Improve efficiency of modifying resource.dat file

[KnightMiner]

Did a loose benchmark:

• Old startup time:
  • With no resource.dat.bak: around 50 seconds
  • With resource.dat.bak: around 65 seconds
• After changes
  • With no resource.dat.bak: around 27 seconds
  • With resource.dat.bak: around 30 seconds

Breakdown of improvement by change:

• Switching from list search to hash search: 3-4 seconds
• Removing stream copying: 14 seconds with no resource.dat.bak, around 30 seconds with it
• Faster signature scan: around 3 seconds

Note: startup times include the loading bar, which takes about 7 seconds. Meaning all the modloader preloading stuff takes around 40-55 seconds before changes, and around 20-23 seconds after.

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Note: we could possibly save a few more seconds if we inject our signature into the start of resource.dat and break the signature scan loop as soon as its found. Based on how fast it ran with the broken signature scan code I had earlier, I doubt it would be much more than a second gain, so probably not worth it (plus, not sure if there is risk with changing the order of files)

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Testing:

• If you contribute to the modloader, you know how to test
• If not, test by installing the mod loader using this link: ITB-ModLoader-2.7.0-faster-resource-dat.zip

[Lemonymous]

I have not gone through the code, but I did test it on my system. On my system, it cuts the loading of the mod loader without mods to a third of master. From >30 seconds to <10 seconds until the loading bar shows up.

[KnightMiner]

Not sure what could cause that apart from a mod manually modifying the resource.dat, there is no path where assertExists would have worked with the old code where it does not work with the new code