Several performance optimizations

src/15utility.js

@@ -1,9 +1,9 @@
 /*jshint unused:false*/
 /*
-    Utilities for Alasql.js
+	Utilities for Alasql.js
 
-    @todo Review the list of utilities
-    @todo Find more effective utilities
+	@todo Review the list of utilities
+	@todo Find more effective utilities
 */
 
 /**
@@ -59,7 +59,7 @@ function returnTrue() {
   @function
   @return {undefined} Always undefined
   */
-function returnUndefined() {}
+function returnUndefined() { }
 
 /**
   Escape string
@@ -354,7 +354,7 @@ var loadFile = (utils.loadFile = function (path, asy, success, error) {
 	} else if (utils.isCordova) {
 		/* If Cordova */
 		utils.global.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function (fileSystem) {
-			fileSystem.root.getFile(path, {create: false}, function (fileEntry) {
+			fileSystem.root.getFile(path, { create: false }, function (fileEntry) {
 				fileEntry.file(function (file) {
 					var fileReader = new FileReader();
 					fileReader.onloadend = function (e) {
@@ -565,7 +565,7 @@ var removeFile = (utils.removeFile = function (path, cb) {
 		utils.global.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function (fileSystem) {
 			fileSystem.root.getFile(
 				path,
-				{create: false},
+				{ create: false },
 				function (fileEntry) {
 					fileEntry.remove(cb);
 					cb && cb(); // jshint ignore:line
@@ -633,7 +633,7 @@ var fileExists = (utils.fileExists = function (path, cb) {
 		utils.global.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function (fileSystem) {
 			fileSystem.root.getFile(
 				path,
-				{create: false},
+				{ create: false },
 				function (fileEntry) {
 					cb(true);
 				},
@@ -699,7 +699,7 @@ var saveFile = (utils.saveFile = function (path, data, cb, opts) {
 		} else if (utils.isCordova) {
 			utils.global.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function (fileSystem) {
 				//                alasql.utils.removeFile(path,function(){
-				fileSystem.root.getFile(path, {create: true}, function (fileEntry) {
+				fileSystem.root.getFile(path, { create: true }, function (fileEntry) {
 					fileEntry.createWriter(function (fileWriter) {
 						fileWriter.onwriteend = function () {
 							if (cb) {
@@ -774,7 +774,7 @@ var saveFile = (utils.saveFile = function (path, data, cb, opts) {
 				disableAutoBom: false,
 			};
 			alasql.utils.extend(opt, opts);
-			var blob = new Blob([data], {type: 'text/plain;charset=utf-8'});
+			var blob = new Blob([data], { type: 'text/plain;charset=utf-8' });
 			saveAs(blob, path, opt.disableAutoBom);
 			if (cb) {
 				res = cb(res);
@@ -1175,43 +1175,46 @@ var domEmptyChildren = (utils.domEmptyChildren = function (container) {
   @parameter {string} escape Escape character (optional)
   @return {boolean} If value LIKE pattern ESCAPE escape
   */
-
+var patternCache = {};
 var like = (utils.like = function (pattern, value, escape) {
-	// Verify escape character
-	if (!escape) escape = '';
-
-	var i = 0;
-	var s = '^';
-
-	while (i < pattern.length) {
-		var c = pattern[i],
-			c1 = '';
-		if (i < pattern.length - 1) c1 = pattern[i + 1];
-
-		if (c === escape) {
-			s += '\\' + c1;
-			i++;
-		} else if (c === '[' && c1 === '^') {
-			s += '[^';
+	if (!patternCache[pattern]) {
+		// Verify escape character
+		if (!escape) escape = '';
+
+		var i = 0;
+		var s = '^';
+
+		while (i < pattern.length) {
+			var c = pattern[i],
+				c1 = '';
+			if (i < pattern.length - 1) c1 = pattern[i + 1];
+
+			if (c === escape) {
+				s += '\\' + c1;
+				i++;
+			} else if (c === '[' && c1 === '^') {
+				s += '[^';
+				i++;
+			} else if (c === '[' || c === ']') {
+				s += c;
+			} else if (c === '%') {
+				s += '[\\s\\S]*';
+			} else if (c === '_') {
+				s += '.';
+			} else if ('/.*+?|(){}'.indexOf(c) > -1) {
+				s += '\\' + c;
+			} else {
+				s += c;
+			}
 			i++;
-		} else if (c === '[' || c === ']') {
-			s += c;
-		} else if (c === '%') {
-			s += '[\\s\\S]*';
-		} else if (c === '_') {
-			s += '.';
-		} else if ('/.*+?|(){}'.indexOf(c) > -1) {
-			s += '\\' + c;
-		} else {
-			s += c;
 		}
-		i++;
-	}
 
-	s += '$';
-	//    if(value == undefined) return false;
-	//console.log(s,value,(value||'').search(RegExp(s))>-1);
-	return ('' + (value ?? '')).search(RegExp(s, 'i')) > -1;
+		s += '$';
+		//    if(value == undefined) return false;
+		//console.log(s,value,(value||'').search(RegExp(s))>-1);
+		patternCache[pattern] = RegExp(s, 'i');
+	}
+	return ('' + (value ?? '')).search(patternCache[pattern]) > -1;
 });
 
 utils.glob = function (value, pattern) {

src/17alasql.js

@@ -15,32 +15,32 @@ alasql.parser.parseError = function (str, hash) {
 };
 
 /**
- 	Jison parser
- 	@param {string} sql SQL statement
- 	@return {object} AST (Abstract Syntax Tree)
+	  Jison parser
+	  @param {string} sql SQL statement
+	  @return {object} AST (Abstract Syntax Tree)
 
- 	@todo Create class AST
- 	@todo Add other parsers
+	  @todo Create class AST
+	  @todo Add other parsers
 
- 	@example
- 	alasql.parse = function(sql) {
+	  @example
+	  alasql.parse = function(sql) {
 		// My own parser here
- 	}
+	  }
  */
 alasql.parse = function (sql) {
 	return alasqlparser.parse(alasql.utils.uncomment(sql));
 };
 
 /**
- 	List of engines of external databases
- 	@type {object}
- 	@todo Create collection type
+	  List of engines of external databases
+	  @type {object}
+	  @todo Create collection type
  */
 alasql.engines = {};
 
 /**
- 	List of databases
- 	@type {object}
+	  List of databases
+	  @type {object}
  */
 alasql.databases = {};
 
@@ -51,7 +51,7 @@ alasql.databases = {};
 alasql.databasenum = 0;
 
 /**
- 	Alasql options object
+	  Alasql options object
  */
 alasql.options = {
 	/** Log or throw error */
@@ -119,12 +119,15 @@ alasql.options = {
 	/** Check for NaN and convert it to undefined */
 	nan: false,
 
-	excel: {cellDates: true},
+	excel: { cellDates: true },
 
 	/** Option for SELECT * FROM a,b */
 	joinstar: 'overwrite',
 
 	loopbreak: 100000,
+
+	/** Whether GETDATE() and NOW() return dates as string. If false, then a Date object is returned */
+	dateAsString: true,
 };
 
 //alasql.options.worker = false;
@@ -207,7 +210,7 @@ alasql.autoval = function (tablename, colname, getNext, databaseid) {
 
 	return (
 		db.tables[tablename].identities[colname].value -
-			db.tables[tablename].identities[colname].step || null
+		db.tables[tablename].identities[colname].step || null
 	);
 };
 
@@ -246,19 +249,28 @@ alasql.dexec = function (databaseid, sql, params, cb, scope) {
 	//	if(db.databaseid != databaseid) console.trace('got!');
 	//	console.log(3,db.databaseid,databaseid);
 
-	var hh;
+	var hh = hash(sql);
+
 	// Create hash
 	if (alasql.options.cache) {
-		hh = hash(sql);
 		var statement = db.sqlCache[hh];
 		// If database structure was not changed since last time return cache
 		if (statement && db.dbversion === statement.dbversion) {
 			return statement(params, cb);
 		}
 	}
 
-	// Create AST
-	var ast = alasql.parse(sql);
+	var ast = db.astCache[hh];
+	if (alasql.options.cache && !ast) {
+		// Create AST cache
+		ast = alasql.parse(sql);
+		if (ast) {
+			// add to AST cache
+			db.astCache[hh] = ast;
+		}
+	} else {
+		ast = alasql.parse(sql);
+	}
 	if (!ast.statements) {
 		return;
 	}

src/20database.js

@@ -67,6 +67,7 @@ var Database = (alasql.Database = function (databaseid) {
 Database.prototype.resetSqlCache = function () {
 	this.sqlCache = {}; // Cache for compiled SQL statements
 	this.sqlCacheSize = 0;
+	this.astCache = {}; // Cache for AST objects
 };
 
 // Main SQL function

src/50expression.js

@@ -483,14 +483,17 @@
 					s += '.indexOf(';
 					s += 'alasql.utils.getValueOf(' + leftJS() + '))>-1)';
 				} else if (Array.isArray(this.right)) {
-					//			if(this.right.length == 0) return 'false';
-					s =
-						'([' +
-						this.right.map(ref).join(',') +
-						'].indexOf(alasql.utils.getValueOf(' +
-						leftJS() +
-						'))>-1)';
-					//console.log(s);
+					// Added patch to have a better performance for when you have a lot of entries in an IN statement
+					if (!alasql.sets) {
+						alasql.sets = {};
+					}
+					const allValues = this.right.map((value) => value.value);
+					const allValuesStr = allValues.join(",");
+					if (!alasql.sets[allValuesStr]) {
+						// leverage JS Set, which is faster for lookups than arrays
+						alasql.sets[allValuesStr] = new Set(allValues);
+					}
+					s = 'alasql.sets["' + allValuesStr + '"].has(alasql.utils.getValueOf(' + leftJS() + '))';
 				} else {
 					s = '(' + rightJS() + '.indexOf(' + leftJS() + ')>-1)';
 					//console.log('expression',350,s);
@@ -506,8 +509,17 @@
 					s += '.indexOf(';
 					s += 'alasql.utils.getValueOf(' + leftJS() + '))<0)';
 				} else if (Array.isArray(this.right)) {
-					s = '([' + this.right.map(ref).join(',') + '].indexOf(';
-					s += 'alasql.utils.getValueOf(' + leftJS() + '))<0)';
+					// Added patch to have a better performance for when you have a lot of entries in a NOT IN statement
+					if (!alasql.sets) {
+						alasql.sets = {};
+					}
+					const allValues = this.right.map((value) => value.value);
+					const allValuesStr = allValues.join(",");
+					if (!alasql.sets[allValuesStr]) {
+						// leverage JS Set, which is faster for lookups than arrays
+						alasql.sets[allValuesStr] = new Set(allValues);
+					}
+					s = '!alasql.sets["' + allValuesStr + '"].has(alasql.utils.getValueOf(' + leftJS() + '))';
 				} else {
 					s = '(' + rightJS() + '.indexOf(';
 					s += leftJS() + ')==-1)';
@@ -750,7 +762,7 @@
 
 		toString() {
 			var s;
-			const {op, right} = this;
+			const { op, right } = this;
 			const res = right.toString();
 
 			if (op === '~') {

src/61date.js

@@ -43,27 +43,30 @@ stdfn.OBJECT_ID = function (objid) {
 };
 
 stdfn.DATE = function (d) {
-	if (/\d{8}/.test(d)) return new Date(+d.substr(0, 4), +d.substr(4, 2) - 1, +d.substr(6, 2));
+	if (!isNaN(d) && d.length === 8) return new Date(+d.substr(0, 4), +d.substr(4, 2) - 1, +d.substr(6, 2));
 	return newDate(d);
 };
 
 stdfn.NOW = function () {
-	var d = new Date();
-	var s =
-		d.getFullYear() +
-		'-' +
-		('0' + (d.getMonth() + 1)).substr(-2) +
-		'-' +
-		('0' + d.getDate()).substr(-2);
-	s +=
-		' ' +
-		('0' + d.getHours()).substr(-2) +
-		':' +
-		('0' + d.getMinutes()).substr(-2) +
-		':' +
-		('0' + d.getSeconds()).substr(-2);
-	s += '.' + ('00' + d.getMilliseconds()).substr(-3);
-	return s;
+	if (alasql.options.dateAsString) {
+		var d = new Date();
+		var s =
+			d.getFullYear() +
+			'-' +
+			('0' + (d.getMonth() + 1)).substr(-2) +
+			'-' +
+			('0' + d.getDate()).substr(-2);
+		s +=
+			' ' +
+			('0' + d.getHours()).substr(-2) +
+			':' +
+			('0' + d.getMinutes()).substr(-2) +
+			':' +
+			('0' + d.getSeconds()).substr(-2);
+		s += '.' + ('00' + d.getMilliseconds()).substr(-3);
+		return s;
+	}
+	return new Date();
 };
 
 stdfn.GETDATE = stdfn.NOW;

test/test202.js

@@ -6,14 +6,24 @@ if (typeof exports === 'object') {
 }
 
 describe('Test 202 GETTIME and CAST', function () {
-	it('1. GETDATE()', function (done) {
+	it('1a. GETDATE() as String', function (done) {
 		var res = alasql('SELECT ROW NOW(),GETDATE()');
 		//        console.log(res);
-		assert(res[0].substr(0, 20) == res[1].substr(0, 20));
+		assert(res[0].substr(0, 20) === res[1].substr(0, 20));
 		done();
 	});
 
-	it('2. CONVERT(,,110)', function (done) {
+	it('1b. GETDATE() as Date', function (done) {
+		alasql.options.dateAsString = false;
+		var res = alasql('SELECT ROW NOW(),GETDATE()');
+		//        console.log(res);
+		assert(res[0] instanceof Date);
+		assert(res[1] instanceof Date);
+		assert(res[1].toISOString() === res[0].toISOString());
+		done();
+	});
+
+	it('2. CONVERT(,,110) as String', function (done) {
 		var res = alasql('SELECT VALUE CONVERT(NVARCHAR(10),GETDATE(),110)');
 		//        console.log(res);
 		assert(res.substr(-4) == new Date().getFullYear());