Class: SuperSettings::Storage::JSONStorage

Inherits:
StorageAttributes show all
Includes:
Transaction
Defined in:
lib/super_settings/storage/json_storage.rb

Overview

This is an abstract storage class that provides support for storing settings in a JSON file. The settings are stored in JSON as an array of hashes with each hash representing a setting.

Setting history should be stored in separate JSON files per key and are loaded separately from the main settings file.

This class can be used as the base for any storage class where the settings are all stored together in a single JSON payload.

Writes are serialized within a process, but there is no coordination between processes. If multiple processes write settings at the same time, the last write wins and can overwrite changes made by another process. Storage backends based on this class are best suited for setups where settings are updated from a single process at a time.

Subclasses must implement the following methods:

  • self.all
  • self.last_updated_at
  • save!

Direct Known Subclasses

S3Storage

Defined Under Namespace

Classes: HistoryStorage

Instance Attribute Summary

Attributes inherited from StorageAttributes

#created_at, #description, #key, #raw_value, #updated_at, #value_type

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Transaction

included, #persisted=, #persisted?, #save!

Methods inherited from StorageAttributes

#deleted=, #deleted?, #initialize, #persisted=, #persisted?

Methods included from SuperSettings::Storage

#==, #create_history, #created_at, #deleted=, #deleted?, #description, #description=, included, #key, #key=, #persisted?, #raw_value, #raw_value=, #save!, #updated_at, #value_type, #value_type=

Constructor Details

This class inherits a constructor from SuperSettings::Storage::StorageAttributes

Class Method Details

.all ⇒ Object 



62
63
64
 
# File 'lib/super_settings/storage/json_storage.rb', line 62

def all
  parse_settings(settings_json_payload)
end

.create_history(key:, changed_by:, created_at:, value: nil, deleted: false) ⇒ Object 



74
75
76
 
# File 'lib/super_settings/storage/json_storage.rb', line 74

def create_history(key:, changed_by:, created_at:, value: nil, deleted: false)
  HistoryStorage.create!(key: key, value: value, changed_by: changed_by, created_at: created_at, deleted: deleted, storage: self)
end

.find_by_key(key) ⇒ Object 



70
71
72
 
# File 'lib/super_settings/storage/json_storage.rb', line 70

def find_by_key(key)
  active.detect { |setting| setting.key == key }
end

.parse_settings(json) ⇒ Array<SuperSettings::Storage::JSONStorage>

Helper method to load settings from a JSON string.

Parameters:

  • json (String) —

    JSON string to parse.

Returns:



132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
 
# File 'lib/super_settings/storage/json_storage.rb', line 132

def parse_settings(json)
  return [] if Coerce.blank?(json)

  JSON.parse(json).collect do |attributes|
    setting = new(
      key: attributes["key"],
      raw_value: attributes["value"],
      description: attributes["description"],
      value_type: attributes["value_type"],
      updated_at: Time.parse(attributes["updated_at"]),
      created_at: Time.parse(attributes["created_at"]),
      deleted: attributes["deleted"]
    )
    setting.persisted = true
    setting
  end
end

.save_all(changes) ⇒ Object 



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
 
# File 'lib/super_settings/storage/json_storage.rb', line 78

def save_all(changes)
  SAVE_MUTEX.synchronize do
    existing = {}
    parse_settings(settings_json_payload).each do |setting|
      existing[setting.key] = setting
    end

    history_items = []
    changes.each do |record|
      if record.is_a?(HistoryStorage)
        history_items << record
      else
        existing[record.key] = record
      end
    end

    settings = existing.values.sort_by(&:key)

    changed_histories = {}
    history_items.each do |history_item|
      setting = existing[history_item.key]
      next unless setting

      history = changed_histories[history_item.key]
      unless history
        history = setting.history.dup
        changed_histories[history_item.key] = history
      end
      history.unshift(history_item)
    end

    settings_json = JSON.dump(settings.collect(&:as_json))
    save_settings_json(settings_json)

    changed_histories.each do |setting_key, setting_history|
      ordered_history = setting_history.sort_by { |history_item| history_item.created_at }.reverse
      payload = ordered_history.collect do |history_item|
        {
          value: history_item.value,
          changed_by: history_item.changed_by,
          created_at: history_item.created_at.iso8601(6),
          deleted: history_item.deleted?
        }
      end
      history_json = JSON.dump(payload)
      save_history_json(setting_key, history_json)
    end
  end
end

.updated_since(timestamp) ⇒ Object 



66
67
68
 
# File 'lib/super_settings/storage/json_storage.rb', line 66

def updated_since(timestamp)
  all.select { |setting| setting.updated_at > timestamp }
end

Instance Method Details

#as_json ⇒ Object 



201
202
203
204
205
206
207
208
209
210
211
 
# File 'lib/super_settings/storage/json_storage.rb', line 201

def as_json
  {
    key: key,
    value: raw_value,
    value_type: value_type,
    description: description,
    created_at: created_at&.iso8601(6),
    updated_at: updated_at&.iso8601(6),
    deleted: deleted?
  }
end

#created_at=(val) ⇒ Object 



185
186
187
 
# File 'lib/super_settings/storage/json_storage.rb', line 185

def created_at=(val)
  super(TimePrecision.new(val).time)
end

#history(limit: nil, offset: 0) ⇒ Object 



193
194
195
196
197
198
199
 
# File 'lib/super_settings/storage/json_storage.rb', line 193

def history(limit: nil, offset: 0)
  history = fetch_history
  limit ||= history.length
  history[offset, limit].collect do |record|
    HistoryItem.new(key: key, value: record.value, changed_by: record.changed_by, created_at: record.created_at, deleted: record.deleted?)
  end
end

#updated_at=(val) ⇒ Object 



189
190
191
 
# File 'lib/super_settings/storage/json_storage.rb', line 189

def updated_at=(val)
  super(TimePrecision.new(val).time)
end