Optimization for Read

[MeltingBrain 12]

Hello, I would like help optimizing my custom filesystem library, more precisely the 'readLine' function.
It takes ages to read one line, and I think it's because it's badly optimized.

 

Here is the code:
 

local line = ""
local data = nil
repeat
local data = fs.read(handle, 1) -- Reads 1 character
if data and data ~= "\n" then
line = line .. (data or "")
else
data = nil
end
until not data
return line ~= "" and line or nil

If possible, it would be nice to help me upgrade the code, as at the end you see it should return nil instead of a text, it's my bad code and in the final return text, there is sometimes a weird icon at the end (the \n char when printing the result).

Thanks from advance.

 

[Molinko 43]

Part of the reason you can't detect newline characters is because your data variable will only ever be one char where the newline pattern is a 2 char string. As for the rest I don't see the point of reading files with a custom lua func. The java Scala background can do this better than the ingame lua interpreter.. Reason?

[MeltingBrain 12]

Part of the reason you can't detect newline characters is because your data variable will only ever be one char where the newline pattern is a 2 char string. As for the rest I don't see the point of reading files with a custom lua func. The java Scala background can do this better than the ingame lua interpreter.. Reason?

 

I can detect a new line, as \n is one byte (Special Character for end of line), and it reads 1 byte per scan.

 

But OpenComputers made it VERY SLOW to read 1 per 1 until new line...

 

I'll search more about the java Scala as you said.

 

+ TO THE MODS CHECKING MY POST: Please say thanks from me to fnucke.

[Sangar 92]

Yes, reading a file byte by byte is slow. This is normal. If you were to read a file byte by byte that'd also be - comparatively - very very slow.

 

That's why there's buffering, and when you open a file using io.open you get a buffered handle and can do this way more comfortably, too (`f=io.open('blah'); f:read(1)`).