Module: QueryDam

Defined in:
lib/query_dam.rb,
lib/query_dam/version.rb,
lib/query_dam/concerns/trackable.rb

Defined Under Namespace

Modules: Trackable

Constant Summary collapse

DEFAULT_EXPIRATION = 
5.minutes
VERSION = 
'0.2.0'

Class Method Summary collapse

Class Method Details

.expiration ⇒ Object 



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# File 'lib/query_dam.rb', line 54

def expiration
  @expiration || DEFAULT_EXPIRATION
end

.expiration=(value) ⇒ Object 



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# File 'lib/query_dam.rb', line 50

def expiration=(value)
  @expiration = value
end

.get_updates(tracking_key) ⇒ Object 



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# File 'lib/query_dam.rb', line 23

def get_updates(tracking_key)
  query_hash = Redis::HashKey.new(tracking_key)
  return nil unless query_hash.exists?
  query_hash.expire(expiration)

  model = query_hash[:model].constantize
  additions_set, updates_set, removals_set = query_sets(tracking_key)

  updated_ids = (additions_set.members + updates_set.members).uniq
  removed_ids = removals_set.members

  result = {
    model: model,
    updates: model.where(id: updated_ids),
    exclusions: removed_ids.map(&:to_i) }

  [additions_set, updates_set, removals_set].each(&:clear)

  result
end

.query_sets(tracking_key) ⇒ Object 



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# File 'lib/query_dam.rb', line 44

def query_sets(tracking_key)
  %w[additions updates removals].map do |set_type|
    Redis::Set.new("#{tracking_key} #{set_type}")
  end
end

.watch_relation(relation) ⇒ Object 



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# File 'lib/query_dam.rb', line 13

def watch_relation(relation)
  tracking_key = SecureRandom.uuid
  query = relation.select("`#{relation.model.table_name}`.`id`").to_sql
  query_hash = Redis::HashKey.new(tracking_key)
  query_hash.bulk_set(model: relation.model.name, query: query)
  query_hash.expire(expiration)
  Redis::Set.new(relation.model.name) << tracking_key
  tracking_key
end