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
111 def initialize(db, opts=OPTS) # SEQUEL6: Remove second argument, always use db.opts
112   @db = db
113   @use_old_connect_api = false # SEQUEL6: Remove
114   @after_connect = opts[:after_connect] # SEQUEL6: Remove
115   @connect_sqls = opts[:connect_sqls] # SEQUEL6: Remove
116   @error_classes = db.send(:database_error_classes).dup.freeze
117 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
92 def after_connect=(v) # SEQUEL6: Remove
93   @use_old_connect_api = true
94   @after_connect = v
95 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
102 def connect_sqls=(v) # SEQUEL6: Remove
103   @use_old_connect_api = true
104   @connect_sqls = v
105 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
120 def servers
121   [:default]
122 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
128 def disconnect_connection(conn)
129   db.disconnect_connection(conn)
130 end
disconnect_error?(exception) click to toggle source

Whether the given exception is a disconnect exception.

    # File lib/sequel/connection_pool.rb
133 def disconnect_error?(exception)
134   exception.is_a?(Sequel::DatabaseDisconnectError) || db.send(:disconnect_error?, exception, OPTS)
135 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
139 def make_new(server)
140   begin
141     if @use_old_connect_api
142       # SEQUEL6: Remove block
143       conn = @db.connect(server)
144 
145       if ac = @after_connect
146         if ac.arity == 2
147           ac.call(conn, server)
148         else
149           ac.call(conn)
150         end
151       end
152 
153       if cs = @connect_sqls
154         cs.each do |sql|
155           db.send(:log_connection_execute, conn, sql)
156         end
157       end
158 
159       conn
160     else
161       @db.new_connection(server)
162     end
163   rescue Exception=>exception
164     raise Sequel.convert_exception_class(exception, Sequel::DatabaseConnectionError)
165   end || raise(Sequel::DatabaseConnectionError, "Connection parameters not valid")
166 end