Class: GetProcessMem

Inherits:
Object
  • Object
show all
Includes:
Sys
Defined in:
lib/get_process_mem.rb,
lib/get_process_mem/version.rb

Overview

Cribbed from Unicorn Worker Killer, thanks!

Constant Summary collapse

KB_TO_BYTE =

2**10 = 1024

1024
MB_TO_BYTE =

1024**2 = 1_048_576

1_048_576
GB_TO_BYTE =

1024**3 = 1_073_741_824

1_073_741_824
CONVERSION = 
{ "kb" => KB_TO_BYTE, "mb" => MB_TO_BYTE, "gb" => GB_TO_BYTE }
ROUND_UP = 
BigDecimal.new("0.5")
RUNS_ON_WINDOWS = 
Gem.win_platform?
VERSION = 
"0.2.1"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(pid = Process.pid) ⇒ GetProcessMem

Returns a new instance of GetProcessMem.



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# File 'lib/get_process_mem.rb', line 26

def initialize(pid = Process.pid)
  @status_file  = Pathname.new "/proc/#{pid}/status"
  @process_file = Pathname.new "/proc/#{pid}/smaps"
  @pid          = pid
  @linux        = @status_file.exist?
end

Instance Attribute Details

#pid ⇒ Object (readonly)

Returns the value of attribute pid.



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# File 'lib/get_process_mem.rb', line 11

def pid
  @pid
end

Instance Method Details

#bytes ⇒ Object 



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# File 'lib/get_process_mem.rb', line 37

def bytes
  memory =   linux_status_memory if linux?
  memory ||= ps_memory
end

#gb(b = bytes) ⇒ Object 



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# File 'lib/get_process_mem.rb', line 50

def gb(b = bytes)
  (b/BigDecimal.new(GB_TO_BYTE)).to_f
end

#inspect ⇒ Object 



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# File 'lib/get_process_mem.rb', line 54

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) ⇒ Object 



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# File 'lib/get_process_mem.rb', line 42

def kb(b = bytes)
  (b/BigDecimal.new(KB_TO_BYTE)).to_f
end

#linux? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/get_process_mem.rb', line 33

def linux?
  @linux
end

#linux_memory(file = @process_file) ⇒ Object

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



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# File 'lib/get_process_mem.rb', line 71

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 = BigDecimal.new(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) ⇒ Object

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



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# File 'lib/get_process_mem.rb', line 61

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) ⇒ Object 



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# File 'lib/get_process_mem.rb', line 46

def mb(b = bytes)
  (b/BigDecimal.new(MB_TO_BYTE)).to_f
end

#ps_memory ⇒ Object

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



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# File 'lib/get_process_mem.rb', line 88

def ps_memory
  if RUNS_ON_WINDOWS
    size = ProcTable.ps(pid).working_set_size
    BigDecimal.new(size)
  else
    KB_TO_BYTE * BigDecimal.new(`ps -o rss= -p #{pid}`)
  end
end