Re: Does network data really cons strings?

[Jesper Harder <harder@myrealbox.com>]

Kevin Rodgers <ihs_4664@yahoo.com> writes:

> Jesper Harder wrote:
>
>> I was a bit surprised to see that network data (or any data received
>> from processes) conses Lisp strings.
>>
>> Is it just a quirk of `memory-use-counts' or is it for real?  Why
>> does it need to cons Lisp strings if the data is only inserted in a
>> buffer?
>
> So that the data is available to the process filter?

Right, it would need to cons strings if there are filters.  But it
also happens when there are no filters.

Hmm, I now notice that it also conses cons cells like mad:

(let (m1 process)
    (with-current-buffer (get-buffer-create " *test*")
      (erase-buffer))
    (setq process (open-network-stream "test" " *test*" "news.gmane.org" 119))
    (setq m1 (memory-use-counts))
    (process-send-string process "LIST\n")
    (sit-for 50)
    (process-send-string process "QUIT\n")
    (mapcar* '- (memory-use-counts) m1))

=> (48055 3 0 0 509059 2 0 2063)

(with-current-buffer " *test*" (buffer-size))
=> 252123

Roughly two char-cells for every byte of data received!  That seems
rather excessive ... and I wonder what all those cons cells are used
for.

Emacs 20.5 seems to do _far_ better for the same data (on a faster
network connection, though):

     (4103 0 0 0 4168 0 0)