[Xerte-dev] Re: example_zipper issue revisited

[Smith, John]

Hi Ron

I get what Dave is saying completely and agree that we need cross platform support. It must be the php zip library that is crashing while building the zip.

I think it will be interesting to get my new code tested on a server which was already failing to see if we can establish an upper limit. Because the 128Mb is php memory and its taking in 8k chunks and dumping straight to user then the memory might be more efficiently used or might even be able to use more than 128Mb, i have no idea.

Why yours doesn't fail though at 128 and others do though is a mystery but could be related to what else is on the box - php can ask for 128Mb but if that isn't available then it won't get it all.

You can watch the files via ftp. Watch a user folder then start a zip download. While download is in progress refresh the ftp and you should see all the files requiring zipping. They are delete by the code at very end so that isn't being reached on the problem servers.

Regards

John Smith
Learning Technologist
School of Health and Life Sciences

Sent from Samsung Galaxy SII



Ron Mitchell <ronm at mitchellmedia.co.uk> wrote:


Hi John
I was just going to test your export code on a server where I don't have
access to change php settings so the memory limit is fixed at 128MB. I know
what David means that ideally we want cross platform code but as you say
there are inevitably different solutions/restrictions for some e.g. no
control over memory limit. In fact the upload limit on this particular
shared server is set at the default 2MB so I had to upload the test 62MB mp4
via ftp. However I'm now confused further because this is the same XOT code
as the other servers I was using for testing so I expected the export to
fail when testing before replacing the export code with yours and yet it
didn't fail and I was able to download the zip which didn't contain any
example_zipper files.

I'm glad you're able to reproduce the issue but not sure how a server with
128MB memory limit is able to export ok without a change of code or memory
limit :-(



-----Original Message-----
From: xerte-dev-bounces at lists.nottingham.ac.uk
[mailto:xerte-dev-bounces at lists.nottingham.ac.uk] On Behalf Of Smith, John
Sent: 01 May 2014 08:38
To: xerte-dev at lists.nottingham.ac.uk
Subject: [Xerte-dev] Re: example_zipper issue revisited

All i know Dave is that, with the commented code uncommented, my system
couldn't download a 56Mb an 79Mb zip but with this code 79Mb came down no
problem.

We may have to use what we have access to on different systems. There may be
a similar way to pipe the result into windows or we fall back to the old
code and crank the memory requirements up yo 300Mb which not everyone can
most likely do anyway...

Regards

John Smith
Learning Technologist
School of Health and Life Sciences

Sent from Samsung Galaxy SII



David Goodwin <david at palepurple.co.uk> wrote:



<snip>
Uses the unix command zip and pipes the stream back into PHP in 8192 chunks

<snip>
Also, might not work on Windows...

So therefore it's not worth using?


Technically there is no benefit to doing the fread(....) over a
fpassthru(...) fpassthru does something like 8192 chunks internally.


David.

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Pale Purple Ltd
http://www.palepurple.co.uk @PalePurpleLtd
0845 0046746 / 07792 380669
"Bespoke web and mobile application development"


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