}.merge opts)
end
+ def self.limit_index_columns_read
+ # This method returns a list of column names.
+ # If an index request reads that column from the database,
+ # find_objects_for_index will only fetch objects until it reads
+ # max_index_database_read bytes of data from those columns.
+ []
+ end
+
def find_objects_for_index
@objects ||= model_class.readable_by(*@read_users)
apply_where_limit_order_params
+ limit_database_read if (action_name == "index")
end
def apply_filters model_class=nil
end
end
- def apply_where_limit_order_params *args
- apply_filters *args
+ def apply_where_limit_order_params model_class=nil
+ model_class ||= self.model_class
+ apply_filters model_class
ar_table_name = @objects.table_name
if @where.is_a? Hash and @where.any?
# Map attribute names in @select to real column names, resolve
# those to fully-qualified SQL column names, and pass the
# resulting string to the select method.
- api_column_map = model_class.attributes_required_columns
- columns_list = @select.
- flat_map { |attr| api_column_map[attr] }.
- uniq.
- map { |s| "#{table_name}.#{ActiveRecord::Base.connection.quote_column_name s}" }
+ columns_list = model_class.columns_for_attributes(@select).
+ map { |s| "#{ar_table_name}.#{ActiveRecord::Base.connection.quote_column_name s}" }
@objects = @objects.select(columns_list.join(", "))
end
@objects = @objects.uniq(@distinct) if not @distinct.nil?
end
+ def limit_database_read
+ limit_columns = self.class.limit_index_columns_read
+ limit_columns &= model_class.columns_for_attributes(@select) if @select
+ return if limit_columns.empty?
+ model_class.transaction do
+ limit_query = @objects.
+ except(:select).
+ select("(%s) as read_length" %
+ limit_columns.map { |s| "octet_length(#{s})" }.join(" + "))
+ new_limit = 0
+ read_total = 0
+ limit_query.each do |record|
+ new_limit += 1
+ read_total += record.read_length.to_i
+ if read_total >= Rails.configuration.max_index_database_read
+ new_limit -= 1 if new_limit > 1
+ break
+ elsif new_limit >= @limit
+ break
+ end
+ end
+ @limit = new_limit
+ @objects = @objects.limit(@limit)
+ # Force @objects to run its query inside this transaction.
+ @objects.each { |_| break }
+ end
+ end
+
def resource_attrs
return @attrs if @attrs
@attrs = params[resource_name]
end
accept_param_as_json :reader_tokens, Array
- def render_list
- @object_list = {
+ def object_list
+ list = {
:kind => "arvados##{(@response_resource_name || resource_name).camelize(:lower)}List",
:etag => "",
:self_link => "",
:items => @objects.as_api_response(nil, {select: @select})
}
if @objects.respond_to? :except
- @object_list[:items_available] = @objects.
+ list[:items_available] = @objects.
except(:limit).except(:offset).
count(:id, distinct: true)
end
- send_json @object_list
+ list
+ end
+
+ def render_list
+ send_json object_list
end
def remote_ip