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
165
166
167
168
|
# frozen_string_literal: true
require "monitor"
module ActiveSupport
module Cache
# A cache store implementation which stores everything into memory in the
# same process. If you're running multiple Ruby on Rails server processes
# (which is the case if you're using Phusion Passenger or puma clustered mode),
# then this means that Rails server process instances won't be able
# to share cache data with each other and this may not be the most
# appropriate cache in that scenario.
#
# This cache has a bounded size specified by the :size options to the
# initializer (default is 32Mb). When the cache exceeds the allotted size,
# a cleanup will occur which tries to prune the cache down to three quarters
# of the maximum size by removing the least recently used entries.
#
# MemoryStore is thread-safe.
class MemoryStore < Store
def initialize(options = nil)
options ||= {}
super(options)
@data = {}
@key_access = {}
@max_size = options[:size] || 32.megabytes
@max_prune_time = options[:max_prune_time] || 2
@cache_size = 0
@monitor = Monitor.new
@pruning = false
end
# Delete all data stored in a given cache store.
def clear(options = nil)
synchronize do
@data.clear
@key_access.clear
@cache_size = 0
end
end
# Preemptively iterates through all stored keys and removes the ones which have expired.
def cleanup(options = nil)
options = merged_options(options)
instrument(:cleanup, size: @data.size) do
keys = synchronize { @data.keys }
keys.each do |key|
entry = @data[key]
delete_entry(key, options) if entry && entry.expired?
end
end
end
# To ensure entries fit within the specified memory prune the cache by removing the least
# recently accessed entries.
def prune(target_size, max_time = nil)
return if pruning?
@pruning = true
begin
start_time = Time.now
cleanup
instrument(:prune, target_size, from: @cache_size) do
keys = synchronize { @key_access.keys.sort { |a, b| @key_access[a].to_f <=> @key_access[b].to_f } }
keys.each do |key|
delete_entry(key, options)
return if @cache_size <= target_size || (max_time && Time.now - start_time > max_time)
end
end
ensure
@pruning = false
end
end
# Returns true if the cache is currently being pruned.
def pruning?
@pruning
end
# Increment an integer value in the cache.
def increment(name, amount = 1, options = nil)
modify_value(name, amount, options)
end
# Decrement an integer value in the cache.
def decrement(name, amount = 1, options = nil)
modify_value(name, -amount, options)
end
# Deletes cache entries if the cache key matches a given pattern.
def delete_matched(matcher, options = nil)
options = merged_options(options)
instrument(:delete_matched, matcher.inspect) do
matcher = key_matcher(matcher, options)
keys = synchronize { @data.keys }
keys.each do |key|
delete_entry(key, options) if key.match(matcher)
end
end
end
def inspect # :nodoc:
"<##{self.class.name} entries=#{@data.size}, size=#{@cache_size}, options=#{@options.inspect}>"
end
# Synchronize calls to the cache. This should be called wherever the underlying cache implementation
# is not thread safe.
def synchronize(&block) # :nodoc:
@monitor.synchronize(&block)
end
private
PER_ENTRY_OVERHEAD = 240
def cached_size(key, entry)
key.to_s.bytesize + entry.size + PER_ENTRY_OVERHEAD
end
def read_entry(key, options)
entry = @data[key]
synchronize do
if entry
@key_access[key] = Time.now.to_f
else
@key_access.delete(key)
end
end
entry
end
def write_entry(key, entry, options)
entry.dup_value!
synchronize do
old_entry = @data[key]
return false if @data.key?(key) && options[:unless_exist]
if old_entry
@cache_size -= (old_entry.size - entry.size)
else
@cache_size += cached_size(key, entry)
end
@key_access[key] = Time.now.to_f
@data[key] = entry
prune(@max_size * 0.75, @max_prune_time) if @cache_size > @max_size
true
end
end
def delete_entry(key, options)
synchronize do
@key_access.delete(key)
entry = @data.delete(key)
@cache_size -= cached_size(key, entry) if entry
!!entry
end
end
def modify_value(name, amount, options)
synchronize do
options = merged_options(options)
if num = read(name, options)
num = num.to_i + amount
write(name, num, options)
num
end
end
end
end
end
end
|
