blob: 95a8e5cff78af33fdd28aac4de4170ef82234dd3 (
plain) (
blame)
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
|
module ActiveRecord
# = Active Record Identity Map
#
# Ensures that each object gets loaded only once by keeping every loaded
# object in a map. Looks up objects using the map when referring to them.
#
# More information on Identity Map pattern:
# http://www.martinfowler.com/eaaCatalog/identityMap.html
#
# == Configuration
#
# In order to enable IdentityMap, set <tt>config.active_record.identity_map = true</tt>
# in your <tt>config/application.rb</tt> file.
#
# IdentityMap is disabled by default.
#
module IdentityMap
extend ActiveSupport::Concern
class << self
def enabled=(flag)
Thread.current[:identity_map_enabled] = flag
end
def enabled
Thread.current[:identity_map_enabled]
end
alias enabled? enabled
def repository
Thread.current[:identity_map] ||= Hash.new { |h,k| h[k] = {} }
end
def use
old, self.enabled = enabled, true
yield if block_given?
ensure
self.enabled = old
clear
end
def without
old, self.enabled = enabled, false
yield if block_given?
ensure
self.enabled = old
end
def get(klass, primary_key)
obj = repository[klass.symbolized_base_class][primary_key]
if obj.is_a?(klass)
if ActiveRecord::Base.logger
ActiveRecord::Base.logger.debug "#{klass} with ID = #{primary_key} loaded from Identity Map"
end
obj
else
nil
end
end
def add(record)
repository[record.class.symbolized_base_class][record.id] = record
end
def remove(record)
repository[record.class.symbolized_base_class].delete(record.id)
end
def remove_by_id(symbolized_base_class, id)
repository[symbolized_base_class].delete(id)
end
def clear
repository.clear
end
end
# Reinitialize an Identity Map model object from +coder+.
# +coder+ must contain the attributes necessary for initializing an empty
# model object.
def reinit_with(coder)
@attributes_cache = {}
dirty = @changed_attributes.keys
@attributes.update(coder['attributes'].except(*dirty))
@changed_attributes.update(coder['attributes'].slice(*dirty))
@changed_attributes.delete_if{|k,v| v.eql? @attributes[k]}
set_serialized_attributes
run_callbacks :find
self
end
class Middleware
def initialize(app)
@app = app
end
def call(env)
ActiveRecord::IdentityMap.use do
@app.call(env)
end
end
end
end
end
|
