Class: Duffy::System

Inherits:
Object
  • Object
show all
Defined in:
lib/duffy/system.rb

Overview

Depending on your hardware, you may want to make decisions in your code. I use this to figure out how many processes I can launch in parallel.

Class Method Summary collapse

Class Method Details

.battery_percent ⇒ Object

The battery percentage 0.0 .. 100.0 nil if no battery or error reading value. Darwin: pmset -g batt Linux:



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# File 'lib/duffy/system.rb', line 99

def battery_percent
  case RUBY_PLATFORM
    when /darwin/ then `pmset -g batt`.scan(/^.*\t(.*%);/)[0][0].to_f
    when /linux/  then File.read("/sys/class/power_supply/BAT0/charge_now").to_i * 100 / File.read("/sys/class/power_supply/BAT0/charge_full").to_i
    else nil
  end
rescue
  nil
end

.cores ⇒ Object

How many actual CPU cores do we have not including Hyperthreading Linux: “cpu cores” in cpuinfo is on a per physical processor basis, so we multiply by the number of CPUs Mac: hw.physicalcpu



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# File 'lib/duffy/system.rb', line 22

def cores
  case RUBY_PLATFORM
    when /linux/  then File.read('/proc/cpuinfo').scan(/(cpu cores)(\D)*(\d+)/)[0][2].to_i * cpus
    when /darwin/ then `sysctl -n hw.physicalcpu`.to_i
    else 1
  end
rescue
  1
end

.cpu_percent ⇒ Object

The system’s current CPU utilization. Darwin: Get a list of all processes’ CPU percentage and add them up. Linux: Read /proc/stat twice and take the difference to give cpu time used in that interval.



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# File 'lib/duffy/system.rb', line 62

def cpu_percent
  case RUBY_PLATFORM
    when /darwin/ then `ps -A -o %cpu`.lines.map(&:to_f).inject(:+) / threads
    when /linux/  then proc_diff
    else 0
  end
rescue
  0
end

.cpus ⇒ Object

How many Physical CPUs do you have. Linux: Detected by counting unique physical IDs Mac: hw.packages



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# File 'lib/duffy/system.rb', line 9

def cpus
  case RUBY_PLATFORM
    when /linux/  then File.read('/proc/cpuinfo').scan(/^physical id.*/).uniq.count
    when /darwin/ then `sysctl -n hw.packages`.to_i
    else 1
  end
rescue
  1
end

.freespace ⇒ Object

Disk Freespace Looks at current working directory



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# File 'lib/duffy/system.rb', line 74

def freespace
  case RUBY_PLATFORM
    when /darwin/ then `df -m #{Shellwords.shellescape(Dir.pwd)}`.lines[1].split[3].to_i
    when /linux/  then `df -m #{Shellwords.shellescape(Dir.pwd)}`.lines[1].split[3].to_i
    else 0
  end
end

.mem_available ⇒ Object

Memory available for use in Megabytes Darwin: vm_stat (Pages Free + Pages Inactive) Linux: Read /proc/meminfo



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# File 'lib/duffy/system.rb', line 112

def mem_available
  case RUBY_PLATFORM
    when /darwin/ then `vm_stat`.lines.grep(/(free:|inactive:)\s*(\d+)/){$2}.map(&:to_i).inject(:+) * 4 / 1024
    when /linux/  then File.read("/proc/meminfo").lines.grep(/MemAvail|MemFree/).sort.first.split[1].to_i / 1024
    else 0
  end
rescue
  0
end

.mem_percent ⇒ Object

Percentage of Memory used, 0.0 .. 100.0



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# File 'lib/duffy/system.rb', line 130

def mem_percent
  (100.0 * mem_used / mem_total).round(1)
rescue
  0
end

.mem_total ⇒ Object

Total system memory in Megabytes Darwin: hw.memsize (bytes) Linux: Read /proc/meminfo



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# File 'lib/duffy/system.rb', line 85

def mem_total
  case RUBY_PLATFORM
    when /darwin/ then `sysctl -n hw.memsize`.to_i / 1024 / 1024
    when /linux/  then File.read("/proc/meminfo").scan(/MemTotal:\s*(\d+)/)[0][0].to_i / 1024
    else 0
  end
rescue
  0
end

.mem_used ⇒ Object

Memory used Subtract mem_available from mem_total. This ignores file cache etc that is not actually used by programs.



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# File 'lib/duffy/system.rb', line 125

def mem_used
  mem_total - mem_available
end

.sane_load ⇒ Object

What is a sane number of threads to use for data processing. You want to leave some headroom for your database etc running in other processes.



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# File 'lib/duffy/system.rb', line 55

def sane_load
  threads * 3 / 4
end

.threads ⇒ Object

How many threads does the system have.



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# File 'lib/duffy/system.rb', line 33

def threads
  case RUBY_PLATFORM
    when /linux/  then File.read('/proc/cpuinfo').scan(/^processor\s*:/).size
    when /darwin/ then `sysctl -n hw.ncpu`.to_i
    else 1
  end
rescue
  1
end

.virtual? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/duffy/system.rb', line 43

def virtual?
  case RUBY_PLATFORM
    when /linux/  then !!File.read('/proc/cpuinfo').scan(/^flags.*(hypervisor)/)[0]
    when /darwin/ then false # PENDING
    else false
  end
rescue
  false
end