Arsenal - Improve performance of loadout verification

[LinkIsGrim]

When merged this pull request will:

• Title.
• Remove amount of unavailable/nullItems, list is checked directly instead.

Switched to single iteration through the loadout array. See previous optimizations below.

Old

Optimization 1: Add items to nullItemsList along with configCase changes, since we know that `configName _x == ""` means the class doesn't exist anywhere.

Optimization 2: Replace null items with empty string directly when changing loadout contents to configCase. This removes the need to check for isClass _x on the second iteration through the loadout.

Optimization 3: Check all classnames against GVAR(virtualItemsFlatAll) instead of categories, since hashmap lookup time is constant. This allowed for removing the index checking in _fnc_weaponCheck and others.

Optimization 4: Change use of pushBackUnique to combo pushBack and arrayIntersect as that is faster in most cases now, particularly with large arrays.

Optimization 5: Switch use of count of unavailable/null items for checking the lists against a default value in relevant places.

Optimization 6: Replaced some loop logic (assignedItems now uses forEach, and container item checking was changed to use the _containerItems array already defined in _x params).

Optimization 7: Due to all of the above, config lookups and some variable assignments could be removed.

To make this work, the unavailable items list needs to be checked against [""]. Otherwise array modification or explicit checking for _x != "" would be needed for everything, which would reduce performance gain.

End result, loading just CBA and ACE and checking against a full arsenal, is a 13% improvement:

testLoadout = [[["rhs_weap_m4a1_blockII_KAC_bk","rhsusf_acc_nt4_black","","rhsusf_acc_su230",["rhs_mag_30Rnd_556x45_Mk262_Stanag",30],[],"rhsusf_acc_grip2"],["rhs_weap_M136_hp","","","",[],[],""],["rhsusf_weap_glock17g4","","","",["rhsusf_mag_17Rnd_9x19_JHP",17],[],""],["VSM_Multicam_Crye_SS_od_shirt_Camo",[["ACE_CableTie",2],["ACE_EarPlugs",2],["ACE_EntrenchingTool",1],["ACE_epinephrine",3],["ACE_RangeCard",1],["ACE_splint",4],["ACE_tourniquet",4],["ACE_M26_Clacker",1],["ACE_MapTools",1],["ACE_Flashlight_XL50",1],["ACE_packingBandage",15],["ACE_IR_Strobe_Item",1],["ACE_morphine",3]]],["VSM_FAPC_Breacher_OGA_OD",[["rhs_mag_30Rnd_556x45_Mk262_Stanag",8,30],["HandGrenade",2,1],["ACE_M84",4,1],["rhs_mag_an_m14_th3",2,1],["SmokeShell",4,1],["SmokeShellBlue",1,1],["SmokeShellGreen",1,1],["SmokeShellRed",1,1],["rhsusf_mag_17Rnd_9x19_JHP",4,17]]],["VSM_OGA_OD_Backpack_Compact",[["DemoCharge_Remote_Mag",2,1]]],"VSM_OD_spray_OPS","VSM_Shemagh_Balaclava2_OD_Peltor_Goggles",["Laserdesignator_01_khk_F","","","",["Laserbatteries",1],[],""],["ItemMap","B_UavTerminal","ItemRadio","ItemCompass","ACE_Altimeter","ACE_NVG_Wide"]],[]]

Result:
0.768012 ms

Cycles:
1303/10000

Code:
[testLoadout] call ace_arsenal_fnc_verifyLoadoutOld

Result:
0.676349 ms

Cycles:
1479/10000

Code:
[testLoadout] call ace_arsenal_fnc_verifyLoadout

Loadout verification is already pretty fast now thanks to hashmaps but it's still the part of the arsenal where a user is most likely to notice stuttering or hang ups, particularly with large loadout lists and loadouts with many different item types.

Possible issues:

• Items with the same classname in different config types (CfgWeapons and CfgVehicles, for example) could end up not getting registered as null. This is going to be extremely rare, though.
• Third parties might rely on the output of FUNC(verifyLoadout)? It's not public, though.

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[johnb432]

Mostly formatting changes in my review, but also some a very minor performance improvement suggestion.

[johnb432]

Optimization 4: Change use of pushBackUnique to combo pushBack and arrayIntersect as that is faster in most cases now, particularly with large arrays.

Are you sure about this? I had the impression the opposite was true.
That's neat information for the future if true.

[jonpas]

Yeah, that is true IIRC. With pushBackUnique you check if the value already exists (so you iterate through the whole thing) each time you call it. With pushBack you don't do that, and you only do it once with arrayIntersect at the end.

[LinkIsGrim]

Mostly formatting changes in my review, but also some a very minor performance improvement suggestion.

I was under the assumption that creating a hashmap/setting a key is slower than using arrays, and I was specifically avoiding using - [""]. Have you profiled that to see if it's actually faster?

[johnb432]

I was under the assumption that creating a hashmap/setting a key is slower than using arrays, and I was specifically avoiding using - [""]. Have you profiled that to see if it's actually faster?

It really depends on what is being done:

Hashmaps will be roughly 80-90x faster if there are loads of different entries, like here:

private _nullItemsList = createHashMap;

for "_i" from 1 to 10000 do {
	_nullItemsList set [_i, nil];
};

keys _nullItemsList

Arrays will be 2x faster if there are loads of the same entry:

private _nullItemsList = [];

for "_i" from 1 to 10000 do {
	_nullItemsList pushback 1; // Not _i like in example above!
};

_nullItemsList arrayIntersect _nullItemsList

I'm guessing in this application it's more of the first case, however in game it doesn't make a measurable difference.
I'll edit/remove my suggestions if you want to stick with an array.

---

If a loadout were to have all items available _unavailableItemsList wouldn't contain "", so it has to be removed. Also feels like whack to have to check for [""] specifically instead of [] imo.

[johnb432]

If a loadout were to have all items available _unavailableItemsList wouldn't contain "", so it has to be removed. Also feels like whack to have to check for [""] specifically instead of [] imo.

Updated my suggestions @LinkIsGrim

[LinkIsGrim]

LinkIsGrim@e5950f2 switches to a single iteration through the loadout array (turning everything into configCase, checking for null and availability all at once).

Output for the same test loadout:

Result:
0.676349 ms

Cycles:
1479/10000

Code:
[testLoadout] call ace_arsenal_fnc_verifyLoadout

Readability isn't the best, though.

[johnb432]

I've tested it, but I feel it could do with some more by others.