organize dbal sorted code

src/database/redis/sorted/intersect.js

@@ -0,0 +1,79 @@
+
+'use strict';
+
+module.exports = function (redisClient, module) {
+
+	module.sortedSetIntersectCard = function (keys, callback) {
+		if (!Array.isArray(keys) || !keys.length) {
+			return callback(null, 0);
+		}
+		var tempSetName = 'temp_' + Date.now();
+
+		var interParams = [tempSetName, keys.length].concat(keys);
+
+		var multi = redisClient.multi();
+		multi.zinterstore(interParams);
+		multi.zcard(tempSetName);
+		multi.del(tempSetName);
+		multi.exec(function (err, results) {
+			if (err) {
+				return callback(err);
+			}
+
+			callback(null, results[1] || 0);
+		});
+	};
+
+	module.getSortedSetIntersect = function (params, callback) {
+		params.method = 'zrange';
+		getSortedSetRevIntersect(params, callback);
+	};
+
+	module.getSortedSetRevIntersect = function (params, callback) {
+		params.method = 'zrevrange';
+		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 tempSetName = 'temp_' + Date.now();
+
+		var interParams = [tempSetName, sets.length].concat(sets);
+		if (weights.length) {
+			interParams = interParams.concat(['WEIGHTS'].concat(weights));
+		}
+
+		if (params.aggregate) {
+			interParams = interParams.concat(['AGGREGATE', params.aggregate]);
+		}
+
+		var rangeParams = [tempSetName, start, stop];
+		if (params.withScores) {
+			rangeParams.push('WITHSCORES');
+		}
+
+		var multi = redisClient.multi();
+		multi.zinterstore(interParams);
+		multi[params.method](rangeParams);
+		multi.del(tempSetName);
+		multi.exec(function (err, results) {
+			if (err) {
+				return callback(err);
+			}
+
+			if (!params.withScores) {
+				return callback(null, results ? results[1] : null);
+			}
+			results = results[1] || [];
+			var objects = [];
+			for(var i = 0; i < results.length; i += 2) {
+				objects.push({value: results[i], score: parseFloat(results[i + 1])});
+			}
+			callback(null, objects);
+		});
+	}
+};