def write_metadata(fd, metadata, xattr_size=65536, md_key=None):
"""
Helper function to write pickled metadata for an object file.
:param fd: file descriptor or filename to write the metadata
:param md_key: metadata key to be write to object file
:param metadata: metadata to write
"""
meta_key = SWIFT_METADATA_KEY
metastr = pickle.dumps(metadata, PICKLE_PROTOCOL)
key = 0
while metastr:
try:
xattr.setxattr(fd, '%s%s' % (meta_key, key or ''),
metastr[:xattr_size])
metastr = metastr[xattr_size:]
key += 1
except IOError as e:
for err in 'ENOTSUP', 'EOPNOTSUPP':
if hasattr(errno, err) and e.errno == getattr(errno, err):
msg = "Filesystem at %s does not support xattr" % \
_get_filename(fd)
logging.exception(msg)
raise DiskFileXattrNotSupported(e)
if e.errno in (errno.ENOSPC, errno.EDQUOT):
msg = "No space left on device for %s" % _get_filename(fd)
logging.exception(msg)
raise DiskFileNoSpace()
raise
def write_metadata(fd, metadata, xattr_size=65536, md_key=None):
"""
Helper function to write pickled metadata for an object file.
:param fd: file descriptor or filename to write the metadata
:param md_key: metadata key to be write to object file
:param metadata: metadata to write
"""
meta_key = SWIFT_METADATA_KEY
metastr = pickle.dumps(metadata, PICKLE_PROTOCOL)
key = 0
while metastr:
try:
xattr.setxattr(fd, '%s%s' % (meta_key, key or ''),
metastr[:xattr_size])
metastr = metastr[xattr_size:]
key += 1
except IOError as e:
for err in 'ENOTSUP', 'EOPNOTSUPP':
if hasattr(errno, err) and e.errno == getattr(errno, err):
msg = "Filesystem at %s does not support xattr" % \
_get_filename(fd)
logging.exception(msg)
raise DiskFileXattrNotSupported(e)
if e.errno in (errno.ENOSPC, errno.EDQUOT):
msg = "No space left on device for %s" % _get_filename(fd)
logging.exception(msg)
raise DiskFileNoSpace()
raise
def read_metadata(fd, md_key=None):
"""
Helper function to read the pickled metadata from an object file.
:param fd: file descriptor or filename to load the metadata from
:param md_key: metadata key to be read from object file
:returns: dictionary of metadata
"""
meta_key = SWIFT_METADATA_KEY
metadata = ''
key = 0
try:
while True:
metadata += xattr.getxattr(fd, '%s%s' % (meta_key,
(key or '')))
key += 1
except (IOError, OSError) as e:
if metadata == '':
return False
for err in 'ENOTSUP', 'EOPNOTSUPP':
if hasattr(errno, err) and e.errno == getattr(errno, err):
msg = "Filesystem at %s does not support xattr" % \
_get_filename(fd)
logging.exception(msg)
raise DiskFileXattrNotSupported(e)
if e.errno == errno.ENOENT:
raise DiskFileNotExist()
return pickle.loads(metadata)
def read_metadata(fd, md_key=None):
"""
Helper function to read the pickled metadata from an object file.
:param fd: file descriptor or filename to load the metadata from
:param md_key: metadata key to be read from object file
:returns: dictionary of metadata
"""
meta_key = SWIFT_METADATA_KEY
metadata = ''
key = 0
try:
while True:
metadata += xattr.getxattr(fd, '%s%s' % (meta_key,
(key or '')))
key += 1
except (IOError, OSError) as e:
if metadata == '':
return False
for err in 'ENOTSUP', 'EOPNOTSUPP':
if hasattr(errno, err) and e.errno == getattr(errno, err):
msg = "Filesystem at %s does not support xattr" % \
_get_filename(fd)
logging.exception(msg)
raise DiskFileXattrNotSupported(e)
if e.errno == errno.ENOENT:
raise DiskFileNotExist()
return pickle.loads(metadata)
