The code was actually already rather well adapted for this.
We more or less just have to skip ParseDisc and run
ParsePartitionData directly. This required the PartitionHeader
struct to be removed (which wasn't that useful anyway).
If we start 31 KiB into a 32 KiB block and want to mark 2 KiB
of data as used, we need to mark 2 blocks as used, not just 1.
This problem is avoided when calling MarkAsUsed from
MarkAsUsedE, since MarkAsUsedE aligns to 32 KiB on its own.
Most calls to MarkAsUsed are from MarkAsUsedE, which is why
this hasn't been a noticeable problem in the past.
The constant DESIRED_BUFFER_SIZE was determined by multiplying the
old hardcoded value 32 with the default GCZ block size 16 KiB.
Not sure if it actually is the best value, but it seems fine.
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.
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.
This file is pretty small now that it doesn't handle Wii
partitions anymore, so let's move its contents to Volume.cpp.
This is also more consistent with how blob creation works.
By removing mutable state in VolumeWiiCrypted, this change makes
partition-related code simpler. It also gets rid of other ugly things,
like ISOProperties's "over 9000" loop that creates a list of
partitions by trying possible combinations, and DiscScrubber's
volume swapping that recreates the entire volume when it needs to
change partition.
Rather than rely on the developer to do the right thing,
just make the default behavior safely deallocate resources.
If shared semantics are ever needed in the future, the
constructor that takes a unique_ptr for shared_ptr can
be used.
The offset in a directory FileInfo is an FST offset, not a disc offset.
Treating it as a disc offset doesn't make sense. Directories don't take
up space outside of the FST, so they don't need to be marked as used. The
old behavior may have prevented some scrubbable areas from being scrubbed.
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