如何存储和读取RubyVM :: InstructionSequence？

Question

有没有办法将RubyVM :: InstructionSequence存储到文件中并在以后读取？

我尝试Marshal.dump没有成功.我收到以下错误:

`dump': no _dump_data is defined for class RubyVM::InstructionSequence (TypeError)

Answer 1

是的,有一种方法.

首先,您需要make access load方法InstructionSequence,默认情况下禁用:

require 'fiddle'

class RubyVM::InstructionSequence
  # Retrieve Ruby Core's C-ext `iseq_load' function address
  load_fn_addr  = Fiddle::Handle::DEFAULT['rb_iseq_load']
  # Retrieve `iseq_load' C function representation
  load_fn       = Fiddle::Function.new(load_fn_addr,
                                       [Fiddle::TYPE_VOIDP] * 3,
                                       Fiddle::TYPE_VOIDP)

  # Make `iseq_load' accessible as `load' class method
  define_singleton_method(:load) do |data, parent = nil, opt = nil|
    load_fn.call(Fiddle.dlwrap(data), parent, opt).to_value
  end
end

因为该RubyVM::InstructionSequence.load方法可以将编译的VM指令作为数组加载,所以您可以自由地将其用于(反)序列化目的:

irb> # compile simple ruby program into its instruction sequence
irb> seq = RubyVM::InstructionSequence.new <<-EOS
irb:   p 'Hello, world !'
irb:   EOS
=> <RubyVM::InstructionSequence:<compiled>@<compiled>

irb> # serialize sequence as Array instance representation
irb> data = Marshal.dump seq.to_a
=> "\x04\b[\x13\"-YARVInstructionSequence/SimpleDataFormat … ]"

irb> # de-serialize previously serialized sequence
irb> seq_loaded = Marshal.load data
=> ["YARVInstructionSequence/SimpleDataFormat", 2, 2, 1, { … ]

irb> # load deserialized Array back into instruction sequence
irb> new_iseq = RubyVM::InstructionSequence.load seq_loaded
=> <RubyVM::InstructionSequence:<compiled>@<compiled>>

irb> # execute instruction sequence in current context
irb> new_iseq.eval
"Hello, world !"
=> "Hello, world !"

那是所有人;)

Answer 2

鉴于该类的方法有限，您可以尝试的事情也有限。也许你唯一能做的就是将其实例保存为字符串：

puts RubyVM::InstructionSequence.disasm(proc{puts "foo"})

结果：

== disasm: <RubyVM::InstructionSequence:block in irb_binding@(irb)>=====
== catch table
| catch type: redo   st: 0002 ed: 0009 sp: 0000 cont: 0002
| catch type: next   st: 0002 ed: 0009 sp: 0000 cont: 0009
|------------------------------------------------------------------------
0000 trace            256                                             (   1)
0002 trace            1
0004 putself          
0005 putstring        \"foo\"
0007 opt_send_without_block <callinfo!mid:puts, argc:1, FCALL|ARGS_SIMPLE>
0009 trace            512
0011 leave            

当你想反序列化它时，你需要解析这个字符串。