[TYPO3-core] RFC #5045, #5077, #8649: Import/Export requires lot of memory

[Steffen Kamper]

Hi Bernhard,


Bernhard Kraft schrieb:
> 
  > When writing the files to the container I can not use "gzwrite" as 
later
> on - when importing it might be required to extract a file from the 
> "middle" of the container - and gz-files must/should always get 
> read/written serially - no skipping should occur:
> ---------------------------
> http://de.php.net/manual/en/function.gzseek.php
> If the file is opened for reading, this function is emulated but can be 
> extremely slow. If the file is opened for writing, only forward seeks 
> are supported; gzseek() then compresses a sequence of zeroes up to the 
> new starting position.
> ---------------------------

I did a simular in mysqldumper. The code is old, so it's not best style, 
but it works writing to gz.
I simply used
$fp = gzopen ($df,'ab');
gzwrite ($fp,$dump['data']);

so you append the data without any seek.
Do you write the data not sequentially?

btw - for XML the XMLReader is much more powerful. I will check this out 
   for better performance / less memory usage in EM

vg Steffen