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Forked from camertron/measure.rb
Last active August 29, 2015 14:20
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#!/bin/env ruby
# lazy hack from Robert Klemme
module Memory
# sizes are guessed, I was too lazy to look
# them up and then they are also platform
# dependent
REF_SIZE = 4 # ?
OBJ_OVERHEAD = 4 # ?
FIXNUM_SIZE = 4 # ?
# informational output from analysis
MemoryInfo = Struct.new :roots, :objects, :bytes, :loops
def self.analyze(*roots)
an = Analyzer.new
an.roots = roots
an.analyze
end
class Analyzer
attr_accessor :roots
attr_reader :result
def analyze
@result = MemoryInfo.new roots, 0, 0, 0
@objs = {}
queue = roots.dup
until queue.empty?
obj = queue.shift
case obj
# special treatment for some types
# some are certainly missing from this
when IO
visit(obj)
when String
visit(obj) { @result.bytes += obj.size }
when Fixnum
@result.bytes += FIXNUM_SIZE
when Array
visit(obj) do
@result.bytes += obj.size * REF_SIZE
queue.concat(obj)
end
when Hash
visit(obj) do
@result.bytes += obj.size * REF_SIZE * 2
obj.each {|k,v| queue.push(k).push(v)}
end
when Enumerable
visit(obj) do
obj.each do |o|
@result.bytes += REF_SIZE
queue.push(o)
end
end
else
visit(obj) do
obj.instance_variables.each do |var|
@result.bytes += REF_SIZE
queue.push(obj.instance_variable_get(var))
end
end
end
end
@result
end
private
def visit(obj)
id = obj.object_id
if @objs.has_key? id
@result.loops += 1
false
else
@objs[id] = true
@result.bytes += OBJ_OVERHEAD
@result.objects += 1
yield obj if block_given?
true
end
end
end
end
puts Memory.analyze({ :hello => "world" })
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