Hello, I want to get the accurate size of data.
local HttpService = game:GetService("HttpService")
local function getDataSize(data)
return #HttpService:JSONEncode(data)
end
This function is according to MessagingService not correct.
local t = {}
for i = 1, 71 do
table.insert(t, 1111111111111)
end
print(getDataSize(t)) --prints under 1000, 1kB is 1024
game:GetService("MessagingService"):PublishAsync("Test", t)
MessagingService says that the data exceeded 1kb.
Any help is appreciated!
What do you mean with that? 
The # operator gets the size of the table in terms of how many elements it has, not how much memory it takes up.
Although I suppose you could create a function to get the sizeof a table in memory, though you would have to count for a lot of cases. Though here is how you do it if you only had an array of numbers as in your second example
-- Lua uses 64 bit integers and 64 bit double precision floats
function sizeof(t)
return #t * 64
end
JSONEncode converts a table into a JSON string. That means that the # operator returns how long the string is, not how many elements in the table are.
What are you trying to solve by figuring out the exact max payload?
I’m trying to make a packet switching system where data gets split into packets when it’s bigger than 1kB.
Is the “size of message” limit of 1kB maybe calculated including the Data/Sent fields?
This would explain why 976B is the maximum size:
MessagingService:PublishAsync("Test", string.rep("a", 974)) --has a size of 976
MessagingService:PublishAsync("Test", string.rep("a", 975)) --too large
Yes, that sounds accurate. At one point we looked at increasing it so the data alone could be 1kB but we never prioritized that fix.
Ah okay, thanks for your help! 