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
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
require 'active_support/core_ext/object/duplicable'
require 'active_support/core_ext/string/inflections'
module ActiveSupport
module Cache
module Strategy
# Caches that implement LocalCache will be backed by an in memory cache for the
# duration of a block. Repeated calls to the cache for the same key will hit the
# in memory cache for faster access.
module LocalCache
# Simple memory backed cache. This cache is not thread safe and is intended only
# for serving as a temporary memory cache for a single thread.
class LocalStore < Store
def initialize
super
@data = {}
end
# Don't allow synchronizing since it isn't thread safe,
def synchronize # :nodoc:
yield
end
def clear(options = nil)
@data.clear
end
def read_entry(key, options)
@data[key]
end
def write_entry(key, value, options)
@data[key] = value
true
end
def delete_entry(key, options)
!!@data.delete(key)
end
end
# Use a local cache for the duration of block.
def with_local_cache
save_val = Thread.current[thread_local_key]
begin
Thread.current[thread_local_key] = LocalStore.new
yield
ensure
Thread.current[thread_local_key] = save_val
end
end
# Middleware class can be inserted as a Rack handler to be local cache for the
# duration of request.
def middleware
@middleware ||= begin
klass = Class.new
klass.class_eval(<<-EOS, __FILE__, __LINE__ + 1)
class << self
def name
"ActiveSupport::Cache::Strategy::LocalCache"
end
alias :to_s :name
end
def initialize(app)
@app = app
end
def call(env)
Thread.current[:#{thread_local_key}] = LocalStore.new
@app.call(env)
ensure
Thread.current[:#{thread_local_key}] = nil
end
EOS
klass
end
end
def clear(options = nil) # :nodoc:
local_cache.clear(options) if local_cache
super
end
def cleanup(options = nil) # :nodoc:
local_cache.clear(options) if local_cache
super
end
def increment(name, amount = 1, options = nil) # :nodoc:
value = bypass_local_cache{super}
if local_cache
local_cache.mute do
if value
local_cache.write(name, value, options)
else
local_cache.delete(name, options)
end
end
end
value
end
def decrement(name, amount = 1, options = nil) # :nodoc:
value = bypass_local_cache{super}
if local_cache
local_cache.mute do
if value
local_cache.write(name, value, options)
else
local_cache.delete(name, options)
end
end
end
value
end
protected
def read_entry(key, options) # :nodoc:
if local_cache
entry = local_cache.read_entry(key, options)
unless entry
entry = super
local_cache.write_entry(key, entry, options)
end
entry
else
super
end
end
def write_entry(key, entry, options) # :nodoc:
local_cache.write_entry(key, entry, options) if local_cache
super
end
def delete_entry(key, options) # :nodoc:
local_cache.delete_entry(key, options) if local_cache
super
end
private
def thread_local_key
@thread_local_key ||= "#{self.class.name.underscore}_local_cache_#{object_id}".gsub(/[\/-]/, '_').to_sym
end
def local_cache
Thread.current[thread_local_key]
end
def bypass_local_cache
save_cache = Thread.current[thread_local_key]
begin
Thread.current[thread_local_key] = nil
yield
ensure
Thread.current[thread_local_key] = save_cache
end
end
end
end
end
end
|
