Start refactoring channel storage

src/channel-storage/channelstore.js

@@ -0,0 +1,11 @@
+import { FileStore } from './filestore';
+
+var CHANNEL_STORE = new FileStore();
+
+export function load(channelName) {
+    return CHANNEL_STORE.load(channelName);
+}
+
+export function save(channelName, data) {
+    return CHANNEL_STORE.save(channelName, data);
+}

src/channel-storage/filestore.js

@@ -0,0 +1,46 @@
+import * as Promise from 'bluebird';
+import { stat } from 'fs';
+import * as fs from 'graceful-fs';
+import path from 'path';
+
+const readFileAsync = Promise.promisify(fs.readFile);
+const writeFileAsync = Promise.promisify(fs.writeFile);
+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 Error('Channel state file is too large: ' + 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) {
+            let error = new Error('Channel state size is too large');
+            error.limit = SIZE_LIMIT;
+            error.size = fileContents.length;
+            return Promise.reject(error);
+        }
+
+        return writeFileAsync(filename, fileContents);
+    }
+}

src/channel/channel.js

@@ -8,6 +8,8 @@ var fs = require("graceful-fs");
 var path = require("path");
 var sio = require("socket.io");
 var db = require("../database");
+var ChannelStore = require("../channel-storage/channelstore");
+var Promise = require("bluebird");
 
 const SIZE_LIMIT = 1048576;
 
@@ -150,17 +152,15 @@ 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
@@ -168,99 +168,73 @@ 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(err => {
+        if (err.code === 'ENOENT') {
+            Object.keys(this.modules).forEach(m => {
+                this.modules[m].load({});
+            });
+            this.setFlag(Flags.C_READY);
+            return;
+        }
+
+        let message;
+        if (/Channel state file is too large/.test(err.message)) {
+            message = "This channel's state size has exceeded the memory limit " +
+                    "enforced by this server.  Please contact an administrator " +
+                    "for assistance.";
+        } else {
+            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);
-
-    // 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) {
+    return ChannelStore.save(this.uniqueName, data).catch(err => {
+        if (/Channel state size is too large/.test(err.message)) {
+            this.users.forEach(u => {
                 if (u.account.effectiveRank >= 2) {
                     u.socket.emit("warnLargeChandump", {
-                        limit: SIZE_LIMIT,
-                        actual: size
+                        limit: err.limit,
+                        actual: err.size
                     });
                 }
             });
+
+            Logger.errlog.log(`Not saving ${this.uniqueName} because it exceeds ` +
+                    "the size limit");
+        } else {
+            Logger.errlog.log(`Failed to save ${this.uniqueName}: ${err.stack}`);
         }
     });
 };

src/server.js

@@ -1,6 +1,7 @@
 const VERSION = require("../package.json").version;
 var singleton = null;
 var Config = require("./config");
+var Promise = require("bluebird");
 
 module.exports = {
     init: function () {
@@ -226,13 +227,15 @@ 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);
+    });
 };
 

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");
     }
 }