Limit periodical rnd clearing

Periodical persistent rnd clearing does not clear in active tabs.

Fixes #518

lib/main.js

@@ -90,7 +90,7 @@
 				}
 			}
 			if (data["canvasBlocker-clear-domain-rnd"]){
-				persistentRndStorage.clear();
+				persistentRndStorage.clear(data["canvasBlocker-clear-domain-rnd"] === "force");
 				if (keys.length === 1){
 					return;
 				}

lib/persistentRndStorage.js

@@ -123,14 +123,14 @@
 		scope.persistentIncognitoRnd = Object.create(null);
 		settings.persistentIncognitoRndStorage = JSON.stringify(scope.persistentIncognitoRnd);
 	}
-	function clear(){
+	function clear(force = false){
 		logging.verbose("domain rnd cleared");
 		scope.persistentRnd = Object.create(null);
 		settings.persistentRndStorage = JSON.stringify(scope.persistentRnd);
 		settings.lastPersistentRndClearing = Date.now();
 		clearIncognito();
 		registerTimeout();
-		broadcast({"canvasBlocker-clear-domain-rnd": true});
+		broadcast({"canvasBlocker-clear-domain-rnd": force? "force": true});
 	}
 	function setDomainData(domain, incognito, rnd){
 		logging.verbose("got new domain rnd for ", domain, " (incognito:", incognito, "):", rnd);

lib/randomSupplies.js

@@ -82,6 +82,12 @@
 
 	let persistentRnd = Object.create(null);
 	let cookieStoreId = false;
+	function getCookieStoreId(){
+		while (cookieStoreId === false){
+			extension.waitSync("to wait for cookie store id");
+		}
+		return cookieStoreId;
+	}
 	settings.onloaded(function(){
 		try {
 			let storedData = JSON.parse(
@@ -116,15 +122,24 @@
 				}
 			}
 			if (data["canvasBlocker-clear-domain-rnd"]){
+				const domain = getCookieStoreId() + getDomain(window);
+				let ownPersistendRnd = data["canvasBlocker-clear-domain-rnd"] !== "force"? persistentRnd[domain]: false;
 				persistentRnd = Object.create(null);
+				if (ownPersistendRnd){
+					persistentRnd[domain] = ownPersistendRnd;
+					extension.message.send({
+						"canvasBlocker-new-domain-rnd": {
+							domain,
+							incognito: extension.inIncognitoContext,
+							rnd: Array.from(persistentRnd[domain])
+						}
+					});
+				}
 			}
 		});
 		
 		return function getPersistentRnd(window){
-			while (cookieStoreId === false){
-				extension.waitSync("to wait for cookie store id");
-			}
-			const domain = cookieStoreId + getDomain(window);
+			const domain = getCookieStoreId() + getDomain(window);
 			if (!persistentRnd[domain]){
 				// create the (sub-)domains random numbers if not existing
 				persistentRnd[domain] = new Uint8Array(128);

options/options.js

@@ -36,7 +36,7 @@
 			logging.notice("empty storage");
 			settings.persistentRndStorage = "";
 			logging.notice("send message to main script");
-			extension.message.send({"canvasBlocker-clear-domain-rnd": true});
+			extension.message.send({"canvasBlocker-clear-domain-rnd": "force"});
 		},
 		clearPersistentRndForContainer: async function(){
 			const identities = await browser.contextualIdentities.query({});

releaseNotes.txt

@@ -1,6 +1,6 @@
 Version 1.6:
 	changes:
-		-
+		- periodical persistent rnd clearing does not clear in active tabs
 	
 	new features:
 		- try to not break tabs when updating