diff heaps used for memory leak detection

script/diff_heaps.rb

@@ -0,0 +1,40 @@
+# to be used to compare ruby heaps generated in 2.1
+# can isolate memory leaks
+#
+# rbtrace -p 15193 -e 'Thread.new{require "objspace"; ObjectSpace.trace_object_allocations_start; GC.start(full_mark: true); ObjectSpace.dump_all(output: File.open("heap.json","w"))}.join'
+#
+#
+require 'set'
+require 'json'
+
+if ARGV.length != 2
+  puts "Usage: diff_heaps [ORIG.json] [AFTER.json]"
+  exit 1
+end
+
+origs = Set.new
+
+File.open(ARGV[0], "r").each_line do |line|
+  parsed = JSON.parse(line)
+  origs << parsed["address"] if parsed && parsed["address"]
+end
+
+diff = []
+
+File.open(ARGV[1], "r").each_line do |line|
+  parsed = JSON.parse(line)
+  if parsed && parsed["address"]
+    diff << parsed unless origs.include? parsed["address"]
+  end
+end
+
+diff.group_by do |x|
+  [x["type"], x["file"], x["line"]]
+end.map {|x,y|
+ [x, y.count]
+}.sort{ |a,b|
+ b[1] <=> a[1]
+}.each{ |x,y|
+  puts "Leaked #{y} #{x[0]} objects at: #{x[1]}:#{x[2]}"
+}
+