Change CPU usage implementation to use ivars

README.md

@@ -38,9 +38,9 @@ app = Hardware::PID.new "firefox" # Take the first matching PID
 
 loop do
   sleep 1
-  cpu.used.to_i     #=> 17
-  pid.cpu_used      #=> 1.5
-  app.cpu_used.to_i #=> 4
+  cpu.usage.to_i     #=> 17
+  pid.cpu_usage      #=> 1.5
+  app.cpu_usage.to_i #=> 4
 end
 ```
 ## Development

shard.yml

@@ -1,5 +1,5 @@
 name: hardware
-version: 0.3.1
+version: 0.4.0
 
 authors:
   - bararchy <[email protected]>

spec/cpu_spec.cr

@@ -3,15 +3,18 @@ require "./spec_helper"
 describe Hardware::CPU do
   cpu = Hardware::CPU.new
   it "parses '/proc/stat'" do
-    cpu.info.should be_a NamedTuple(used: Int32, idle: Int32, total: Int32)
+    cpu.stat.should be_a Array(Int32)
   end
 
   it "checks the percentage used" do
-    Hardware::CPU.previous_info.should be_a NamedTuple(used: Int32, idle: Int32, total: Int32)
+    cpu.previous_used.should be_a Int32
+    cpu.previous_idle_wait.should be_a Int32
   end
 
   it "checks the percentage used" do
     sleep 0.1
-    (0 <= cpu.used <= 100).should be_true
+    usage = cpu.usage
+    usage.should be >= 0
+    usage.should be <= 100
   end
 end

spec/memory_spec.cr

@@ -20,10 +20,14 @@ describe Hardware::Memory do
   end
 
   it "checks the percentage available" do
-    (1 < memory.percent(used: false) <= 100).should be_true
+    percent = memory.percent(used: false)
+    percent.should be > 1
+    percent.should be <= 100
   end
 
   it "checks the percentage used" do
-    (1 < memory.percent(used: true) <= 100).should be_true
+    percent = memory.percent(used: true)
+    percent.should be > 1
+    percent.should be <= 100
   end
 end

spec/net_spec.cr

@@ -4,7 +4,7 @@ describe Hardware::Net do
   net = Hardware::Net.new
 
   it "checks some types" do
-    net.in_octets.should be_a Int64
-    net.out_octets.should be_a Int64
+    net.in_octets.should be > 0_i64
+    net.out_octets.should be > 0_i64
   end
 end

spec/pid_spec.cr

@@ -3,7 +3,7 @@ require "./spec_helper"
 describe Hardware::PID do
   describe "class methods" do
     it "tests .all " do
-      Hardware::PID.all { |pid| pid.should be_a Hardware::PID }
+      Hardware::PID.all &.should be_a Hardware::PID
     end
 
     it "tests .get_pids of the current process" do
@@ -17,7 +17,7 @@ describe Hardware::PID do
 
   describe "instance methods" do
     it "creates a Hardware::PID based on a name" do
-      Hardware::PID.new("crystal-run-spec.tmp", cpu_time: false, cpu_total: false).pid.should eq Process.pid
+      Hardware::PID.new("crystal-run-spec.tmp", cpu_total: false).pid.should eq Process.pid
     end
 
     pid = Hardware::PID.new
@@ -29,7 +29,7 @@ describe Hardware::PID do
     end
 
     it "parses exe" do
-      File.basename(pid.exe.not_nil!).should eq "crystal-run-spec.tmp"
+      File.basename(pid.exe).should eq "crystal-run-spec.tmp"
     end
 
     it "parses command" do
@@ -40,39 +40,40 @@ describe Hardware::PID do
       describe "cpu_time" do
         pid1 = Hardware::PID.new(pid: 1)
         it "without children" do
-          (1 < pid1.cpu_time).should be_true
+          pid1.cpu_time.should be > 1
         end
 
         it "with children" do
-          (1 < pid1.cpu_time(children: true)).should be_true
+          pid1.cpu_time(children: true).should be > 1
         end
       end
 
-      describe "cpu_used with updates" do
+      describe "cpu_usage" do
         pid1 = Hardware::PID.new(pid: 1)
 
         it "percentage" do
           # Simulate CPU use if no activity
-          pid1.cpu_time_previous = pid1.cpu_time - 9
           sleep 0.1
-          (1 < pid1.cpu_used <= 100).should be_true
+          usage = pid1.cpu_usage
+          usage.should be > 0_f32
+          usage.should be <= 100_f32
         end
 
         it "cpu_total_previous equal to cpu_total_current" do
           pid1.cpu_total_previous.should eq Hardware::PID.cpu_total_current
         end
       end
-      describe "cpu_used with no updates" do
+      describe "cpu_usage with no updates" do
         Hardware::PID.cpu_total_current = -1
-        pid1 = Hardware::PID.new(pid: 1, cpu_time: false, cpu_total: false)
+        pid1 = Hardware::PID.new(pid: 1, cpu_total: false)
         pid1.cpu_time_previous = -1
 
         it "type" do
-          pid1.cpu_used.should be_a Float32
+          pid1.cpu_usage.should be_a Float32
         end
 
-        it "cpu_time_previous not updated" do
-          pid1.cpu_time_previous.should eq -1
+        it "cpu_time_previous" do
+          pid1.cpu_time_previous.should be > 1
         end
 
         it "cpu_total_current not updated" do
@@ -85,7 +86,7 @@ describe Hardware::PID do
       end
     end
 
-    it "returns memory used" { (1 < pid.memory).should be_true }
+    it "returns memory usage" { pid.memory.should be > 1 }
 
     it "parses name" { pid.name.should eq "crystal-run-spec.tmp" }
 

src/hardware.cr

@@ -1,5 +1,5 @@
 require "./hardware/**"
 
 module Hardware
-  VERSION = "0.3.1"
+  VERSION = "0.4.0"
 end

src/hardware/cpu.cr

@@ -4,23 +4,37 @@
 # cpu = Hardware::CPU.new
 # loop do
 #   sleep 1
-#   cpu.used.to_i # => 17
+#   cpu.usage.to_i # => 17
 # end
 # ```
 struct Hardware::CPU
-  # Returns the previous used, idle and total CPU time. Used to store the previous CPU time informations to calculate the percentage in`.used`.
-  class_property previous_info : NamedTuple(used: Int32, idle: Int32, total: Int32) = {used: 0, idle: 0, total: 0}
-  @stat = Array(Int32).new
+  # Previous used CPU time
+  getter previous_used : Int32 = 0
+  # Previous idle CPU time
+  getter previous_idle_wait : Int32 = 0
+  # Returns a parsed `/proc/stat`
+  getter stat : Array(Int32)
 
   # Creates a new `Hardware::CPU` based on the current memory state.
   def initialize
+    @stat = update_stat
   end
 
-  # Returns a parsed `/proc/stat`.
-  def stat : Array(Int32)
+  # Update the stats stored in `#stat`
+  def update_stat : Array(Int32)
     @stat = File.read("/proc/stat").lines.first[5..-1].split(' ').map &.to_i
   end
 
+  # Returns the CPU time used, which includes `idle` and `iowait`
+  def idle_wait : Int32
+    idle + iowait
+  end
+
+  # Returns the used CPU time, which includes `user`, `nice`, `system`, `irq`, `softirq` and `steal`
+  def used : Int32
+    user + nice + system + irq + softirq + steal
+  end
+
   # Generate methods based on stat
   {% begin %}{% i = 0 %}
   {% for num in %w(user nice system idle iowait irq softirq steal guest guest_nice) %}
@@ -31,26 +45,21 @@ struct Hardware::CPU
     {% i = i + 1 %}
   {% end %}{% end %}
 
-  # Returns the current used, idle and total CPU time.
-  def info : NamedTuple(used: Int32, idle: Int32, total: Int32)
-    # update stat
-    stat
-    # Array: user nice system idle iowait irq softirq steal guest guest_nice
-    {
-      used:  used = user + nice + system + irq + softirq + steal,
-      idle:  idle_cpu = idle + iowait,
-      total: used + idle_cpu,
-    }
+  # Returns the total CPU time, the sum of `#idle` and `#used`
+  def total : Int32
+    idle_wait + used
   end
 
   # Returns the CPU used in percentage based on `.previous_info`.
-  def used(update = true) : Float32
-    current_info = info
+  def usage(update = true) : Float32
+    # Update stats
+    update_stat
+    current_used, current_idle_wait = used, idle_wait
 
     # 100 * Usage / Total
-    result = (current_info[:used] - @@previous_info[:used]).to_f32 / (current_info[:total] - @@previous_info[:total]) * 100
+    result = (current_used - @previous_used).to_f32 / (current_used + current_idle_wait - @previous_used - @previous_idle_wait) * 100
 
-    @@previous_info = current_info if update
+    @previous_used, @previous_idle_wait = current_used, current_idle_wait if update
     result
   end
 end