1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
|
# frozen_string_literal: true
# Released under the MIT License.
# Copyright, 2020-2024, by Samuel Williams.
require_relative "local/version"
require 'fiber/storage'
class Fiber
module Local
def self.extended(klass)
attribute_name = klass.name.gsub('::', '_').gsub(/\W/, '').downcase.to_sym
# This is used for the general interface and fiber storage key:
klass.instance_variable_set(:@fiber_local_attribute_name, attribute_name)
klass.singleton_class.attr :fiber_local_attribute_name
# This is used for reading and writing directly to the thread instance variables:
klass.instance_variable_set(:@fiber_local_variable_name, :"@#{attribute_name}")
Thread.attr_accessor(attribute_name)
end
# Instantiate a new thread-local object.
# By default, invokes {new} to generate the instance.
# @returns [Object]
def local
self.new
end
# Get the current thread-local instance. Create it if required.
# @returns [Object] The thread-local instance.
def instance
# This is considered a local "override" in the dynamic scope of the fiber:
if instance = Fiber[@fiber_local_attribute_name]
return instance
end
# This is generally the fast path:
thread = Thread.current
unless instance = thread.instance_variable_get(@fiber_local_variable_name)
if instance = self.local
thread.instance_variable_set(@fiber_local_variable_name, instance)
end
end
return instance
end
# Assigns to the fiber-local instance.
# @parameter instance [Object] The object that will become the thread-local instance.
def instance= instance
Fiber[@fiber_local_attribute_name] = instance
end
end
end
|
