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
169
170
171
172
173
174
175
176
177
178
|
require 'active_support/core_ext/file/atomic'
require 'active_support/core_ext/string/conversions'
require 'active_support/core_ext/object/inclusion'
require 'rack/utils'
module ActiveSupport
module Cache
# A cache store implementation which stores everything on the filesystem.
#
# FileStore implements the Strategy::LocalCache strategy which implements
# an in-memory cache inside of a block.
class FileStore < Store
attr_reader :cache_path
DIR_FORMATTER = "%03X"
FILENAME_MAX_SIZE = 230 # max filename size on file system is 255, minus room for timestamp and random characters appended by Tempfile (used by atomic write)
EXCLUDED_DIRS = ['.', '..'].freeze
def initialize(cache_path, options = nil)
super(options)
@cache_path = cache_path.to_s
extend Strategy::LocalCache
end
def clear(options = nil)
root_dirs = Dir.entries(cache_path).reject{|f| f.in?(EXCLUDED_DIRS)}
FileUtils.rm_r(root_dirs.collect{|f| File.join(cache_path, f)})
end
def cleanup(options = nil)
options = merged_options(options)
each_key(options) do |key|
entry = read_entry(key, options)
delete_entry(key, options) if entry && entry.expired?
end
end
def increment(name, amount = 1, options = nil)
file_name = key_file_path(namespaced_key(name, options))
lock_file(file_name) do
options = merged_options(options)
if num = read(name, options)
num = num.to_i + amount
write(name, num, options)
num
else
nil
end
end
end
def decrement(name, amount = 1, options = nil)
file_name = key_file_path(namespaced_key(name, options))
lock_file(file_name) do
options = merged_options(options)
if num = read(name, options)
num = num.to_i - amount
write(name, num, options)
num
else
nil
end
end
end
def delete_matched(matcher, options = nil)
options = merged_options(options)
instrument(:delete_matched, matcher.inspect) do
matcher = key_matcher(matcher, options)
search_dir(cache_path) do |path|
key = file_path_key(path)
delete_entry(key, options) if key.match(matcher)
end
end
end
protected
def read_entry(key, options)
file_name = key_file_path(key)
if File.exist?(file_name)
File.open(file_name) { |f| Marshal.load(f) }
end
rescue
nil
end
def write_entry(key, entry, options)
file_name = key_file_path(key)
ensure_cache_path(File.dirname(file_name))
File.atomic_write(file_name, cache_path) {|f| Marshal.dump(entry, f)}
true
end
def delete_entry(key, options)
file_name = key_file_path(key)
if File.exist?(file_name)
begin
File.delete(file_name)
delete_empty_directories(File.dirname(file_name))
true
rescue => e
# Just in case the error was caused by another process deleting the file first.
raise e if File.exist?(file_name)
false
end
end
end
private
# Lock a file for a block so only one process can modify it at a time.
def lock_file(file_name, &block) # :nodoc:
if File.exist?(file_name)
File.open(file_name, 'r+') do |f|
begin
f.flock File::LOCK_EX
yield
ensure
f.flock File::LOCK_UN
end
end
else
yield
end
end
# Translate a key into a file path.
def key_file_path(key)
fname = Rack::Utils.escape(key)
hash = Zlib.adler32(fname)
hash, dir_1 = hash.divmod(0x1000)
dir_2 = hash.modulo(0x1000)
fname_paths = []
# Make sure file name doesn't exceed file system limits.
begin
fname_paths << fname[0, FILENAME_MAX_SIZE]
fname = fname[FILENAME_MAX_SIZE..-1]
end until fname.blank?
File.join(cache_path, DIR_FORMATTER % dir_1, DIR_FORMATTER % dir_2, *fname_paths)
end
# Translate a file path into a key.
def file_path_key(path)
fname = path[cache_path.size, path.size].split(File::SEPARATOR, 4).last
Rack::Utils.unescape(fname)
end
# Delete empty directories in the cache.
def delete_empty_directories(dir)
return if dir == cache_path
if Dir.entries(dir).reject{|f| f.in?(EXCLUDED_DIRS)}.empty?
File.delete(dir) rescue nil
delete_empty_directories(File.dirname(dir))
end
end
# Make sure a file path's directories exist.
def ensure_cache_path(path)
FileUtils.makedirs(path) unless File.exist?(path)
end
def search_dir(dir, &callback)
return if !File.exist?(dir)
Dir.foreach(dir) do |d|
next if d.in?(EXCLUDED_DIRS)
name = File.join(dir, d)
if File.directory?(name)
search_dir(name, &callback)
else
callback.call name
end
end
end
end
end
end
|
