Sjoerd Mullender:

Added support for unseekable files.

(I use unqualified excepts since we don't know why the seek/tell might
fail.  In my case it was because of an AttributeError.)
This commit is contained in:
Guido van Rossum 1999-06-16 12:25:34 +00:00
parent f2f0594587
commit 7bb11d68bf
1 changed files with 24 additions and 8 deletions

View File

@ -63,7 +63,12 @@ class Chunk:
raise EOFError
self.chunksize = self.chunksize - 8 # subtract header
self.size_read = 0
try:
self.offset = self.file.tell()
except:
self.seekable = 0
else:
self.seekable = 1
def getname(self):
"""Return the name (ID) of the current chunk."""
@ -87,6 +92,8 @@ class Chunk:
if self.closed:
raise ValueError, "I/O operation on closed file"
if not self.seekable:
raise IOError, "cannot seek"
if mode == 1:
pos = pos + self.size_read
elif mode == 2:
@ -133,11 +140,20 @@ class Chunk:
if self.closed:
raise ValueError, "I/O operation on closed file"
if self.seekable:
try:
self.file.seek(self.chunksize - self.size_read, 1)
except RuntimeError:
n = self.chunksize - self.size_read
# maybe fix alignment
if self.align and (self.chunksize & 1):
n = n + 1
self.file.seek(n, 1)
self.size_read = self.size_read + n
return
except:
pass
while self.size_read < self.chunksize:
dummy = self.read(8192)
n = min(8192, self.chunksize - self.size_read)
dummy = self.read(n)
if not dummy:
raise EOFError