Merge pull request #77 from tycrek/check-existing-ids

routers/upload.js

@@ -64,10 +64,37 @@ router.post('/', (req, res, next) => {
 	// Fix spaces in originalname
 	req.file.originalname = req.file.originalname.replace(/\s/g, spaceReplace === '!' ? '' : spaceReplace);
 
-	// Save the file information
-	const resourceId = generateId(generator, resourceIdSize, req.headers['x-ass-gfycat'] || gfyIdSize, req.file.originalname);
+	// Generate a unique resource ID
+	let resourceId = '';
+
+	// Function to call to generate a fresh ID. Used for multiple attempts in case an ID is already taken
+	const gen = () => generateId(generator, resourceIdSize, req.headers['x-ass-gfycat'] || gfyIdSize, req.file.originalname);
+
+	// Keeps track of the number of attempts in case all ID's are taken
+	const attempts = {
+		count: 0,
+		max: 50
+	};
+
+	// Called by a promise, this will recursively resolve itself until a unique ID is found
+	function genCheckId(resolve, reject) {
+		const uniqueId = gen();
+		attempts.count++;
+		data.has(uniqueId)
+			.then((exists) => {
+				log.debug('ID check', exists ? 'Taken' : 'Available');
+				return attempts.count - 1 >= attempts.max ? reject(new Error('No ID\'s remaining')) : exists ? genCheckId(resolve, reject) : resolve(uniqueId);
+			})
+			.catch(reject);
+	}
+
+	new Promise((resolve, reject) => genCheckId(resolve, reject))
+		.then((uniqueId) => {
+			resourceId = uniqueId;
 			log.debug('Saving data', data.name);
-	data.put(resourceId.split('.')[0], req.file).then(() => {
+		})
+		.then(() => data.put(resourceId.split('.')[0], req.file))
+		.then(() => {
 			// Log the upload
 			const logInfo = `${req.file.originalname} (${req.file.mimetype}, ${formatBytes(req.file.size)})`;
 			log.success('File uploaded', logInfo, `uploaded by ${users[req.token] ? users[req.token].username : '<token-only>'}`);