Module: Mongoid::Clients::Sessions::ClassMethods

Included in:
Mongoid
Defined in:
lib/mongoid/clients/sessions.rb

Instance Method Summary collapse

Instance Method Details

#transaction(options = {}, session_options: {}) { ... } ⇒ Object

Executes a block within the context of a transaction.

If the block does not raise an error, the transaction is committed. If an error is raised, the transaction is aborted. The error is passed on except for the ‘Mongoid::Errors::Rollback`. This error is not passed on, so you can raise is if you want to deliberately rollback the transaction.

Parameters:

  • options (Hash) (defaults to: {}) —

    The transaction options. Please see the driver documentation for the available session options.

  • session_options (Hash) (defaults to: {}) —

    The session options. A MongoDB transaction must be started inside a session, therefore a session will be started. Please see the driver documentation for the available session options.

Yields:

  • Provided block will be executed inside a transaction.

Raises:



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# File 'lib/mongoid/clients/sessions.rb', line 83

def transaction(options = {}, session_options: {})
  with_session(session_options) do |session|
    begin
      session.start_transaction(options)
      yield
      commit_transaction(session)
    rescue Mongoid::Errors::Rollback
      abort_transaction(session)
    rescue Mongoid::Errors::InvalidSessionNesting
      # Session should be ended here.
      raise Mongoid::Errors::InvalidTransactionNesting.new
    rescue Mongo::Error::InvalidSession, Mongo::Error::InvalidTransactionOperation => e
      abort_transaction(session)
      raise Mongoid::Errors::TransactionError(e)
    rescue StandardError => e
      abort_transaction(session)
      raise e
    end
  end
end

#with_session(options = {}) {|The| ... } ⇒ Object

Execute a block within the context of a session.

Examples:

Execute some operations in the context of a session.

Band.with_session(causal_consistency: true) do
  band = Band.create
  band.records << Record.new
  band.save
  band.reload.records
end

Parameters:

  • options (Hash) (defaults to: {}) —

    The session options. Please see the driver documentation for the available session options.

Yield Parameters:

  • The (Mongo::Session) —

    session being used for the block.

Returns:

  • (Object) —

    The result of calling the block.

Raises:

  • (Errors::InvalidSessionUse) —

    If an operation is attempted on a model using another client from which the session was started or if sessions are nested.



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# File 'lib/mongoid/clients/sessions.rb', line 38

def with_session(options = {})
  if Threaded.get_session(client: persistence_context.client)
    raise Mongoid::Errors::InvalidSessionNesting.new
  end
  session = persistence_context.client.start_session(options)
  Threaded.set_session(session, client: persistence_context.client)
  yield(session)
rescue Mongo::Error::InvalidSession => ex
  if Mongo::Error::SessionsNotSupported === ex
    raise Mongoid::Errors::SessionsNotSupported.new
  else
    raise ex
  end
rescue Mongo::Error::OperationFailure => ex
  if (ex.code == 40415 && ex.server_message =~ /startTransaction/) ||
     (ex.code == 20 && ex.server_message =~ /Transaction/)
    raise Mongoid::Errors::TransactionsNotSupported.new
  else
    raise ex
  end
ensure
  Threaded.clear_session(client: persistence_context.client)
end