Feature #3246: thread-local yamler

• Status: Rejected
• Assignee: tenderlovemaking (Aaron Patterson)
• Target version: -

[nobu (Nobuyoshi Nakada)]

=begin
Hi,

Currently, YAML.yamler= has an effect on the whole process.
What about making it thread-local?

diff --git a/lib/yaml.rb b/lib/yaml.rb
index 9b5a9b2..236489b 100644
--- a/lib/yaml.rb
+++ b/lib/yaml.rb
@@ -1,43 +1,68 @@
module YAML

• class EngineManager # :nodoc:
• attr_reader :yamler

• class << self
• def engine

•  ::Thread.current[:yamler] or
  

•    (ENGINE.yamler = ENGINE.default; ::Thread.current[:yamler])
  

• end

• def initialize

•  @yamler = nil
  

• def const_defined?(name)

•  engine.const_defined?(name)
  

  end

• def syck?

•  'syck' == @yamler
  

• def const_get(name)

•  engine = self.engine
  

•  begin
  

•    engine.const_get(name)
  

•  rescue NameError => e
  

•    raise NameError, "uninitialized constant #{self}::#{name}", caller(2)
  

•  end
  

  end

• def yamler= engine

•  raise(ArgumentError, "bad engine") unless %w{syck psych}.include?(engine)
  

• alias const_missing const_get

•  require engine
  

• def method_missing(name, *args, &block)

•  engine.__send__(name, *args, &block)
  

• end

•  Object.class_eval <<-eorb, __FILE__, __LINE__ + 1
  

•    remove_const 'YAML'
  

•    YAML = #{engine.capitalize}
  

•    remove_method :to_yaml
  

•    alias :to_yaml :#{engine}_to_yaml
  

•  eorb
  

• def respond_to_missing?(name)

•  engine.respond_to?(name)
  

• end
• private
• def extend_object(obj)

•  engine.__send__(:extend_object, obj)
  

• end

•  @yamler = engine
  

•  engine
  

• def append_features(mod)

•  engine.__send__(:append_features, mod)
  

  end
  end

• ENGINE = YAML::EngineManager.new
  -end

• class << (ENGINE = Object.new) # :nodoc:
• def default

•  !defined?(Syck) && defined?(Psych) ? 'psych' : 'syck'
  

• end

-engine = (!defined?(Syck) && defined?(Psych) ? 'psych' : 'syck')

• def yamler

•  if engine = YAML.engine
  

•    engine.name.downcase
  

•  else
  

•    default
  

•  end
  

• end

-module Syck

• ENGINE = YAML::ENGINE
  -end

• def syck?

•  'syck' == yamler
  

• end

-module Psych

• ENGINE = YAML::ENGINE
  -end

• def yamler= engine

•  raise(ArgumentError, "bad engine") unless %w{syck psych}.include?(engine)
  

•  require engine
  

•  engine = ::Object.const_get(engine.capitalize)
  

•  ::Thread.current[:yamler] = engine
  

• end
• end

-YAML::ENGINE.yamler = engine

• ENGINE.freeze
  +end
  

--
Nobu Nakada
=end

[tenderlovemaking (Aaron Patterson)]

• Assignee set to tenderlovemaking (Aaron Patterson)

=begin

=end

[tenderlovemaking (Aaron Patterson)]

• Status changed from Open to Rejected

=begin
Seems useful, but I don't think we can do this. This code was removed in the patch:

•  Object.class_eval <<-eorb, __FILE__, __LINE__ + 1
  

•    remove_const 'YAML'
  

•    YAML = #{engine.capitalize}
  

•    remove_method :to_yaml
  

•    alias :to_yaml :#{engine}_to_yaml
  

•  eorb
  

But it is necessary for switching the behavior of Object#to_yaml. Aliasing the method will be global to the process too.
=end