import types
import os
class FileAdaptor:
"""A FileAdaptor instance takes a 'file-like' object having at
least a 'read' method and, via the file method, returns a true file
object."""
def __init__(self, fileObj):
self.fileObj = fileObj
self.chunksize = 1024 * 10
# If the input file-like object is actually a true file object,
# we don't need to do anything.
if type(self.fileObj) != types.FileType:
# The file-like object must have a read method.
if not hasattr(fileObj, "read"):
raise ValueError, "not a file-like object"
# Create our true file object as a temp file.
self.tmpFileObj = os.tmpfile()
# Read from the input file-like object (via its read method)
# in chunks so we don't chew up too much memory, and write
# out to the temp file.
while True:
data = fileObj.read(self.chunksize)
if len(data) == 0:
break
self.tmpFileObj.write(data)
del data
# Make sure the temp file is ready to be read from its start.
self.tmpFileObj.flush()
self.tmpFileObj.seek(0, 0)
self.fileObj = self.tmpFileObj
return
def file(self):
"""Return the true file object."""
return self.fileObj
