Zip archive

bogdan · 2015-10-16T21:17:11+00:00

Thank you,I also found an older thread on the same issue: https://groups.google.com/forum/#!topic/openresty-en/6OwhJioFVooOn Thursday, October 15, 2015 at 6:...

Zip archive

bogdan

Hello, everybody

In our OpenResty web application we need to dinamically create a coupleof text files (based on user input) and then to create a Zip archive ofthese files and to make this archive downloadable. The files should notbe written to disk, to minimize disk IO.

What would be the best way to achieve this?

Thank you!

aapo.talvensaari

On Friday, 16 October 2015 16:17:13 UTC+3, bogdan wrote:

Hello, everybody

In our OpenResty web application we need to dinamically create a couple
of text files (based on user input) and then to create a Zip archive of
these files and to make this archive downloadable. The files should not
be written to disk, to minimize disk IO.
What would be the best way to achieve this?

This looks to be doing what you want:

https://github.com/brimworks/lua-zip

Haven't tested it though. Requires libzip.

agentzh

Hello!

On Sat, Oct 17, 2015 at 5:47 AM, Aapo Talvensaari wrote:
> On Friday, 16 October 2015 16:17:13 UTC+3, bogdan wrote:
>> In our OpenResty web application we need to dinamically create a couple
>> of text files (based on user input) and then to create a Zip archive of
>> these files and to make this archive downloadable. The files should not
>> be written to disk, to minimize disk IO.
>> What would be the best way to achieve this?
>
>
> This looks to be doing what you want:
> https://github.com/brimworks/lua-zip
>
> Haven't tested it though. Requires libzip.

If the output can be large (I'd say 100KB+ is large), then you'd
better use the streaming processing and outputting approach if
feasible. The Zip format itself should be streaming friendly :)

Regards,
-agentzh

bogdan

Thank you

Currently, the zip archives aren't 100KB+, but in the future they definetly can be. I was thinking about the streaming approach, but I don't know exactly how to do it. Any help would be greatly appreciated.

Thank you again

Bogdan

Yichun Zhang (agentzh) wrote:

Hello!

On Sat, Oct 17, 2015 at 5:47 AM, Aapo Talvensaari wrote:

On Friday, 16 October 2015 16:17:13 UTC+3, bogdan wrote:

In our OpenResty web application we need to dinamically create a couple
of text files (based on user input) and then to create a Zip archive of
these files and to make this archive downloadable. The files should not
be written to disk, to minimize disk IO.
What would be the best way to achieve this?

This looks to be do ing what you want:
https://github.com/brimworks/lua-zip

Haven't tested it though. Requires libzip.

If the output can be large (I'd say 100KB+ is large), then you'd
better use the streaming processing and outputting approach if
feasible. The Zip format itself should be streaming friendly :)

Regards,
-agentzh

aapo.talvensaari

On Monday, 19 October 2015 12:13:14 UTC+3, bogdan wrote:

Currently, the zip archives aren't 100KB+, but in the future they definetly can be. I was thinking about the streaming approach, but I don't know exactly how to do it. Any help would be greatly appreciated.

This is another library:

https://github.com/moteus/ZipWriter

I think you will need to implement stream for OpenResty for it, something like:

local stream = {}

function stream:write(chunk)
    ngx.print(chunk)
end

function stream:close()
    ngx.flush(true)
end

return stream

I haven't tested the above in anyway. If you end up implementing anything, please OpenSource it as a library so that others can benefit that as well.

ZipWriter has dependencies to:

lzip

struct

bit32 or bit

optionally iconv

Regards

Aapo

aapo.talvensaari

On Monday, 19 October 2015 13:38:35 UTC+3, Aapo Talvensaari wrote:

On Monday, 19 October 2015 12:13:14 UTC+3, bogdan wrote:
Currently, the zip archives aren't 100KB+, but in the future they definetly can be. I was thinking about the streaming approach, but I don't know exactly how to do it. Any help would be greatly appreciated.

This is another library:
https://github.com/moteus/ZipWriter

And here is Nginx module:

https://github.com/evanmiller/mod_zip