Module: ActiveRecord::ConnectionAdapters::QueryCache
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Defined in: | activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb |
Constant Summary
-
DEFAULT_SIZE =
Internal use only
# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 9100
Class Method Summary
- .dirties_query_cache(base, *method_names)
- .included(base) Internal use only
Instance Attribute Summary
- #query_cache rw
Instance Method Summary
-
#cache(&block)
Enable the query cache within the block.
-
#clear_query_cache
Clears the query cache.
- #disable_query_cache!
- #enable_query_cache!
- #initialize
- #query_cache_enabled
-
#uncached(dirties: true, &block)
Disable the query cache within the block.
-
#cache_notification_info(sql, name, binds)
private
Database adapters can override this method to provide custom cache information.
- #cache_notification_info_result(sql, name, binds, result) private
- #cache_sql(sql, name, binds) private
- #lookup_sql_cache(sql, name, binds) private
- #unset_query_cache! private
- #select_all(arel, name = nil, binds = [], preparable: nil, async: false, allow_retry: false) Internal use only
Class Method Details
.dirties_query_cache(base, *method_names)
[ GitHub ]# File 'activerecord/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)
# File 'activerecord/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 Attribute Details
#query_cache (rw)
[ GitHub ]# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 194
attr_accessor :query_cache
Instance Method Details
#cache(&block)
Enable the query cache within the block.
# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 206
def cache(&block) pool.enable_query_cache(&block) end
#cache_notification_info(sql, name, binds) (private)
Database adapters can override this method to provide custom cache information.
# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 308
def cache_notification_info(sql, name, binds) { sql: sql, binds: binds, type_casted_binds: -> { type_casted_binds(binds) }, name: name, connection: self, transaction: current_transaction.user_transaction.presence, cached: true } end
#cache_notification_info_result(sql, name, binds, result) (private)
[ GitHub ]# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 300
def cache_notification_info_result(sql, name, binds, result) payload = cache_notification_info(sql, name, binds) payload[:row_count] = result.length payload end
#cache_sql(sql, name, binds) (private)
[ GitHub ]# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 278
def cache_sql(sql, name, binds) key = binds.empty? ? sql : [sql, binds] result = nil hit = true @lock.synchronize do result = @query_cache.compute_if_absent(key) do hit = false yield end end if hit ActiveSupport::Notifications.instrument( "sql.active_record", cache_notification_info_result(sql, name, binds, result) ) end result.dup end
#clear_query_cache
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.
# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 232
def clear_query_cache pool.clear_query_cache end
#disable_query_cache!
[ GitHub ]# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 222
def disable_query_cache! pool.disable_query_cache! end
#enable_query_cache!
[ GitHub ]# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 210
def enable_query_cache! pool.enable_query_cache! end
#initialize
[ GitHub ]# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 196
def initialize(*) super @query_cache = nil end
#lookup_sql_cache(sql, name, binds) (private)
[ GitHub ]# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 260
def lookup_sql_cache(sql, name, binds) key = binds.empty? ? sql : [sql, binds] result = nil @lock.synchronize do result = @query_cache[key] end if result ActiveSupport::Notifications.instrument( "sql.active_record", cache_notification_info_result(sql, name, binds, result) ) end result end
#query_cache_enabled
[ GitHub ]# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 201
def query_cache_enabled @query_cache&.enabled? end
#select_all(arel, name = nil, binds = [], preparable: nil, async: false, allow_retry: false)
# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 236
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)
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.)
# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 218
def uncached(dirties: true, &block) pool.disable_query_cache(dirties: dirties, &block) end
#unset_query_cache! (private)
[ GitHub ]# File 'activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb', line 256
def unset_query_cache! @query_cache = nil end