[En-Nut-Discussion] tap stream of Request

[Bernd Walter]

On Tue, May 10, 2011 at 09:08:46AM +0200, Landsperger, Werner wrote:
> Hey together,
> 
> thanks for your responses but actually it works ;) If I'm honest, I
> can't say exactly why but now my code works and I can transfer files
> from my webinterface to my memory-card. I've just overlooked that
> NutHttpProcessQueryString just execute when a "?" is in the url. :) But
> actualy it's extreme slowly. For example, a file with 600kb needs to
> transfer about 30 secounds. Did anyone have an idea to accelerate the
> transfer? Actually i use an buffersize of 128 Bytes.

If you have enough RAM left you might try with buffers in the range
of the packet size.
Also 128 Bytes writing on SD is smaller than the media size, so a
lot of read/modify writes are required and modern SD cards are very
picky in performance if the same physical 4k block is written all over
again - expensive SLC cell based cards are much better, but my personal
opinion is that this is about flash usage and not because of SLC vs. MLC
cells.

> Is there any limit of sizes for memory-cards? I've tried to use an 4GB
> card but with no success. 

As far as I know oly plain SD-cards are supported.
According to specification SD cards are limited to 2G, although a few
non standard 4G cards exists - however I don't know if they are supported.


Now I have a question to you.
How do you initiate the upload?
As far as I know with HTML and browsers all you can do is sending
a "multipart/form-data", which required mime parsing.

-- 
B.Walter <bernd at bwct.de> http://www.bwct.de
Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.