bench-hash-0.lua

local ffi = require('ffi')
local clock = require('clock')
local builtin = ffi.C

local datetime_t = ffi.typeof('struct datetime')
local SECS_PER_DAY     = 86400
local DT_EPOCH_1970_OFFSET = 719163LL

local function datetime_new_raw(secs, nsec, offset)
    local dt_obj = ffi.new(datetime_t)
    dt_obj.secs = secs
    dt_obj.nsec = nsec
    dt_obj.offset = offset
    return dt_obj
end

local function datetime_new_dt(dt, secs, frac, offset)
    local epochV = dt ~= nil and (builtin.tnt_dt_rdn(dt) - DT_EPOCH_1970_OFFSET) *
                   SECS_PER_DAY or 0
    local secsV = secs ~= nil and secs or 0
    local fracV = frac ~= nil and frac or 0
    local ofsV = offset ~= nil and offset or 0
    return datetime_new_raw(epochV + secsV - ofsV * 60, fracV, ofsV)
end

-- create datetime given attribute values from obj
local function datetime_new(obj)
    if obj == nil then
        return datetime_new_raw(0, 0, 0)
    end
    local secs = 0
    local nsec = 0
    local offset = 0
    local easy_way = false
    local y = 0
    local M = 0
    local d = 0
    local ymd = false

    local h = 0
    local m = 0
    local s = 0
    local frac = 0
    local hms = false

    local dt = 0

    local handlers = {
        secs = function(_, v)
            secs = v
            easy_way = true
        end,

        nsec = function(_, v)
            nsec = v
            easy_way = true
        end,

        offset = function (_, v)
            offset = v
            easy_way = true
        end,

        year = function(k, v)
            y = v
            ymd = true
        end,

        month = function(k, v)
            M = v
            ymd = true
        end,

        day = function(k, v)
            d = v
            ymd = true
        end,

        hour = function(k, v)
            h = v
            hms = true
        end,

        minute = function(k, v)
            m = v
            hms = true
        end,

        second = function(k, v)
            s, frac = math_modf(v)
            frac = frac * 1e9 -- convert fraction to nanoseconds
            hms = true
        end,

        -- tz offset in minutes
        tz = function(k, v)
            offset = v
        end
    }
    for key, value in pairs(obj) do
        handlers[key](key, value)
    end

    -- .sec, .nsec, .offset
    if easy_way then
        return datetime_new_raw(secs, nsec, offset)
    end

    -- .year, .month, .day
    if ymd then
        dt = dt + builtin.tnt_dt_from_ymd(y, M, d)
    end

    -- .hour, .minute, .second
    if hms then
        secs = h * 3600 + m * 60 + s
    end

    return datetime_new_dt(dt, secs, frac, offset)
end

-- create datetime given attribute values from obj
local function datetime_new_2(obj)
    if obj == nil then
        return datetime_new_raw(0, 0, 0)
    end
    local secs = 0
    local nsec = 0
    local offset = 0
    local easy_way = false
    local y = 0
    local M = 0
    local d = 0
    local ymd = false

    local h = 0
    local m = 0
    local s = 0
    local frac = 0
    local hms = false

    local dt = 0

    for key, value in pairs(obj) do
        if key == 'secs' then
            secs = value
            easy_way = true
        elseif key == 'nsec' then
            nsec = value
            easy_way = true
        elseif key == 'offset' then
            offset = value
            easy_way = true
        elseif key == 'year' then
            y = value
            ymd = true
        elseif key == 'month' then
            M = value
            ymd = true
        elseif key == 'day' then
            d = value
            ymd = true
        elseif key == 'hour' then 
            h = value
            hms = true
        elseif key == 'minute' then
            m = value
            hms = true
        elseif key == 'second' then
            s, frac = math_modf(value)
            frac = frac * 1e9 -- convert fraction to nanoseconds
            hms = true
        elseif key == 'tz' then
            offset = value
        end
    end

    -- .sec, .nsec, .offset
    if easy_way then
        return datetime_new_raw(secs, nsec, offset)
    end

    -- .year, .month, .day
    if ymd then
        dt = dt + builtin.tnt_dt_from_ymd(y, M, d)
    end

    -- .hour, .minute, .second
    if hms then
        secs = h * 3600 + m * 60 + s
    end

    return datetime_new_dt(dt, secs, frac, offset)
end


local _

local start = clock.time()
for _ = 1, 1e6 do
    _ = datetime_new_dt(DT_EPOCH_1970_OFFSET, 60, 100000, 180)
end
print('datetime_new_dt', clock.time() - start)

collectgarbage()
collectgarbage()

start = clock.time()
for _ = 1, 1e6 do
    _ = datetime_new{ secs = 60, nsec = 100000, offset = 180}
end
print('datetime_new', clock.time() - start)

collectgarbage()
collectgarbage()

local o = { secs = 60, nsec = 100000, offset = 180}
start = clock.time()
for _ = 1, 1e6 do
    _ = datetime_new(o)
end
print('datetime_new(precreated)', clock.time() - start)

collectgarbage()
collectgarbage()

start = clock.time()
for _ = 1, 1e6 do
    _ = datetime_new_2(o)
end
print('datetime_new_2(ifs)', clock.time() - start)

gistfile1.txt

✔ ~/datetime/tarantoolt/build [tsafin/gh-5941-datetime-v4 ↓·8↑·24|✚ 3…8⚑ 3] 
12:39 $ ./src/tarantool ../../bench-hash-0.lua
datetime_new_dt 0.0030450820922852
datetime_new    9.1180400848389
datetime_new(precreated)        7.1469388008118
datetime_new_2(ifs)     0.38320755958557
✔ ~/datetime/tarantoolt/build [tsafin/gh-5941-datetime-v4 ↓·8↑·24|✚ 3…8⚑ 3] 
12:39 $ ./src/tarantool ../../bench-hash-0.lua
datetime_new_dt 0.0036327838897705
datetime_new    7.5975275039673
datetime_new(precreated)        6.8448140621185
datetime_new_2(ifs)     0.49595499038696