Expose total system memory.

Author: ioquatix

lib/process/metrics/command/summary.rb

@@ -109,15 +109,7 @@ def call
 					format_memory_usage = self.method(:format_memory_usage).curry
 					shared_memory_usage = 0
 					private_memory_usage = 0
-					total_memory_usage = 0
-					
-					summary.each do |pid, general|
-						if memory = general.memory
-							total_memory_usage += memory.proportional_size + memory.unique_size
-						else
-							total_memory_usage += general.resident_size
-						end
-					end
+					total_memory_usage = Process::Metrics::Memory.total_size
 
 					proportional = true
 

lib/process/metrics/memory/darwin.rb

@@ -13,6 +13,18 @@ def self.supported?
 				File.executable?(VMMAP)
 			end
 
+			# @returns [Numeric] Total memory size in kilobytes.
+			def self.total_size
+				# sysctl hw.memsize
+				IO.popen(["sysctl", "hw.memsize"], "r") do |io|
+					io.each_line do |line|
+						if line =~ /hw.memsize: (\d+)/
+							return $1.to_i / 1024
+						end
+					end
+				end
+			end
+			
 			# Parse a size string into kilobytes.
 			def self.parse_size(string)
 				return 0 unless string
@@ -91,6 +103,10 @@ def supported?
 					return true
 				end
 
+				def total_size
+					return Memory::Darwin.total_size
+				end
+				
 				def capture(pids)
 					return Memory::Darwin.capture(pids)
 				end

lib/process/metrics/memory/linux.rb

@@ -6,6 +6,15 @@
 module Process
 	module Metrics
 		class Memory::Linux
+			# @returns [Numeric] Total memory size in kilobytes.
+			def self.total_size
+				File.read("/proc/meminfo").each_line do |line|
+					if /MemTotal:\s+(?<total>\d+) kB/ =~ line
+						return total.to_i
+					end
+				end
+			end
+			
 			# The fields that will be extracted from the `smaps` data.
 			SMAP = {
 				"Rss" => :resident_size,
@@ -89,6 +98,10 @@ def supported?
 					return true
 				end
 
+				def total_size
+					return Memory::Linux.total_size
+				end
+				
 				def capture(pids)
 					return Memory::Linux.capture(pids)
 				end

test/process/memory.rb

@@ -6,6 +6,12 @@
 require "process/metrics"
 
 describe Process::Metrics::Memory do
+	with ".total_size" do
+		it "can get the total available memory" do
+			expect(Process::Metrics::Memory.total_size).to be > 0
+		end
+	end
+	
 	with ".capture" do
 		let(:pid) {Process.pid}
 		let(:capture) {Process::Metrics::General.capture(pid: pid)}