Contents

# frozen_string_literal: true

require 'ffi'

module Facter
  module Bsd
    module FfiHelper
      module Libc
        extend FFI::Library

        ffi_lib 'c'
        attach_function :getloadavg, %i[pointer int], :int
        attach_function :sysctl, %i[pointer uint pointer pointer pointer size_t], :int
      end

      def self.read_load_averages
        raw_loadavg = FFI::MemoryPointer.new(:double, 3)

        res = Libc.getloadavg(raw_loadavg, 3)
        return unless res == 3

        raw_loadavg.read_array_of_double(res)
      end

      def self.sysctl(type, oids)
        name = FFI::MemoryPointer.new(:uint, oids.size)
        name.write_array_of_uint(oids)
        namelen = oids.size

        oldp = FFI::Pointer::NULL
        oldlenp = FFI::MemoryPointer.new(:size_t)

        newp = FFI::Pointer::NULL
        newlen = 0

        if type == :string
          res = Libc.sysctl(name, namelen, oldp, oldlenp, newp, newlen)
          return nil if res.negative?
        else
          oldlenp.write(:size_t, FFI.type_size(type))
        end

        oldp = FFI::MemoryPointer.new(:uint8_t, oldlenp.read(:size_t))
        res = Libc.sysctl(name, namelen, oldp, oldlenp, newp, newlen)
        return nil if res.negative?

        case type
        when :string
          oldp.read_string
        else
          oldp.read(type)
        end
      end
    end
  end
end

Version data entries

6 entries across 6 versions & 1 rubygems

Version	Path
facter-4.0.33	lib/facter/resolvers/bsd/ffi/ffi_helper.rb
facter-4.0.32	lib/facter/resolvers/bsd/ffi/ffi_helper.rb
facter-4.0.31	lib/facter/resolvers/bsd/ffi/ffi_helper.rb
facter-4.0.30	lib/facter/resolvers/bsd/ffi/ffi_helper.rb
facter-4.0.29	lib/resolvers/bsd/ffi/ffi_helper.rb
facter-4.0.28	lib/resolvers/bsd/ffi/ffi_helper.rb