Class ActiveRecord::ConnectionAdapters::ConnectionHandler
In: vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
Parent: Object

ConnectionHandler is a collection of ConnectionPool objects. It is used for keeping separate connection pools for ActiveRecord models that connect to different databases.

For example, suppose that you have 5 models, with the following hierarchy:

 |
 +-- Book
 |    |
 |    +-- ScaryBook
 |    +-- GoodBook
 +-- Author
 +-- BankAccount

Suppose that Book is to connect to a separate database (i.e. one other than the default database). Then Book, ScaryBook and GoodBook will all use the same connection pool. Likewise, Author and BankAccount will use the same connection pool. However, the connection pool used by Author/BankAccount is not the same as the one used by Book/ScaryBook/GoodBook.

Normally there is only a single ConnectionHandler instance, accessible via ActiveRecord::Base.connection_handler. ActiveRecord models use this to determine that connection pool that they should use.

Methods

Public Class methods

[Source]

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 287
287:       def initialize(pools = {})
288:         @connection_pools = pools
289:       end

Public Instance methods

Returns any connections in use by the current thread back to the pool, and also returns connections to the pool cached by threads that are no longer alive.

[Source]

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 302
302:       def clear_active_connections!
303:         @connection_pools.each_value {|pool| pool.release_connection }
304:       end

[Source]

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 311
311:       def clear_all_connections!
312:         @connection_pools.each_value {|pool| pool.disconnect! }
313:       end

Clears the cache which maps classes

[Source]

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 307
307:       def clear_reloadable_connections!
308:         @connection_pools.each_value {|pool| pool.clear_reloadable_connections! }
309:       end

Returns true if a connection that‘s accessible to this class has already been opened.

[Source]

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 331
331:       def connected?(klass)
332:         conn = retrieve_connection_pool(klass)
333:         conn ? conn.connected? : false
334:       end

[Source]

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 291
291:       def connection_pools
292:         @connection_pools ||= {}
293:       end

[Source]

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 295
295:       def establish_connection(name, spec)
296:         @connection_pools[name] = ConnectionAdapters::ConnectionPool.new(spec)
297:       end

Remove the connection for this class. This will close the active connection and the defined connection (if they exist). The result can be used as an argument for establish_connection, for easily re-establishing the connection.

[Source]

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 340
340:       def remove_connection(klass)
341:         pool = @connection_pools[klass.name]
342:         @connection_pools.delete_if { |key, value| value == pool }
343:         pool.disconnect! if pool
344:         pool.spec.config if pool
345:       end

[Source]

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 347
347:       def retrieve_connection_pool(klass)
348:         pool = @connection_pools[klass.name]
349:         return pool if pool
350:         return nil if ActiveRecord::Base == klass
351:         retrieve_connection_pool klass.superclass
352:       end

[Validate]