Hello,
As I continue experimenting with advanced streams, I'm currently
beginning an important modification of io's Buffered and Text streams
(removal of locks, adding of methods...), to fit the optimization
process of the whole library.
However, I'm now wondering what the idea is behind the 3 main buffer
classes : Bufferedwriter, Bufferedreader and Bufferedrandom.
The i/o PEP claimed that the two first ones were for sequential streams
only, and the latter for all kinds of seekable streams; but as it is
implemented, actually the 3 classes can be returned by open() for
seekable files.
Am I missing some use case in which this distinction would be useful
(for optimizations ?) ? Else, I guess I should just create a
RSBufferedStream class which handles all kinds of situations, raising
InsupportedOperation exceptions whenever needed.... after all, text
streams act that way (there is no TextWriter or TextReader stream), and
they seem fine.
Also, io.open() might return a raw file stream when we set buffering=0.
The problem is that raw file streams are NOT like buffered streams with
a buffer limit of zero : raw streams might fail writing/reading all the
data asked, without raising errors. I agree this case should be rare,
but it might be a gotcha for people wanting direct control of the stream
(eg. for locking purpose), but no silently incomplete read/write operation.
Shouldn't we rather return a "write through" buffered stream in this
case "buffering=0", to cleanly handle partial read/write ops ?
regards,
Pascal
PS : if you have 3 minutes, I'd be very interested by your opinion on
the "advanced modes" draft below.
Does it seem intuitive to you ? In particular, shouldn't the "+" and "-"
flags have the opposite meaning ?
http://bytebucket.org/pchambon/python-rock-solid-tools/wiki/rsopen.html
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