[TYPO3-english] Downloading large files

[Jan Kornblum]

Hi group,

i'm currently working on an extension to exchange large (huge) files 
(upload, download) between fe_users and be_users. I want the extension 
to be independent from any provider restrictions (PHP limits, Apache 
limits) as much as possible.

The upload part is already working fine using html5 file api and 
chunked uploads. It is possible to upload e.g. 2 GB sized files even 
when the site is hosted on any shared webspace (1&1 etc.).

The problem crrently is the download part: As the files are not 
accessable directly, the download is handeled through php and there are 
several things to take care about:

- the file must not be completely read into memory to be indepedent 
from php "memory_limit" restrictions
- the process must not take too long to be independent from 
"max_execution_time" restrictions
- and so on...

Could anybody give me a hint about how to realize the download process 
best respecting lare files and most independence from provider 
restrictions? There seem to be several possibilities like using 
readfile(), fopen(), fread(), fpassthru() etc. or a mixture of them but 
i still didn't find a 100% solid solution.

Thanks in advice an regards, Jan