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_acquired_connection(conn, *) click to toggle source

Only for use by extension that need to disconnect a connection inside acquire. Takes the connection and any arguments accepted by acquire.

    # File lib/sequel/connection_pool.rb
136 def disconnect_acquired_connection(conn, *)
137   disconnect_connection(conn)
138 end

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
141 def disconnect_error?(exception)
142   exception.is_a?(Sequel::DatabaseDisconnectError) || db.send(:disconnect_error?, exception, OPTS)
143 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
147 def make_new(server)
148   begin
149     if @use_old_connect_api
150       # SEQUEL6: Remove block
151       conn = @db.connect(server)
152 
153       if ac = @after_connect
154         if ac.arity == 2
155           ac.call(conn, server)
156         else
157           ac.call(conn)
158         end
159       end
160 
161       if cs = @connect_sqls
162         cs.each do |sql|
163           db.send(:log_connection_execute, conn, sql)
164         end
165       end
166 
167       conn
168     else
169       @db.new_connection(server)
170     end
171   rescue Exception=>exception
172     raise Sequel.convert_exception_class(exception, Sequel::DatabaseConnectionError)
173   end || raise(Sequel::DatabaseConnectionError, "Connection parameters not valid")
174 end