Hello,
the following code throws a stack overflow error with luajit, but it
works fine (although slowly) with lua 5.1.4.
Also, if you have suggestions on how to improve the running time of it
that'd be nice.
--save as : test-bench-luajit.lua
-- convert big or small number in scientific notation into a decimal string
function to_dec_string(s)
s = tostring(s)
local start, stop = string.find(s, "e", 1, true)
-- not scientific
if not start then return s end
local positif = true
if string.sub(s, 1, 1) == "-" then
s = tonumber(string.sub(s, 2))
positif = false
end
local t = split(s, "e")
local m, e = t[1], t[2]
local t = split(m, ".")
if t[2] then
m = t[1]..t[2]
end
if string.sub(e, 1, 1) == "-" then
e = tonumber(string.sub(e, 2))
for i = 1, e - 1 do
m = "0"..m
end
m = "0."..m
else
e = tonumber(e) - #m + 1
for i = 1, e do
m = m.."0"
end
end
if not positif then m = "-"..m end
return m
end
function encode(data)
local t = type(data)
if t == 'table' then -- list(array) or hash
local i = 1
local list = true
for k, v in pairs(data) do
if k ~= i then
list = false
break
end
i = i + 1
end
local out = ''
if list then
out = 'l'
for k, v in pairs(data) do
out = out..encode(v)
end
else -- hash
out = 'd'
for k, v in pairs(data) do
out = out..encode(k)..encode(v)
end
end
return out..'e'
elseif t == 'string' then
return #data..':'..data
elseif t == 'number' then
-- we need to convert scientific notation to decimal
return 'i'..to_dec_string(data)..'e'
elseif t == 'nil' then -- extension of benc
return 'n'
elseif t == 'boolean' then -- extension of benc
if data then
return 't'
else
return 'f'
end
end
end
data_sizes={1000,10000,100000,1000000}
print("Bench nested arrays with fixed-size string")
for k,v in pairs(data_sizes) do
local gen="a"
for i=1,(v/100) do --to avoid stackoverlow
gen={gen}
end
start=os.clock()
enc_data=encode(gen)
print((v/100), os.clock()-start)
end
best regards,
Valerio
