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
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
# frozen_string_literal: true
module CacheConcern
extend ActiveSupport::Concern
module ActiveRecordCoder
EMPTY_HASH = {}.freeze
class << self
def dump(record)
instances = InstanceTracker.new
serialized_associations = serialize_associations(record, instances)
serialized_records = instances.map { |r| serialize_record(r) }
[serialized_associations, *serialized_records]
end
def load(payload)
instances = InstanceTracker.new
serialized_associations, *serialized_records = payload
serialized_records.each { |attrs| instances.push(deserialize_record(*attrs)) }
deserialize_associations(serialized_associations, instances)
end
private
# Records without associations, or which have already been visited before,
# are serialized by their id alone.
#
# Records with associations are serialized as a two-element array including
# their id and the record's association cache.
#
def serialize_associations(record, instances)
return unless record
if (id = instances.lookup(record))
payload = id
else
payload = instances.push(record)
cached_associations = record.class.reflect_on_all_associations.select do |reflection|
record.association_cached?(reflection.name)
end
unless cached_associations.empty?
serialized_associations = cached_associations.map do |reflection|
association = record.association(reflection.name)
serialized_target = if reflection.collection?
association.target.map { |target_record| serialize_associations(target_record, instances) }
else
serialize_associations(association.target, instances)
end
[reflection.name, serialized_target]
end
payload = [payload, serialized_associations]
end
end
payload
end
def deserialize_associations(payload, instances)
return unless payload
id, associations = payload
record = instances.fetch(id)
associations&.each do |name, serialized_target|
begin
association = record.association(name)
rescue ActiveRecord::AssociationNotFoundError
raise AssociationMissingError, "undefined association: #{name}"
end
target = if association.reflection.collection?
serialized_target.map! { |serialized_record| deserialize_associations(serialized_record, instances) }
else
deserialize_associations(serialized_target, instances)
end
association.target = target
end
record
end
def serialize_record(record)
arguments = [record.class.name, attributes_for_database(record)]
arguments << true if record.new_record?
arguments
end
if Rails.gem_version >= Gem::Version.new('7.0')
def attributes_for_database(record)
attributes = record.attributes_for_database
attributes.transform_values! { |attr| attr.is_a?(::ActiveModel::Type::Binary::Data) ? attr.to_s : attr }
attributes
end
else
def attributes_for_database(record)
attributes = record.instance_variable_get(:@attributes).send(:attributes).transform_values(&:value_for_database)
attributes.transform_values! { |attr| attr.is_a?(::ActiveModel::Type::Binary::Data) ? attr.to_s : attr }
attributes
end
end
def deserialize_record(class_name, attributes_from_database, new_record = false) # rubocop:disable Style/OptionalBooleanParameter
begin
klass = Object.const_get(class_name)
rescue NameError
raise ClassMissingError, "undefined class: #{class_name}"
end
# Ideally we'd like to call `klass.instantiate`, however it doesn't allow to pass
# wether the record was persisted or not.
attributes = klass.attributes_builder.build_from_database(attributes_from_database, EMPTY_HASH)
klass.allocate.init_with_attributes(attributes, new_record)
end
end
class Error < StandardError
end
class ClassMissingError < Error
end
class AssociationMissingError < Error
end
class InstanceTracker
def initialize
@instances = []
@ids = {}.compare_by_identity
end
def map(&block)
@instances.map(&block)
end
def fetch(...)
@instances.fetch(...)
end
def push(instance)
id = @ids[instance] = @instances.size
@instances << instance
id
end
def lookup(instance)
@ids[instance]
end
end
end
def render_with_cache(**options)
raise ArgumentError, 'only JSON render calls are supported' unless options.key?(:json) || block_given?
key = options.delete(:key) || [[params[:controller], params[:action]].join('/'), options[:json].respond_to?(:cache_key) ? options[:json].cache_key : nil, options[:fields].nil? ? nil : options[:fields].join(',')].compact.join(':')
expires_in = options.delete(:expires_in) || 3.minutes
body = Rails.cache.read(key, raw: true)
if body
render(options.except(:json, :serializer, :each_serializer, :adapter, :fields).merge(json: body))
else
if block_given?
options[:json] = yield
elsif options[:json].is_a?(Symbol)
options[:json] = send(options[:json])
end
render(options)
Rails.cache.write(key, response.body, expires_in: expires_in, raw: true)
end
end
def set_cache_headers
response.headers['Vary'] = public_fetch_mode? ? 'Accept' : 'Accept, Signature'
end
def cache_collection(raw, klass)
return raw unless klass.respond_to?(:with_includes)
raw = raw.cache_ids.to_a if raw.is_a?(ActiveRecord::Relation)
return [] if raw.empty?
cached_keys_with_value = begin
Rails.cache.read_multi(*raw, namespace: 'v2').transform_keys(&:id).transform_values { |r| ActiveRecordCoder.load(r) }
rescue ActiveRecordCoder::Error
{} # The serialization format may have changed, let's pretend it's a cache miss.
end
uncached_ids = raw.map(&:id) - cached_keys_with_value.keys
klass.reload_stale_associations!(cached_keys_with_value.values) if klass.respond_to?(:reload_stale_associations!)
unless uncached_ids.empty?
uncached = klass.where(id: uncached_ids).with_includes.index_by(&:id)
uncached.each_value do |item|
Rails.cache.write(item, ActiveRecordCoder.dump(item), namespace: 'v2')
end
end
raw.filter_map { |item| cached_keys_with_value[item.id] || uncached[item.id] }
end
def cache_collection_paginated_by_id(raw, klass, limit, options)
cache_collection raw.cache_ids.to_a_paginated_by_id(limit, options), klass
end
end
|
