123456789_123456789_123456789_123456789_123456789_

Class: Mongo::Session

Relationships & Source Files
Namespace Children
Classes:
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, Forwardable
Instance Chain:
Inherits: Object
Defined in: lib/mongo/session.rb,
lib/mongo/session/server_session.rb,
lib/mongo/session/session_pool.rb,
lib/mongo/session/server_session/dirtyable.rb

Overview

Note:

Session objects are not thread-safe. An application may use a session from only one thread or process at a time.

A logical session representing a set of sequential operations executed by an application that are related in some way.

Since:

  • 2.5.0

Constant Summary

  • MISMATCHED_CLUSTER_ERROR_MSG =

    Error message indicating that the session was retrieved from a client with a different cluster than that of the client through which it is currently being used.

    Since:

    • 2.5.0

    # File 'lib/mongo/session.rb', line 289
    'The configuration of the client used to create this session does not match that ' +
    'of the client owning this operation. Please only use this session for operations through its parent ' +
    'client.'.freeze
  • NO_TRANSACTION_STATE =

    The state of a session in which the last operation was not related to any transaction or no operations have yet occurred.

    Since:

    • 2.6.0

    # File 'lib/mongo/session.rb', line 309
    :no_transaction
  • SESSIONS_NOT_SUPPORTED =
    Deprecated.

    Error message describing that sessions are not supported by the server version.

    Since:

    • 2.5.0

    # File 'lib/mongo/session.rb', line 302
    'Sessions are not supported by the connected servers.'.freeze
  • SESSION_ENDED_ERROR_MSG =

    Error message describing that the session cannot be used because it has already been ended.

    Since:

    • 2.5.0

    # File 'lib/mongo/session.rb', line 296
    'This session has ended and cannot be used. Please create a new one.'.freeze
  • STARTING_TRANSACTION_STATE =

    The state of a session in which a user has initiated a transaction but no operations within the transactions have occurred yet.

    Since:

    • 2.6.0

    # File 'lib/mongo/session.rb', line 315
    :starting_transaction
  • TRANSACTION_ABORTED_STATE =

    The state of a session in which the last operation executed was a transaction abort.

    Since:

    • 2.6.0

    # File 'lib/mongo/session.rb', line 332
    :transaction_aborted
  • TRANSACTION_COMMITTED_STATE =

    The state of a session in which the last operation executed was a transaction commit.

    Since:

    • 2.6.0

    # File 'lib/mongo/session.rb', line 327
    :transaction_committed
  • TRANSACTION_IN_PROGRESS_STATE =

    The state of a session in which a transaction has been started and at least one operation has occurred, but the transaction has not yet been committed or aborted.

    Since:

    • 2.6.0

    # File 'lib/mongo/session.rb', line 322
    :transaction_in_progress
  • UNLABELED_WRITE_CONCERN_CODES = Internal use only

    Since:

    • 2.5.0

    # File 'lib/mongo/session.rb', line 335
    [
      79,  # UnknownReplWriteConcern
      100, # CannotSatisfyWriteConcern,
    ].freeze

Loggable - Included

PREFIX

Class Method Summary

Instance Attribute Summary

ClusterTime::Consumer - Included

#cluster_time

The cluster time tracked by the object including this module.

Instance Method Summary

ClusterTime::Consumer - Included

#advance_cluster_time

Advance the tracked cluster time document for the object including this module.

Loggable - Included

#log_debug

Convenience method to log debug messages with the standard prefix.

#log_error

Convenience method to log error messages with the standard prefix.

#log_fatal

Convenience method to log fatal messages with the standard prefix.

#log_info

Convenience method to log info messages with the standard prefix.

#log_warn

Convenience method to log warn messages with the standard prefix.

#logger

Get the logger instance.

#_mongo_log_prefix, #format_message

Retryable - Included

#read_worker

Returns the read worker for handling retryable reads.

#select_server

This is a separate method to make it possible for the test suite to assert that server selection is performed during retry attempts.

#write_worker

Returns the write worker for handling retryable writes.

Instance Attribute Details

#aborting_transaction?true | false (readonly)

This method is for internal use only.

Returns:

  • (true | false)

    Whether the session is currently aborting a transaction.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 774

def aborting_transaction?
  !!@aborting_transaction
end

#causal_consistency?Boolean (readonly, private)

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1184

def causal_consistency?
  @causal_consistency ||= (if @options.key?(:causal_consistency)
                             !!@options[:causal_consistency]
                           else
                             true
                           end)
end

#clientClient (readonly)

Returns:

  • (Client)

    The client through which this session was created.

Since:

  • 2.5.1

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 109

attr_reader :client

#committing_transaction?true | false (readonly)

This method is for internal use only.

Returns:

  • (true | false)

    Whether the session is currently committing a transaction.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 766

def committing_transaction?
  !!@committing_transaction
end

#dirty?true | false | nil (readonly)

This method is for internal use only.

Returns:

  • (true | false | nil)

    whether the underlying server session is dirty. If no server session exists for this session, returns nil.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 139

def dirty?
  @server_session&.dirty?
end

#ended?true, false (readonly)

Whether this session has ended.

Examples:

session.ended?

Returns:

  • (true, false)

    Whether the session has ended.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 236

def ended?
  !!@ended
end

#explicit?true, false (readonly)

Is this session an explicit one (i.e. user-created).

Examples:

Is the session explicit?

session.explicit?

Returns:

  • (true, false)

    Whether this session is explicit.

Since:

  • 2.5.2

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 171

def explicit?
  !implicit?
end

#implicit?true, false (readonly)

Is this session an implicit one (not user-created).

Examples:

Is the session implicit?

session.implicit?

Returns:

  • (true, false)

    Whether this session is implicit.

Since:

  • 2.5.1

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 159

def implicit?
  @implicit ||= !!(@options.key?(:implicit) && @options[:implicit] == true)
end

#in_transaction?true | false (readonly)

Whether or not the session is currently in a transaction.

Examples:

Is the session in a transaction?

session.in_transaction?

Returns:

  • (true | false)

    Whether or not the session in a transaction.

Since:

  • 2.6.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 758

def in_transaction?
  within_states?(STARTING_TRANSACTION_STATE, TRANSACTION_IN_PROGRESS_STATE)
end

#materialized?Boolean (readonly)

This method is for internal use only.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1097

def materialized?
  if ended?
    raise Error::SessionEnded
  end

  !@server_session.nil?
end

#operation_timeBSON::Timestamp (readonly)

Returns:

  • (BSON::Timestamp)

    The latest seen operation time for this session.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 124

attr_reader :operation_time

#optionsHash (readonly)

Returns:

  • (Hash)

    The options for this session.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 104

attr_reader :options

#pinned_connection_global_idInteger | nil (readonly)

This method is for internal use only.

Returns:

  • (Integer | nil)

    The connection global id that this session is pinned to, if any.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 277

attr_reader :pinned_connection_global_id

#pinned_serverServer | nil (readonly)

This method is for internal use only.

Returns:

  • (Server | nil)

    The server (which should be a mongos) that this session is pinned to, if any.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 271

attr_reader :pinned_server

#recovery_tokenBSON::Document | nil (rw)

This method is for internal use only.

Returns:

  • (BSON::Document | nil)

    Recovery token for the sharded transaction being executed on this session, if any.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 283

attr_accessor :recovery_token

#retry_reads?Boolean (readonly)

This method is for internal use only.

Whether reads executed with this session can be retried according to the modern retryable reads specification.

If this method returns true, the modern retryable reads have been requested by the application. If the server selected for a read operation supports modern retryable reads, they will be used for that particular operation. If the server selected for a read operation does not support modern retryable reads, the read will not be retried.

If this method returns false, legacy retryable reads have been requested by the application. Legacy retryable read logic will be used regardless of server version of the server(s) that the client is connected to. The number of read retries is given by :max_read_retries client option, which is 1 by default and can be set to 0 to disable legacy read retries.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 191

def retry_reads?
  client.options[:retry_reads] != false
end

#retry_writes?true, false (readonly)

Note:

Retryable writes are only available on server versions at least 3.6 and with sharded clusters, replica sets, or load-balanced topologies.

Will writes executed with this session be retried.

Examples:

Will writes be retried.

session.retry_writes?

Returns:

  • (true, false)

    If writes will be retried.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 206

def retry_writes?
  !!client.options[:retry_writes] && (cluster.replica_set? || cluster.sharded? || cluster.load_balanced?)
end

#snapshot?true | false (readonly)

Returns:

  • (true | false)

    Whether the session is configured for snapshot reads.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 117

def snapshot?
  !!options[:snapshot]
end

#snapshot_timestamp (rw)

This method is for internal use only.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1139

attr_accessor :snapshot_timestamp

#starting_transaction?Boolean (readonly)

This method is for internal use only.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 746

def starting_transaction?
  within_states?(STARTING_TRANSACTION_STATE)
end

Instance Method Details

#abort_transaction

Abort the currently active transaction without making any changes to the database.

Examples:

Abort the transaction.

session.abort_transaction

Raises:

Since:

  • 2.6.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 691

def abort_transaction
  QueryCache.clear

  check_if_ended!
  check_if_no_transaction!

  if within_states?(TRANSACTION_COMMITTED_STATE)
    raise Mongo::Error::InvalidTransactionOperation.new(
      Mongo::Error::InvalidTransactionOperation.cannot_call_after_msg(
        :commitTransaction, :abortTransaction))
  end

  if within_states?(TRANSACTION_ABORTED_STATE)
    raise Mongo::Error::InvalidTransactionOperation.new(
      Mongo::Error::InvalidTransactionOperation.cannot_call_twice_msg(:abortTransaction))
  end

  begin
    unless starting_transaction?
      @aborting_transaction = true
      context = Operation::Context.new(client: @client, session: self)
      write_with_retry(txn_options[:write_concern],
        ending_transaction: true, context: context,
      ) do |connection, txn_num, context|
        begin
          Operation::Command.new(
            selector: { abortTransaction: 1 },
            db_name: 'admin',
            session: self,
            txn_num: txn_num
          ).execute_with_connection(connection, context: context)
        ensure
          unpin
        end
      end
    end

    @state = TRANSACTION_ABORTED_STATE
  rescue Mongo::Error::InvalidTransactionOperation
    raise
  rescue Mongo::Error
    @state = TRANSACTION_ABORTED_STATE
  rescue Exception
    @state = TRANSACTION_ABORTED_STATE
    raise
  ensure
    @aborting_transaction = false
  end

  # No official return value, but return true so that in interactive
  # use the method hints that it succeeded.
  true
end

#add_autocommit!(command) ⇒ Hash, BSON::Document

This method is for internal use only.

Add the autocommit field to a command document if applicable.

Examples:

session.add_autocommit!(cmd)

Returns:

  • (Hash, BSON::Document)

    The command document.

Since:

  • 2.6.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 854

def add_autocommit!(command)
  command.tap do |c|
    c[:autocommit] = false if in_transaction?
  end
end

#add_start_transaction!(command) ⇒ Hash, BSON::Document

This method is for internal use only.

Add the startTransaction field to a command document if applicable.

Examples:

session.add_start_transaction!(cmd)

Returns:

  • (Hash, BSON::Document)

    The command document.

Since:

  • 2.6.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 869

def add_start_transaction!(command)
  command.tap do |c|
    if starting_transaction?
      c[:startTransaction] = true
    end
  end
end

#add_txn_num!(command) ⇒ Hash, BSON::Document

This method is for internal use only.

Add the transaction number to a command document if applicable.

Examples:

session.add_txn_num!(cmd)

Returns:

  • (Hash, BSON::Document)

    The command document.

Since:

  • 2.6.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 886

def add_txn_num!(command)
  command.tap do |c|
    c[:txnNumber] = BSON::Int64.new(@server_session.txn_num) if in_transaction?
  end
end

#add_txn_opts!(command, read) ⇒ Hash, BSON::Document

This method is for internal use only.

Add the transactions options if applicable.

Examples:

session.add_txn_opts!(cmd)

Returns:

  • (Hash, BSON::Document)

    The command document.

Since:

  • 2.6.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 901

def add_txn_opts!(command, read)
  command.tap do |c|
    # The read concern should be added to any command that starts a transaction.
    if starting_transaction?
      # https://jira.mongodb.org/browse/SPEC-1161: transaction's
      # read concern overrides collection/database/client read concerns,
      # even if transaction's read concern is not set.
      # Read concern here is the one sent to the server and may
      # include afterClusterTime.
      if rc = c[:readConcern]
        rc = rc.dup
        rc.delete(:level)
      end
      if txn_read_concern
        if rc
          rc.update(txn_read_concern)
        else
          rc = txn_read_concern.dup
        end
      end
      if rc.nil? || rc.empty?
        c.delete(:readConcern)
      else
        c[:readConcern ] = Options::Mapper.transform_values_to_strings(rc)
      end
    end

    # We need to send the read concern level as a string rather than a symbol.
    if c[:readConcern]
      c[:readConcern] = Options::Mapper.transform_values_to_strings(c[:readConcern])
    end

    if c[:commitTransaction]
      if max_time_ms = txn_options[:max_commit_time_ms]
        c[:maxTimeMS] = max_time_ms
      end
    end

    # The write concern should be added to any abortTransaction or commitTransaction command.
    if (c[:abortTransaction] || c[:commitTransaction])
      if @already_committed
        wc = BSON::Document.new(c[:writeConcern] || txn_write_concern || {})
        wc.merge!(w: :majority)
        wc[:wtimeout] ||= 10000
        c[:writeConcern] = wc
      elsif txn_write_concern
        c[:writeConcern] ||= txn_write_concern
      end
    end

    # A non-numeric write concern w value needs to be sent as a string rather than a symbol.
    if c[:writeConcern] && c[:writeConcern][:w] && c[:writeConcern][:w].is_a?(Symbol)
      c[:writeConcern][:w] = c[:writeConcern][:w].to_s
    end
  end
end

#advance_operation_time(new_operation_time) ⇒ BSON::Timestamp

Advance the cached operation time for this session.

Examples:

Advance the operation time.

session.advance_operation_time(timestamp)

Parameters:

  • new_operation_time (BSON::Timestamp)

    The new operation time.

Returns:

  • (BSON::Timestamp)

    The max operation time, considering the current and new times.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1070

def advance_operation_time(new_operation_time)
  if @operation_time
    @operation_time = [ @operation_time, new_operation_time ].max
  else
    @operation_time = new_operation_time
  end
end

#causal_consistency_doc (private)

Returns causal consistency document if the last operation time is known and causal consistency is enabled, otherwise returns nil.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1176

def causal_consistency_doc
  if operation_time && causal_consistency?
    {:afterClusterTime => operation_time}
  else
    nil
  end
end

#check_if_ended! (private)

Raises:

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1198

def check_if_ended!
  raise Mongo::Error::InvalidSession.new(SESSION_ENDED_ERROR_MSG) if ended?
end

#check_if_no_transaction! (private)

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1162

def check_if_no_transaction!
  return unless within_states?(NO_TRANSACTION_STATE)

  raise Mongo::Error::InvalidTransactionOperation.new(
    Mongo::Error::InvalidTransactionOperation::NO_TRANSACTION_STARTED)
end

#check_matching_cluster!(client) (private)

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1202

def check_matching_cluster!(client)
  if @client.cluster != client.cluster
    raise Mongo::Error::InvalidSession.new(MISMATCHED_CLUSTER_ERROR_MSG)
  end
end

#check_transactions_supported! (private)

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1208

def check_transactions_supported!
  raise Mongo::Error::TransactionsNotSupported, "standalone topology" if cluster.single?

  cluster.next_primary.with_connection do |conn|
    if cluster.replica_set? && !conn.features.transactions_enabled?
      raise Mongo::Error::TransactionsNotSupported, "server version is < 4.0"
    end
    if cluster.sharded? && !conn.features.sharded_transactions_enabled?
      raise Mongo::Error::TransactionsNotSupported, "sharded transactions require server version >= 4.2"
    end
  end
end

#cluster

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 111

def cluster
  @client.cluster
end

#commit_transaction(options = nil)

Commit the currently active transaction on the session.

Examples:

Commits the transaction.

session.commit_transaction

Parameters:

  • options (Hash) (defaults to: nil)

    a customizable set of options

Options Hash (options):

  • :write_concern (nil | WriteConcern::Base)

    The write concern to use for this operation.

Raises:

Since:

  • 2.6.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 618

def commit_transaction(options=nil)
  QueryCache.clear
  check_if_ended!
  check_if_no_transaction!

  if within_states?(TRANSACTION_ABORTED_STATE)
    raise Mongo::Error::InvalidTransactionOperation.new(
      Mongo::Error::InvalidTransactionOperation.cannot_call_after_msg(
        :abortTransaction, :commitTransaction))
  end

  options ||= {}

  begin
    # If commitTransaction is called twice, we need to run the same commit
    # operation again, so we revert the session to the previous state.
    if within_states?(TRANSACTION_COMMITTED_STATE)
      @state = @last_commit_skipped ? STARTING_TRANSACTION_STATE : TRANSACTION_IN_PROGRESS_STATE
      @already_committed = true
    end

    if starting_transaction?
      @last_commit_skipped = true
    else
      @last_commit_skipped = false
      @committing_transaction = true

      write_concern = options[:write_concern] || txn_options[:write_concern]
      if write_concern && !write_concern.is_a?(WriteConcern::Base)
        write_concern = WriteConcern.get(write_concern)
      end

      context = Operation::Context.new(client: @client, session: self)
      write_with_retry(write_concern, ending_transaction: true,
        context: context,
      ) do |connection, txn_num, context|
        if context.retry?
          if write_concern
            wco = write_concern.options.merge(w: :majority)
            wco[:wtimeout] ||= 10000
            write_concern = WriteConcern.get(wco)
          else
            write_concern = WriteConcern.get(w: :majority, wtimeout: 10000)
          end
        end
        spec = {
          selector: { commitTransaction: 1 },
          db_name: 'admin',
          session: self,
          txn_num: txn_num,
          write_concern: write_concern,
        }
        Operation::Command.new(spec).execute_with_connection(connection, context: context)
      end
    end
  ensure
    @state = TRANSACTION_COMMITTED_STATE
    @committing_transaction = false
  end

  # No official return value, but return true so that in interactive
  # use the method hints that it succeeded.
  true
end

#dirty!(mark = true)

Sets the dirty state to the given value for the underlying server session. If there is no server session, this does nothing.

Parameters:

  • mark (true | false) (defaults to: true)

    whether to mark the server session as dirty, or not.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 131

def dirty!(mark = true)
  @server_session&.dirty!(mark)
end

#end_sessionnil

End this session.

If there is an in-progress transaction on this session, the transaction is aborted. The server session associated with this session is returned to the server session pool. Finally, this session is marked ended and is no longer usable.

If this session is already ended, this method does nothing.

Note that this method does not directly issue an endSessions command to this server, contrary to what its name might suggest.

Examples:

session.end_session

Returns:

  • (nil)

    Always nil.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 370

def end_session
  if !ended? && @client
    if within_states?(TRANSACTION_IN_PROGRESS_STATE)
      begin
        abort_transaction
      rescue Mongo::Error, Error::AuthError
      end
    end
    if @server_session
      @client.cluster.session_pool.checkin(@server_session)
    end
  end
ensure
  @server_session = nil
  @ended = true
end

#inspectString

Get a formatted string for use in inspection.

Examples:

Inspect the session object.

session.inspect

Returns:

  • (String)

    The session inspection.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 348

def inspect
  "#<Mongo::Session:0x#{object_id} session_id=#{session_id} options=#{@options}>"
end

#materialize_if_neededSession

This method is for internal use only.

If not already set, populate a session objects’s server_session by checking out a session from the session pool.

Returns:

  • (Session)

    Self.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1084

def materialize_if_needed
  if ended?
    raise Error::SessionEnded
  end

  return unless implicit? && !@server_session

  @server_session = cluster.session_pool.checkout

  self
end

#next_txn_numInteger

This method is for internal use only.

Increment and return the next transaction number.

Examples:

Get the next transaction number.

session.next_txn_num

Returns:

  • (Integer)

    The next transaction number.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1114

def next_txn_num
  if ended?
    raise Error::SessionEnded
  end

  @server_session.next_txn_num
end

#pin_to_connection(connection_global_id)

This method is for internal use only.

Pins this session to the specified connection.

this session to.

Parameters:

  • connection_global_id (Integer)

    The global id of connection to pin

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 801

def pin_to_connection(connection_global_id)
  if connection_global_id.nil?
    raise ArgumentError, 'Cannot pin to a nil connection id'
  end
  @pinned_connection_global_id = connection_global_id
end

#pin_to_server(server)

This method is for internal use only.

Pins this session to the specified server, which should be a mongos.

Parameters:

  • server (Server)

    The server to pin this session to.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 783

def pin_to_server(server)
  if server.nil?
    raise ArgumentError, 'Cannot pin to a nil server'
  end
  if Lint.enabled?
    unless server.mongos?
      raise Error::LintError, "Attempted to pin the session to server #{server.summary} which is not a mongos"
    end
  end
  @pinned_server = server
end

#process(result) ⇒ Operation::Result

This method is for internal use only.

Process a response from the server that used this session.

Examples:

Process a response from the server.

session.process(result)

Parameters:

Returns:

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1042

def process(result)
  unless implicit?
    set_operation_time(result)
    if cluster_time_doc = result.cluster_time
      advance_cluster_time(cluster_time_doc)
    end
  end
  @server_session.set_last_use!

  if doc = result.reply && result.reply.documents.first
    if doc[:recoveryToken]
      self.recovery_token = doc[:recoveryToken]
    end
  end

  result
end

#session_idBSON::Document

Get the server session id of this session, if the session has not been ended. If the session had been ended, raises Error::SessionEnded.

Returns:

  • (BSON::Document)

    The server session id.

Raises:

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 248

def session_id
  if ended?
    raise Error::SessionEnded
  end

  # An explicit session will always have a session_id, because during
  # construction a server session must be provided. An implicit session
  # will not have a session_id until materialized, thus calls to
  # session_id might fail. An application should not have an opportunity
  # to experience this failure because an implicit session shouldn't be
  # accessible to applications due to its lifetime being constrained to
  # operation execution, which is done entirely by the driver.
  unless materialized?
    raise Error::SessionNotMaterialized
  end

  @server_session.session_id
end

#set_operation_time(result) (private)

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1192

def set_operation_time(result)
  if result && result.operation_time
    @operation_time = result.operation_time
  end
end

#start_transaction(options = nil)

Places subsequent operations in this session into a new transaction.

Note that the transaction will not be started on the server until an operation is performed after start_transaction is called.

Examples:

Start a new transaction

session.start_transaction(options)

Parameters:

  • options (Hash) (defaults to: nil)

    The options for the transaction being started.

Options Hash (options):

  • :max_commit_time_ms (Integer)

    The maximum amount of time to allow a single commitTransaction command to run, in milliseconds.

  • :read_concern (Hash)

    The read concern options hash, with the following optional keys:

    • :level – the read preference level as a symbol; valid values

      are *:local*, *:majority*, and *:snapshot*
  • :write_concern (Hash)

    The write concern options. Can be :w => Integer|String, :fsync => Boolean, :j => Boolean.

  • :read (Hash)

    The read preference options. The hash may have the following items:

    • :mode – read preference specified as a symbol; the only valid value is :primary.

Raises:

Since:

  • 2.6.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 557

def start_transaction(options = nil)
  check_transactions_supported!

  if options
    Lint.validate_read_concern_option(options[:read_concern])

=begin
    # It would be handy to detect invalid read preferences here, but
    # some of the spec tests require later detection of invalid read prefs.
    # Maybe we can do this when lint mode is on.
    mode = options[:read] && options[:read][:mode].to_s
    if mode && mode != 'primary'
      raise Mongo::Error::InvalidTransactionOperation.new(
        "read preference in a transaction must be primary (requested: #{mode})"
      )
    end
=end
  end

  if snapshot?
    raise Mongo::Error::SnapshotSessionTransactionProhibited
  end

  check_if_ended!

  if within_states?(STARTING_TRANSACTION_STATE, TRANSACTION_IN_PROGRESS_STATE)
    raise Mongo::Error::InvalidTransactionOperation.new(
      Mongo::Error::InvalidTransactionOperation::TRANSACTION_ALREADY_IN_PROGRESS)
  end

  unpin

  next_txn_num
  @txn_options = (@options[:default_transaction_options] || {}).merge(options || {})

  if txn_write_concern && !WriteConcern.get(txn_write_concern).acknowledged?
    raise Mongo::Error::InvalidTransactionOperation.new(
      Mongo::Error::InvalidTransactionOperation::UNACKNOWLEDGED_WRITE_CONCERN)
  end

  @state = STARTING_TRANSACTION_STATE
  @already_committed = false

  # This method has no explicit return value.
  # We could return nil here but true indicates to the user that the
  # operation succeeded. This is intended for interactive use.
  # Note that the return value is not documented.
  true
end

#suppress_read_write_concern!(command) ⇒ Hash, BSON::Document

This method is for internal use only.

Remove the read concern and/or write concern from the command if not applicable.

Examples:

session.suppress_read_write_concern!(cmd)

Returns:

  • (Hash, BSON::Document)

    The command document.

Since:

  • 2.6.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 967

def suppress_read_write_concern!(command)
  command.tap do |c|
    next unless in_transaction?

    c.delete(:readConcern) unless starting_transaction?
    c.delete(:writeConcern) unless c[:commitTransaction] || c[:abortTransaction]
  end
end

#txn_numInteger

Get the current transaction number.

Examples:

Get the current transaction number.

session.txn_num

Returns:

  • (Integer)

    The current transaction number.

Since:

  • 2.6.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1130

def txn_num
  if ended?
    raise Error::SessionEnded
  end

  @server_session.txn_num
end

#txn_optionsHash

on this session.

Returns:

  • (Hash)

    The options for the transaction currently being executed

Since:

  • 2.6.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 147

def txn_options
  @txn_options or raise ArgumentError, "There is no active transaction"
end

#txn_read_concernHash (private)

Get the read concern the session will use when starting a transaction.

This is a driver style hash with underscore keys.

Examples:

Get the session’s transaction read concern.

session.txn_read_concern

Returns:

  • (Hash)

    The read concern used for starting transactions.

Since:

  • 2.9.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1153

def txn_read_concern
  # Read concern is inherited from client but not db or collection.
  txn_options[:read_concern] || @client.read_concern
end

#txn_read_preferenceHash

Get the read preference the session will use in the currently active transaction.

This is a driver style hash with underscore keys.

Examples:

Get the transaction’s read preference

session.txn_read_preference

Returns:

  • (Hash)

    The read preference of the transaction.

Since:

  • 2.6.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 221

def txn_read_preference
  rp = txn_options[:read] ||
    @client.read_preference
  Mongo::Lint.validate_underscore_read_preference(rp)
  rp
end

#txn_write_concern (private)

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1169

def txn_write_concern
  txn_options[:write_concern] ||
    (@client.write_concern && @client.write_concern.options)
end

#unpin(connection = nil)

This method is for internal use only.

Unpins this session from the pinned server or connection, if the session was pinned.

Parameters:

  • connection (Connection | nil) (defaults to: nil)

    Connection to unpin from.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 814

def unpin(connection = nil)
  @pinned_server = nil
  @pinned_connection_global_id = nil
  connection.unpin unless connection.nil?
end

#unpin_maybe(error, connection = nil)

This method is for internal use only.

Unpins this session from the pinned server or connection, if the session was pinned and the specified exception instance and the session’s transaction state require it to be unpinned.

The exception instance should already have all of the labels set on it (both client- and server-side generated ones).

Parameters:

  • error (Error)

    The exception instance to process.

  • connection (Connection | nil) (defaults to: nil)

    Connection to unpin from.

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 831

def unpin_maybe(error, connection = nil)
  if !within_states?(Session::NO_TRANSACTION_STATE) &&
    error.label?('TransientTransactionError')
  then
    unpin(connection)
  end

  if committing_transaction? &&
    error.label?('UnknownTransactionCommitResult')
  then
    unpin(connection)
  end
end

#update_state!

This method is for internal use only.

Update the state of the session due to a (non-commit and non-abort) operation being run.

Since:

  • 2.6.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1003

def update_state!
  case @state
  when STARTING_TRANSACTION_STATE
    @state = TRANSACTION_IN_PROGRESS_STATE
  when TRANSACTION_COMMITTED_STATE, TRANSACTION_ABORTED_STATE
    @state = NO_TRANSACTION_STATE
  end
end

#validate!(client) ⇒ Session

This method is for internal use only.

Validate the session for use by the specified client.

The session must not be ended and must have been created by a client with the same cluster as the client that the session is to be used with.

Parameters:

  • client (Client)

    The client the session is to be used with.

Returns:

  • (Session)

    self, if the session is valid.

Raises:

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1025

def validate!(client)
  check_matching_cluster!(client)
  check_if_ended!
  self
end

#validate_read_preference!(command)

This method is for internal use only.

Ensure that the read preference of a command primary.

Examples:

session.validate_read_preference!(command)

Raises:

Since:

  • 2.6.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 986

def validate_read_preference!(command)
  return unless in_transaction?
  return unless command['$readPreference']

  mode = command['$readPreference']['mode'] || command['$readPreference'][:mode]

  if mode && mode != 'primary'
    raise Mongo::Error::InvalidTransactionOperation.new(
      "read preference in a transaction must be primary (requested: #{mode})"
    )
  end
end

#with_transaction(options = nil)

Note:

with_transaction contains a loop, therefore the if with_transaction itself is placed in a loop, its block should not call next or break to control the outer loop because this will instead affect the loop in with_transaction. The driver will warn and abort the transaction if it detects this situation.

Executes the provided block in a transaction, retrying as necessary.

Returns the return value of the block.

Exact number of retries and when they are performed are implementation details of the driver; the provided block should be idempotent, and should be prepared to be called more than once. The driver may retry the commit command within an active transaction or it may repeat the transaction and invoke the block again, depending on the error encountered if any. Note also that the retries may be executed against different servers.

Transactions cannot be nested - InvalidTransactionOperation will be raised if this method is called when the session already has an active transaction.

Exceptions raised by the block which are not derived from Error stop processing, abort the transaction and are propagated out of with_transaction. Exceptions derived from Error may be handled by with_transaction, resulting in retries of the process.

Currently, with_transaction will retry commits and block invocations until at least 120 seconds have passed since with_transaction started executing. This timeout is not configurable and may change in a future driver version.

Examples:

Execute a statement in a transaction

session.with_transaction(write_concern: {w: :majority}) do
  collection.update_one({ id: 3 }, { '$set' => { status: 'Inactive'} },
                        session: session)

end

Execute a statement in a transaction, limiting total time consumed

Timeout.timeout(5) do
  session.with_transaction(write_concern: {w: :majority}) do
    collection.update_one({ id: 3 }, { '$set' => { status: 'Inactive'} },
                          session: session)

  end
end

Parameters:

  • options (Hash) (defaults to: nil)

    The options for the transaction being started. These are the same options that start_transaction accepts.

Raises:

Since:

  • 2.7.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 441

def with_transaction(options=nil)
  # Non-configurable 120 second timeout for the entire operation
  deadline = Utils.monotonic_time + 120
  transaction_in_progress = false
  loop do
    commit_options = {}
    if options
      commit_options[:write_concern] = options[:write_concern]
    end
    start_transaction(options)
    transaction_in_progress = true
    begin
      rv = yield self
    rescue Exception => e
      if within_states?(STARTING_TRANSACTION_STATE, TRANSACTION_IN_PROGRESS_STATE)
        log_warn("Aborting transaction due to #{e.class}: #{e}")
        abort_transaction
        transaction_in_progress = false
      end

      if Utils.monotonic_time >= deadline
        transaction_in_progress = false
        raise
      end

      if e.is_a?(Mongo::Error) && e.label?('TransientTransactionError')
        next
      end

      raise
    else
      if within_states?(TRANSACTION_ABORTED_STATE, NO_TRANSACTION_STATE, TRANSACTION_COMMITTED_STATE)
        transaction_in_progress = false
        return rv
      end

      begin
        commit_transaction(commit_options)
        transaction_in_progress = false
        return rv
      rescue Mongo::Error => e
        if e.label?('UnknownTransactionCommitResult')
          if Utils.monotonic_time >= deadline ||
            e.is_a?(Error::OperationFailure) && e.max_time_ms_expired?
          then
            transaction_in_progress = false
            raise
          end
          wc_options = case v = commit_options[:write_concern]
            when WriteConcern::Base
              v.options
            when nil
              {}
            else
              v
            end
          commit_options[:write_concern] = wc_options.merge(w: :majority)
          retry
        elsif e.label?('TransientTransactionError')
          if Utils.monotonic_time >= deadline
            transaction_in_progress = false
            raise
          end
          @state = NO_TRANSACTION_STATE
          next
        else
          transaction_in_progress = false
          raise
        end
      rescue Error::AuthError
        transaction_in_progress = false
        raise
      end
    end
  end

  # No official return value, but return true so that in interactive
  # use the method hints that it succeeded.
  true
ensure
  if transaction_in_progress
    log_warn('with_transaction callback broke out of with_transaction loop, aborting transaction')
    begin
      abort_transaction
    rescue Error::OperationFailure, Error::InvalidTransactionOperation
    end
  end
end

#within_states?(*states) ⇒ Boolean (private)

Since:

  • 2.5.0

[ GitHub ]

  
# File 'lib/mongo/session.rb', line 1158

def within_states?(*states)
  states.include?(@state)
end