Zip/unzip large dataset (7k/22k files) causing out of memory (with reasonable memory limit of 64MB)

[marek-hanzal]

Q	A
Library version(s) affected:	3.3.3
PHP version(s):	7.2
OS (with bit depth):	Alpine Docker

Description
When an archive contains a lot of entries (for example 22k+), library always loads it into memory (internal array) of entries, which leads to out of memory problems (adding more RAM is not a solution). Also the same is for zipping large amount of files (around 7k is enough) where is the same problem: entries are collected into an internal array.

Maybe it's kind of limitation of this library to zip/unzip relatively small amount of files as it's not probably intended to do such huge works; my original reason is making deployment packages using ZIP (both zip/unzip) in quite dark environment, so a lot of processed files are required in a bit restricted environment.

How to reproduce
Set memory limit of php script to for example 32MB and try zip/unzip folder with 10k files; it will die on memory usage.

Possible Solution
This could be hard to do as there is an internal array of entries; solution could be zipping on fly when an entry is added and also reading entries using for example stream/iterator. Functions like hasEntry() would work with quite low performance on huge entry set as it has to go through all entries in the stream.

Additional context
Nothing to say here.

[fakhamatia]

I have this problem.
I want zip nested folders and thousands of photos with small sizes. Eventually, they become gigs
But I get Allowed memory size of.....
Server don't have enough RAM, so ini_set('memory_limit', '-1') not an option.
Maybe zipping files into disk step by step? not at once.