class Mongo::Operation::Commands::Aggregate

A MongoDB aggregate operation.

@note An aggregate operation can behave like a read and return a

result set, or can behave like a write operation and
output results to a user-specified collection.

@example Create the aggregate operation.

Aggregate.new({
  :selector => {
    :aggregate => 'test_coll', :pipeline => [{ '$out' => 'test-out' }]
  },
  :db_name => 'test_db'
})

Initialization:

param [ Hash ] spec The specifications for the operation.

option spec :selector [ Hash ] The aggregate selector.
option spec :db_name [ String ] The name of the database on which
  the operation should be executed.
option spec :options [ Hash ] Options for the aggregate command.

@since 2.0.0

Aggregate result wrapper.

@since 2.0.0

Private Instance Methods

filter_selector(server) click to toggle source

# File lib/mongo/operation/commands/aggregate.rb, line 46
def filter_selector(server)
  return selector if server.features.write_command_enabled?
  selector.reject{ |option, value| option.to_s == 'cursor' }
end

update_selector(server) click to toggle source

# File lib/mongo/operation/commands/aggregate.rb, line 51
def update_selector(server)
  if server.mongos? && read_pref = read.to_mongos
    sel = selector[:$query] ? filter_selector(server) : { :$query => filter_selector(server) }
    sel.merge(:$readPreference => read_pref)
  else
    filter_selector(server)
  end
end