FieldLoader, use dictionary for GetValue to make it twice as fast.

[anvilvapre]

Replace the very large if-then-else clause with a dictionary lookup making it 52% faster.

The total time spent in the GetValue until right after game launch or after game replay is half (189720686/91038340).

Improves game loading speed and there is some gain in-game.

(I had expected the difference to be far less. Which may have to do with the order of entries in the if-then-else clause, or many calls to typeof.)

[pchote]

@teinarss can you comment on how this fits with your work to pull FieldLoader out into its own package?

[teinarss]

@teinarss can you comment on how this fits with your work to pull FieldLoader out into its own package?

I'm rewriting the parser from scratch so this is fine!

[pchote]

LGTM overall, i've verified that this is just moving around the existing parsing code without appearing to change any behaviour. For this reason, i'm okay with leaving any style nits that existed in the original code (several unnecessary sets of braces) to a followup PR.

Just one question/request:

[teinarss]

Can we use this syntax here? And on GenericTypeParsers below?

			TypeParsers = new Dictionary<Type, Func<string, Type, string, MemberInfo, object>>
			{
				{ typeof(int), ParseInt },
				{ typeof(ushort), ParseUShort },
				{ typeof(long), ParseLong },
				{ typeof(float), ParseFloat },
				{ typeof(decimal), ParseDecimal },
				{ typeof(string), ParseString },
				{ typeof(Color), ParseColor },
				{ typeof(Hotkey), ParseHotkey },
				{ typeof(HotkeyReference), ParseHotkeyReference },
				{ typeof(WDist), ParseWDist },
				{ typeof(WVec), ParseWVec },
				{ typeof(WVec[]), ParseWVecArray },
				{ typeof(WPos), ParseWPos },
				{ typeof(WAngle), ParseWAngle },
				{ typeof(WRot), ParseWRot },
				{ typeof(CPos), ParseCPos },
				{ typeof(CVec), ParseCVec },
				{ typeof(CVec[]), ParseCVecArray },
				{ typeof(BooleanExpression), ParseBooleanExpression },
				{ typeof(IntegerExpression), ParseIntegerExpression },
				{ typeof(Enum), ParseEnum },
				{ typeof(bool), ParseBool },
				{ typeof(int2[]), ParseInt2Array },
				{ typeof(Size), ParseSize },
				{ typeof(int2), ParseInt2 },
				{ typeof(float2), ParseFloat2 },
				{ typeof(float3), ParseFloat3 },
				{ typeof(Rectangle), ParseRectangle },
				{ typeof(DateTime), ParseDateTime }
			};

[teinarss]

https://github.com/OpenRA/OpenRA/wiki/Changelog-(bleed)/_compare/d6d0a8229bc4432de3418a1a5dd28eeffea41a8a...d3bd82e2ff58e811cea5eae47821a39cca1b0c8d