module Parallel

# File lib/parallel.rb, line 29
def self.each(array, options={}, &block)
  map(array, options.merge(:preserve_results => false), &block)
  array
end

# File lib/parallel.rb, line 34
def self.each_with_index(array, options={}, &block)
  each(array, options.merge(:with_index => true), &block)
end

# File lib/parallel.rb, line 23
def self.in_processes(options = {}, &block)
  count, options = extract_count_from_options(options)
  count ||= processor_count
  map(0...count, options.merge(:in_processes => count), &block)
end

# File lib/parallel.rb, line 6
def self.in_threads(options={:count => 2})
  count, options = extract_count_from_options(options)

  out = []
  threads = []

  count.times do |i|
    threads[i] = Thread.new do
      out[i] = yield(i)
    end
  end

  wait_for_threads(threads)

  out
end

# File lib/parallel.rb, line 38
def self.map(array, options = {}, &block)
  array = array.to_a # turn Range and other Enumerable-s into an Array

  if options[:in_threads]
    method = :in_threads
    size = options[method]
  else
    method = :in_processes
    size = options[method] || processor_count
  end
  size = [array.size, size].min

  return work_direct(array, options, &block) if size == 0

  if method == :in_threads
    work_in_threads(array, options.merge(:count => size), &block)
  else
    work_in_processes(array, options.merge(:count => size), &block)
  end
end

# File lib/parallel.rb, line 59
def self.map_with_index(array, options={}, &block)
  map(array, options.merge(:with_index => true), &block)
end

# File lib/parallel.rb, line 86
def self.physical_processor_count
  case RbConfig::CONFIG['host_os']
  when %rdarwin1/, %rfreebsd/
    %xsysctl -n hw.physicalcpu`.to_i
  when %rlinux/
    %xgrep cores /proc/cpuinfo`[%r\d+/].to_i
  when %rmswin|mingw/
    require 'win32ole'
    wmi = WIN32OLE.connect("winmgmts://")
    cpu = wmi.ExecQuery("select NumberOfProcessors from Win32_Processor")
    cpu.to_enum.first.NumberOfLogicalProcessors
  else
    processor_count
  end
end

# File lib/parallel.rb, line 63
def self.processor_count
  case RbConfig::CONFIG['host_os']
  when %rdarwin9/
    %xhwprefs cpu_count`.to_i
  when %rdarwin/
    (hwprefs_available? ? %xhwprefs thread_count` : %xsysctl -n hw.ncpu`).to_i
  when %rlinux|cygwin/
    %xgrep -c processor /proc/cpuinfo`.to_i
  when %r(open|free)bsd/
    %xsysctl -n hw.ncpu`.to_i
  when %rmswin|mingw/
    require 'win32ole'
    wmi = WIN32OLE.connect("winmgmts://")
    cpu = wmi.ExecQuery("select NumberOfLogicalProcessors from Win32_Processor")
    cpu.to_enum.first.NumberOfLogicalProcessors
  when %rsolaris2/
    %xpsrinfo -p`.to_i # this is physical cpus afaik
  else
    $stderr.puts "Unknown architecture ( #{RbConfig::CONFIG["host_os"]} ) assuming one processor."
    1
  end
end