Module: RubyExt::DeclarativeCache

Defined in:
lib/ruby_ext/more/declarative_cache.rb

Class Method Summary collapse

Class Method Details

.cache_method(klass, *methods) ⇒ Object 



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
 
# File 'lib/ruby_ext/more/declarative_cache.rb', line 4

def cache_method klass, *methods
  methods.each do |method|
    klass.class_eval do
      escaped_method = escape_method method
      method_with_cache    = :"#{escaped_method}_with_cache"
      method_without_cache = :"#{escaped_method}_without_cache"
      iv_check = "@#{escaped_method}_cache_check"
      iv       = "@#{escaped_method}_cache"

      alias_method method_without_cache, method

      define_method method_with_cache do |*args|
        raise "You tried to use cache without params for method with \
params (use 'cache_method_with_params' instead)!" unless args.empty?

        unless cached = instance_variable_get(iv)
          unless check = instance_variable_get(iv_check)
            cached = send method_without_cache
            instance_variable_set iv, cached
            instance_variable_set iv_check, true
          end
        end
        cached
      end

      alias_method method, method_with_cache
    end
  end
end

.cache_method_with_params(klass, *methods) ⇒ Object 



34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
 
# File 'lib/ruby_ext/more/declarative_cache.rb', line 34

def cache_method_with_params klass, *methods
  methods.each do |method|
    klass.class_eval do
      escaped_method = escape_method method
      method_with_cache    = :"#{escaped_method}_with_cache"
      method_without_cache = :"#{escaped_method}_without_cache"
      iv_check = "@#{escaped_method}_cache_check"
      iv       = "@#{escaped_method}_cache"

      alias_method method_without_cache, method

      define_method method_with_cache do |*args|
        unless results = instance_variable_get(iv)
          results = Hash.new(NotDefined)
          instance_variable_set iv, results
        end

        result = results[args]

        if result.equal? NotDefined
          result = send method_without_cache, *args
          results[args] = result
        end

        result
      end

      alias_method method, method_with_cache
    end
  end
end