Module: ActiveRecord::ConnectionAdapters::QueryCache

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

Defined Under Namespace

Modules: ConnectionPoolConfiguration Classes: QueryCacheRegistry, 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 



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# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 201

def query_cache
  if @pinned && @owner != ActiveSupport::IsolatedExecutionState.context
    # With transactional tests, if the connection is pinned, any thread
    # other than the one that pinned the connection need to go through the
    # query cache pool, so each thread get a different cache.
    pool.query_cache
  else
    @query_cache
  end
end

Class Method Details

.dirties_query_cache(base, *method_names) ⇒ Object 



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# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 20

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:



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# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 12

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.



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# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 217

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.



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# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 243

def clear_query_cache
  pool.clear_query_cache
end

#disable_query_cache! ⇒ Object 



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# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 233

def disable_query_cache!
  pool.disable_query_cache!
end

#enable_query_cache! ⇒ Object 



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# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 221

def enable_query_cache!
  pool.enable_query_cache!
end

#initialize ⇒ Object 



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

def initialize(*)
  super
  @query_cache = nil
end

#query_cache_enabled ⇒ Object 



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# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 212

def query_cache_enabled
  query_cache&.enabled?
end

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

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 247

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.)



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# File 'lib/active_record/connection_adapters/abstract/query_cache.rb', line 229

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