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gmod-lua-performance

A simple comparison of performance optimizations for gLUA

These are a few benchmarks that are tested on a Garry's Mod Server idling with DarkRP with only 1 player online. Some of those benchmarks, if possible, were also tested in a LUA5.3 console on Debian 10. If not otherwise stated differently all tests have been done on a 32bit gmod server on linux.

These benchmark results mean nothing compared to other benchmark results. Your numbers will probably look completely different than my numbers. Please compare your benchmark results only with your own numbers, as every small change in Hardware changes the result notably.

The goal of this collection of benchmarks is to show the actual performance gain by implementing "Coding Tips" from the web.

Everyone can test the code for themselves and see the difference. Source code is always linked at the bottom of a comparison.

The sources for some of the "Coding Tips" are:

lua-users.org
lua.org
stackoverflow.com

If you want to read more about gmod lua then you could also visit my wiki at luctus.at/wiki

Foreword

Garry's Mod doesn't use only lua. It uses lua-jit.
This means the following benchmarks show, where applicable, also a comparison of lua and lua-jit.
Many of the performance tips online are supposed to be for lua, not luajit.

An example of lua vs lua-jit with the "multiplication vs division" example:

$ time luajit-2.1.0-beta3 mult_vs_div.lua
Multiplication: 0.00111624
Division: 0.00110691

real    0m1.255s
user    0m1.054s
sys     0m0.182s

$ time lua5.3 mult_vs_div.lua
Multiplication: 0.0284177
Division: 0.03088507

real    0m21.773s
user    0m21.623s
sys     0m0.120s

If you find any error, mistake or completely different result on your side please create a pull request.
I want this page to be as accurate as possible so that everyone can see and learn what actually benefits your code's performance.

caching functions in HUDPaint

TL;DR: If you use a a function, e.g. LocalPlayer(), often in a HUDPaint hook then I highly suggest caching it once at the beginning.

This is a comparison of the following code bits. The question is: "Should you cache a function you only use 3 times?".

The unoptimized version:

draw.RoundedBox(0, LocalPlayer():Health(), 500, 500, 500, color_white )
draw.RoundedBox(0, LocalPlayer():Health(), 200, 200, 200, color_white )
draw.RoundedBox(0, LocalPlayer():Health(), 10, 10, 10, color_white )

and the better version:

local lph = LocalPlayer():Health()
draw.RoundedBox(0, lph, 500, 500, 500, color_white )
draw.RoundedBox(0, lph, 200, 200, 200, color_white )
draw.RoundedBox(0, lph, 10, 10, 10, color_white )

The result (10000 frametimes):

Non-Local:  0.00001756282000116   (1.756282000116e-05)
Local:      0.000006777780000516  (6.777780000516e-06)

Code: files/hudpaint_3call_cache.lua

Caching LocalPlayer function

TL;DR: It is faster to cache the response of LocalPlayer() and overwrite the function to always return this value.

Pretty self explanatory. LocalPlayer() always returns you, the player, but takes more time than if you were to simply cache the player entity and return it everytime.
Check the code for more info.

Result:

--- Benchmark complete
On Client
reps	20	rounds	50000
old LocalPlayer	7.4946100011402e-08
fastLocalPlayer	6.2921299662776e-08

The Code: files/localplayer_cache.lua

Caching LocalPlayer with "or"

TL;DR: It is a bit faster to "ply = ply or LocalPlayer()" instead of always using LocalPlayer(), but the time save is barely noticable.

Pretty self explanatory. This caches LocalPlayer() on first run and then always reuses this value.
Check the code for more info.

Result:

--- Benchmark complete
On Client
reps	20	rounds	10000
Cached	5.8824900024945e-07
Plain 	6.021605001348e-07

The Code: files/localplayer_cached_or.lua

Angle:Zero() vs new Angle()

TL;DR: It is a faster to reuse the same Angle object and zero it before use than to create a new Angle object everytime.

The wiki states this as fact, and it is true. It saves you the overhead of creating a new object and garbage-collecting the old one.
Check the code for more info.

Result:

--- Benchmark complete
On Server
reps	30	rounds	5000
Zero'd	1.3485066712595e-07
Create	2.3365133318293e-07
--- Benchmark complete
On Client
reps	30	rounds	5000
Zero'd	1.1277866673481e-07
Create	2.4979333345679e-07

The Code: files/angle_zero_vs_new.lua

Caching SteamID function

TL;DR: It is faster to cache the response of ply:SteamID() and overwrite the function to always return this value for a player from a caching table.

Pretty self explanatory. Same as "Caching LocalPlayer function" above.

Result:

--- Benchmark complete
On Server
reps	20	rounds	50000
SteamID Classic	4.6951399998613e-07
SteamID Cached	7.0017300033214e-08
--- Benchmark complete
On Client
reps	20	rounds	50000
SteamID Classic	5.2189459993372e-07
SteamID Cached	6.247109999822e-08

The Code: files/steamid_cache.lua

GetNWString vs getDarkRPVar

TL;DR: getDarkRPVar is always faster on server while on client it seems to be random. I would recommend using getDarkRPVar, as it is more optimized for network usage in comparison to NW1's constant network traffic every 10 seconds.

This is a comparison between ply:GetNWString("job") and ply:getDarkRPVar("job").

Result:

--- Benchmark complete
reps	10	rounds	10000
On Server
darkrpvar	1.2346400001078e-07
gmodnwvar	2.0404500001689e-07
--- Benchmark complete
reps	10	rounds	10000
On Client
darkrpvar	2.4343500003823e-07
gmodnwvar	2.036369999766e-07

As you can see, the result is different on client and server. The result on the client is always different everytime i run these tests. Sometimes, on the client , the gmodnwvar is faster by 25% and other times it is 300% slower than darkrpvar.

Code: files/nwvar_vs_darkrpvar.lua

Config Table vs Variable

TL;DR: Using a table is slower than using a variable.

This is a comparison between using a config table like myaddon.config.color = and a simple variable like myaddon_config_color =. This mainly exists because some people don't believe me.

The result:

--SERVER
tab=	1.9999993128295e-07
var=	1.0000007932831e-07
--CLIENT
tab=	1.0000007932831e-07
var=	0

As you can see above, using a single variable instead of a table structure is faster.

Explanation

Getting a variable is as simple as "getting" it. But with a table you have to get the table and then the table element inside.
You can inspect this with lua's luac command, e.g. luac5.4 -l file.lua.
An example: print(abc) vs print(a.b.c)

$ luac5.4 -l var.lua
[...]
        GETTABUP        0 0 2   ; _ENV "print"
        GETTABUP        1 0 0   ; _ENV "abc"
        CALL            0 2 1   ; 1 in 0 out
        RETURN          0 1 1   ; 0 out

$ luac5.4 -l tab.lua
[...]
        GETTABUP        0 0 4   ; _ENV "print"
        GETTABUP        1 0 0   ; _ENV "a"
        GETFIELD        1 1 1   ; "b"
        GETFIELD        1 1 2   ; "c"
        CALL            0 2 1   ; 1 in 0 out
        RETURN          0 1 1   ; 0 out

As you can observe above, the table variant simply has more executions and is thus slower in theory and practice as shown above.

Code: files/table_vs_variable.lua

pairs vs ipairs vs for i=1

TL;DR: They are not as different as people make it out to be. Pairs is slower because it also works on non-sequential tables.

The result (10 tests of 100 runs each with calculating the sum of a 10.000 number table):

pairs 	8.8780000373845e-07
ipairs	2.4300000836774e-07
for #t	1.639000013256e-07

Code: files/pairs_vs_ipairs_vs_for.lua

looping through string vs number tables

TL;DR: Numbered and Sequential tables are always faster thanks to ipairs and for loops being able to speed up the loop. There is no difference between the string index length in terms of speed. Sequentially-numbered tables are faster than non-sequential number tables.

With a 100 element table and 1000 runs for each of the 5 testruns:

short string pairs	1.016059995527e-06
big   string pairs	9.8490000327729e-07
sequent  int pairs	8.060999940426e-07
sequent int ipairs	2.9101999789418e-07
unsorted int pairs	1.0006600032284e-06

There is barely any difference between long and short string tables. The main difference in terms of speed comes with sequential number index tables, which can utilize ipairs to be faster than using pairs.

Code: files/string_vs_number_table.lua

Distance vs DistToSqr

TL;DR: The time difference between Distance and DistToSqr is barely noticable.

The result (average of 10000 calculations):

Distance:   0.00000026040000557259 (2.6040000557259e-07)
DistToSqr:  0.00000025130000176432 (2.5130000176432e-07)

The Code: files/distance_vs_disttosqr.lua

ternary vs if

TL;DR: They take the same amount of time. The difference is randomly swinging a tiny bit to each side every test.

Tested: a = t and 7 or 1 vs a=1 if t then a=7 end

The result (average of 1000000 calculations):

if:      4.1537399886693e-08
ternary: 4.168440006697e-08

The Code: files/ternary_vs_if.lua

table.insert vs table[#table+1] =

TL;DR: The time difference between using table.insert(myTable,9) and myTable[#myTable+1] = 9 is barely noticable, as the results were mostly the same. (Even if tested on Lua5.3 console)

The result (inserting 1million values):

table.insert:         0.066328400000003
local table.insert:   0.07047399999999
[#res+1]:             0.066876700000023

The Code: files/table.insert_vs_table.lua

table.HasValue(table,x) vs table[x]

TL;DR: Directly checking the table key with table[value] is way faster.

The result (1million lookups):

table.HasValue:   0.032319600000051
table[value]:     0.00024150000001555

The Code: files/table.hasvalue_vs_table.lua

Note: This is a O(n) vs O(1) situation. This means the bigger the table the slower table.HasValue will get.
For other examples visit https://wiki.facepunch.com/gmod/table.HasValue
To learn more about the "Big O Notation" visit, for example, https://web.mit.edu/16.070/www/lecture/big_o.pdf

table.Empty(tab) vs tab = {}

TL;DR: Assigning an empty table is overall faster than emptying it.

The following test compares small (10 elements) and big (10.000) tables with each method. It also differentiates between numerical tables (key 1,2,3,...) and string index tables (key a,b,c,...).
Result:

--- Benchmark complete
reps	1	rounds	1000
On Server
table.Empty numerical on small	1.5931000018554e-06
table.Empty numerical on big  	5.295060000276e-05
table.Empty stringind on small	4.9099999841928e-07
table.Empty stringind on big  	4.7529999847029e-07
table = {} numerical on small	9.8249999609834e-07
table = {} numerical on big  	6.0400000597838e-07
table = {} stringind on small	5.8179999678032e-07
table = {} stringind on big  	4.8149999975067e-07

The above times vary greatly by table count and amount of tests included. In general, assigning a new table is faster than emptying one, the only exception being small string-indexed tables. The biggest difference is between emptying a big numerical table and assigning a new one.
An advantage of always assigning a new table: The time taken is nearly constant, so you don't have to worry about it.

The Code: files/table_empty_vs_new.lua

ply:IsDoing() vs IsDoing(ply)

TL;DR: Not using metatables is faster.

This is a comparison of using the MetaTable PLAYER vs simply passing the player as an argument.

The result (100.000 rounds, 100 times):

ply:IsVal()	2.5642945799856e-06
IsVal(ply) 	1.4792759700133e-06

As you can see above, not using the metatable is faster. This is because with ply:Func() you have to check if the function exists (which is calling the __index method of the PLAYER metatable) which is slow, while in comparison with Func(ply) you already have the function at hand.

The code: files/meta_vs_argument.lua

String Concat vs Table Concat

TL;DR: It is faster to add strings together via tables instead of stringing them together directly.

The result (10000 strings):

GMOD SERVERSIDE CONSOLE
String Concat:  0.32185959999993
Table Concat:   0.0099451999999474
LUA5.3 CONSOLE
String Concat:  0.086629
Table Concat:   0.006428

The Code: files/string_vs_table_concat.lua

string.format vs .. concat

TL;DR: They both have nearly the same speed of execution. It varies between who is faster every run, it's that close.
What is better depends on the use case, I recommend using string.format for cases where the input is not fixed, because with this function you can add entities/players without having to convert them to a string explicitly.

This is a comparison of the 2 ways of creating a single string out of multiple pieces, either with string.format or with .. between the arguments. Example:

format = string.format("%s has steamid %s",ply:Nick(),ply:SteamID())
concat = ply:Nick().." has steamid "..ply:SteamID()

Result:

--- Benchmark complete
reps	10	rounds	1000
On Server
concat str	8.088840000346e-06
format str	8.3178000002022e-06
concat int	8.2556100002705e-06
format int	7.6555600000233e-06

As you can see above, the speed is varying a lot and here the format function is tied with the string concat.

The Code: files/string_format_vs_concat.lua

surface.DrawText vs draw.DrawText

TL;DR: Using draw.SimpleText is nearly as fast as using the surface.* functions. DrawText is a bit slower and SimpleTextOutlined is by far the slowest.

This test simply draws a word on 3 different coordinates on your screen with 4 different functions and measures the time taken.
Result:

surface 	4.4340000022203e-05
simple  	4.8489999971935e-05
drawtext	5.563999984588e-05
outlined	0.00012634444445009

As you can see above the surface.* method is the fastest closely followed by draw.SimpleText. It is (maybe) faster than draw.DrawText because it doesn't "handle newlines properly" according to the gmod wiki. SimpleTextOutlined is the slowest because it has to draw an extra outline in comparison to the 3 other functions.

The Code: files/surface_vs_draw_text.lua

file.Read vs sql.Query

TL;DR: Using file.Read is a tiny bit faster but there is barely any difference between the 2 methods.

If you want to save text and get it later, which method is faster: Saving it to a file and reading it or saving it into sqlite and reading it?
Result:

--- Benchmark complete
reps	20	rounds	100
On Server
file	0.00013605510000012
sql 	0.00014516330000007

There is no real speed difference, so it is not recommended to pick your storage type based on speed. You should pick your storage type based on what you need and how often you want to change data.

The Code: files/file_vs_sql_text.lua

sql Query vs QueryRow vs QueryValue

TL;DR: They are not comparable as Query is a C function and the others LUA functions using it.

If you print the "short source" of these 3 functions with debug.getinfo you get:

Query	    [C]
QueryRow	lua/includes/util/sql.lua
QueryValue	lua/includes/util/sql.lua

The (shortened) source of QueryRow is:

function sql.QueryRow(query,row)
    row = row or 1
    local r = sql.Query(query)
    if r then return r[row] end
    return r
end

This means that it doesn't really matter (for speed) if you use Query and select the first row or use QueryRow directly.

Finding Entities near a player

TL;DR: ents.FindInBox and ents.FindInCone are the fastest ways to find entities close to a player because they are easy to calculate and do not return too many entities.

The tested methods of getting entities around a player are:

  • ents.FindInPVS
  • ents.FindInCone
  • ents.FindInSphere
  • ents.FindInBox

Result:

--- Benchmark complete
On Server
reps	10	rounds	10000
inPVS	2.2498948000473e-05
inBox	1.9315759995857e-06
Sphere	3.8246590005724e-06
Cone	1.6260100000977e-06

The Code: files/finding_entities.lua

Finding players near you

TL;DR: It is faster to loop through all players and check their distance to you instead of using ents.FindInSphere and filtering for players.

This was tested with 40 players (bots) on a server. By looping through all players and checking the distance between you and them you are faster than by finding and looping through all the entities near you and checking if they are a player.

Result:

--- Benchmark complete
On Server
reps	10	rounds	1000
FindInSphere	0.00011627801000012
PlyGetAllChk	1.9475780000045e-05
--- Benchmark complete
On Client
reps	10	rounds	1000
FindInSphere	8.301507999995e-05
PlyGetAllChk	2.4392489999832e-05

The Code: files/finding_players.lua

Hashes (MD5, SHA1, SHA256)

TL;DR: As expected, the more uniqueness you need the longer it takes to calculate it. This means MD5 is the fastest but has a higher probability of colissions than the slower SHA256.

CRC32 and Base64 are just in there as comparisons. They are not a "good hash algorithm" in the same category as e.g. MD5.
Every function tested is defined in C and not in LUA. (According to debug.getinfo's short_src)

Result:

--- Benchmark complete
On Server
reps	10	rounds	10000
CRC32	4.5670400035306e-07
MD5	    2.5526380002202e-06
SHA1	3.5287520001384e-06
SHA256	7.7691459993503e-06
Base64	4.1977299973951e-07

The Code: files/hashes.lua

Is looking at each other comparison

TL;DR: Using the distance between normalized vectors of players viewing direction is the fastest method.

The question is: How do you calculate "Do these 2 players see each other on their screen right now?" the fastest?
This was a problem for a gameplay mechanic which needed to be calculated efficiently to not cause any lag.

Result:

--- Benchmark complete
On Server
reps	5	rounds	100
AngleBetweenVectorsManual     	1.1895999687113e-06
AngleBetweenYawOnly           	6.7819999458152e-07
WikisLookingAtVecDotFunction	1.0634000118444e-06
DistanceBetweenNormVecManual	1.5873999782343e-06
DistanceBetweenNormVecAuto	    1.0834000095201e-06
DistanceBetweenAimVectors     	8.4879999485565e-07

The fastest way is to use the ply:GetAimVector() of both players, negate one of those vectors and check the distance between them.

Detailed explanation

The default problem that many know is: Do these 2 vectors point in the same direction.
This problem is similar to ours: Do these 2 players look at each other.
The main difference is: One of the vectors is reversed.

This means we just have to reverse one of the 2 vectors and then we can use the standard mathematical formulas to calculate the "default problem" I mentioned above.
The slowdown while calculating this comes from using math.acos (arc cos) in the official formula. You need this to calculate the vector from the vector dot product formula.

An easier way is to simply use the distance between the 2 AimVectors. GetAimVector returns a normalized Vector which always has a length of 1. This means the maximum distance between the 2 vectors is 2 (if the vectors look in exactly the opposite direction) and the minimum is 0 (if the vectors look directly at each other). This makes it faster than all the other methods because you skip an angle calculation and just compare the distance directly.

The Code: files/looking_at_each_other.lua

for v in plys hook.Run vs hook.Run plys

TL;DR: It is faster to call a hook once with all players looping inside than to loop through players and calling a hook on each one by one.

This is a comparison between:

  • Calling a hook for every player
  • Calling a hook with a list of every player

Result:

--- Benchmark complete
On Server
reps	10	rounds	10000
single	9.2695600087609e-07
many  	2.602249987649e-07

The Code: files/hook_many_vs_hook_once.lua

DarkRP's fn vs normal lua

TL;DR: DarkRP's fn library is (most of the time) slower and more difficult to understand than simple lua code.

This is a comparison between 2 functions that do the same but are written completely different.
Please look at the Code to see exactly what the 2 tested codepieces were.

Result:

--- Benchmark complete
On Server
reps	10	rounds	1000
darkrp  7.9022700008863e-06 (0.0000079022700008863)
default	8.2877000014605e-07 (0.00000082877000014605)

Not only is DarkRP's fn code more difficult to read but it is up to 10 times slower than a simple chain of functions that do the same.

The Code: files/darkrp_fn_vs_standard_lua.lua

surface.DrawRect vs draw.RoundedBox

TL;DR: It is very slightly faster to use surface.DrawRect instead of draw.RoundedBox.
It should not be important for performance though as draw.RoundedBox also supports round edges and is simpler to read and write.

surface.DrawRect:   7.4859800010245e-06
draw.RoundedBox:    8.335099999681e-06

The Code: files/surface_vs_draw_box.lua

surface.SetDrawColor object vs rgb split

TL;DR: It is faster to call SetDrawColor with the rgb colors split up than if you were to use a Color object.

You can use the SetDrawColor function in 2 ways:

  • surface.SetDrawColor(color_white)
  • surface.SetDrawColor(255,255,255)

This is a comparison between these 2 methods. "Full" means passing the color object and "Split" means passing 3 numbers (rgb) to the function.

--- Benchmark complete
On Client
reps	10	rounds	10000
SetColorFull	6.0781200035763e-07
SetColorSplit	1.1340800017479e-07

The Code: files/setdrawcolor_comparison.lua

table creation assignments vs index

TL;DR: It is faster to assign all your variables in a table in the opening brackets.

I see 2 different ways of initializing tables in code nowadays.
The first simply being

local tab = {}
tab.name = "Test"
tab.money = 9

and the second being

local tab = {
    name = "Test",
    money = 9,
}

This is a comparison of both:

--- Benchmark complete
On Server
reps	10	rounds	10000
table = { x = y,	4.5506299968565e-07
table.x = y      	6.2055800030748e-07

As you can see, it is faster if you create the table with the data already inside.

The Code: files/table_assignments.lua

print vs Msg

TL;DR: MsgN and Msg are faster than print. Msg is only a bit faster than MsgN, because it doesn't append a newline at the end.

The test simply prints messages by using Msg, MsgN and print and checks the time taken.

Result:

--- Benchmark complete
reps	90	rounds	10
On Server
Msg	            1.9603333061645e-06
print	        3.1246666549123e-06
MsgN	        2.0377778006756e-06

Msg vars	    2.9552222390016e-06
MsgN vars	    2.9710000045371e-06
print vars	    9.2549999974128e-06

MsgN vars+tab	3.3575555587757e-06

The test is split into 2 sections: The first one where we only print a single string and the second one where we print varargs of 2 strings and 1 number.
As you can see, print is always the slowest.
The last benchmark is using MsgN with tabs to immitate what the print function does, and it is still faster than using print directly.

The Code: files/print_vs_msgn.lua

Multiplication vs Division

TL;DR: In Garry's Mod it is not faster to calculate x * 0.5 than x / 2. BUT: It is faster to multiply instead of divide in LUA5.3.

The result (average of 100 rounds with 1000000 calculations each):

GMOD SERVERSIDE CONSOLE
Multiplication:   0.00081622600000003
Division:         0.00081775100000215
LUA5.3 CONSOLE
Multiplication:   0.01865942
Division:         0.02342666

The Code: files/multiplication_vs_division.lua

math.Clamp vs math.min and math.max

TL;DR: It is a very tiny bit faster to use math.min in combination with math.max instead of math.Clamp, but the difference is negligible.

Result:

--- Benchmark complete
On Server
reps	20	rounds	50000
clamp  	6.9868600001882e-08
max/min	6.806609987666e-08
--- Benchmark complete
On Client
reps	20	rounds	50000
clamp  	6.9836399990663e-08
max/min	6.7090800087044e-08

The Code: files/math_clamp.lua

Local vs Global variable speed

TL;DR: It is a little itsy-bitsy bit faster to make all variables local in Garry's Mod. (14% in this example)

The result (average of 100 rounds with 10000 calculations each):

GMOD SERVERSIDE CONSOLE
global math.sin:      0.0000059390000023996 (5.9390000023996e-06)
local math.sin:       0.0000056840000024749 (5.6840000024749e-06)
LUA5.3 CONSOLE
global math.sin:      0.00057612
local math.sin:       0.00049858

The Code: files/local_vs_global.lua

x^2 vs x*x

This was tested with the inbuilt math.pow function and also the default power-of operator.

TL;DR: Using the "roof" operator is slightly faster in gmod. The speed is the same in Lua5.4.

The result (average of 100 rounds with 10000 calculations each):

GMOD SERVERSIDE CONSOLE
x^2 math.pow:  4.0210000111074e-06
x*x:           3.7120000251889e-06
x^2 ^:         3.5500000080901e-06
LUA5.4 CONSOLE
x^2 math.pow:  0.00015625
x^2 ^:         0.00015625
x*x:           0.00015625

The Code: files/x_squared_vs_x_times.lua

while vs for

TL;DR: A for loop is way faster than while.

The result (100x 10000):

GMOD SERVERSIDE CONSOLE
while:    0.00000957507999874 (9.57507999874e-06)
for:      0.0000024306500009516 (2.4306500009516e-06)
LUA5.3 CONSOLE
while:    0.00015975869999999
for:      0.000092178400000006 (9.2178400000006e-05)

The Code: files/while_vs_for.lua

local Color() vs Color()

TL;DR: Defining the color once is faster than using Color() in a loop.

The result (1000x in SysTime() time taken):

Local:     0.0000070583999997496 (7.0583999997496e-06)
Non-Local: 0.0000091475999998067 (9.1475999998067e-06)

The Code: files/local_color_vs_redefining.lua

Global variables slow down

TL;DR: Creating a lot of global variables neither slows down the game nor creates any noticable impact on performance.

I heard from multiple sources that "creating many global variables is bad".
I tested this by creating 10.000 global variables and observing the game afterwards. An example with the runtime of 10.000 math function calls:

Time    _G-count    time taken
Before	3133        0.00044090000005781
After	13144       0.00043160000018361

The FProfiler statistics and general gameplay feel didn't change either.
For more details on the test (or if you want to verify it yourself) check out my script I used:
files/global_variables.lua

table.Count vs #

TL;DR: It is better to always use the # operator instead of table.Count for sequential tables.

This comparison only works on sequential (or numerical) tables. These are tables that have a numerical, rising number as a key, in other languages you would call this "list" or array.

Table.count would always be used if you want to count a string-index table (also called dictionary or map), but in cases like this both can be used.

Result:

# Table size: 1000
Hashtag: 6.2949998141448e-08
TbCount: 1.5430600009495e-06
# Table size: 10
Hashtag: 4.4980000029682e-08
TbCount: 9.0410000939301e-08

As you can see above, the table.Count method is getting slower the larger the table becomes. This is because it loops through all the elements in the table and counts them, according to an old edit from the gmod wiki.

The Code: files/table_count_vs_hashtag.lua

ply.x vs tab[ply][x]

TL;DR: It is faster to get variables from a table than from the ply object. Setting a variable has nearly the same speed though, only getting the variable is slower on ply.

I and many others use code like ply.lastSpawned = CurTime(). This is quite easy to use and understand, but in performance aspects it is slower than using a table. An example with a table would be tab[ply]["lastSpawned"] = CurTime().
This is because reading this variable from a player uses a (slower) __index method. If you ever used FProfiler then you would probably have seen this "metamethod __index player" function near the top of "most runtime in ms".

I tested this by setting and getting random numbers with both methods 10.000 times, and I ran this 1000 times and calculated the average time taken. Result:

ply:	0.0033284901999953
tab:	0.0016247142000013

As you can see, it is quite faster (by 2x) with a table.
Using a table also has its downsides, like having to clean it up regularly to avoid ram leaks and having to check 2 table indexes each time you want to verify it.
Source code: files/ply_vs_table_index.lua

MySQL vs SQLite

For the full documentation please look at https://shira.at/gmod/mysql_sqlite.html.
Setup: MariaDB on Debian 10 installed on the same server as the Garry's Mod Server. Tested with DarkRP's MySQL functions and the mysqloo module.

The time is measured from first requesting the data until we can use the data.

Summary: MySQL is slower in comparison to SQLite. It needs an external connection and needs to wait for request/response delays either via network or via internal linux sockets. It's great for synchronisation of multiple servers, but it's not a "must-have" for servers.

Query Delay Comparison

To get the delay for a query without read or write operation we can query SELECT 1+1.

Result:

--First Test
SQLite   ResponseTime:   0.000045883003622293s
DRPMySQL ResponseTime:   0.020215623022523s
--Second Test
SQLite   ResponseTime:   0.000027909001801163s
DRPMySQL ResponseTime:   0.049109992978629s

Read and Write Comparison

Query: SELECT rpname FROM darkrp_player WHERE uid = 76561198071737444

Result:

SQLite   Read Time:   0.00016302999938489s
DRPMySQL Read Time:   0.048014674001024s

Query: INSERT INTO darkrp_player VALUES(123123,'Test User',1,2)

Result:

SQLite   Write Time:   0.00020395400133566s
DRPMySQL Write Time:   0.06270497100013s

1000 inserts (Bulk Inserts)

DarkRP's SQLite method uses sql.Begin and sql.Commit for SQLite based bulk imports. This makes it way faster than doing 1000 inserts after each other.

DarkRP's MySQL method simply puts the queries into a table and sents them one after the other to the mysql-server. This is way slower, as the time neede is simply the time one insert takes times 1000.

Result:

SQlite   1000 Inserts:     0.004849937000472s
DRPMySQL 1000 Inserts:   ~30.000000000000000s (calculated)

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A simple comparison of performance optimizations for gLUA

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