OHAI-431: provide basic memory information for Mac OS X

lib/ohai/plugins/darwin/memory.rb

@@ -0,0 +1,54 @@
+#
+# Author:: Patrick Collins (<pat@burned.com>)
+# Copyright:: Copyright (c) 2013 Opscode, Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+provides 'memory'
+
+memory Mash.new
+
+installed_memory = from("sysctl -n hw.memsize").to_i / 1024 / 1024.0
+memory[:total] = "#{installed_memory.to_i}MB"
+
+total_consumed = 0
+active = 0
+inactive = 0
+vm_stat = from("vm_stat")
+page_size = begin; /page size of (\d+) bytes/.match(vm_stat)[1].to_i; rescue; 4096; end
+vm_stat.split("\n").each do |line|
+  ['wired down', 'active', 'inactive'].each do |match|
+    unless line.index("Pages #{match}:").nil? or page_size.nil?
+      pages = line.split.last.to_i
+      megabyte_val = (pages * page_size) / 1024 / 1024.0
+      total_consumed += megabyte_val
+      case match
+      when 'wired down'
+        active += megabyte_val.to_i
+      when 'active'
+        active += megabyte_val.to_i
+      when 'inactive'
+        inactive += megabyte_val.to_i
+      end
+    end
+  end
+end
+
+memory[:active] = "#{active}MB" if active > 0
+memory[:inactive] = "#{inactive}MB" if inactive > 0
+
+free_memory = installed_memory - total_consumed
+memory[:free] = "#{free_memory.to_i}MB" if total_consumed > 0
+

spec/unit/plugins/darwin/memory_spec.rb

@@ -0,0 +1,67 @@
+#
+# Author:: Patrick Collins (<pat@burned.com>)
+# Copyright:: Copyright (c) 2013 Opscode, Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require File.expand_path(File.dirname(__FILE__) + '/../../../spec_helper.rb')
+
+describe Ohai::System, "Darwin Memory Plugin" do
+  before do
+    darwin_memsize = <<-DARWIN_MEMSIZE
+17179869184
+    DARWIN_MEMSIZE
+    darwin_vm_stat = <<-DARWIN_VM_STAT
+Mach Virtual Memory Statistics: (page size of 4096 bytes)
+Pages free:                        2155305.
+Pages active:                       924164.
+Pages inactive:                     189127.
+Pages speculative:                  531321.
+Pages wired down:                   391749.
+"Translation faults":             14107520.
+Pages copy-on-write:                810071.
+Pages zero filled:                 6981505.
+Pages reactivated:                    1397.
+Pageins:                            630064.
+Pageouts:                                0.
+Object cache: 12 hits of 139872 lookups (0% hit rate)
+    DARWIN_VM_STAT
+
+    @ohai = Ohai::System.new
+    @ohai.stub!(:require_plugin).and_return(true)
+
+    @ohai.stub(:from).with("sysctl -n hw.memsize").and_return(darwin_memsize)
+    @ohai.stub(:from).with("vm_stat").and_return(darwin_vm_stat)
+
+    @ohai._require_plugin("memory")
+  end
+
+  describe "gathering memory info" do
+    before do
+      @ohai._require_plugin("darwin::memory")
+    end
+
+    it "completes the run" do
+      @ohai['memory'].should_not be_nil
+    end
+
+    it "detects the correct memory levels" do
+      @ohai['memory']['total'].should == '16384MB'
+      @ohai['memory']['active'].should == '5140MB'
+      @ohai['memory']['inactive'].should == '738MB'
+      @ohai['memory']['free'].should == '10504MB'
+    end
+  end
+end