Module: ActiveRecord::ConnectionAdapters::QueryCache

Included in:
AbstractAdapter
Defined in:
lib/active_record/connection_adapters/abstract/query_cache.rb

Defined Under Namespace

Modules: ConnectionPoolConfiguration Classes: Store

Constant Summary collapse

DEFAULT_SIZE =

:nodoc:

100

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#query_cache ⇒ Object

Returns the value of attribute query_cache.



165
166
167
 
# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 165

def query_cache
  @query_cache
end

Class Method Details

.dirties_query_cache(base, *method_names) ⇒ Object 



19
20
21
22
23
24
25
26
27
28
29
30
 
# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 19

def dirties_query_cache(base, *method_names)
  method_names.each do |method_name|
    base.class_eval <<-end_code, __FILE__, __LINE__ + 1
      def #{method_name}(...)
        if pool.dirties_query_cache
          ActiveRecord::Base.clear_query_caches_for_current_thread
        end
        super
      end
    end_code
  end
end

.included(base) ⇒ Object

:nodoc:



11
12
13
14
15
16
17
 
# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 11

def included(base) # :nodoc:
  dirties_query_cache base, :exec_query, :execute, :create, :insert, :update, :delete, :truncate,
    :truncate_tables, :rollback_to_savepoint, :rollback_db_transaction, :restart_db_transaction,
    :exec_insert_all

  base.set_callback :checkin, :after, :unset_query_cache!
end

Instance Method Details

#cache(&block) ⇒ Object

Enable the query cache within the block.



177
178
179
 
# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 177

def cache(&block)
  pool.enable_query_cache(&block)
end

#clear_query_cache ⇒ Object

Clears the query cache.

One reason you may wish to call this method explicitly is between queries that ask the database to randomize results. Otherwise the cache would see the same SQL query and repeatedly return the same result each time, silently undermining the randomness you were expecting.



203
204
205
 
# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 203

def clear_query_cache
  pool.clear_query_cache
end

#disable_query_cache! ⇒ Object 



193
194
195
 
# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 193

def disable_query_cache!
  pool.disable_query_cache!
end

#enable_query_cache! ⇒ Object 



181
182
183
 
# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 181

def enable_query_cache!
  pool.enable_query_cache!
end

#initialize ⇒ Object 



167
168
169
170
 
# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 167

def initialize(*)
  super
  @query_cache = nil
end

#query_cache_enabled ⇒ Object 



172
173
174
 
# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 172

def query_cache_enabled
  @query_cache&.enabled?
end

#select_all(arel, name = nil, binds = [], preparable: nil, async: false, allow_retry: false) ⇒ Object

:nodoc:



207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
 
# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 207

def select_all(arel, name = nil, binds = [], preparable: nil, async: false, allow_retry: false) # :nodoc:
  arel = arel_from_relation(arel)

  # If arel is locked this is a SELECT ... FOR UPDATE or somesuch.
  # Such queries should not be cached.
  if @query_cache&.enabled? && !(arel.respond_to?(:locked) && arel.locked)
    sql, binds, preparable, allow_retry = to_sql_and_binds(arel, binds, preparable)

    if async
      result = lookup_sql_cache(sql, name, binds) || super(sql, name, binds, preparable: preparable, async: async, allow_retry: allow_retry)
      FutureResult.wrap(result)
    else
      cache_sql(sql, name, binds) { super(sql, name, binds, preparable: preparable, async: async, allow_retry: allow_retry) }
    end
  else
    super
  end
end

#uncached(dirties: true, &block) ⇒ Object

Disable the query cache within the block.

Set dirties: false to prevent query caches on all connections from being cleared by write operations. (By default, write operations dirty all connections’ query caches in case they are replicas whose cache would now be outdated.)



189
190
191
 
# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 189

def uncached(dirties: true, &block)
  pool.disable_query_cache(dirties: dirties, &block)
end