usage.rb in cpu-0.0.1

- old
+ new

@@ -1,10 +1,11 @@
 module CPU
   class Usage < Struct.new('Usage', :usage, :processor_id, :user, :nice,
                            :system, :idle, :start_at, :stop_at)
     include Shared
 
+    # Add this CPU::Usage instance to the other and return a resulting sum object.
     def +(other)
       self.class.new(*(
         [
           usage,
           processor_id == other.processor_id ? processor_id : 0,
@@ -15,14 +16,17 @@
           [ stop_at, other.stop_at ].max
         ])
       )
     end
 
+    # Subtract the other from this CPU::Usage instance the other and return a
+    # resulting difference object.
     def -(other)
       self + other * -1
     end
 
+    # Multiply the cpu times in this CPU::Usage instance with +scalar+.
     def *(scalar)
       scalar = scalar.to_f
       self.class.new(*(
         [
           usage,
@@ -34,25 +38,33 @@
           stop_at,
         ])
       )
     end
 
+    # Divide the cpu times in this CPU::Usage instance by +scalar+.
     def /(scalar)
       self * (1.0 / scalar)
     end
 
+    # Return the cpu time that where used to process instructions since booting
+    # up the system.
     def process_time
       user + nice + system
     end
 
+    # Return the real time passed in the range of all CPU::Usage instances,
+    # that were used to create this summed up CPU::Usage instance. If this
+    # isn't a sum object, this value will be 0.0.
     def real_time
       stop_at - start_at
     end
 
+    # Return the total cpu time that has passed since booting the system.
     def total_time
       values_at(2..-3).inject(0.0) { |s,  x| s + x }
     end
 
+    # Return the CPU usage as a percentage number between 0.0..100.0.
     def percentage(time = total_time)
       100.0 * process_time / time
     end
 
     def inspect