NIFFile might not always be created from a file or stream containing NIF data.
Basically there are 2 different responsibilities for this class:
1. Read NIF file
2. Provide input for nifosg and bulletnifloader.
Remove no longer needed NIFFileMock since the state of NIFFfile can be
initialized independently from reading NIF file.
CanOptimizeCallback::isReservedName function may be executed by multiple threads
simultaneously. One of them creates a static but both of them run if statement
and see it's empty because none of them added elements there yet. Both of them
go to the branch where new elements are added doing it without any
synchronization possibly causing SIGSEGV.
Use LRU cache for ESMReaders. When cache capacity is reached close least
recently used ESMReader. Remember the file name if a reader was open. Once the
reader requested again open the file if there is stored name for it. Put
released ESMReader to the back of the free items list. Close ESMReader's from
the front of the free items list.
Cached item can be used only by one client at the same time. If the same item is
requested twice exception is thrown. This should never happen in practice. If
this happens need to fix the client logic.
It's allowed to go over the capacity limit when requesting different readers.
Ideally this should never happen but there will be system error anyway
signalizing about too many open files. Need to fix client logic in this case.
All places that were using a vector of ESMReaders now using the cache. Cache is
local for each use case and there is no need for a thread safety.
Perform all request to db in a single thread to avoid blocking navmesh
generator threads due to slow write operations.
Write to db navmesh for all changes except update as it done for memory cache.
Batch multiple db operations into a single transaction to speed up writing by
not executing fsync after each insert/update query. All reads are performed in
the same transaction so they see uncommited data.
With this PR we refactor `StringUtils::replaceAll` to accept `string_view` as suggested in a code comment. In addition, while we are touching this rebuild happy file, we slim it down a bit by moving a few sparingly used functions elsewhere.
