_G.math.randomseed = function()

in kong/kong/globalpatches.lua [275:375]

• 78 lines of code
• 16 McCabe index (conditional complexity)

    _G.math.randomseed = function()
      local pid = ngx.worker.pid()
      local id
      local is_seeded
      local phase = ngx.get_phase()
      if phase == "init" then
        id = "master"
        is_seeded = seeded.master

      else
        id = ngx.worker.id()
        is_seeded = seeded[pid]
      end


      if is_seeded then
        ngx.log(ngx.DEBUG, debug.traceback("attempt to seed already seeded random number " ..
                                           "generator on process #" .. tostring(pid), 2))
        return
      end

      if not options.cli and (phase ~= "init_worker" and phase ~= "init") then
        ngx.log(ngx.WARN, debug.traceback("math.randomseed() must be called in " ..
                                          "init or init_worker context", 2))
      end

      local seed
      local bytes, err = util.get_rand_bytes(8)
      if bytes then
        ngx.log(ngx.DEBUG, "seeding PRNG from OpenSSL RAND_bytes()")

        local t = {}
        for i = 1, #bytes do
          local byte = string.byte(bytes, i)
          t[#t+1] = byte
        end

        local str = table.concat(t)
        if #str > 12 then
          
          
          
          
          
          
          str = string.sub(str, 1, 12)
        end

        seed = tonumber(str)

      else
        ngx.log(ngx.ERR, "could not seed from OpenSSL RAND_bytes, seeding ",
                         "PRNG with time and process id instead (this can ",
                         "result to duplicated seeds): ", err)

        seed = ngx.now() * 1000 + pid
      end

      if not options.cli then
        local kong_shm = ngx.shared.kong
        if id == "master" then
          local worker_count = ngx.worker.count()
          local old_worker_count = kong_shm:get("worker:count")
          if old_worker_count and old_worker_count > worker_count then
            for i = worker_count, old_worker_count - 1 do
              local old_worker_pid = kong_shm:get("pids:" .. i)
              if old_worker_pid then
                seeded[old_worker_pid] = nil
                kong_shm:delete("pids:" .. i)
                kong_shm:delete("kong:mem:" .. old_worker_pid)
              end
            end
          end

          if old_worker_count ~= worker_count then
            local ok, err = kong_shm:safe_set("worker:count", worker_count)
            if not ok then
              ngx.log(ngx.WARN, "could not store worker count in kong shm: ", err)
            end
          end

          seeded.master = true

        else
          local old_worker_pid = kong_shm:get("pids:" .. id)
          if old_worker_pid then
            seeded[old_worker_pid] = nil
            kong_shm:delete("kong:mem:" .. old_worker_pid)
          end

          local ok, err = kong_shm:safe_set("pids:" .. id, pid)
          if not ok then
            ngx.log(ngx.WARN, "could not store process id in kong shm: ", err)
          end

          seeded[pid] = true
        end
      end

      return randomseed(seed)
    end