mongoid – mongodb，mapreduce获取范围可变或将其传递给输出

在mapreduce中，我有一个范围total_count，用于在分组内容后计算一些东西。 如何在输出中恢复该范围可变？

编辑：

map = %Q{ function() { ttotal_commission += this.commission; tuniq_commission += this.commission; // add first if it not goto reduce emit({ip: this.ip, campaign_id: this.campaign_id}, {commission: this.commission, abc: this.commission}); } } reduce = %Q{ function(key, values) { tuniq_commission += values[0].commission; // add 1 and substract laster for uniq var total_commission = 0; values.forEach(function(value) { tuniq_commission -= value.commission; total_commission += value.commission; }); return {}; } } final = %Q{ function(key, reduceVal){ reduceVal.ttotal_commission = ttotal_commission; reduceVal.tuniq_commission = tuniq_commission; return reduceVal; } } temp = Transaction.all.limit(45000).map_reduce(map, reduce).scope(ttotal_commission: 0, tuniq_commission: 0).finalize(final).out(inline: true).first