Having DiscContents with size 0 would mean that some DiscContents
might not get added to the std::set because of them comparing
identically to another DiscContent.
This replaces an older piece of code in WriteDirectory that ensures
that no two files have the same starting offset. (We now care about
the ending offset, not the starting offset. The new solution both
ensures that no two files have the same ending offset and that no
two files have the same starting offset.)
For instance, we don't want to show TGC files that might be
inside the /files/ directory of a GameCube DirectoryBlob,
and we don't want to show the /sys/main.dol files for extra
partitions of Wii DirectoryBlobs.
Now it's clearer that SetDOL depends on SetApploader
and BuildFST depends on SetDOL.
As a side note, we now load the DOL even if there's
no apploader. (I don't think it matters whether we
do it, but it was easier to implement this way.)
This lets VolumeDirectory/DirectoryBlob skip implementing
various volume functions like GetGameID, GetBanner, etc.
It also lets us view extracted discs in the game list.
This ends up breaking the boot process for Wii
DirectoryBlobs due to workarounds being removed from the
boot process, but that will be fixed later by adding
proper DirectoryBlob support for things like TMDs.
We now expect the directories to be laid out in a certain
format (based on the format that WIT uses) instead of requiring
the user to set the DVD root and apploader path settings.
This is useful for blob types that store Wii data unencrypted
(such as WIA and discs extracted to directories) so that
we don't have to waste CPU time encrypting in the blob code
just to decrypt right afterwards in the volume code.
According to http://scanlines16.com/en/blog-3/retro-gaming/game-cube/gamecube-korean-master-list/,
Korean GC releases use the following country codes:
- E or W for games in English
- K for games in Korean
- Unknown value for games in Japanese (my guess is that they might
have made the discs bit-for-bit identical to Japanese releases
because the regions of these games are already set to NTSC-J)
As far as I know, the GC has no Taiwanese releases, which is what
the W country code is used for on the Wii. But I could be wrong.
A small note: The country_byte == 'K' check in the code isn't
actually necessary as long as RegionSwitchGC returns NTSC_J
for 'K', but I thought it would be better to not rely on that.
The county code isn't 100% reliable for detecting the region.
For instance, some games released in Korea have the country
code E even though they're region-locked to NTSC-J consoles.
This commit makes the GC disc region detection match the Wii
disc region detection (apart from the region value being in
a different place on the disc).
Some code was calling more than one of these functions in a row
(in particular, FileUtil.cpp itself did it a lot...), which is
a waste since it's possible to call stat a single time and then
read all three values from the stat struct. This commit adds a
File::FileInfo class that calls stat once on construction and
then lets Exists/IsDirectory/GetSize be executed very quickly.
The performance improvement mostly matters for functions that
can be handling a lot of files, such as File::ScanDirectoryTree.
I've also done some cleanup in code that uses these functions.
For instance, some code had checks like !Exists() || !IsDirectory(),
which is functionally equivalent to !IsDirectory(), and some
code was using File::GetSize even though there was an IOFile
object that the code could call GetSize on.
Before, if you extracted a directory like /map/Final/Release/,
Dolphin would create the nested folders map, Final and Release
in the output directory and put the files in Release instead of
just putting the files directly in the output directory.
This makes it possible to catch errors earlier so that file systems
simply fail to load instead of behaving oddly. It also makes it possible
to check for errors that weren't checkable before, like the end of a
directory being after the end of the parent directory.
Instead of expecting callers to know how the size of directory file infos
relates to which files are in which directories, filesystems now offer a
GetRoot() method, and file infos offer a way to get their children. As
a bonus, m_FileInfoVector no longer has to be created and kept around
in RAM. Only the file info objects that actually are used are created.
Not initializing until the filesystem is used is good when
a filesystem is constructed and then never used, but nobody does that.
This simplifies the code a little and lets all methods be const.
Instead of using lots of small scattered reads to read the FST,
only one big read is used, which is more efficient.
This also means that the FST only allocates memory once and stores all
strings close to each other - good for the CPU cache. The file info
objects use pointers to this FST memory of containing data themselves.
Keeping around the big m_FileInfoVector containing objects with only
pointers is a bit unnecessary, but that will be fixed soon.
Instead of calling GetPathFromFSTOffset for every file info, FindFileInfo
now only looks at names in directories that are included in the path.
For the common case of searching for "opening.bnr", this means that
only root-level files and directories have to be searched through.
Some callers already have the file info, making the relatively slow
FindFileInfo calls unnecessary. Callers that didn't have the file info
will now need to call FindFileInfo on their own.
Some callers (i.e. ISOProperties) don't want the full path, so giving them
it is unnecessary. Those that do want it can use GetPathFromFSTOffset.
Not storing full paths everywhere also saves a small bit of RAM and is
necessary for a later commit. The code isn't especially pretty right now
(callers need to use FST offsets...) but it'll become better later.
GC/Wii filesystem internals shouldn't be exposed to other classes.
This change isn't especially useful by itself, but it opens up the
way for some neat stuff in the following commits.
You may want to read the PR #2047 comments before reading this.
Dolphin attempts to support an unencrypted type of Wii discs
that apparently is identified by a 4-byte integer at 0x60
being non-zero. I don't know what discs (if any) would be
using that format, so I haven't been able to test Dolphin's
support for it, but it has probably been broken for a while.
The old implementation is very short but also strange.
In CreateVolumeFromFilename, we read a 4-byte integer from
0x60, and if it's non-zero, we create a CVolumeGC object
instead of a CVolumeWiiCrypted object. This might seem like
it makes no sense, but it presumably worked in the past
because IsVolumeWiiDisc used to check the volume type by
reading the magic word for Wii straight from the disc,
meaning that CVolumeGC objects representing unencrypted Wii
discs would be treated as Wii discs by pretty much all of
Dolphin's code except for the volume implementation code.
(It wasn't possible to simply use CVolumeWiiCrypted, because
that class only handled encrypted discs, like the name says.)
However, that stopped working as intended because of ace0607.
And furthermore, bb93336 made it even more broken by making
parts of Dolphin expect that data read from Wii discs needed
to be decrypted (rather than the volume implementation
implicitly deciding whether to decrypt when Read was called).
Disclaimer: Like I said before, I haven't been able to test
any of this because I don't have any discs that use this
unencrypted Wii disc format, so this is all theoretical.
Later, PR #2047 tried to remove Dolphin's support for
the unencrypted Wii disc format because seemingly no
discs used it, but the PR got closed without being merged.
At the end of that PR, I said that I would make a new PR
with a better implementation for the format after PR #2353
was merged. Now that PR #2353 is merged (two years later...)
and PR #5521 is merged, the new implementation was easy to
make, and here it is!
Untested.
JosJuice