Add name_dedupe column instead of using LIKE kludge for similar-looking names

package.json

@@ -2,7 +2,7 @@
   "author": "Calvin Montgomery",
   "name": "CyTube",
   "description": "Online media synchronizer and chat",
-  "version": "3.31.0",
+  "version": "3.32.0",
   "repository": {
     "url": "http://github.com/calzoneman/sync"
   },

src/database.js

@@ -48,6 +48,7 @@ module.exports.init = function () {
     global_ipbans = {};
     module.exports.users = require("./database/accounts");
     module.exports.channels = require("./database/channels");
+    module.exports.pool = pool;
 };
 
 /**

src/database/accounts.js

@@ -7,15 +7,6 @@ var Logger = require("../logger");
 var registrationLock = {};
 var blackHole = function () { };
 
-/**
- * Replaces look-alike characters with "_" (single character wildcard) for
- * use in LIKE queries.  This prevents guests from taking names that look
- * visually identical to existing names in certain fonts.
- */
-function wildcardSimilarChars(name) {
-    return name.replace(/_/g, "\\_").replace(/[Il1oO0]/g, "_");
-}
-
 function parseProfile(data) {
     try {
         var profile = JSON.parse(data.profile);
@@ -31,12 +22,23 @@ module.exports = {
     init: function () {
     },
 
+    /**
+     * Convert a username for deduplication purposes.
+     * Collapses visibily similar characters into a single character.
+     * @param name
+     */
+    dedupeUsername: function dedupeUsername(name) {
+        return name.replace(/[Il1]/ig, '1')
+            .replace(/[o0]/ig, '0')
+            .replace(/[_-]/g, '_');
+    },
+
     /**
      * Check if a username is taken
      */
     isUsernameTaken: function (name, callback) {
-        db.query("SELECT name FROM `users` WHERE name LIKE ? ESCAPE '\\\\'",
+        db.query("SELECT name FROM `users` WHERE name = ? or name_dedupe = ?",
-                 [wildcardSimilarChars(name)],
+                 [name, module.exports.dedupeUsername(name)],
         function (err, rows) {
             if (err) {
                 callback(err, true);
@@ -175,10 +177,10 @@ module.exports = {
                     }
 
                     db.query("INSERT INTO `users` " +
-                             "(`name`, `password`, `global_rank`, `email`, `profile`, `ip`, `time`)" +
+                             "(`name`, `password`, `global_rank`, `email`, `profile`, `ip`, `time`, `name_dedupe`)" +
                              " VALUES " +
-                             "(?, ?, ?, ?, '', ?, ?)",
+                             "(?, ?, ?, ?, '', ?, ?, ?)",
-                             [name, hash, 1, email, ip, Date.now()],
+                             [name, hash, 1, email, ip, Date.now(), module.exports.dedupeUsername(name)],
                     function (err, res) {
                         delete registrationLock[lname];
                         if (err) {

src/database/tables.js

@@ -8,8 +8,10 @@ const TBL_USERS = "" +
         "`profile` TEXT CHARACTER SET utf8mb4 NOT NULL," +
         "`ip` VARCHAR(39) NOT NULL," +
         "`time` BIGINT NOT NULL," +
+        "`name_dedupe` VARCHAR(20) DEFAULT NULL," +
         "PRIMARY KEY(`id`)," +
-        "UNIQUE(`name`)) " +
+        "UNIQUE(`name`)," +
+        "UNIQUE(`name_dedupe`)) " +
     "CHARACTER SET utf8";
 
 const TBL_CHANNELS = "" +

src/database/update.js

@@ -1,8 +1,9 @@
 var db = require("../database");
 var Logger = require("../logger");
 var Q = require("q");
+import Promise from 'bluebird';
 
-const DB_VERSION = 7;
+const DB_VERSION = 9;
 var hasUpdates = [];
 
 module.exports.checkVersion = function () {
@@ -58,6 +59,10 @@ function update(version, cb) {
         fixCustomEmbeds(cb);
     } else if (version < 7) {
         fixCustomEmbedsInUserPlaylists(cb);
+    } else if (version < 8) {
+        addUsernameDedupeColumn(cb);
+    } else if (version < 9) {
+        populateUsernameDedupeColumn(cb);
     }
 }
 
@@ -330,3 +335,56 @@ function fixCustomEmbedsInUserPlaylists(cb) {
             Logger.errlog.log(err.stack);
         });
 }
+
+function addUsernameDedupeColumn(cb) {
+    Logger.syslog.log("Adding name_dedupe column on the users table");
+    db.query("ALTER TABLE users ADD COLUMN name_dedupe VARCHAR(20) UNIQUE DEFAULT NULL", (error) => {
+        if (error) {
+            Logger.errlog.log(`Unable to add name_dedupe column: ${error}`);
+        } else {
+            cb();
+        }
+    });
+}
+
+function populateUsernameDedupeColumn(cb) {
+    const dbUsers = require("./accounts");
+    Logger.syslog.log("Populating name_dedupe column on the users table");
+    db.query("SELECT id, name FROM users WHERE name_dedupe IS NULL", (err, rows) => {
+        if (err) {
+            Logger.errlog.log("Unable to perform database upgrade to add dedupe column: " + err);
+            return;
+        }
+
+        Promise.map(rows, row => {
+            return new Promise((resolve, reject) => {
+                db.pool.getConnection((error, conn) => {
+                    if (error) {
+                        reject(error);
+                        return;
+                    }
+
+                    const dedupedName = dbUsers.dedupeUsername(row.name);
+                    Logger.syslog.log(`Deduping [${row.name}] as [${dedupedName}]`);
+                    conn.query("UPDATE users SET name_dedupe = ? WHERE id = ?", [dedupedName, row.id], (error, res) => {
+                        conn.release();
+                        if (error) {
+                            if (error.errno === 1062) {
+                                Logger.syslog.log(`WARNING: could not set name_dedupe for [${row.name}] due to an existing row for [${dedupedName}]`);
+                                resolve();
+                            } else {
+                                reject(error);
+                            }
+                        } else {
+                            resolve();
+                        }
+                    });
+                });
+            });
+        }, { concurrency: 10 }).then(() => {
+            cb();
+        }).catch(error => {
+            Logger.errlog.log("Unable to perform database upgrade to add dedupe column: " + (error.stack ? error.stack : error));
+        })
+    });
+}