Performance optimisations

In some situations, I’m seeing x2.5 speedups with these optimisations

Starts fixing #1864

boot/boot.js

@@ -62,22 +62,22 @@ $tw.utils.isDate = function(value) {
 Iterate through all the own properties of an object or array. Callback is invoked with (element,title,object)
 */
 $tw.utils.each = function(object,callback) {
-	var next,f;
+	var next,f,length;
 	if(object) {
 		if(Object.prototype.toString.call(object) == "[object Array]") {
-			for (f=0; f<object.length; f++) {
+			for (f=0, length=object.length; f<length; f++) {
 				next = callback(object[f],f,object);
 				if(next === false) {
 					break;
 				}
 		    }
 		} else {
-			for(f in object) {
-				if(Object.prototype.hasOwnProperty.call(object,f)) {
-					next = callback(object[f],f,object);
-					if(next === false) {
-						break;
-					}
+			var keys = Object.keys(object);
+			for (f=0, length=keys.length; f<length; f++) {
+				var key = keys[f];
+				next = callback(object[key],key,object);
+				if(next === false) {
+					break;
 				}
 			}
 		}

core/modules/filters/tags.js

@@ -16,13 +16,16 @@ Filter operator returning all the tags of the selected tiddlers
 Export our filter function
 */
 exports.tags = function(source,operator,options) {
-	var results = [];
+	var tags = {};
 	source(function(tiddler,title) {
+		var t, length;
 		if(tiddler && tiddler.fields.tags) {
-			$tw.utils.pushTop(results,tiddler.fields.tags);
+			for(t=0, length=tiddler.fields.tags.length; t<length; t++) {
+				tags[tiddler.fields.tags[t]] = true;
+			}
 		}
 	});
-	return results;
+	return Object.keys(tags);
 };
 
 })();

core/modules/parsers/parseutils.js

@@ -32,29 +32,39 @@ The exception is `skipWhiteSpace`, which just returns the position after the whi
 Look for a whitespace token. Returns null if not found, otherwise returns {type: "whitespace", start:, end:,}
 */
 exports.parseWhiteSpace = function(source,pos) {
-	var node = {
-		type: "whitespace",
-		start: pos
-	};
-	var re = /(\s)+/g;
-	re.lastIndex = pos;
-	var match = re.exec(source);
-	if(match && match.index === pos) {
-		node.end = pos + match[0].length;
-		return node;
+	var p = pos,c;
+	while(true) {
+		c = source.charAt(p);
+		if((c === " ") || (c === "\f") || (c === "\n") || (c === "\r") || (c === "\t") || (c === "\v") || (c === "\u00a0")) { // Ignores some obscure unicode spaces
+			p++;
+		} else {
+			break;
+		}
+	}
+	if(p === pos) {
+		return null;
+	} else {
+		return {
+			type: "whitespace",
+			start: pos,
+			end: p
+		}
 	}
-	return null;
 };
 
 /*
 Convenience wrapper for parseWhiteSpace. Returns the position after the whitespace
 */
 exports.skipWhiteSpace = function(source,pos) {
-	var whitespace = $tw.utils.parseWhiteSpace(source,pos);
-	if(whitespace) {
-		return whitespace.end;
+	var c;
+	while(true) {
+		c = source.charAt(pos);
+		if((c === " ") || (c === "\f") || (c === "\n") || (c === "\r") || (c === "\t") || (c === "\v") || (c === "\u00a0")) { // Ignores some obscure unicode spaces
+			pos++;
+		} else {
+			return pos;
+		}
 	}
-	return pos;
 };
 
 /*

core/modules/startup/startup.js

@@ -18,7 +18,7 @@ exports.after = ["load-modules"];
 exports.synchronous = true;
 
 // Set to `true` to enable performance instrumentation
-var PERFORMANCE_INSTRUMENTATION = false;
+var PERFORMANCE_INSTRUMENTATION = true;
 
 var widget = require("$:/core/modules/widgets/widget.js");
 

core/modules/wiki.js

@@ -621,18 +621,20 @@ exports.getTiddlerData = function(titleOrTiddler,defaultData) {
 		tiddler = this.getTiddler(tiddler);	
 	}
 	if(tiddler && tiddler.fields.text) {
-		switch(tiddler.fields.type) {
-			case "application/json":
-				// JSON tiddler
-				try {
-					data = JSON.parse(tiddler.fields.text);
-				} catch(ex) {
-					return defaultData;
-				}
-				return data;
-			case "application/x-tiddler-dictionary":
-				return $tw.utils.parseFields(tiddler.fields.text);
-		}
+		return this.getCacheForTiddler(tiddler.fields.title,"data",function() {
+			switch(tiddler.fields.type) {
+				case "application/json":
+					// JSON tiddler
+					try {
+						data = JSON.parse(tiddler.fields.text);
+					} catch(ex) {
+						return defaultData;
+					}
+					return data;
+				case "application/x-tiddler-dictionary":
+					return $tw.utils.parseFields(tiddler.fields.text);
+			}
+		});
 	}
 	return defaultData;
 };