[En-Nut-Discussion] tap stream of Request

[Landsperger, Werner]

Hello Bernd,


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.

-> Thanks, I will try it with fitted Blocksize.


> 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.

-> To be honest, I have to admit that I haven't know the difference of
MMC and SD Cards. So actually I use a 64MB MMC-Card. Im my research I
found out that a MMC-Card also can have until 8GB but would that be
supported? You said that SD-Cards are supportet but how can I identify a
"plain SD-Card"?


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.

->What exactly do you mean? Actually I send the file via Post and right
I use multipart/form-data. And right, there is some overhead like the
boundary which must be filter out. Actually I've wrote a small algorthm
which pares the header. At the moment it isn't really performant but it
works. :) I will work out it in a view days. Is your question be
answered?

Greets!



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