zip archive always loaded into RAM

[paroj]

currently, we load the complete zip archive into RAM when opening:

ogre/OgreMain/src/OgreZip.cpp

Line 104 in aa76042

mBuffer.reset(new MemoryDataStream(_openFileStream(mName, std::ios::binary)));

this increases the loading time, if the majority of the contents are not read.

this is a zip API limitation, which only allows passing buffers when externally opening the file.
The underlying miniz API actually allows passing read callbacks:
https://github.com/richgel999/miniz/blob/5a38f5564a092462817b97014f4477c8f0783f8f/miniz_zip.h#L173-L175

using these would allow seeking in the file, which improves loading time in the above scenario.

[tritonas00]

Is this the reason we experience slower cache generation in RoR with Ogre 13 also?

[paroj]

probably. Although generation should not be noticeable slower. update should be - i.e. if you only want to read some file metadata without reading the whole file.
Maybe you triggering some bad behavior where a zip file is loaded twice? Previously, you would only pay on reading, but now you pay regardless.

[tritonas00]

eh dont really know, here we parse https://github.com/tritonas00/rigs-of-rods/blob/12d8ece21d0453f66803e356fd2cebe6943e1875/source/main/resources/CacheSystem.cpp#L997

i remember though if we dont unload at the end, we had massive ram usage