# Macros to constrain resource use during the build process

# outputs build flag overrides to be used in conjunction with

# %%make_build, %%cmake_build etc.

#

# if no override is needed, this macro outputs nothing

#

# - m   memory limit in MBs per core; default is 1024

#

# Usage:

# e.g. %make_build %{limit_build -m 2048}

#   => /usr/bin/make -O -j16 V=1 VERBOSE=1

#      %make_build %{limit_build -m 40960}

#   => /usr/bin/make -O -j16 V=1 VERBOSE=1 -j1

# 

%limit_build(m:) %{lua:

  local mem_per_process=rpm.expand("%{-m*}")

  if mem_per_process == "" then

    mem_per_process = 1024

  else

    mem_per_process = tonumber(mem_per_process)

  end

  local mem_total = 0

  for line in io.lines('/proc/meminfo') do

    if line:sub(1, 9) == "MemTotal:" then

      local tokens = {}

      for token in line:gmatch("%w+") do

        tokens[#tokens + 1] = token

      end

      mem_total = tonumber(tokens[2])

      break

    end

  end

  local max_jobs = mem_total // (mem_per_process * 1024)

  if max_jobs < 1 then

    max_jobs = 1

  end

  cur_max_jobs=tonumber(rpm.expand("%{_smp_build_ncpus}"))

  if cur_max_jobs > max_jobs then

    print("-j" .. max_jobs)

  end

}