Re: Question about an error with ports

[Olivier Dion via General Guile related discussions <guile-user@gnu.org>]

On Thu, 10 Mar 2022, Zelphir Kaltstahl <zelphirkaltstahl@posteo.de> wrote:

> Just one question: Why is get-bytevector-some better than
> get-bytevector-n and specifying a number of bytes?

I haven't check the implementation details, but I think it's just a
question of buffering.  `get-bytevector-n` will block just like
`get-bytevector-some` when the port is empty.  The former will return up
to N bytes and the latter might return more than N bytes.  The former
probably also lead to less memory allocation since N is known in
advanced, a singled allocation can be made, while the latter might do
multiple allocations.  This can be useful depending on your usage of the
port.  For example, you could make a web server that only accepts HTTP
body up to 4096 bytes (1 system page).  This is what some web server
does I think.

There's also `get-bytevector-all`, but this would lead to more memory
usage and multiple allocations.  Again, it depends on the usage.

Regards,
old

-- 
Olivier Dion
Polymtl