Class: ActiveRecord::ConnectionAdapters::ConnectionHandler
- Inherits:
-
Object
- Object
- ActiveRecord::ConnectionAdapters::ConnectionHandler
- Defined in:
- lib/active_record/connection_adapters/abstract/connection_pool.rb
Overview
ConnectionHandler is a collection of ConnectionPool objects. It is used for keeping separate connection pools for Active Record 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. Active Record models use this to determine that connection pool that they should use.
Instance Attribute Summary collapse
-
#connection_pools ⇒ Object
readonly
Returns the value of attribute connection_pools.
Instance Method Summary collapse
-
#clear_active_connections! ⇒ Object
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.
- #clear_all_connections! ⇒ Object
-
#clear_reloadable_connections! ⇒ Object
Clears the cache which maps classes.
-
#connected?(klass) ⇒ Boolean
Returns true if a connection that’s accessible to this class has already been opened.
- #establish_connection(name, spec) ⇒ Object
-
#initialize(pools = {}) ⇒ ConnectionHandler
constructor
A new instance of ConnectionHandler.
-
#remove_connection(klass) ⇒ Object
Remove the connection for this class.
-
#retrieve_connection(klass) ⇒ Object
Locate the connection of the nearest super class.
- #retrieve_connection_pool(klass) ⇒ Object
-
#verify_active_connections! ⇒ Object
Verify active connections.
Constructor Details
#initialize(pools = {}) ⇒ ConnectionHandler
Returns a new instance of ConnectionHandler.
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# File 'lib/active_record/connection_adapters/abstract/connection_pool.rb', line 283 def initialize(pools = {}) @connection_pools = pools end |
Instance Attribute Details
#connection_pools ⇒ Object (readonly)
Returns the value of attribute connection_pools.
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# File 'lib/active_record/connection_adapters/abstract/connection_pool.rb', line 281 def connection_pools @connection_pools end |
Instance Method Details
#clear_active_connections! ⇒ Object
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.
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# File 'lib/active_record/connection_adapters/abstract/connection_pool.rb', line 294 def clear_active_connections! @connection_pools.each_value {|pool| pool.release_connection } end |
#clear_all_connections! ⇒ Object
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# File 'lib/active_record/connection_adapters/abstract/connection_pool.rb', line 303 def clear_all_connections! @connection_pools.each_value {|pool| pool.disconnect! } end |
#clear_reloadable_connections! ⇒ Object
Clears the cache which maps classes
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# File 'lib/active_record/connection_adapters/abstract/connection_pool.rb', line 299 def clear_reloadable_connections! @connection_pools.each_value {|pool| pool.clear_reloadable_connections! } end |
#connected?(klass) ⇒ Boolean
Returns true if a connection that’s accessible to this class has already been opened.
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# File 'lib/active_record/connection_adapters/abstract/connection_pool.rb', line 323 def connected?(klass) conn = retrieve_connection_pool(klass) conn && conn.connected? end |
#establish_connection(name, spec) ⇒ Object
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# File 'lib/active_record/connection_adapters/abstract/connection_pool.rb', line 287 def establish_connection(name, spec) @connection_pools[name] = ConnectionAdapters::ConnectionPool.new(spec) end |
#remove_connection(klass) ⇒ Object
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.
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# File 'lib/active_record/connection_adapters/abstract/connection_pool.rb', line 332 def remove_connection(klass) pool = @connection_pools[klass.name] return nil unless pool @connection_pools.delete_if { |key, value| value == pool } pool.disconnect! pool.spec.config end |
#retrieve_connection(klass) ⇒ Object
Locate the connection of the nearest super class. This can be an active or defined connection: if it is the latter, it will be opened and set as the active connection for the class it was defined for (not necessarily the current class).
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# File 'lib/active_record/connection_adapters/abstract/connection_pool.rb', line 316 def retrieve_connection(klass) #:nodoc: pool = retrieve_connection_pool(klass) (pool && pool.connection) or raise ConnectionNotEstablished end |
#retrieve_connection_pool(klass) ⇒ Object
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# File 'lib/active_record/connection_adapters/abstract/connection_pool.rb', line 341 def retrieve_connection_pool(klass) pool = @connection_pools[klass.name] return pool if pool return nil if ActiveRecord::Base == klass retrieve_connection_pool klass.superclass end |
#verify_active_connections! ⇒ Object
Verify active connections.
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# File 'lib/active_record/connection_adapters/abstract/connection_pool.rb', line 308 def verify_active_connections! #:nodoc: @connection_pools.each_value {|pool| pool.verify_active_connections! } end |