class HttpFile(ufsi.FileInterface):
"""
HttpFile is an implementation of ``ufsi.FileInterface`` that
provides an interface to HTTP file systems. HTTP file systems
(unless they are enhanced with WebDAV, or some other equivalent
technology) are read-only file systems. Therefore, trying to write
to one will result in an UnsupportedOperationError being raised.
"""
def __init__(self, path):
"""
Creates a HttpFile instance.
"""
self.__path = path
self.__pathStr = str(path)
self.__fileHandle = None
def __str__(self):
"""
Returns the path (string) to the file.
"""
return self.__pathStr
def open(self, mode='r'):
"""
Opens a HTTP connection to the file. If a previous connection
was opened it is first closed. TODO: currently, mode is
ignored but we should do a little more validation on it.
TODO: add this level of error checking to other open methods
TODO: make mode='r' for all, ie part of the interface
TODO: write Interface Implementation certification code to
ensure an implementation adheres to at least the method sigs
Note: if you get freezes from any of the methods that open a
connection to the server, it may be some issue between the
sockets (or something to do with the makefile layer of
socket). I have only experienced these problems using
IIS5.something. Good Luck! :-)
"""
self.close()
if mode in ('r', 'rb'):
try:
self.__fileHandle = urllib2.urlopen(self.__pathStr)
except Exception, e:
HttpUtils.handleException(e, self.__pathStr)
elif mode in ('w', 'wb', 'a', 'ab'):
raise ufsi.UnsupportedOperationError(
'HTTP has no facility to write.')
class TarFile(ufsi.FileInterface):
"""
"""
def __init__(self,path):
"""
"""
self.__path=path
self.__tarPathStr=path.getPathString()
self.__fileHandle=None
self.__tarFileObject=None
def __str__(self):
"""
"""
return str(self.__path)
def open(self,mode='r'):
"""
"""
if mode in ['r','rb']:
tarFile=self.__path.getTarFilePath()
tf=tarFile.getFile()
tf.open('r')
self.__tarFileObject=tar=tarfile.TarFile('','r',tf)
try:
self.__fileHandle=tar.extractfile(self.__tarPathStr)
except KeyError,e:
raise ufsi.PathNotFoundError('Path "%s" not found'
%self.__tarPathStr,e)
elif mode in ['w','wb','a','ab']:
raise ufsi.UnsupportedOperationError("Write is not supported")
def writeLines(self, lines):
"""
HTTP doesn't allow writing. This method raises an
UnsupportedOperationError.
"""
raise ufsi.UnsupportedOperationError('HTTP has no facility to write.')
def writeLines(self,lines):
raise ufsi.UnsupportedOperationError('Tar files can only be read.')