Faster insertion into table

[ghost]

minetest/minetest_game#732

-- table.insert
local time1 = os.clock()
local testtable1 = {}
for i = 1, 1000 do
    table.insert(testtable1, i)
end
print(os.clock()-time1)

-- tbl[#tbl+1]
local time2 = os.clock()
local testtable2 = {}
for i = 1, 1000 do
    testtable2[#testtable2+1] = i
end
print(os.clock()-time2)

table.insert :0.00020699999999996
tbl[#tbl+1] :0.00011100000000003

[ghost]

👍

[PilzAdam]

What about Lua vs. LuaJIT? Is it better for both?

Also you probably shouldn't waste your time optimizing non performance critical code.

[ShadowNinja]

My timings (with iterations multiplied by 1000 for better sample size):

Lua 5.3.2:
0.266029
0.16961
LuaJIT 2.0.4:
0.141926
0.126934

This doesn't matter unless the code is very performance-critical though.

[est31]

We don't use 5.3 we use 5.1.

[ShadowNinja]

@est31: Yes, but I don't have Lua 5.1 installed, I'd have to turn the script into a mod and run it through Minetest by starting a world.

[sapier]

doesn't seem to cause side effects on non indexed (key based) tables too

[sapier]

come on guys this is a minor change can those denying it please explain why?

[est31]

From reading http://www.lua.org/manual/5.1/manual.html#2.5.5 I saw that #tablename +1 is guaranteed to be nil. thats very fine

👍 if the whitespace issue (tablename[#tablename+1]) is fixed (should be tablename[#tablename + 1]).

[ghost]

Updated.

[est31]

👍 looks good

[ghost]

Rebased.

[paramat]

👍 Will merge soon.

[paramat]

24e8b0a