bottleneck: string2hex

[Valerio Schiavoni <valerio.schiavoni@...>]

Hello,

profiling my application, the big bottleneck of it comes from this function:

function string2hex(str)

assert(str,"String2hex got null argument")

local h,s =  string.gsub(str, "(.)", function(c) return string.format("%02X", string.byte(c)) end) 

return h

end

The size of input strings can be from 1kb to 1Mb.

How would you optimize it ? 

thanks for any suggestion,

valerio