Class: DbCharmer::Sharding::StubConnection

Inherits:
Object
  • Object
show all
Defined in:
lib/db_charmer/sharding/stub_connection.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(sharded_connection) ⇒ StubConnection

Returns a new instance of StubConnection.



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# File 'lib/db_charmer/sharding/stub_connection.rb', line 12

def initialize(sharded_connection)
  @sharded_connection = sharded_connection
  @real_conn = nil
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(meth, *args, &block) ⇒ Object 



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# File 'lib/db_charmer/sharding/stub_connection.rb', line 40

def method_missing(meth, *args, &block)
  # Fail on database statements
  if ::ActiveRecord::ConnectionAdapters::DatabaseStatements.instance_methods.member?(meth.to_s)
    raise ::ActiveRecord::ConnectionNotEstablished, "You have to switch connection on your model before using it!"
  end

  # Fail if no connection has been established yet
  unless real_connection
    raise ::ActiveRecord::ConnectionNotEstablished, "No real connection to proxy this method to!"
  end

  if real_connection.kind_of?(DbCharmer::Sharding::StubConnection)
    raise ::ActiveRecord::ConnectionNotEstablished, "You have to switch connection on your model before using it!"
  end

  # Proxy the call to our real connection target
  real_connection.__send__(meth, *args, &block)
end

Instance Attribute Details

#sharded_connection ⇒ Object

Returns the value of attribute sharded_connection.



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# File 'lib/db_charmer/sharding/stub_connection.rb', line 10

def sharded_connection
  @sharded_connection
end

Instance Method Details

#db_charmer_connection_name ⇒ Object 



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# File 'lib/db_charmer/sharding/stub_connection.rb', line 21

def db_charmer_connection_name
  "StubConnection"
end

#real_connection ⇒ Object 



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# File 'lib/db_charmer/sharding/stub_connection.rb', line 25

def real_connection
  # Return memoized real connection
  return @real_conn if @real_conn

  # If sharded connection supports shards enumeration, get the first shard
  conn = sharded_connection.shard_connections.try(:first)

  # If we do not have real connection yet, try to use the default one (if it is supported by the sharder)
  conn ||= sharded_connection.sharder.shard_for_key(:default) if sharded_connection.support_default_shard?

  # Get connection proxy for our real connection
  return nil unless conn
  @real_conn = ::ActiveRecord::Base.coerce_to_connection_proxy(conn, DbCharmer.connections_should_exist?)
end

#set_real_connection(real_conn) ⇒ Object 



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# File 'lib/db_charmer/sharding/stub_connection.rb', line 17

def set_real_connection(real_conn)
  @real_conn = real_conn
end