Added value cache for DOMRect

Fixes #272

lib/modifiedDOMRectAPI.js

@@ -26,6 +26,9 @@
 	function getHash(domRect){
 		return hash(new Float64Array([domRect.x, domRect.y, domRect.width, domRect.height]));
 	}
+	function getValueHash(value){
+		return hash(new Float32Array([value]));
+	}
 	
 	const registeredRects = new WeakMap();
 	function registerDOMRect(domRect, notify){
@@ -46,21 +49,32 @@
 	}
 	
 	const cache = {};
+	const valueCache = [{}, {}, {}, {}];
 	function getFakeDomRect(window, domRect, prefs, notify){
-		
-		var rng = randomSupply.getRng(4, window);
-		function getFakeValue(value, i){
-			if ((value * prefs("domRectIntegerFactor", window.location)) % 1 === 0){
-				return value;
-			}
-			else {
-				return value + 0.01 * (rng(i) / 0xffffffff - 0.5);
-			}
-		}
 		const hash = getHash(domRect);
 		let cached = cache[hash];
 		if (!cached){
 			notify("fakedDOMRectReadout");
+			const rng = randomSupply.getRng(4, window);
+			const getFakeValue = function getFakeValue(value, i){
+				const valueHash = getValueHash(value);
+				const cache = valueCache[i];
+				let cachedValue = cache[valueHash];
+				if (typeof cachedValue === "number"){
+					return cachedValue;
+				}
+				if ((value * prefs("domRectIntegerFactor", window.location)) % 1 === 0){
+					cache[valueHash] = value;
+					return value;
+				}
+				else {
+					const fakedValue = value + 0.01 * (rng(i) / 0xffffffff - 0.5);
+					const fakedHash = getValueHash(fakedValue);
+					cache[valueHash] = fakedValue;
+					cache[fakedHash] = fakedValue;
+					return fakedValue;
+				}
+			};
 			cached = new domRect.constructor(
 				getFakeValue(domRect.x, 0),
 				getFakeValue(domRect.y, 1),

releaseNotes.txt

@@ -6,7 +6,7 @@ Version 0.5.5:
 		- 
 	
 	fixes:
-		- 
+		- Google images did not work for some users
 	
 	known issues:
 		- if a data URL is blocked the page action button does not appear