class GetProcessMem

Cribbed from Unicorn Worker Killer, thanks!

Constants

CONVERSION
GB_TO_BYTE
KB_TO_BYTE
MB_TO_BYTE
ROUND_UP
RUNS_ON_DARWIN
RUNS_ON_WINDOWS
VERSION

Attributes

pid[R]

Public Class Methods

new(pid = Process.pid) click to toggle source

# File lib/get_process_mem.rb, line 48
def initialize(pid = Process.pid)
  @status_file = Pathname.new "/proc/#{pid}/status"
  @process_file = Pathname.new "/proc/#{pid}/smaps"
  @pid = Integer(pid)
  @linux = @status_file.exist?
end

Private Class Methods

number_to_bigdecimal(value) click to toggle source

# File lib/get_process_mem.rb, line 6
                     def self.number_to_bigdecimal(value)
  BigDecimal(value)
end

Public Instance Methods

bytes() click to toggle source

# File lib/get_process_mem.rb, line 59
def bytes
  memory = linux_status_memory if linux?
  memory ||= darwin_memory if RUNS_ON_DARWIN
  memory ||= ps_memory
  memory
end

darwin_memory() click to toggle source

# File lib/get_process_mem.rb, line 122
def darwin_memory
  Darwin.resident_size(pid)
rescue Errno::EPERM
  nil
end

gb(b = bytes) click to toggle source

# File lib/get_process_mem.rb, line 74
def gb(b = bytes)
  (b / GB_TO_BYTE).to_f
end

inspect() click to toggle source

# File lib/get_process_mem.rb, line 78
def inspect
  b = bytes
  "#<#{self.class}:0x%08x @mb=#{mb b} @gb=#{gb b} @kb=#{kb b} @bytes=#{b}>" % (object_id * 2)
end

kb(b = bytes) click to toggle source

# File lib/get_process_mem.rb, line 66
def kb(b = bytes)
  (b / KB_TO_BYTE).to_f
end

linux?() click to toggle source

# File lib/get_process_mem.rb, line 55
def linux?
  @linux
end

linux_memory(file = @process_file) click to toggle source

linux stores detailed memory info in a file “/proc/#{pid}/smaps”

# File lib/get_process_mem.rb, line 95
def linux_memory(file = @process_file)
  lines = file.each_line.select { |line| line.match(/^Rss/) }
  return if lines.empty?
  lines.reduce(0) do |sum, line|
    line.match(/(?<value>\d*\.{0,1}\d+)\s+(?<unit>\w\w)/) do |m|
      value = number_to_bigdecimal(m[:value]) + ROUND_UP
      unit = m[:unit].downcase
      sum += CONVERSION[unit] * value
    end
    sum
  end
rescue Errno::EACCES
  0
end

linux_status_memory(file = @status_file) click to toggle source

linux stores memory info in a file “/proc/#{pid}/status” If it's available it uses less resources than shelling out to ps

# File lib/get_process_mem.rb, line 85
def linux_status_memory(file = @status_file)
  line = file.each_line.detect { |line| line.start_with? "VmRSS".freeze }
  return unless line
  return unless (_name, value, unit = line.split(nil)).length == 3
  CONVERSION[unit.downcase!] * value.to_i
rescue Errno::EACCES, Errno::ENOENT
  0
end

mb(b = bytes) click to toggle source

# File lib/get_process_mem.rb, line 70
def mb(b = bytes)
  (b / MB_TO_BYTE).to_f
end

ps_memory() click to toggle source

Pull memory from `ps` command, takes more resources and can freeze in low memory situations

# File lib/get_process_mem.rb, line 112
def ps_memory
  if RUNS_ON_WINDOWS
    size = ProcTable.ps(pid: pid).working_set_size
    number_to_bigdecimal(size)
  else
    mem = `ps -o rss= -p #{pid}`
    KB_TO_BYTE * number_to_bigdecimal((mem == "") ? 0 : mem)
  end
end

Private Instance Methods

number_to_bigdecimal(value) click to toggle source

# File lib/get_process_mem.rb, line 10
        def number_to_bigdecimal(value)
  self.class.send(:number_to_bigdecimal, value)
end