class Sequel::ConnectionPool

The base connection pool class, which all other connection pools are based on. This class is not instantiated directly, but subclasses should at the very least implement the following API:

initialize(Database, Hash)

Initialize using the passed Sequel::Database object and options hash.

hold(Symbol, &block)

Yield a connection object (obtained from calling the block passed to initialize) to the current block. For sharded connection pools, the Symbol passed is the shard/server to use.

disconnect(Symbol)

Disconnect the connection object. For sharded connection pools, the Symbol passed is the shard/server to use.

servers

An array of shard/server symbols for all shards/servers that this connection pool recognizes.

size

an integer representing the total number of connections in the pool, or for the given shard/server if sharding is supported.

max_size

an integer representing the maximum size of the connection pool, or the maximum size per shard/server if sharding is supported.

For sharded connection pools, the sharded API adds the following methods:

add_servers(Array of Symbols)

start recognizing all shards/servers specified by the array of symbols.

remove_servers(Array of Symbols)

no longer recognize all shards/servers specified by the array of symbols.

Constants

OPTS
POOL_CLASS_MAP

Attributes

after_connect[R]

The after_connect proc used for this pool. This is called with each new connection made, and is usually used to set custom per-connection settings. Deprecated.

connect_sqls[R]

An array of sql strings to execute on each new connection. Deprecated.

db[RW]

The Sequel::Database object tied to this connection pool.

Public Class Methods

new(db, opts=OPTS) click to toggle source

Instantiates a connection pool with the given Database and options.

    # File lib/sequel/connection_pool.rb
113 def initialize(db, opts=OPTS) # SEQUEL6: Remove second argument, always use db.opts
114   @db = db
115   @use_old_connect_api = false # SEQUEL6: Remove
116   @after_connect = opts[:after_connect] # SEQUEL6: Remove
117   @connect_sqls = opts[:connect_sqls] # SEQUEL6: Remove
118   @error_classes = db.send(:database_error_classes).dup.freeze
119 end

Public Instance Methods

after_connect=(v) click to toggle source

Override the after_connect proc for the connection pool. Deprecated. Disables support for shard-specific :after_connect and :connect_sqls if used.

   # File lib/sequel/connection_pool.rb
94 def after_connect=(v) # SEQUEL6: Remove
95   @use_old_connect_api = true
96   @after_connect = v
97 end
connect_sqls=(v) click to toggle source

Override the connect_sqls for the connection pool. Deprecated. Disables support for shard-specific :after_connect and :connect_sqls if used.

    # File lib/sequel/connection_pool.rb
104 def connect_sqls=(v) # SEQUEL6: Remove
105   @use_old_connect_api = true
106   @connect_sqls = v
107 end
servers() click to toggle source

An array of symbols for all shards/servers, which is a single :default by default.

    # File lib/sequel/connection_pool.rb
122 def servers
123   [:default]
124 end

Private Instance Methods

disconnect_connection(conn) click to toggle source

Remove the connection from the pool. For threaded connections, this should be called without the mutex, because the disconnection may block.

    # File lib/sequel/connection_pool.rb
130 def disconnect_connection(conn)
131   db.disconnect_connection(conn)
132 end
disconnect_error?(exception) click to toggle source

Whether the given exception is a disconnect exception.

    # File lib/sequel/connection_pool.rb
135 def disconnect_error?(exception)
136   exception.is_a?(Sequel::DatabaseDisconnectError) || db.send(:disconnect_error?, exception, OPTS)
137 end
make_new(server) click to toggle source

Return a new connection by calling the connection proc with the given server name, and checking for connection errors.

    # File lib/sequel/connection_pool.rb
141 def make_new(server)
142   begin
143     if @use_old_connect_api
144       # SEQUEL6: Remove block
145       conn = @db.connect(server)
146 
147       if ac = @after_connect
148         if ac.arity == 2
149           ac.call(conn, server)
150         else
151           ac.call(conn)
152         end
153       end
154 
155       if cs = @connect_sqls
156         cs.each do |sql|
157           db.send(:log_connection_execute, conn, sql)
158         end
159       end
160 
161       conn
162     else
163       @db.new_connection(server)
164     end
165   rescue Exception=>exception
166     raise Sequel.convert_exception_class(exception, Sequel::DatabaseConnectionError)
167   end || raise(Sequel::DatabaseConnectionError, "Connection parameters not valid")
168 end