From a9c3f67a44a4c93fa1bd372724d68ddb1d02a4bd Mon Sep 17 00:00:00 2001
From: Tom Preston-Werner <tom@mojombo.com>
Date: Sat, 16 Jun 2007 21:52:28 -0700
Subject: [PATCH] added MemoryUsage and factored out ProcessCondition

---
 Manifest.txt                                       |  2 +-
 bin/devgod                                         |  8 ---
 lib/god.rb                                         |  3 ++
 lib/god/condition.rb                               | 32 +++++++++++-
 lib/god/conditions/memory_usage.rb                 | 44 ++++++++++++++++
 lib/god/conditions/process_not_running.rb          | 57 ++++++++------------
 lib/god/conditions/timeline.rb                     | 17 ++++++
 lib/god/meddle.rb                                  |  4 +-
 ...process_not_running.rb => process_condition.rb} | 26 ++++-----
 lib/god/watch.rb                                   | 61 +++++++++++++++++-----
 test/configs/real.rb                               | 20 +++++--
 test/test_condition.rb                             |  4 +-
 test/test_timeline.rb                              | 24 +++++++++
 test/test_watch.rb                                 | 26 +++++++++
 14 files changed, 241 insertions(+), 87 deletions(-)
 delete mode 100755 bin/devgod
 create mode 100644 lib/god/conditions/memory_usage.rb
 rewrite lib/god/conditions/process_not_running.rb (93%)
 create mode 100644 lib/god/conditions/timeline.rb
 copy lib/god/{conditions/process_not_running.rb => process_condition.rb} (50%)
 create mode 100644 test/test_timeline.rb

diff --git a/Manifest.txt b/Manifest.txt
index 8792cd4..53985d4 100644
--- a/Manifest.txt
+++ b/Manifest.txt
@@ -15,8 +15,8 @@ lib/god/watch.rb
 test/configs/no_watches.rb
 test/configs/real.rb
 test/configs/sample.rb
+test/helper.rb
 test/test_condition.rb
-test/test_helper.rb
 test/test_meddle.rb
 test/test_system_process.rb
 test/test_watch.rb
diff --git a/bin/devgod b/bin/devgod
deleted file mode 100755
index fb3d589..0000000
--- a/bin/devgod
+++ /dev/null
@@ -1,8 +0,0 @@
-#!/usr/bin/env ruby
-
-require 'rubygems'
-require File.join(File.dirname(__FILE__), *%w[.. lib god])
-
-file = ARGV[0]
-
-load file
\ No newline at end of file
diff --git a/lib/god.rb b/lib/god.rb
index a55a6be..44152c3 100644
--- a/lib/god.rb
+++ b/lib/god.rb
@@ -7,7 +7,10 @@ require 'god/errors'
 require 'god/system/process'
 
 require 'god/condition'
+require 'god/process_condition'
+require 'god/conditions/timeline'
 require 'god/conditions/process_not_running'
+require 'god/conditions/memory_usage'
 
 require 'god/watch'
 require 'god/meddle'
diff --git a/lib/god/condition.rb b/lib/god/condition.rb
index f442d06..0f68ba9 100644
--- a/lib/god/condition.rb
+++ b/lib/god/condition.rb
@@ -3,9 +3,17 @@ module God
   class Condition < Base
     def self.generate(kind)
       sym = kind.to_s.capitalize.gsub(/_(.)/){$1.upcase}.intern
-      God.const_get(sym).new
+      God::Conditions.const_get(sym).new
     rescue NameError
-      raise NoSuchConditionError.new("No Condition found with the class name God::#{sym}")
+      raise NoSuchConditionError.new("No Condition found with the class name God::Conditions::#{sym}")
+    end
+    
+    # Override this method in your Conditions (optional)
+    #
+    # Called once after the Condition has been sent to the block and attributes have been
+    # set. Do any post-processing on attributes here
+    def prepare
+      
     end
     
     # Override this method in your Conditions (optional)
@@ -32,6 +40,26 @@ module God
     def after
     end
     
+    #######
+    
+    def before_start
+    end
+    
+    def after_start
+    end
+    
+    def before_restart
+    end
+    
+    def after_restart
+    end
+    
+    def before_stop
+    end
+    
+    def after_stop
+    end
+    
     protected
     
     def complain(text)
diff --git a/lib/god/conditions/memory_usage.rb b/lib/god/conditions/memory_usage.rb
new file mode 100644
index 0000000..a5b4bc1
--- /dev/null
+++ b/lib/god/conditions/memory_usage.rb
@@ -0,0 +1,44 @@
+module God
+  module Conditions
+    
+    class MemoryUsage < ProcessCondition
+      attr_accessor :above, :times
+    
+      def initialize
+        super
+        self.above = nil
+        self.times = [1, 1]
+      end
+      
+      def prepare
+        p self.times.class
+        
+        if self.times.kind_of?(Integer)
+          self.times = [self.times, self.times]
+        end
+        
+        @timeline = Timeline.new(self.times[1])
+      end
+    
+      def valid?
+        valid = super
+        valid = complain("You must specify the 'above' attribute for :memory_usage") if self.above.nil?
+        valid
+      end
+    
+      def test
+        return false unless super
+        pid = File.open(self.pid_file).read.strip
+        process = System::Process.new(pid)
+        @timeline.push(process.memory)
+        if @timeline.select { |x| x > self.above }.size < self.times.first
+          return true
+        else
+          @timeline.clear
+          return false
+        end
+      end
+    end
+    
+  end
+end
\ No newline at end of file
diff --git a/lib/god/conditions/process_not_running.rb b/lib/god/conditions/process_not_running.rb
dissimilarity index 93%
index ac33a98..f9cb1d8 100644
--- a/lib/god/conditions/process_not_running.rb
+++ b/lib/god/conditions/process_not_running.rb
@@ -1,36 +1,21 @@
-module God
-  class ProcessNotRunning < Condition
-    attr_accessor :pid_file, :clean
-    
-    def initialize
-      self.pid_file = nil
-      self.clean = true
-    end
-    
-    def valid?
-      valid = true
-      valid = complain("You must specify the 'pid_file' attribute for :process_not_running") if self.pid_file.nil?
-      valid
-    end
-    
-    def test
-      return false unless File.exist?(self.pid_file)
-      pid = File.open(self.pid_file).read.strip
-      process_running?(pid)
-    end
-    
-    def after
-      if self.clean
-        File.delete(self.pid_file) rescue nil
-      end
-    end
-    
-    private
-    
-    def process_running?(pid)
-      cmd_name = RUBY_PLATFORM =~ /solaris/i ? "args" : "command"
-      ps_output = `ps -o #{cmd_name}= -p #{pid}`
-      !ps_output.strip.empty?
-    end 
-  end
-end
+module God
+  module Conditions
+    
+    class ProcessNotRunning < ProcessCondition
+      def test
+        return false unless super
+        pid = File.open(self.pid_file).read.strip
+        process_running?(pid)
+      end
+        
+      private
+    
+      def process_running?(pid)
+        cmd_name = RUBY_PLATFORM =~ /solaris/i ? "args" : "command"
+        ps_output = `ps -o #{cmd_name}= -p #{pid}`
+        !ps_output.strip.empty?
+      end 
+    end
+    
+  end
+end
\ No newline at end of file
diff --git a/lib/god/conditions/timeline.rb b/lib/god/conditions/timeline.rb
new file mode 100644
index 0000000..1459dcb
--- /dev/null
+++ b/lib/god/conditions/timeline.rb
@@ -0,0 +1,17 @@
+module God
+  module Conditions
+    
+    class Timeline < Array
+      def initialize(max_size)
+        super()
+        @max_size = max_size
+      end
+      
+      def push(val)
+        unshift(val)
+        pop if size > @max_size
+      end
+    end
+    
+  end
+end
\ No newline at end of file
diff --git a/lib/god/meddle.rb b/lib/god/meddle.rb
index b68194a..cd88c75 100644
--- a/lib/god/meddle.rb
+++ b/lib/god/meddle.rb
@@ -27,9 +27,7 @@ module God
       @watches.each do |w|
         threads << Thread.new do
           while true do
-            if a = w.run
-              w.action(a)
-            end
+            w.run
             sleep self.interval
           end
         end
diff --git a/lib/god/conditions/process_not_running.rb b/lib/god/process_condition.rb
similarity index 50%
copy from lib/god/conditions/process_not_running.rb
copy to lib/god/process_condition.rb
index ac33a98..97f5e76 100644
--- a/lib/god/conditions/process_not_running.rb
+++ b/lib/god/process_condition.rb
@@ -1,36 +1,28 @@
 module God
-  class ProcessNotRunning < Condition
+  
+  class ProcessCondition < Condition
     attr_accessor :pid_file, :clean
     
     def initialize
       self.pid_file = nil
       self.clean = true
     end
-    
+  
     def valid?
       valid = true
       valid = complain("You must specify the 'pid_file' attribute for :process_not_running") if self.pid_file.nil?
       valid
     end
-    
+  
     def test
-      return false unless File.exist?(self.pid_file)
-      pid = File.open(self.pid_file).read.strip
-      process_running?(pid)
+      File.exist?(self.pid_file)
     end
-    
-    def after
+  
+    def before_start
       if self.clean
         File.delete(self.pid_file) rescue nil
       end
     end
-    
-    private
-    
-    def process_running?(pid)
-      cmd_name = RUBY_PLATFORM =~ /solaris/i ? "args" : "command"
-      ps_output = `ps -o #{cmd_name}= -p #{pid}`
-      !ps_output.strip.empty?
-    end 
   end
-end
+  
+end
\ No newline at end of file
diff --git a/lib/god/watch.rb b/lib/god/watch.rb
index 8418163..42ba7ae 100644
--- a/lib/god/watch.rb
+++ b/lib/god/watch.rb
@@ -2,7 +2,7 @@ module God
   
   class Watch < Base
     # config
-    attr_accessor :name, :cwd, :start, :stop, :grace
+    attr_accessor :name, :cwd, :start, :stop, :restart, :grace
     
     # api
     attr_accessor :conditions
@@ -16,7 +16,8 @@ module God
       @action = nil
       
       # the list of conditions for each action
-      self.conditions = {:start => []}
+      self.conditions = {:start => [],
+                         :restart => []}
     end
     
     def start_if
@@ -25,6 +26,12 @@ module God
       @action = nil
     end
     
+    def restart_if
+      @action = :restart
+      yield(self)
+      @action = nil
+    end
+    
     # Instantiate a Condition of type +kind+ and pass it into the mandatory
     # block. Attributes of the condition must be set in the config file
     def condition(kind)
@@ -42,8 +49,12 @@ module God
         exit
       end
       
+      # send to block so config can set attributes
       yield(c)
       
+      # call prepare on the condition
+      c.prepare
+      
       # exit if the Condition is invalid, the Condition will have printed
       # out its own error messages by now
       unless c.valid?
@@ -54,28 +65,52 @@ module God
     end
     
     def run
-      self.conditions[:start].each do |c|
-        if c.test
-          puts self.name + ' ' + c.class.name + ' [ok]'
-        else
-          puts self.name + ' ' + c.class.name + ' [fail]'
-          c.after
-          return :start
+      [:start, :restart].each do |cmd|
+        self.conditions[cmd].each do |c|
+          if c.test
+            puts self.name + ' ' + c.class.name + ' [ok]'
+          else
+            puts self.name + ' ' + c.class.name + ' [fail]'
+            c.after
+            action(cmd, c)
+            return
+          end
         end
       end
-      
-      nil
     end
     
-    def action(a)
+    def action(a, c)
       case a
       when :start
         puts self.start
         Dir.chdir(self.cwd) do
+          c.before_start
           system(self.start)
+          c.after_start
         end
         sleep(self.grace)
-      end
+      when :restart
+        if self.restart
+          puts self.restart
+          Dir.chdir(self.cwd) do
+            c.before_restart
+            system(self.restart)
+            c.after_restart
+          end
+        else
+          self.action(:stop, c)
+          self.action(:start, c)
+        end
+        sleep(self.grace)
+      when :stop
+        puts self.stop
+        Dir.chdir(self.cwd) do
+          c.before_stop
+          system(self.stop)
+          c.after_stop
+        end
+        sleep(self.grace)
+      end      
     end
   end
   
diff --git a/test/configs/real.rb b/test/configs/real.rb
index d689648..ced8948 100644
--- a/test/configs/real.rb
+++ b/test/configs/real.rb
@@ -1,5 +1,5 @@
 if $0 == __FILE__
-  require File.join(File.dirname(__FILE__), *%w[.. lib god])
+  require File.join(File.dirname(__FILE__), *%w[.. .. lib god])
 end
 
 RAILS_ROOT = "/Users/tom/dev/gravatar2"
@@ -12,11 +12,21 @@ God.meddle do |god|
     w.cwd = RAILS_ROOT
     w.start = "mongrel_rails start -P ./log/mongrel.pid -d"
     w.stop = "mongrel_rails stop -P ./log/mongrel.pid"
-    w.grace = 10
+    w.grace = 5
+    
+    pid_file = File.join(RAILS_ROOT, "log/mongrel.pid")
   
-    w.start_if do |r|
-      r.condition(:process_not_running) do |c|
-        c.pid_file = File.join(RAILS_ROOT, "log/mongrel.pid")
+    w.start_if do |start|
+      start.condition(:process_not_running) do |c|
+        c.pid_file = pid_file
+      end
+    end
+    
+    w.restart_if do |restart|
+      restart.condition(:memory_usage) do |c|
+        c.pid_file = pid_file
+        c.above = 10 # kb
+        c.times = [3, 5]
       end
     end
   end
diff --git a/test/test_condition.rb b/test/test_condition.rb
index 10e360d..2abd6cf 100644
--- a/test/test_condition.rb
+++ b/test/test_condition.rb
@@ -2,7 +2,7 @@ require 'helper'
 
 class TestCondition < Test::Unit::TestCase
   def test_generate_should_return_an_object_corresponding_to_the_given_type
-    assert_equal ProcessNotRunning, Condition.generate(:process_not_running).class
+    assert_equal Conditions::ProcessNotRunning, Condition.generate(:process_not_running).class
   end
   
   def test_generate_should_raise_on_invalid_type
@@ -12,7 +12,7 @@ class TestCondition < Test::Unit::TestCase
   end
   
   def test_generate_should_return_a_good_error_message_for_invalid_types
-    emsg = "No Condition found with the class name God::FooBar"
+    emsg = "No Condition found with the class name God::Conditions::FooBar"
     rmsg = nil
     
     begin
diff --git a/test/test_timeline.rb b/test/test_timeline.rb
new file mode 100644
index 0000000..8935173
--- /dev/null
+++ b/test/test_timeline.rb
@@ -0,0 +1,24 @@
+require 'helper'
+
+class TestTimeline < Test::Unit::TestCase
+  def setup
+    @timeline = Conditions::Timeline.new(5)
+  end
+  
+  def test_new_should_be_empty
+    assert_equal 0, @timeline.size
+  end
+  
+  def test_should_not_grow_to_more_than_size
+    (1..10).each do |i|
+      @timeline.push(i)
+    end
+    
+    assert_equal [10, 9, 8, 7, 6], @timeline
+  end
+  
+  def test_clear_should_clear_array
+    @timeline.push(1)
+    assert_equal [], @timeline.clear
+  end
+end
\ No newline at end of file
diff --git a/test/test_watch.rb b/test/test_watch.rb
index 431fe8d..c09fe28 100644
--- a/test/test_watch.rb
+++ b/test/test_watch.rb
@@ -9,15 +9,22 @@ class TestWatch < Test::Unit::TestCase
     assert_equal [], @watch.conditions[:start]
   end
   
+  def test_should_have_empty_restart_conditions
+    assert_equal [], @watch.conditions[:restart]
+  end
+  
   def test_should_have_standard_attributes
     assert_nothing_raised do
       @watch.name = 'foo'
       @watch.cwd = '/foo'
       @watch.start = 'start'
       @watch.stop = 'stop'
+      @watch.restart = 'restart'
     end
   end
   
+  # _if methods
+  
   def test_start_if_should_modify_action_within_scope
     assert_equal nil, @watch.instance_variable_get(:@action)
     @watch.start_if do |w|
@@ -26,6 +33,16 @@ class TestWatch < Test::Unit::TestCase
     assert_equal nil, @watch.instance_variable_get(:@action)
   end
   
+  def test_restart_if_should_modify_action_within_scope
+    assert_equal nil, @watch.instance_variable_get(:@action)
+    @watch.restart_if do |w|
+      assert_equal :restart, @watch.instance_variable_get(:@action)
+    end
+    assert_equal nil, @watch.instance_variable_get(:@action)
+  end
+  
+  # condition
+  
   def test_condition_should_record_condition_in_correct_list
     cond = nil
     @watch.start_if do |w|
@@ -35,6 +52,15 @@ class TestWatch < Test::Unit::TestCase
     assert_equal cond, @watch.conditions[:start].first
   end
   
+  def test_condition_should_record_condition_in_correct_list
+    cond = nil
+    @watch.restart_if do |w|
+      w.condition(:fake_condition) { |c| cond = c }
+    end
+    assert_equal 1, @watch.conditions[:restart].size
+    assert_equal cond, @watch.conditions[:restart].first
+  end
+  
   def test_condition_called_from_outside_if_block_should_raise
     assert_raise ExitCalledError do
       @watch.condition(:fake_condition) { |c| cond = c }
-- 
2.11.4.GIT