1 files changed, 75 insertions, 0 deletions
diff --git a/tools/profile b/tools/profile
new file mode 100755
index 0000000000..927467bc4e
--- /dev/null
+++ b/tools/profile
@@ -0,0 +1,75 @@
+#!/usr/bin/env ruby
+# Example:
+#   tools/profile_requires activesupport/lib/active_support.rb
+#   tools/profile_requires activeresource/examples/simple.rb
+abort 'Use REE so you can profile memory and object allocation' unless GC.respond_to?(:enable_stats)
+
+ENV['NO_RELOAD'] ||= '1'
+ENV['RAILS_ENV'] ||= 'development'
+
+GC.enable_stats
+require 'rubygems'
+Gem.source_index
+require 'benchmark'
+
+module RequireProfiler
+  def require(file, *args) RequireProfiler.profile(file) { super } end
+  def load(file, *args) RequireProfiler.profile(file) { super } end
+
+  @depth, @stats = 0, []
+  class << self
+    attr_accessor :depth
+    attr_accessor :stats
+
+    def profile(file)
+      stats << [file, depth]
+      self.depth += 1
+      heap_before, objects_before = GC.allocated_size, ObjectSpace.allocated_objects
+      result = nil
+      elapsed = Benchmark.realtime { result = yield }
+      heap_after, objects_after = GC.allocated_size, ObjectSpace.allocated_objects
+      self.depth -= 1
+      stats.pop if stats.last.first == file
+      stats << [file, depth, elapsed, heap_after - heap_before, objects_after - objects_before] if result
+      result
+    end
+  end
+end
+
+GC.start
+before = GC.allocated_size
+before_rss = `ps -o rss= -p #{Process.pid}`.to_i
+before_live_objects = ObjectSpace.live_objects
+
+path = ARGV.shift
+if mode = ARGV.shift
+  require 'ruby-prof'
+  RubyProf.measure_mode = RubyProf.const_get(mode.upcase)
+  RubyProf.start
+else
+  Object.instance_eval { include RequireProfiler }
+end
+
+elapsed = Benchmark.realtime { require path }
+results = RubyProf.stop if mode
+
+GC.start
+after_live_objects = ObjectSpace.live_objects
+after_rss = `ps -o rss= -p #{Process.pid}`.to_i
+after = GC.allocated_size
+usage = (after - before) / 1024.0
+
+if mode
+  File.open("#{File.basename(path, '.rb')}.#{mode}.callgrind", 'w') do |out|
+    RubyProf::CallTreePrinter.new(results).print(out)
+  end
+end
+
+RequireProfiler.stats.each do |file, depth, sec, bytes, objects|
+  if sec
+    puts "%10.2f KB %10d obj %8.1f ms  %s%s" % [bytes / 1024.0, objects, sec * 1000, ' ' * depth, file]
+  else
+    puts "#{' ' * (42 + depth)}#{file}"
+  end
+end
+puts "%10.2f KB %10d obj %8.1f ms  %d KB RSS" % [usage, after_live_objects - before_live_objects, elapsed * 1000, after_rss - before_rss]