On 01 Dec 2004 15:55:18 -0500, David Bolen <[EMAIL PROTECTED]> wrote:
>Jp Calderone <[EMAIL PROTECTED]> writes:
>
> > def nonBlockingReadAll(fileObj):
> > bytes = []
> > while True:
> > b = fileObj.read(1024)
> > bytes.append(b)
> > if len(b) < 1024:
> > break
> > return ''.join(bytes)
>
> Wouldn't this still block if the input just happened to end at a
> multiple of the read size (1024)?
Only if the file has not been put into non-blocking mode. But the function
as given is wrong, I left out the exception handling in the case you mention.
Rather than blocking forever, fileObj.read(1024) will raise IOError (EAGAIN) if
the input happened to be a multiple of 1024 bytes long. Here is the corrected
version:
def nonBlockingReadAll(fileObj):
bytes = []
while True:
try:
b = fileObj.read(1024)
except IOError, e:
if e.args[0] == errno.EAGAIN:
break
raise
bytes.append(b)
if len(b) < 1024:
break
return ''.join(bytes)
Arguably, there is no longer any point to checking the length of b in this
version, since at worst you will break on the next iteration of the loop. It
doesn't hurt, though.
Jp
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