organize dbal sorted code

src/database/mongo/sorted/intersect.js

@@ -0,0 +1,99 @@
+'use strict';
+
+module.exports = function (db, module) {
+
+	module.sortedSetIntersectCard = function (keys, callback) {
+		if (!Array.isArray(keys) || !keys.length) {
+			return callback(null, 0);
+		}
+
+		var pipeline = [
+			{ $match: { _key: {$in: keys}} },
+			{ $group: { _id: {value: '$value'}, count: {$sum: 1}} },
+			{ $match: { count: keys.length} },
+			{ $group: { _id: null,  count: { $sum: 1 } } }
+		];
+
+		db.collection('objects').aggregate(pipeline, function (err, data) {
+			callback(err, Array.isArray(data) && data.length ? data[0].count : 0);
+		});
+	};
+
+
+	module.getSortedSetIntersect = function (params, callback) {
+		params.sort = 1;
+		getSortedSetRevIntersect(params, callback);
+	};
+
+	module.getSortedSetRevIntersect = function (params, callback) {
+		params.sort = -1;
+		getSortedSetRevIntersect(params, callback);
+	};
+
+	function getSortedSetRevIntersect(params, callback) {
+		var sets = params.sets;
+		var start = params.hasOwnProperty('start') ? params.start : 0;
+		var stop = params.hasOwnProperty('stop') ? params.stop : -1;
+		var weights = params.weights || [];
+		var aggregate = {};
+
+		if (params.aggregate) {
+			aggregate['$' + params.aggregate.toLowerCase()] = '$score';
+		} else {
+			aggregate.$sum = '$score';
+		}
+
+		var limit = stop - start + 1;
+		if (limit <= 0) {
+			limit = 0;
+		}
+
+		var pipeline = [{ $match: { _key: {$in: sets}} }];
+
+		weights.forEach(function (weight, index) {
+			if (weight !== 1) {
+				pipeline.push({
+					$project: {
+						value: 1,
+						score: {
+							$cond: { if: { $eq: [ "$_key", sets[index] ] }, then: { $multiply: [ '$score', weight ] }, else: '$score' }
+						}
+					}
+				});
+			}
+		});
+
+		pipeline.push({ $group: { _id: {value: '$value'}, totalScore: aggregate, count: {$sum: 1}} });
+		pipeline.push({ $match: { count: sets.length} });
+		pipeline.push({ $sort: { totalScore: params.sort} });
+
+		if (start) {
+			pipeline.push({ $skip: start });
+		}
+
+		if (limit > 0) {
+			pipeline.push({ $limit: limit });
+		}
+
+		var project = { _id: 0, value: '$_id.value'};
+		if (params.withScores) {
+			project.score = '$totalScore';
+		}
+		pipeline.push({ $project: project });
+
+		db.collection('objects').aggregate(pipeline, function (err, data) {
+			if (err || !data) {
+				return callback(err);
+			}
+
+			if (!params.withScores) {
+				data = data.map(function (item) {
+					return item.value;
+				});
+			}
+
+			callback(null, data);
+		});
+	}
+
+};