Merge pull request #507 from calzoneman/channel-store

Refactor channel storage to allow database store

NEWS.md

@@ -1,3 +1,22 @@
+2015-10-04
+==========
+
+  * The channel data storage system has been refactored a bit.  For
+    compatibility, the default remains to store JSON objects for each channel in
+    the `chandump` folder, however there is now also the option of storing
+    channel data in the database.  You can take advantage of this by setting
+    `channel-storage: type: 'database'` in your `config.yaml`.
+    - In order to migrate existing channel data from the `chandump` files to the
+      database, run `node lib/channel-storage/migrate.js`.
+  * The database storage method uses foreign keys to associate the channel data
+    with the corresponding row in the `channels` table.  This requires that the
+    tables be stored using the InnoDB engine rather than MyISAM.  If your CyTube
+    tables defaulted to MyISAM, you can fix them by running
+
+    ```sql
+    ALTER TABLE `channels` ENGINE = InnoDB;
+    ```
+
 2015-09-21
 ==========
 

config.template.yaml

@@ -219,3 +219,13 @@ setuid:
   user: 'user'
 # how long to wait in ms before changing uid/gid
   timeout: 15
+
+# Determines channel data storage mechanism.
+# Defaults to 'file', in which channel data is JSON stringified and saved to a file
+# in the `chandump/` folder.  This is the legacy behavior of CyTube.
+# The other possible option is 'database', in which case each key-value pair of
+# channel data is stored as a row in the `channel_data` database table.
+# To migrate legacy chandump files to the database, shut down CyTube (to prevent
+# concurrent updates), then run `node lib/channel-storage/migrate.js`.
+channel-storage:
+  type: 'file'

package.json

@@ -2,7 +2,7 @@
   "author": "Calvin Montgomery",
   "name": "CyTube",
   "description": "Online media synchronizer and chat",
-  "version": "3.10.0",
+  "version": "3.11.0",
   "repository": {
     "url": "http://github.com/calzoneman/sync"
   },
@@ -10,10 +10,12 @@
   "dependencies": {
     "babel": "^5.8.23",
     "bcrypt": "^0.8.5",
+    "bluebird": "^2.10.1",
     "body-parser": "^1.14.0",
     "cheerio": "^0.19.0",
     "compression": "^1.5.2",
     "cookie-parser": "^1.4.0",
+    "create-error": "^0.3.1",
     "csrf": "^3.0.0",
     "cytube-mediaquery": "git://github.com/CyTube/mediaquery",
     "cytubefilters": "git://github.com/calzoneman/cytubefilters#095b7956",
@@ -37,9 +39,9 @@
   },
   "scripts": {
     "build-player": "$npm_node_execpath build-player.js",
-    "build-server": "babel --source-maps --out-dir lib/ src/",
+    "build-server": "babel --source-maps --loose es6.destructuring,es6.forOf --out-dir lib/ src/",
     "postinstall": "./postinstall.sh",
-    "server-dev": "babel --watch --source-maps --out-dir lib/ src/"
+    "server-dev": "babel --watch --source-maps --loose es6.destructuring,es6.forOf --out-dir lib/ src/"
   },
   "devDependencies": {
     "coffee-script": "^1.9.2"

src/bgtask.js

@@ -64,7 +64,9 @@ function initChannelDumper(Server) {
         for (var i = 0; i < Server.channels.length; i++) {
             var chan = Server.channels[i];
             if (!chan.dead && chan.users && chan.users.length > 0) {
-                chan.saveState();
+                chan.saveState().catch(err => {
+                    Logger.errlog.log(`Failed to save /r/${chan.name}: ${err.stack}`);
+                });
             }
         }
     }, CHANNEL_SAVE_INTERVAL);

src/channel-storage/channelstore.js

@@ -0,0 +1,36 @@
+import { FileStore } from './filestore';
+import { DatabaseStore } from './dbstore';
+import Config from '../config';
+import Promise from 'bluebird';
+
+var CHANNEL_STORE = null;
+
+export function init() {
+    CHANNEL_STORE = loadChannelStore();
+}
+
+export function load(channelName) {
+    if (CHANNEL_STORE === null) {
+        return Promise.reject(new Error('ChannelStore not initialized yet'));
+    }
+
+    return CHANNEL_STORE.load(channelName);
+}
+
+export function save(channelName, data) {
+    if (CHANNEL_STORE === null) {
+        return Promise.reject(new Error('ChannelStore not initialized yet'));
+    }
+
+    return CHANNEL_STORE.save(channelName, data);
+}
+
+function loadChannelStore() {
+    switch (Config.get('channel-storage.type')) {
+        case 'database':
+            return new DatabaseStore();
+        case 'file':
+        default:
+            return new FileStore();
+    }
+}

src/channel-storage/dbstore.js

@@ -0,0 +1,91 @@
+import Promise from 'bluebird';
+import { ChannelStateSizeError,
+         ChannelNotFoundError } from '../errors';
+import db from '../database';
+import Logger from '../logger';
+
+const SIZE_LIMIT = 1048576;
+const QUERY_CHANNEL_ID_FOR_NAME = 'SELECT id FROM channels WHERE name = ?';
+const QUERY_CHANNEL_DATA = 'SELECT `key`, `value` FROM channel_data WHERE channel_id = ?';
+
+function queryAsync(query, substitutions) {
+    return new Promise((resolve, reject) => {
+        db.query(query, substitutions, (err, res) => {
+            if (err) {
+                if (!(err instanceof Error)) {
+                    err = new Error(err);
+                }
+                reject(err);
+            } else {
+                resolve(res);
+            }
+        });
+    });
+}
+
+function buildUpdateQuery(numEntries) {
+    const values = [];
+    for (let i = 0; i < numEntries; i++) {
+        values.push('(?, ?, ?)');
+    }
+
+    return `INSERT INTO channel_data VALUES ${values.join(', ')} ` +
+           'ON DUPLICATE KEY UPDATE `value` = VALUES(`value`)';
+}
+
+export class DatabaseStore {
+    load(channelName) {
+        return queryAsync(QUERY_CHANNEL_ID_FOR_NAME, [channelName]).then((rows) => {
+            if (rows.length === 0) {
+                throw new ChannelNotFoundError(`Channel does not exist: "${channelName}"`);
+            }
+
+            return queryAsync(QUERY_CHANNEL_DATA, [rows[0].id]);
+        }).then(rows => {
+            const data = {};
+            rows.forEach(row => {
+                try {
+                    data[row.key] = JSON.parse(row.value);
+                } catch (e) {
+                    Logger.errlog.log(`Channel data for channel "${channelName}", ` +
+                            `key "${row.key}" is invalid: ${e}`);
+                }
+            });
+
+            return data;
+        });
+    }
+
+    save(channelName, data) {
+        return queryAsync(QUERY_CHANNEL_ID_FOR_NAME, [channelName]).then((rows) => {
+            if (rows.length === 0) {
+                throw new ChannelNotFoundError(`Channel does not exist: "${channelName}"`);
+            }
+
+            let totalSize = 0;
+            let rowCount = 0;
+            const id = rows[0].id;
+            const substitutions = [];
+            for (const key in data) {
+                if (typeof data[key] === 'undefined') {
+                    continue;
+                }
+                rowCount++;
+                const value = JSON.stringify(data[key]);
+                totalSize += value.length;
+                substitutions.push(id);
+                substitutions.push(key);
+                substitutions.push(value);
+            }
+
+            if (totalSize > SIZE_LIMIT) {
+                throw new ChannelStateSizeError('Channel state size is too large', {
+                    limit: SIZE_LIMIT,
+                    actual: totalSize
+                });
+            }
+
+            return queryAsync(buildUpdateQuery(rowCount), substitutions);
+        });
+    }
+}

src/channel-storage/filestore.js

@@ -0,0 +1,56 @@
+import * as Promise from 'bluebird';
+import { stat } from 'fs';
+import * as fs from 'graceful-fs';
+import path from 'path';
+import { ChannelStateSizeError } from '../errors';
+
+const readFileAsync = Promise.promisify(fs.readFile);
+const writeFileAsync = Promise.promisify(fs.writeFile);
+const readdirAsync = Promise.promisify(fs.readdir);
+const statAsync = Promise.promisify(stat);
+const SIZE_LIMIT = 1048576;
+const CHANDUMP_DIR = path.resolve(__dirname, '..', '..', 'chandump');
+
+export class FileStore {
+    filenameForChannel(channelName) {
+        return path.join(CHANDUMP_DIR, channelName);
+    }
+
+    load(channelName) {
+        const filename = this.filenameForChannel(channelName);
+        return statAsync(filename).then(stats => {
+            if (stats.size > SIZE_LIMIT) {
+                throw new ChannelStateSizeError('Channel state file is too large', {
+                    limit: SIZE_LIMIT,
+                    actual: stats.size
+                });
+            } else {
+                return readFileAsync(filename);
+            }
+        }).then(fileContents => {
+            try {
+                return JSON.parse(fileContents);
+            } catch (e) {
+                throw new Error('Channel state file is not valid JSON: ' + e);
+            }
+        });
+    }
+
+    save(channelName, data) {
+        const filename = this.filenameForChannel(channelName);
+        const fileContents = new Buffer(JSON.stringify(data), 'utf8');
+        if (fileContents.length > SIZE_LIMIT) {
+            return Promise.reject(new ChannelStateSizeError(
+                    'Channel state size is too large', {
+                        limit: SIZE_LIMIT,
+                        actual: fileContents.length
+                    }));
+        }
+
+        return writeFileAsync(filename, fileContents);
+    }
+
+    listChannels() {
+        return readdirAsync(CHANDUMP_DIR);
+    }
+}

src/channel-storage/migrator.js

@@ -0,0 +1,164 @@
+import Config from '../config';
+import Promise from 'bluebird';
+import db from '../database';
+import { FileStore } from './filestore';
+import { DatabaseStore } from './dbstore';
+import { sanitizeHTML } from '../xss';
+import { ChannelNotFoundError } from '../errors';
+
+const QUERY_CHANNEL_NAMES = 'SELECT name FROM channels WHERE 1';
+const EXPECTED_KEYS = [
+    'chatbuffer',
+    'chatmuted',
+    'css',
+    'emotes',
+    'filters',
+    'js',
+    'motd',
+    'openPlaylist',
+    'opts',
+    'permissions',
+    'playlist',
+    'poll'
+];
+
+function queryAsync(query, substitutions) {
+    return new Promise((resolve, reject) => {
+        db.query(query, substitutions, (err, res) => {
+            if (err) {
+                if (!(err instanceof Error)) {
+                    err = new Error(err);
+                }
+                reject(err);
+            } else {
+                resolve(res);
+            }
+        });
+    });
+}
+
+function fixOldChandump(data) {
+    const converted = {};
+    EXPECTED_KEYS.forEach(key => {
+        converted[key] = data[key];
+    });
+
+    if (data.queue) {
+        converted.playlist = {
+            pl: data.queue.map(item => {
+                return {
+                    media: {
+                        id: item.id,
+                        title: item.title,
+                        seconds: item.seconds,
+                        duration: item.duration,
+                        type: item.type,
+                        meta: {}
+                    },
+                    queueby: item.queueby,
+                    temp: item.temp
+                };
+            }),
+            pos: data.position,
+            time: data.currentTime
+        };
+    }
+
+    if (data.hasOwnProperty('openqueue')) {
+        converted.openPlaylist = data.openqueue;
+    }
+
+    if (data.hasOwnProperty('playlistLock')) {
+        converted.openPlaylist = !data.playlistLock;
+    }
+
+    if (data.chatbuffer) {
+        converted.chatbuffer = data.chatbuffer.map(entry => {
+            return {
+                username: entry.username,
+                msg: entry.msg,
+                meta: entry.meta || {
+                    addClass: entry.msgclass ? entry.msgclass : undefined
+                },
+                time: entry.time
+            };
+        });
+    }
+
+    if (data.motd && data.motd.motd) {
+        converted.motd = sanitizeHTML(data.motd.motd).replace(/\n/g, '<br>\n');
+    }
+
+    if (data.opts && data.opts.customcss) {
+        converted.opts.externalcss = data.opts.customcss;
+    }
+
+    if (data.opts && data.opts.customjs) {
+        converted.opts.externaljs = data.opts.customjs;
+    }
+
+    if (data.filters && data.filters.length > 0 && Array.isArray(data.filters[0])) {
+        converted.filters = data.filters.map(filter => {
+            let [source, replace, active] = filter;
+            return {
+                source: source,
+                replace: replace,
+                flags: 'g',
+                active: active,
+                filterlinks: false
+            };
+        });
+    }
+
+    return converted;
+}
+
+function migrate(src, dest) {
+    return src.listChannels().then(names => {
+        return Promise.reduce(names, (_, name) => {
+            // A long time ago there was a bug where CyTube would save a different
+            // chandump depending on the capitalization of the channel name in the URL.
+            // This was fixed, but there are still some really old chandumps with
+            // uppercase letters in the name.
+            //
+            // If another chandump exists which is all lowercase, then that one is
+            // canonical.  Otherwise, it's safe to load the existing capitalization,
+            // convert it, and save.
+            if (name !== name.toLowerCase()) {
+                if (names.indexOf(name.toLowerCase()) >= 0) {
+                    return Promise.resolve();
+                }
+            }
+
+            return src.load(name).then(data => {
+                data = fixOldChandump(data);
+                return dest.save(name, data);
+            }).then(() => {
+                console.log(`Migrated /r/${name}`);
+            }).catch(ChannelNotFoundError, err => {
+                console.log(`Skipping /r/${name} (not present in the database)`);
+            }).catch(err => {
+                console.error(`Failed to migrate /r/${name}: ${err.stack}`);
+            });
+        });
+    });
+}
+
+function main() {
+    Config.load('config.yaml');
+    db.init();
+    const src = new FileStore();
+    const dest = new DatabaseStore();
+
+    Promise.delay(1000).then(() => {
+        return migrate(src, dest);
+    }).then(() => {
+        console.log('Migration complete');
+        process.exit(0);
+    }).catch(err => {
+        console.error(`Migration failed: ${err.stack}`);
+        process.exit(1);
+    });
+}
+
+main();

src/channel/channel.js

@@ -8,8 +8,9 @@ var fs = require("graceful-fs");
 var path = require("path");
 var sio = require("socket.io");
 var db = require("../database");
-
-const SIZE_LIMIT = 1048576;
+import * as ChannelStore from '../channel-storage/channelstore';
+import { ChannelStateSizeError } from '../errors';
+import Promise from 'bluebird';
 
 /**
  * Previously, async channel functions were riddled with race conditions due to
@@ -150,17 +151,15 @@ Channel.prototype.getDiskSize = function (cb) {
 };
 
 Channel.prototype.loadState = function () {
-    var self = this;
-    var file = path.join(__dirname, "..", "..", "chandump", self.uniqueName);
-
     /* Don't load from disk if not registered */
-    if (!self.is(Flags.C_REGISTERED)) {
-        self.modules.permissions.loadUnregistered();
-        self.setFlag(Flags.C_READY);
+    if (!this.is(Flags.C_REGISTERED)) {
+        this.modules.permissions.loadUnregistered();
+        this.setFlag(Flags.C_READY);
         return;
     }
 
-    var errorLoad = function (msg) {
+    const self = this;
+    function errorLoad(msg) {
         if (self.modules.customization) {
             self.modules.customization.load({
                 motd: msg
@@ -168,100 +167,69 @@ Channel.prototype.loadState = function () {
         }
 
         self.setFlag(Flags.C_READY | Flags.C_ERROR);
-    };
+    }
 
-    fs.stat(file, function (err, stats) {
-        if (!err) {
-            var mb = stats.size / 1048576;
-            mb = Math.floor(mb * 100) / 100;
-            if (mb > SIZE_LIMIT / 1048576) {
-                Logger.errlog.log("Large chandump detected: " + self.uniqueName +
-                                  " (" + mb + " MiB)");
-                var msg = "This channel's state size has exceeded the memory limit " +
-                          "enforced by this server.  Please contact an administrator " +
-                          "for assistance.";
-                errorLoad(msg);
-                return;
-            }
-        }
-        continueLoad();
-    });
-
-    var continueLoad = function () {
-        fs.readFile(file, function (err, data) {
-            if (err) {
-                /* ENOENT means the file didn't exist.  This is normal for new channels */
-                if (err.code === "ENOENT") {
-                    self.setFlag(Flags.C_READY);
-                    Object.keys(self.modules).forEach(function (m) {
-                        self.modules[m].load({});
-                    });
-                } else {
-                    Logger.errlog.log("Failed to open channel dump " + self.uniqueName);
-                    Logger.errlog.log(err);
-                    errorLoad("Unknown error occurred when loading channel state.  " +
-                              "Contact an administrator for assistance.");
-                }
-                return;
-            }
-
-            self.logger.log("[init] Loading channel state from disk");
+    ChannelStore.load(this.uniqueName).then(data => {
+        Object.keys(this.modules).forEach(m => {
             try {
-                data = JSON.parse(data);
-                Object.keys(self.modules).forEach(function (m) {
-                    self.modules[m].load(data);
-                });
-                self.setFlag(Flags.C_READY);
+                this.modules[m].load(data);
             } catch (e) {
-                Logger.errlog.log("Channel dump for " + self.uniqueName + " is not " +
-                                  "valid");
-                Logger.errlog.log(e);
-                errorLoad("Unknown error occurred when loading channel state.  Contact " +
-                          "an administrator for assistance.");
+                Logger.errlog.log("Failed to load module " + m + " for channel " +
+                        this.uniqueName);
             }
         });
-    };
+        this.setFlag(Flags.C_READY);
+    }).catch(ChannelStateSizeError, err => {
+        const message = "This channel's state size has exceeded the memory limit " +
+                "enforced by this server.  Please contact an administrator " +
+                "for assistance.";
+
+        Logger.errlog.log(err.stack);
+        errorLoad(message);
+    }).catch(err => {
+        if (err.code === 'ENOENT') {
+            Object.keys(this.modules).forEach(m => {
+                this.modules[m].load({});
+            });
+            this.setFlag(Flags.C_READY);
+            return;
+        } else {
+            const message = "An error occurred when loading this channel's data from " +
+                    "disk.  Please contact an administrator for assistance.  " +
+                    `The error was: ${err}`;
+
+            Logger.errlog.log(err.stack);
+            errorLoad(message);
+        }
+    });
 };
 
 Channel.prototype.saveState = function () {
-    var self = this;
-    var file = path.join(__dirname, "..", "..", "chandump", self.uniqueName);
-
-    /**
-     * Don't overwrite saved state data if the current state is dirty,
-     * or if this channel is unregistered
-     */
-    if (self.is(Flags.C_ERROR) || !self.is(Flags.C_REGISTERED)) {
-        return;
+    if (!this.is(Flags.C_REGISTERED)) {
+        return Promise.resolve();
     }
 
-    self.logger.log("[init] Saving channel state to disk");
-    var data = {};
-    Object.keys(this.modules).forEach(function (m) {
-        self.modules[m].save(data);
+    if (this.is(Flags.C_ERROR)) {
+        return Promise.reject(new Error(`Channel is in error state`));
+    }
+
+    this.logger.log("[init] Saving channel state to disk");
+    const data = {};
+    Object.keys(this.modules).forEach(m => {
+        this.modules[m].save(data);
     });
 
-    var json = JSON.stringify(data);
-    /**
-     * Synchronous on purpose.
-     * When the server is shutting down, saveState() is called on all channels and
-     * then the process terminates.  Async writeFile causes a race condition that wipes
-     * channels.
-     */
-    var err = fs.writeFileSync(file, json);
+    return ChannelStore.save(this.uniqueName, data).catch(ChannelStateSizeError, err => {
+        this.users.forEach(u => {
+            if (u.account.effectiveRank >= 2) {
+                u.socket.emit("warnLargeChandump", {
+                    limit: err.limit,
+                    actual: err.actual
+                });
+            }
+        });
 
-    // Check for large chandump and warn moderators/admins
-    self.getDiskSize(function (err, size) {
-        if (!err && size > SIZE_LIMIT && self.users) {
-            self.users.forEach(function (u) {
-                if (u.account.effectiveRank >= 2) {
-                    u.socket.emit("warnLargeChandump", {
-                        limit: SIZE_LIMIT,
-                        actual: size
-                    });
-                }
-            });
-        }
+        throw err;
     });
 };
 

src/config.js

@@ -110,6 +110,9 @@ var defaults = {
         "user": "nobody",
         "timeout": 15
     },
+    "channel-storage": {
+        type: "file"
+    }
 };
 
 /**

src/database.js

@@ -556,6 +556,11 @@ module.exports.listStats = function (callback) {
 
 /* Misc */
 module.exports.loadAnnouncement = function () {
+    // Temporary workaround
+    if (!Server.getServer || !Server.getServer()) {
+        return;
+    }
+
     var query = "SELECT * FROM `meta` WHERE `key`='announcement'";
     module.exports.query(query, function (err, rows) {
         if (err) {

src/database/tables.js

@@ -104,6 +104,15 @@ const TBL_BANS = "" +
     "INDEX (`ip`, `channel`), INDEX (`name`, `channel`)" +
     ") CHARACTER SET utf8";
 
+const TBL_CHANNEL_DATA = "" +
+    "CREATE TABLE IF NOT EXISTS `channel_data` (" +
+        "`channel_id` INT NOT NULL," +
+        "`key` VARCHAR(20) NOT NULL," +
+        "`value` MEDIUMTEXT CHARACTER SET utf8mb4 NOT NULL," +
+    "PRIMARY KEY (`channel_id`, `key`)," +
+    "FOREIGN KEY (`channel_id`) REFERENCES `channels`(`id`) ON DELETE CASCADE" +
+    ") CHARACTER SET utf8";
+
 module.exports.init = function (queryfn, cb) {
     var tables = {
         users: TBL_USERS,
@@ -116,7 +125,8 @@ module.exports.init = function (queryfn, cb) {
         user_playlists: TBL_USER_PLAYLISTS,
         aliases: TBL_ALIASES,
         stats: TBL_STATS,
-        meta: TBL_META
+        meta: TBL_META,
+        channel_data: TBL_CHANNEL_DATA
     };
 
     var AsyncQueue = require("../asyncqueue");

src/errors.js

@@ -0,0 +1,4 @@
+import createError from 'create-error';
+
+export const ChannelStateSizeError = createError('ChannelStateSizeError');
+export const ChannelNotFoundError = createError('ChannelNotFoundError');

src/server.js

@@ -1,6 +1,8 @@
 const VERSION = require("../package.json").version;
 var singleton = null;
 var Config = require("./config");
+var Promise = require("bluebird");
+import * as ChannelStore from './channel-storage/channelstore';
 
 module.exports = {
     init: function () {
@@ -55,6 +57,7 @@ var Server = function () {
     var Database = require("./database");
     self.db = Database;
     self.db.init();
+    ChannelStore.init();
 
     // webserver init -----------------------------------------------------
     self.express = express();
@@ -226,13 +229,18 @@ Server.prototype.announce = function (data) {
 
 Server.prototype.shutdown = function () {
     Logger.syslog.log("Unloading channels");
-    for (var i = 0; i < this.channels.length; i++) {
-        if (this.channels[i].is(Flags.C_REGISTERED)) {
-            Logger.syslog.log("Saving /r/" + this.channels[i].name);
-            this.channels[i].saveState();
-        }
-    }
-    Logger.syslog.log("Goodbye");
-    process.exit(0);
+    Promise.map(this.channels, channel => {
+        return channel.saveState().tap(() => {
+            Logger.syslog.log(`Saved /r/${channel.name}`);
+        }).catch(err => {
+            Logger.errlog.log(`Failed to save /r/${channel.name}: ${err.stack}`);
+        });
+    }).then(() => {
+        Logger.syslog.log("Goodbye");
+        process.exit(0);
+    }).catch(err => {
+        Logger.errlog.log(`Caught error while saving channels: ${err.stack}`);
+        process.exit(1);
+    });
 };
 

www/js/callbacks.js

@@ -1072,8 +1072,9 @@ Callbacks = {
         errDialog("This channel currently exceeds the maximum size of " +
             toHumanReadable(data.limit) + " (channel size is " +
             toHumanReadable(data.actual) + ").  Please reduce the size by removing " +
-            "unneeded playlist items, filters, and/or emotes or else the channel will " +
-            "be unable to load the next time it is reloaded").attr("id", "chandumptoobig");
+            "unneeded playlist items, filters, and/or emotes.  Changes to the channel " +
+            "will not be saved until the size is reduced to under the limit.")
+            .attr("id", "chandumptoobig");
     }
 }