From 093f0737205d00c478516001b3dd5577d94bb124 Mon Sep 17 00:00:00 2001
From: Tom Preston-Werner <tom@mojombo.com>
Date: Sat, 16 Jun 2007 18:34:07 -0700
Subject: [PATCH] started implementation of System::Process

---
 lib/god.rb                  |  6 ++++-
 lib/god/system/process.rb   | 55 +++++++++++++++++++++++++++++++++++++++++++++
 test/test_helper.rb         | 29 ++++++++++++++++++++++++
 test/test_system_process.rb | 51 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 140 insertions(+), 1 deletion(-)
 create mode 100644 lib/god/system/process.rb
 create mode 100644 test/test_system_process.rb

diff --git a/lib/god.rb b/lib/god.rb
index 76c2526..a55a6be 100644
--- a/lib/god.rb
+++ b/lib/god.rb
@@ -3,10 +3,14 @@ $:.unshift File.dirname(__FILE__)     # For use/testing when no gem is installed
 # internal requires
 require 'god/base'
 require 'god/errors'
+
+require 'god/system/process'
+
 require 'god/condition'
+require 'god/conditions/process_not_running'
+
 require 'god/watch'
 require 'god/meddle'
-require 'god/conditions/process_not_running'
 
 module God
   VERSION = '0.1.0'
diff --git a/lib/god/system/process.rb b/lib/god/system/process.rb
new file mode 100644
index 0000000..e2c0e72
--- /dev/null
+++ b/lib/god/system/process.rb
@@ -0,0 +1,55 @@
+module God
+  module System
+  
+    class Process
+      def initialize(pid)
+        @pid = pid.to_i
+      end
+      
+      # Return true if this process is running, false otherwise
+      def exists?
+        !ps_string('command').empty?
+      end
+      
+      # Memory usage in kilobytes (resident set size)
+      def memory
+        ps_int('rss')
+      end
+      
+      # Percentage memory usage
+      def percent_memory
+        ps_float('%mem')
+      end
+      
+      # Percentage CPU usage
+      def percent_cpu
+        ps_float('%cpu')
+      end
+      
+      # Seconds of CPU time (accumulated cpu time, user + system)
+      def cpu_time
+        time_string_to_seconds(ps_string('time'))
+      end
+      
+      private
+      
+      def ps_int(keyword)
+        `ps -o #{keyword}= -p #{@pid}`.to_i
+      end
+      
+      def ps_float(keyword)
+        `ps -o #{keyword}= -p #{@pid}`.to_f
+      end
+      
+      def ps_string(keyword)
+        `ps -o #{keyword}= -p #{@pid}`.strip
+      end
+      
+      def time_string_to_seconds(text)
+        _, minutes, seconds, useconds = *text.match(/(\d+):(\d{2}).(\d{2})/)
+        (minutes.to_i * 60) + seconds.to_i
+      end
+    end
+  
+  end
+end
\ No newline at end of file
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 36f19a4..db0ab66 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -23,3 +23,32 @@ module God
     
   end
 end
+
+# This allows you to be a good OOP citizen and honor encapsulation, but
+# still make calls to private methods (for testing) by doing
+#
+#   obj.bypass.private_thingie(arg1, arg2)
+#
+# Which is easier on the eye than
+#
+#   obj.send(:private_thingie, arg1, arg2)
+#
+class Object
+  class Bypass
+    instance_methods.each do |m|
+      undef_method m unless m =~ /^__/
+    end
+
+    def initialize(ref)
+      @ref = ref
+    end
+  
+    def method_missing(sym, *args)
+      @ref.__send__(sym, *args)
+    end
+  end
+
+  def bypass
+    Bypass.new(self)
+  end
+end
\ No newline at end of file
diff --git a/test/test_system_process.rb b/test/test_system_process.rb
new file mode 100644
index 0000000..e8569da
--- /dev/null
+++ b/test/test_system_process.rb
@@ -0,0 +1,51 @@
+require 'test_helper'
+
+class TestSystemProcessCreation < Test::Unit::TestCase
+  def test_new_should_succeed_for_existing_pid
+    pid = Process.pid
+    assert_nothing_raised do
+      @process = System::Process.new(pid)
+    end
+  end
+end
+
+class TestSystemProcess < Test::Unit::TestCase
+  def setup
+    pid = Process.pid
+    @process = System::Process.new(pid)
+  end
+  
+  def test_exists_should_return_true_for_running_process
+    assert_equal true, @process.exists?
+  end
+  
+  def test_exists_should_return_false_for_non_existant_process
+    assert_equal false, System::Process.new(0).exists?
+  end
+  
+  def test_memory
+    assert_kind_of Integer, @process.memory
+    assert @process.memory > 0
+  end
+  
+  def test_percent_cpu
+    assert_kind_of Float, @process.percent_mem
+  end
+  
+  def test_percent_cpu
+    assert_kind_of Float, @process.percent_cpu
+  end
+  
+  def test_cpu_time
+    assert_kind_of Integer, @process.cpu_time
+  end
+  
+  def test_time_string_to_seconds
+    assert_equal 0, @process.bypass.time_string_to_seconds('0:00:00')
+    assert_equal 0, @process.bypass.time_string_to_seconds('0:00:55')
+    assert_equal 27, @process.bypass.time_string_to_seconds('0:27:32')
+    assert_equal 75, @process.bypass.time_string_to_seconds('1:15:13')
+    assert_equal 735, @process.bypass.time_string_to_seconds('12:15:13')
+  end
+end
+
-- 
2.11.4.GIT