Method: Mongo::Collection::View::Readable#parallel_scan

Defined in:

lib/mongo/collection/view/readable.rb

#parallel_scan(cursor_count, options = {}) ⇒ Object

Since:

• 2.0.0

# File 'lib/mongo/collection/view/readable.rb', line 702

def parallel_scan(cursor_count, options = {})
  if options[:session]
    # The session would be overwritten by the one in +options+ later.
    session = client.get_session(@options)
  else
    session = nil
  end
  server = server_selector.select_server(cluster, nil, session)
  spec = {
    coll_name: collection.name,
    db_name: database.name,
    cursor_count: cursor_count,
    read_concern: read_concern,
    session: session,
  }.update(options)
  session = spec[:session]
  op = Operation::ParallelScan.new(spec)
  # Note that the context object shouldn't be reused for subsequent
  # GetMore operations.
  context = Operation::Context.new(client: client, session: session)
  result = op.execute(server, context: context)
  result.cursor_ids.map do |cursor_id|
    spec = {
      cursor_id: cursor_id,
      coll_name: collection.name,
      db_name: database.name,
      session: session,
      batch_size: batch_size,
      to_return: 0,
      # max_time_ms is not being passed here, I assume intentionally?
    }
    op = Operation::GetMore.new(spec)
    context = Operation::Context.new(
      client: client,
      session: session,
      connection_global_id: result.connection_global_id,
    )
    result = if server.load_balancer?
               # Connection will be checked in when cursor is drained.
               connection = server.pool.check_out(context: context)
               op.execute_with_connection(connection, context: context)
             else
               op.execute(server, context: context)
             end
    Cursor.new(self, result, server, session: session)
  end
end