mirror of
https://github.com/robweber/xbmcbackup.git
synced 2024-12-23 06:27:55 +01:00
54 lines
1.9 KiB
Python
54 lines
1.9 KiB
Python
import os
|
|
|
|
class AnalyzeFileObjBug(Exception):
|
|
msg = ("\n"
|
|
"Expected file object to have %d bytes, instead we read %d bytes.\n"
|
|
"File size detection may have failed (see dropbox.util.AnalyzeFileObj)\n")
|
|
def __init__(self, expected, actual):
|
|
self.expected = expected
|
|
self.actual = actual
|
|
|
|
def __str__(self):
|
|
return self.msg % (self.expected, self.actual)
|
|
|
|
def analyze_file_obj(obj):
|
|
""" Get the size and contents of a file-like object.
|
|
Returns: (size, raw_data)
|
|
size: The amount of data waiting to be read
|
|
raw_data: If not None, the entire contents of the stream (as a string).
|
|
None if the stream should be read() in chunks.
|
|
"""
|
|
pos = 0
|
|
if hasattr(obj, 'tell'):
|
|
pos = obj.tell()
|
|
|
|
# Handle cStringIO and StringIO
|
|
if hasattr(obj, 'getvalue'):
|
|
# Why using getvalue() makes sense:
|
|
# For StringIO, this string is pre-computed anyway by read().
|
|
# For cStringIO, getvalue() is the only way
|
|
# to determine the length without read()'ing the whole thing.
|
|
raw_data = obj.getvalue()
|
|
if pos == 0:
|
|
return (len(raw_data), raw_data)
|
|
else:
|
|
# We could return raw_data[pos:], but that could drastically
|
|
# increase memory usage. Better to read it block at a time.
|
|
size = max(0, len(raw_data) - pos)
|
|
return (size, None)
|
|
|
|
# Handle real files
|
|
if hasattr(obj, 'fileno'):
|
|
size = max(0, os.fstat(obj.fileno()).st_size - pos)
|
|
return (size, None)
|
|
|
|
# User-defined object with len()
|
|
if hasattr(obj, '__len__'):
|
|
size = max(0, len(obj) - pos)
|
|
return (size, None)
|
|
|
|
# We don't know what kind of stream this is.
|
|
# To determine the size, we must read the whole thing.
|
|
raw_data = obj.read()
|
|
return (len(raw_data), raw_data)
|