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58 lines
1.9 KiB
Ruby
58 lines
1.9 KiB
Ruby
require 'active_support/core_ext/module/delegation'
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module ActiveSupport
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# NOTE: This approach has been deprecated for end-user code in favor of thread_mattr_accessor and friends.
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# Please use that approach instead.
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#
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# This module is used to encapsulate access to thread local variables.
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#
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# Instead of polluting the thread locals namespace:
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#
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# Thread.current[:connection_handler]
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#
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# you define a class that extends this module:
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#
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# module ActiveRecord
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# class RuntimeRegistry
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# extend ActiveSupport::PerThreadRegistry
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#
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# attr_accessor :connection_handler
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# end
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# end
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#
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# and invoke the declared instance accessors as class methods. So
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#
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# ActiveRecord::RuntimeRegistry.connection_handler = connection_handler
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#
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# sets a connection handler local to the current thread, and
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#
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# ActiveRecord::RuntimeRegistry.connection_handler
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#
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# returns a connection handler local to the current thread.
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#
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# This feature is accomplished by instantiating the class and storing the
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# instance as a thread local keyed by the class name. In the example above
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# a key "ActiveRecord::RuntimeRegistry" is stored in <tt>Thread.current</tt>.
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# The class methods proxy to said thread local instance.
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#
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# If the class has an initializer, it must accept no arguments.
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module PerThreadRegistry
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def self.extended(object)
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object.instance_variable_set '@per_thread_registry_key', object.name.freeze
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end
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def instance
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Thread.current[@per_thread_registry_key] ||= new
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end
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protected
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def method_missing(name, *args, &block) # :nodoc:
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# Caches the method definition as a singleton method of the receiver.
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#
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# By letting #delegate handle it, we avoid an enclosure that'll capture args.
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singleton_class.delegate name, to: :instance
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send(name, *args, &block)
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end
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end
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end
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