_xattr.py
>
> diff --git a/bin/xattr-helper.py b/bin/xattr-helper.py
> index 6d99521..69b83f7 100755
> --- a/bin/xattr-helper.py
> +++ b/bin/xattr-helper.py
> @@ -17,16 +17,7 @@ import re
> import sys
>
> from portage.util._argparse import ArgumentParser
> -
> -if hasattr(os, "getxattr"):
> -
> - class xattr(object):
> - get = os.getxattr
> - set = os.setxattr
> - list = os.listxattr
> -
> -else:
> - import xattr
> +from portage.util._xattr import xattr
>
>
> _UNQUOTE_RE = re.compile(br'\\[0-7]{3}')
> diff --git a/pym/portage/util/_xattr.py b/pym/portage/util/_xattr.py
> new file mode 100644
> index 0000000..0e594f9
> --- /dev/null
> +++ b/pym/portage/util/_xattr.py
> @@ -0,0 +1,189 @@
> +# Copyright 2010-2013 Gentoo Foundation
> +# Distributed under the terms of the GNU General Public License v2
> +
> +"""Portability shim for xattr support
> +
> +Exported API is the xattr object with get/get_all/set/remove/list operations.
> +
> +See the standard xattr module for more documentation.
> +"""
> +
> +import contextlib
> +import os
> +import subprocess
> +
> +from portage.exception import OperationNotSupported
> +
> +
> +class _XattrGetAll(object):
> + """Implement get_all() using list()/get() if there is no easy bulk
> method"""
> +
> + @classmethod
> + def get_all(cls, item, nofollow=False, namespace=None):
> + return [(name, cls.get(item, name, nofollow=nofollow,
> namespace=namespace))
> + for name in cls.list(item, nofollow=nofollow,
> namespace=namespace)]
> +
> +
> +class _XattrSystemCommands(_XattrGetAll):
> + """Implement things with getfattr/setfattr"""
> +
> + @staticmethod
> + def _parse_output(output):
> + for line in proc.stdout.readlines():
NameError: global name 'proc' is not defined
> + if line.startswith('#'):
> + continue
> + line = line.rstrip()
> + if not line:
> + continue
> + # The line will have the format:
> + # user.name0="value0"
> + yield line.split('=', 1)
> +
> + @classmethod
> + def get(item, name, nofollow=False, namespace=None):
> + if namespace:
> + name = '%s.%s' % (namespace, name)
> + cmd = ['getfattr', '--absolute-names', '-n', name, item]
> + if nofollow:
> + cmd += ['-h']
> + proc = subprocess.call(cmd, stdout=subprocess.PIPE,
> stderr=subprocess.PIPE)
> + proc.wait()
AttributeError: 'int' object has no attribute 'wait'
> +
> + value = None
> + for _, value in cls._parse_output(proc.stdout):
> + break
> +
> + proc.stdout.close()
> + return value
> +
> + @staticmethod
> + def set(item, name, value, flags=0, namespace=None):
> + if namespace:
> + name = '%s.%s' % (namespace, name)
> + cmd = ['setfattr', '-n', name, '-v', value, item]
Calling setfattr once per attribute is slower than once per file (as is now).
> + subprocess.call(cmd)
> +
> + @staticmethod
> + def remove(item, name, nofollow=False, namespace=None):
> + if namespace:
> + name = '%s.%s' % (namespace, name)
> + cmd = ['setfattr', '-x', name, item]
> + subprocess.call(cmd)
> +
> + @classmethod
> + def list(cls, item, nofollow=False, namespace=None, _names_only=True):
> + cmd = ['getfattr', '-d', '--absolute-names', item]
> + if nofollow:
> + cmd += ['-h']
> + cmd += ['-m', ('^%s[.]' % namespace) if namespace else '']
> + proc = subprocess.call(cmd, stdout=subprocess.PIPE,
> stderr=subprocess.PIPE)
> + proc.wait()
AttributeError: 'int' object has no attribute 'wait'
> +
> + ret = []
> + if namespace:
> + namespace = '%s.' % namespace
> + for name, value in cls._parse_output(proc.stdout):
> + if namespace:
> + if name.startswith(namespace):
> + name = name[len(namespace):]
> + else:
> + continue
> + if _names_only:
> + ret.append(name)
> + else:
> + ret.append((name, value))
> +
> + proc.stdout.close()
> + return ret
> +
> + @classmethod
> + def get_all(cls, item, nofollow=False, namespace=None):
> + cls.list(item, nofollow=nofollow, namespace=namespace,
> _names_only=False)
> +
> +
> +class _XattrStub(_XattrGetAll):
> + """Fake object since system doesn't support xattrs"""
> +
> + @staticmethod
> + def _raise():
> + e = OSError('stub')
> + e.errno = OperationNotSupported.errno
> + raise e
> +
> + @staticmethod
> + def get(item, name, nofollow=False, namespace=None):
> + raise OperationNotSupported('stub')
> +
> + @staticmethod
> + def set(item, name, value, flags=0, namespace=None):
> + raise OperationNotSupported('stub')
> +
> + @staticmethod
> + def remove(item, name, nofollow=False, namespace=None):
> + raise OperationNotSupported('stub')
> +
> + @staticmethod
> + def list(item, nofollow=False, namespace=None):
> + raise OperationNotSupported('stub')
> +
> +
> +if hasattr(os, 'getxattr'):
> + # Easy as pie -- active python supports it.
> + class xattr(_XattrGetAll):
> + """Python >=3.3 and GNU/Linux"""
> + get = os.getxattr
> + set = os.setxattr
> + remove = os.removexattr
> + list = os.listxattr
> +
> +else:
> + try:
> + # Maybe we have the xattr module.
> + import xattr
> +
> + except ImportError:
> + try:
> + # Maybe we have the attr package.
> + with open(os.devnull, 'wb') as f:
> + subprocess.call(['getfattr', '--version'],
> stdout=f)
> + subprocess.call(['setfattr', '--version'],
> stdout=f)
> + xattr = _XattrSystemCommands
> +
> + except OSError:
> + # Stub it out completely.
> + xattr = _XattrStub
> +
> +
> +@contextlib.contextmanager
> +def preserve_xattrs(path, nofollow=False, namespace=None):
> + """Context manager to save/restore extended attributes on |path|
> +
> + If you want to rewrite a file (possibly replacing it with a new one),
> but
> + want to preserve the extended attributes, this will do the trick.
> +
> + # First read all the extended attributes.
> + with save_xattrs('/some/file'):
> + ... rewrite the file ...
> + # Now the extended attributes are restored as needed.
> + """
> + kwargs = {
> + 'nofollow': nofollow,
> + 'namespace': namespace,
> + }
> + old_attrs = dict(xattr.get_all(path, **kwargs))
> + try:
> + yield
> + finally:
> + new_attrs = dict(xattrs.get_all(path, **kwargs))
> + for name, value in new_attrs.iteritems():
> + if name not in old_attrs:
> + # Clear out new ones.
> + xattr.remove(path, name, **kwargs)
> + elif new_attrs[name] != old:
> + # Update changed ones.
> + xattr.set(path, name, value, **kwargs)
> +
> + for name, value in old_attrs.iteritems():
> + if name not in new_attr:
> + # Re-add missing ones.
> + xattr.set(path, name, value, **kwargs)
> diff --git a/pym/portage/util/movefile.py b/pym/portage/util/movefile.py
> index 4f158cd..553374a 100644
> --- a/pym/portage/util/movefile.py
> +++ b/pym/portage/util/movefile.py
> @@ -23,6 +23,7 @@ from portage.exception import OperationNotSupported
> from portage.localization import _
> from portage.process import spawn
> from portage.util import writemsg
> +from portage.util._xattr import xattr
>
> def _apply_stat(src_stat, dest):
> _os.chown(dest, src_stat.st_uid, src_stat.st_gid)
> @@ -68,86 +69,32 @@ class _xattr_excluder(object):
>
> return False
>
> -if hasattr(_os, "getxattr"):
> - # Python >=3.3 and GNU/Linux
> - def _copyxattr(src, dest, exclude=None):
> -
> - try:
> - attrs = _os.listxattr(src)
> - except OSError as e:
> - if e.errno != OperationNotSupported.errno:
> - raise
> - attrs = ()
> - if attrs:
> - if exclude is not None and isinstance(attrs[0], bytes):
> - exclude = exclude.encode(_encodings['fs'])
> - exclude = _get_xattr_excluder(exclude)
> -
> - for attr in attrs:
> - if exclude(attr):
> - continue
> - try:
> - _os.setxattr(dest, attr, _os.getxattr(src,
> attr))
> - raise_exception = False
> - except OSError:
> - raise_exception = True
> - if raise_exception:
> - raise OperationNotSupported(_("Filesystem
> containing file '%s' "
> - "does not support extended attribute
> '%s'") %
> - (_unicode_decode(dest),
> _unicode_decode(attr)))
> -else:
> +def _copyxattr(src, dest, exclude=None):
> + """Copy the extended attributes from |src| to |dest|"""
> try:
> - import xattr
> - except ImportError:
> - xattr = None
> - if xattr is not None:
> - def _copyxattr(src, dest, exclude=None):
> -
> - try:
> - attrs = xattr.list(src)
> - except IOError as e:
> - if e.errno != OperationNotSupported.errno:
> - raise
> - attrs = ()
> + attrs = xattr.list(src)
> + except (OSError, IOError) as e:
> + if e.errno != OperationNotSupported.errno:
> + raise
> + attrs = ()
>
> - if attrs:
> - if exclude is not None and isinstance(attrs[0],
> bytes):
> - exclude =
> exclude.encode(_encodings['fs'])
> - exclude = _get_xattr_excluder(exclude)
> + if attrs:
> + if exclude is not None and isinstance(attrs[0], bytes):
> + exclude = exclude.encode(_encodings['fs'])
> + exclude = _get_xattr_excluder(exclude)
>
> - for attr in attrs:
> - if exclude(attr):
> - continue
> - try:
> - xattr.set(dest, attr, xattr.get(src,
> attr))
> - raise_exception = False
> - except IOError:
> - raise_exception = True
> - if raise_exception:
> - raise
> OperationNotSupported(_("Filesystem containing file '%s' "
> - "does not support extended
> attribute '%s'") %
> - (_unicode_decode(dest),
> _unicode_decode(attr)))
> - else:
> + for attr in attrs:
> + if exclude(attr):
> + continue
> try:
> - with open(os.devnull, 'wb') as f:
> - subprocess.call(["getfattr", "--version"],
> stdout=f)
> - subprocess.call(["setfattr", "--version"],
> stdout=f)
> - except OSError:
> - def _copyxattr(src, dest, exclude=None):
> - # TODO: implement exclude
> - getfattr_process =
> subprocess.Popen(["getfattr", "-d", "--absolute-names", src],
> stdout=subprocess.PIPE)
> - getfattr_process.wait()
> - extended_attributes =
> getfattr_process.stdout.readlines()
> - getfattr_process.stdout.close()
> - if extended_attributes:
> - extended_attributes[0] = b"# file: " +
> _unicode_encode(dest) + b"\n"
> - setfattr_process =
> subprocess.Popen(["setfattr", "--restore=-"], stdin=subprocess.PIPE,
> stderr=subprocess.PIPE)
> -
> setfattr_process.communicate(input=b"".join(extended_attributes))
> - if setfattr_process.returncode != 0:
> - raise
> OperationNotSupported("Filesystem containing file '%s' does not support
> extended attributes" % dest)
> - else:
> - def _copyxattr(src, dest, exclude=None):
> - pass
> + xattr.set(dest, attr, xattr.get(src, attr))
> + raise_exception = False
> + except (OSError, IOError) as e:
Unused variable e
> + raise_exception = True
> + if raise_exception:
> + raise OperationNotSupported(_("Filesystem containing
> file '%s' "
> + "does not support extended attribute '%s'") %
> + (_unicode_decode(dest), _unicode_decode(attr)))
>
> def movefile(src, dest, newmtime=None, sstat=None, mysettings=None,
> hardlink_candidates=None, encoding=_encodings['fs']):
>
--
Arfrever Frehtes Taifersar Arahesis
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