lib/datacenter/process.rb in datacenter-0.0.1 vs lib/datacenter/process.rb in datacenter-0.1.0

@@ -11,57 +11,71 @@
       :name,
       :cpu_usage,
       :mem_usage
     ]
 
-    TIME_CACHE = 2
+    EXPIRATION_TIME = 2
 
-    attr_reader :pid, :machine, :cache
+    attr_reader :pid
 
-    def initialize(pid, machine=nil)
+    def initialize(pid, shell=nil)
       @pid = pid
-      @machine = machine
-      @cache = {:fetched=>0, :content=>[]}      
+      @shell = shell || Shell::Local.new
+      @cache = Cache.new EXPIRATION_TIME
     end
 
-    def alive?
-      !(machine.shell.run 'ls /proc').scan("\n#{pid}\n").empty?
-    end
-
     ATTRIBUTES.each do |attribute|
       define_method attribute do
         info[attribute]
       end
     end
 
+    def alive?
+      send_signal 0
+      true
+    rescue Errno::ESRCH
+      false
+    end
+
+    def send_signal(signal)
+      out = shell.run("kill -s #{signal} #{pid}")
+      raise Errno::ESRCH, pid.to_s if out.match 'No such process'
+    end
+
+    def stop
+      send_signal :TERM if alive?
+    end
+
+    def kill
+      send_signal :KILL if alive?
+      while alive?; end
+    end
+
     private
 
+    attr_reader :shell
+
     def info
-      if cache[:content].empty? || (Time.now - cache[:fetched] > TIME_CACHE)
-        ps = machine.shell.run('ps aux').scan(/.*#{pid}.*/)[0].split
+      @cache.fetch(:info) do
+        ps = shell.run('ps aux').scan(/.*#{pid}.*/)[0].split
         Hash.new.tap do |info|
           status = Hash[proc_file(:status).split("\n").map{ |s| s.split(':').map(&:strip) }]
           info[:name] = status['Name']
           info[:user] = ps[0]
           info[:pid]  = ps[1]
           info[:cpu_usage] = ps[2].to_f
           info[:mem_usage] = ps[3].to_f
           info[:virtual_memory] = ps[4].to_i / 1024.0
           info[:memory] = ps[5].to_i / 1024.0
           info[:status] = ps[7] 
-          info[:command] = ps[10..-1].reduce {|acum,e| "#{acum} #{e}"}
-          @cache = {:fetched => Time.now, :content=>info}
+          info[:command] = ps[10..-1].reduce { |acum,e| "#{acum} #{e}" }
         end
-      else
-        cache[:content]
-      end      
+      end
     end
 
-    def proc_dir
-      "/proc/#{pid}"
+    def proc_file(name)
+      filename = File.join '/proc', pid.to_s, name.to_s
+      shell.run "cat #{filename}"
     end
 
-    def proc_file(file)
-      machine.shell.run "cat #{File.join(proc_dir, file.to_s)}"
-    end
   end
 end