pjhyett · April 27, 2009 20:00 · Apr 27, 2009
diff --git a/memory_profiler.rb b/memory_profiler.rb
@@ -0,0 +1,63 @@
+# simple memory profiler
+# can't remember where I found it (thanks whomever wrote it)
+
+class MemoryProfiler
+  DEFAULTS = {:delay => 10, :string_debug => false}
+
+  def self.start(opt={})
+    opt = DEFAULTS.dup.merge(opt)
+
+    Thread.new do
+      prev = Hash.new(0)
+      curr = Hash.new(0)
+      curr_strings = []
+      delta = Hash.new(0)
+
+      file = File.open('log/memory_profiler.log','w')
+
+      loop do
+        begin
+          GC.start
+          curr.clear
+
+          curr_strings = [] if opt[:string_debug]
+
+          ObjectSpace.each_object do |o|
+            curr[o.class] += 1 #Marshal.dump(o).size rescue 1
+            if opt[:string_debug] and o.class == String
+              curr_strings.push o
+            end
+          end
+
+          if opt[:string_debug]
+            File.open("log/memory_profiler_strings.log.#{Time.now.to_i}",'w') do |f|
+              curr_strings.sort.each do |s|
+                f.puts s
+              end
+            end
+            curr_strings.clear
+          end
+
+          delta.clear
+          (curr.keys + delta.keys).uniq.each do |k,v|
+            delta[k] = curr[k]-prev[k]
+          end
+
+          file.puts "Top 20"
+          delta.sort_by { |k,v| -v.abs }[0..19].sort_by { |k,v| -v}.each do |k,v|
+            file.printf "%+5d: %s (%d)\n", v, k.name, curr[k] unless v == 0
+          end
+          file.flush
+
+          delta.clear
+          prev.clear
+          prev.update curr
+          GC.start
+        rescue Exception => err
+          STDERR.puts "** memory_profiler error: #{err}"
+        end
+        sleep opt[:delay]
+      end
+    end
+  end
+end