OpenResty micro benchmark lib

benchmark.lua

local ffi = require "ffi"                                                                     
                                                                                              
local ngx = ngx                                                                               
local ngx_update_time = ngx.update_time                                                       
local ngx_say = ngx.say                                                                       
local tonumber = tonumber                                                                                                             
                                                                                                                                          
ffi.cdef[[                                                                                                                                
    typedef long time_t;                                                                                                                  
                                                                                                                                          
    typedef struct timeval {                                                                                                              
        time_t tv_sec;                                                                                                                    
        time_t tv_usec;                                                                                                                   
    } timeval;                                                                                                                            
                                                                                                                                          
    int gettimeofday(struct timeval* t, void* tzp);                                                                                       
]]                                                                                                                                        
                                                                                                                                          
local gettimeofday_struct = ffi.new("timeval")                                                                                            
local gettimeofday = ffi.C.gettimeofday                                                                                                   
                                                                                                                                          
local _M = {}                                                                                                                             
                                                                                                                                          
local function time()                                                                                                                     
    gettimeofday(gettimeofday_struct, nil)                                                                                                
    return tonumber(gettimeofday_struct.tv_sec) * 1000000 + tonumber(gettimeofday_struct.tv_usec)                                         
end                                                                                                                                       
_M.time = time                                                                                                                            
                                                                                                                                          
function _M.bench(name, rounds, func)                                                                                                     
    ngx_update_time()                                                                                                                     
    local start = time()                                                                                                                  
    for _ = 1,rounds do                                                                                                                   
        func()                                                                                                                            
    end                                                                                                                                   
    local stop = time()                                                                                                                   
    ngx_say(((stop - start) / rounds) .. ": " .. name)                                                                                    
end                                                                                                                                       
                                                                                                                                          
return _M