std::function is internally allowed to allocate, and these functions
aren't being stored anywhere (only called), so we can freely get rid
of some minor overhead here by passing by reference.
This change also creates aliases for the functions, so that there isn't
a lot of visual noise when reading the function signatures.
SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
Back when I wrote this code, I believe I set it to use a custom path
so that the cache would end up in a directory which Android considers
to be a cache directory. But nowadays the directory which Dolphin's
C++ code considers to be the cache directory is such a directory,
so there's no longer any reason to override the default path.
Deduplicates code, and gets rid of some problems the old code had
(such as: bad performance when calling native functions, only one
disc showing up for multi-disc games, Wii banners being low-res,
unnecessarily much effort being needed for adding more metadata).
Regression from 1f1dae3.
This problem doesn't happen in DolphinWX as far as I know, but if
you've ran into the problem in DolphinQt2, it will carry over to
DolphinWX because of the shared game list cache.
The original reason I wanted to do this was so that we can replace
the Android-specific code with this in the future, but of course,
just deduplicating between DolphinWX and DolphinQt2 is nice too.
Fixes:
- DolphinQt2 showing the wrong size for split WBFS disc images.
- DolphinQt2 being case sensitive when checking if a file is a DOL/ELF.
- DolphinQt2 not detecting when a Wii banner has become available
after the game list cache was created.
Removes:
- DolphinWX's ability to load PNGs as custom banners. But it was
already rather broken (see https://bugs.dolphin-emu.org/issues/10365
and https://bugs.dolphin-emu.org/issues/10366). The reason I removed
this was because PNG decoding relied on wx code and we don't have any
good non-wx/Qt code for loading PNG files right now (let's not use
SOIL), but we should be able to use libpng directly to implement PNG
loading in the future.
- DolphinQt2's ability to ignore a cached game if the last modified
time differs. We currently don't have a non-wx/Qt way to get the time.
