PostgreSQL database driver (#5861)

* [test/database/list] Fix test list 4 being used in two different tests

* [database/postgres] PostgreSQL database driver

* [database/postgres] Make transactions work based on continuation scope.

* [database/postgres] Implement nested transactions

* eslint --fix

* Add database changes from earlier this week to the PostgreSQL driver.

* Fix typo

* Fix postgres.incrObjectFieldBy returning undefined instead of null when given NaN

* [database/postgres] Fix sortedSetsCard returning an array of strings.

* Update socket.io postgres adapter

* Fix PostgreSQL erroring when multiple updates are made to the same sorted set entry in a single operation.

Add a test case to catch this error.

* Fix lint errors.

* Only prune sessions on one instance in a cluster to avoid deadlocks.

They're caught and handled by the database server, but they spam the logs.

* Fix arguments.slice.

src/database/postgres/sorted/add.js

@@ -0,0 +1,108 @@
+'use strict';
+
+var async = require('async');
+
+module.exports = function (db, module) {
+	var helpers = module.helpers.postgres;
+
+	module.sortedSetAdd = function (key, score, value, callback) {
+		callback = callback || helpers.noop;
+
+		if (!key) {
+			return callback();
+		}
+
+		if (Array.isArray(score) && Array.isArray(value)) {
+			return sortedSetAddBulk(key, score, value, callback);
+		}
+
+		value = helpers.valueToString(value);
+		score = parseFloat(score);
+
+		module.transaction(function (tx, done) {
+			var query = tx.client.query.bind(tx.client);
+
+			async.series([
+				async.apply(helpers.ensureLegacyObjectType, tx.client, key, 'zset'),
+				async.apply(query, {
+					name: 'sortedSetAdd',
+					text: `
+INSERT INTO "legacy_zset" ("_key", "value", "score")
+VALUES ($1::TEXT, $2::TEXT, $3::NUMERIC)
+    ON CONFLICT ("_key", "value")
+    DO UPDATE SET "score" = $3::NUMERIC`,
+					values: [key, value, score],
+				}),
+			], function (err) {
+				done(err);
+			});
+		}, callback);
+	};
+
+	function sortedSetAddBulk(key, scores, values, callback) {
+		if (!scores.length || !values.length) {
+			return callback();
+		}
+		if (scores.length !== values.length) {
+			return callback(new Error('[[error:invalid-data]]'));
+		}
+
+		values = values.map(helpers.valueToString);
+		scores = scores.map(function (score) {
+			return parseFloat(score);
+		});
+
+		helpers.removeDuplicateValues(values, scores);
+
+		module.transaction(function (tx, done) {
+			var query = tx.client.query.bind(tx.client);
+
+			async.series([
+				async.apply(helpers.ensureLegacyObjectType, tx.client, key, 'zset'),
+				async.apply(query, {
+					name: 'sortedSetAddBulk',
+					text: `
+INSERT INTO "legacy_zset" ("_key", "value", "score")
+SELECT $1::TEXT, v, s
+  FROM UNNEST($2::TEXT[], $3::NUMERIC[]) vs(v, s)
+    ON CONFLICT ("_key", "value")
+    DO UPDATE SET "score" = EXCLUDED."score"`,
+					values: [key, values, scores],
+				}),
+			], function (err) {
+				done(err);
+			});
+		}, callback);
+	}
+
+	module.sortedSetsAdd = function (keys, score, value, callback) {
+		callback = callback || helpers.noop;
+
+		if (!Array.isArray(keys) || !keys.length) {
+			return callback();
+		}
+
+		value = helpers.valueToString(value);
+		score = parseFloat(score);
+
+		module.transaction(function (tx, done) {
+			var query = tx.client.query.bind(tx.client);
+
+			async.series([
+				async.apply(helpers.ensureLegacyObjectsType, tx.client, keys, 'zset'),
+				async.apply(query, {
+					name: 'sortedSetsAdd',
+					text: `
+INSERT INTO "legacy_zset" ("_key", "value", "score")
+SELECT k, $2::TEXT, $3::NUMERIC
+  FROM UNNEST($1::TEXT[]) k
+    ON CONFLICT ("_key", "value")
+    DO UPDATE SET "score" = $3::NUMERIC`,
+					values: [keys, value, score],
+				}),
+			], function (err) {
+				done(err);
+			});
+		}, callback);
+	};
+};