Server refactor, cursor update broadcast, history compaction

This commit is contained in:
Zef Hemel
2022-03-10 14:09:59 +01:00
parent 7ae3496749
commit 5c5e232034
14 changed files with 577 additions and 423 deletions
+1
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@@ -13,6 +13,7 @@
"dependencies": {
"@codemirror/collab": "^0.19.0",
"@codemirror/state": "^0.19.9",
"body-parser": "^1.19.2",
"cors": "^2.8.5",
"express": "^4.17.3",
"socket.io": "^4.4.1",
+79
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@@ -0,0 +1,79 @@
import { readdir, readFile, stat, unlink, writeFile } from "fs/promises";
import path from "path";
import { PageMeta, pagesPath } from "./server";
export class DiskStorage {
rootPath: string;
constructor(rootPath: string) {
this.rootPath = rootPath;
}
async listPages(): Promise<PageMeta[]> {
let fileNames: PageMeta[] = [];
let _this = this;
async function walkPath(dir: string) {
let files = await readdir(dir);
for (let file of files) {
const fullPath = path.join(dir, file);
let s = await stat(fullPath);
if (s.isDirectory()) {
await walkPath(fullPath);
} else {
if (path.extname(file) === ".md") {
fileNames.push({
name: fullPath.substring(
_this.rootPath.length + 1,
fullPath.length - 3
),
lastModified: s.mtime.getTime(),
});
}
}
}
}
await walkPath(this.rootPath);
return fileNames;
}
async readPage(pageName: string): Promise<{ text: string; meta: PageMeta }> {
const localPath = path.join(pagesPath, pageName + ".md");
const s = await stat(localPath);
return {
text: await readFile(localPath, "utf8"),
meta: {
name: pageName,
lastModified: s.mtime.getTime(),
},
};
}
async writePage(pageName: string, text: string): Promise<PageMeta> {
let localPath = path.join(pagesPath, pageName + ".md");
// await pipeline(body, fs.createWriteStream(localPath));
await writeFile(localPath, text);
// console.log(`Wrote to ${localPath}`);
const s = await stat(localPath);
return {
name: pageName,
lastModified: s.mtime.getTime(),
};
}
async getPageMeta(pageName: string): Promise<PageMeta> {
let localPath = path.join(pagesPath, pageName + ".md");
const s = await stat(localPath);
return {
name: pageName,
lastModified: s.mtime.getTime(),
};
}
async deletePage(pageName: string) {
let localPath = path.join(pagesPath, pageName + ".md");
await unlink(localPath);
}
}
+253
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@@ -0,0 +1,253 @@
import fs from "fs";
import { stat } from "fs/promises";
import path from "path";
import { ChangeSet } from "@codemirror/state";
import { Update } from "@codemirror/collab";
import { Server } from "socket.io";
import { Cursor, cursorEffect } from "../../webapp/src/cursorEffect";
import { Socket } from "socket.io";
import { DiskStorage } from "./disk_storage";
import { PageMeta } from "./server";
import { Client, Page } from "./types";
import { safeRun } from "./util";
export class RealtimeStorage extends DiskStorage {
openPages = new Map<string, Page>();
private disconnectClient(client: Client, page: Page) {
page.clients.delete(client);
if (page.clients.size === 0) {
console.log("No more clients for", page.name, "flushing");
this.flushPageToDisk(page.name, page);
this.openPages.delete(page.name);
} else {
page.cursors.delete(client.socket.id);
this.broadcastCursors(page);
}
}
private broadcastCursors(page: Page) {
page.clients.forEach((client) => {
client.socket.emit("cursors", Object.fromEntries(page.cursors.entries()));
});
}
private flushPageToDisk(name: string, page: Page) {
super
.writePage(name, page.text.sliceString(0))
.then((meta) => {
console.log(`Wrote page ${name} to disk`);
page.meta = meta;
})
.catch((e) => {
console.log(`Could not write ${name} to disk:`, e);
});
}
// Override
async readPage(pageName: string): Promise<{ text: string; meta: PageMeta }> {
let page = this.openPages.get(pageName);
if (page) {
console.log("Serving page from memory", pageName);
return {
text: page.text.sliceString(0),
meta: page.meta,
};
} else {
return super.readPage(pageName);
}
}
async writePage(pageName: string, text: string): Promise<PageMeta> {
let page = this.openPages.get(pageName);
if (page) {
for (let client of page.clients) {
client.socket.emit("reload", pageName);
}
this.openPages.delete(pageName);
}
return super.writePage(pageName, text);
}
disconnectPageSocket(socket: Socket, pageName: string) {
let page = this.openPages.get(pageName);
if (page) {
for (let client of page.clients) {
if (client.socket === socket) {
this.disconnectClient(client, page);
}
}
}
}
constructor(rootPath: string, io: Server) {
super(rootPath);
// setInterval(() => {
// console.log("Currently open pages:", this.openPages.keys());
// }, 10000);
// Disk watcher
fs.watch(
rootPath,
{
recursive: true,
persistent: false,
},
(eventType, filename) => {
safeRun(async () => {
if (path.extname(filename) !== ".md") {
return;
}
let localPath = path.join(rootPath, filename);
let pageName = filename.substring(0, filename.length - 3);
let s = await stat(localPath);
// console.log("Edit in", pageName);
const openPage = this.openPages.get(pageName);
if (openPage) {
if (openPage.meta.lastModified < s.mtime.getTime()) {
console.log("Page changed on disk outside of editor, reloading");
this.openPages.delete(pageName);
for (let client of openPage.clients) {
client.socket.emit("reload", pageName);
}
}
}
});
}
);
io.on("connection", (socket) => {
console.log("Connected", socket.id);
let clientOpenPages = new Set<string>();
function onCall(eventName: string, cb: (...args: any[]) => Promise<any>) {
socket.on(eventName, (reqId: number, ...args) => {
cb(...args).then((result) => {
socket.emit(`${eventName}Resp${reqId}`, result);
});
});
}
onCall("openPage", async (pageName: string) => {
let page = this.openPages.get(pageName);
if (!page) {
try {
let { text, meta } = await super.readPage(pageName);
page = new Page(pageName, text, meta);
} catch (e) {
console.log("Creating new page", pageName);
page = new Page(pageName, "", { name: pageName, lastModified: 0 });
}
this.openPages.set(pageName, page);
}
page.clients.add(new Client(socket, page.version));
clientOpenPages.add(pageName);
console.log("Opened page", pageName);
this.broadcastCursors(page);
return page.toJSON();
});
socket.on("closePage", (pageName: string) => {
console.log("Closing page", pageName);
clientOpenPages.delete(pageName);
this.disconnectPageSocket(socket, pageName);
});
onCall(
"pushUpdates",
async (
pageName: string,
version: number,
updates: any[]
): Promise<boolean> => {
let page = this.openPages.get(pageName);
if (!page) {
console.error(
"Received updates for not open page",
pageName,
this.openPages.keys()
);
return;
}
if (version !== page.version) {
console.error("Invalid version", version, page.version);
return false;
} else {
console.log("Applying", updates.length, "updates");
let transformedUpdates = [];
let textChanged = false;
for (let update of updates) {
let changes = ChangeSet.fromJSON(update.changes);
let transformedUpdate = {
changes,
clientID: update.clientID,
effects: update.cursors?.map((c: Cursor) => {
page.cursors.set(c.userId, c);
return cursorEffect.of(c);
}),
};
page.updates.push(transformedUpdate);
transformedUpdates.push(transformedUpdate);
let oldText = page.text;
page.text = changes.apply(page.text);
if (oldText !== page.text) {
textChanged = true;
}
}
if (textChanged) {
if (page.saveTimer) {
clearTimeout(page.saveTimer);
}
page.saveTimer = setTimeout(() => {
this.flushPageToDisk(pageName, page);
}, 1000);
}
while (page.pending.length) {
page.pending.pop()!(transformedUpdates);
}
return true;
}
}
);
onCall(
"pullUpdates",
async (pageName: string, version: number): Promise<Update[]> => {
let page = this.openPages.get(pageName);
// console.log("Pulling updates for", pageName);
if (!page) {
console.error("Fetching updates for not open page");
return [];
}
// TODO: Optimize this
let oldestVersion = Infinity;
page.clients.forEach((client) => {
oldestVersion = Math.min(client.version, oldestVersion);
if (client.socket === socket) {
client.version = version;
}
});
page.flushUpdates(oldestVersion);
if (version < page.version) {
return page.updatesSince(version);
} else {
return new Promise((resolve) => {
page.pending.push(resolve);
});
}
}
);
socket.on("disconnect", () => {
console.log("Disconnected", socket.id);
clientOpenPages.forEach((pageName) => {
this.disconnectPageSocket(socket, pageName);
});
});
});
}
}
+11 -327
View File
@@ -1,24 +1,12 @@
import bodyParser from "body-parser";
import cors from "cors";
import express, { text } from "express";
import fs from "fs";
import { readdir, readFile, stat, unlink } from "fs/promises";
import path from "path";
import stream from "stream";
import { promisify } from "util";
import { debounce } from "lodash";
import { ChangeSet, Text } from "@codemirror/state";
import { Update } from "@codemirror/collab";
import express from "express";
import { readFile } from "fs/promises";
import http from "http";
import { Server } from "socket.io";
import { cursorEffect } from "../../webapp/src/cursorEffect";
function safeRun(fn: () => Promise<void>) {
fn().catch((e) => {
console.error(e);
});
}
import stream from "stream";
import { promisify } from "util";
import { RealtimeStorage } from "./realtime_storage";
const app = express();
const server = http.createServer(app);
@@ -31,324 +19,20 @@ const io = new Server(server, {
const port = 3000;
const pipeline = promisify(stream.pipeline);
const pagesPath = "../pages";
export const pagesPath = "../pages";
const distDir = `${__dirname}/../../webapp/dist`;
type PageMeta = {
export type PageMeta = {
name: string;
lastModified: number;
version?: number;
};
class DiskFS {
rootPath: string;
constructor(rootPath: string) {
this.rootPath = rootPath;
}
async listPages(): Promise<PageMeta[]> {
let fileNames: PageMeta[] = [];
let _this = this;
async function walkPath(dir: string) {
let files = await readdir(dir);
for (let file of files) {
const fullPath = path.join(dir, file);
let s = await stat(fullPath);
if (s.isDirectory()) {
await walkPath(fullPath);
} else {
if (path.extname(file) === ".md") {
fileNames.push({
name: fullPath.substring(
_this.rootPath.length + 1,
fullPath.length - 3
),
lastModified: s.mtime.getTime(),
});
}
}
}
}
await walkPath(this.rootPath);
return fileNames;
}
async readPage(pageName: string): Promise<{ text: string; meta: PageMeta }> {
const localPath = path.join(pagesPath, pageName + ".md");
const s = await stat(localPath);
return {
text: await readFile(localPath, "utf8"),
meta: {
name: pageName,
lastModified: s.mtime.getTime(),
},
};
}
async writePage(pageName: string, body: any): Promise<PageMeta> {
let localPath = path.join(pagesPath, pageName + ".md");
await pipeline(body, fs.createWriteStream(localPath));
// console.log(`Wrote to ${localPath}`);
const s = await stat(localPath);
return {
name: pageName,
lastModified: s.mtime.getTime(),
};
}
async getPageMeta(pageName: string): Promise<PageMeta> {
let localPath = path.join(pagesPath, pageName + ".md");
const s = await stat(localPath);
return {
name: pageName,
lastModified: s.mtime.getTime(),
};
}
async deletePage(pageName: string) {
let localPath = path.join(pagesPath, pageName + ".md");
await unlink(localPath);
}
}
import { Socket } from "socket.io";
class Page {
text: Text;
updates: Update[];
sockets: Set<Socket>;
meta: PageMeta;
pending: ((value: any) => void)[] = [];
saveTimer: NodeJS.Timeout | undefined;
constructor(text: string, meta: PageMeta) {
this.updates = [];
this.text = Text.of(text.split("\n"));
this.meta = meta;
this.sockets = new Set<Socket>();
}
}
class RealtimeEditFS extends DiskFS {
openPages = new Map<string, Page>();
disconnectSocket(socket: Socket, pageName: string) {
let page = this.openPages.get(pageName);
if (page) {
page.sockets.delete(socket);
if (page.sockets.size === 0) {
console.log("No more sockets for", pageName, "flushing");
this.flushPageToDisk(pageName, page);
this.openPages.delete(pageName);
}
}
}
flushPageToDisk(name: string, page: Page) {
super
.writePage(name, page.text.sliceString(0))
.then((meta) => {
console.log(`Wrote page ${name} to disk`);
page.meta = meta;
})
.catch((e) => {
console.log(`Could not write ${name} to disk:`, e);
});
}
// Override
async readPage(pageName: string): Promise<{ text: string; meta: PageMeta }> {
let page = this.openPages.get(pageName);
if (page) {
console.log("Serving page from memory", pageName);
return {
text: page.text.sliceString(0),
meta: page.meta,
};
} else {
return super.readPage(pageName);
}
}
async writePage(pageName: string, body: any): Promise<PageMeta> {
let page = this.openPages.get(pageName);
if (page) {
for (let socket of page.sockets) {
socket.emit("reload", pageName);
}
this.openPages.delete(pageName);
}
return super.writePage(pageName, body);
}
constructor(rootPath: string, io: Server) {
super(rootPath);
setInterval(() => {
console.log("Currently open pages:", this.openPages.keys());
}, 10000);
// Disk watcher
fs.watch(
rootPath,
{
recursive: true,
persistent: false,
},
(eventType, filename) => {
safeRun(async () => {
if (path.extname(filename) !== ".md") {
return;
}
let localPath = path.join(rootPath, filename);
let pageName = filename.substring(0, filename.length - 3);
let s = await stat(localPath);
// console.log("Edit in", pageName);
const openPage = this.openPages.get(pageName);
if (openPage) {
if (openPage.meta.lastModified < s.mtime.getTime()) {
console.log("Page changed on disk outside of editor, reloading");
for (let socket of openPage.sockets) {
socket.emit("reload", pageName);
}
this.openPages.delete(pageName);
}
}
});
}
);
io.on("connection", (socket) => {
console.log("Connected", socket.id);
let socketOpenPages = new Set<string>();
function onCall(eventName: string, cb: (...args: any[]) => Promise<any>) {
socket.on(eventName, (reqId: number, ...args) => {
cb(...args).then((result) => {
socket.emit(`${eventName}Resp${reqId}`, result);
});
});
}
onCall("openPage", async (pageName: string) => {
let page = this.openPages.get(pageName);
if (!page) {
try {
let { text, meta } = await super.readPage(pageName);
page = new Page(text, meta);
} catch (e) {
// console.log(`Could not open ${pageName}:`, e);
// Page does not exist, let's create a new one
console.log("Creating new page", pageName);
page = new Page("", { name: pageName, lastModified: 0 });
}
this.openPages.set(pageName, page);
}
page.sockets.add(socket);
socketOpenPages.add(pageName);
console.log("Opened page", pageName);
return [page.updates.length, page.text.toJSON()];
});
socket.on("closePage", (pageName: string) => {
console.log("Closing page", pageName);
this.disconnectSocket(socket, pageName);
socketOpenPages.delete(pageName);
});
onCall(
"pushUpdates",
async (
pageName: string,
version: number,
updates: any[]
): Promise<boolean> => {
let page = this.openPages.get(pageName);
if (!page) {
console.error(
"Received updates for not open page",
pageName,
this.openPages.keys()
);
return;
}
if (version !== page.updates.length) {
console.error("Invalid version", version, page.updates.length);
return false;
} else {
console.log("Applying", updates.length, "updates");
let transformedUpdates = [];
for (let update of updates) {
let changes = ChangeSet.fromJSON(update.changes);
console.log("Got effect", update);
let transformedUpdate = {
changes,
clientID: update.clientID,
effects: update.cursors?.map((c) => {
return cursorEffect.of(c);
}),
};
page.updates.push(transformedUpdate);
transformedUpdates.push(transformedUpdate);
// TODO: save cursors locally as well
page.text = changes.apply(page.text);
}
if (page.saveTimer) {
clearTimeout(page.saveTimer);
}
page.saveTimer = setTimeout(() => {
this.flushPageToDisk(pageName, page);
}, 1000);
while (page.pending.length) {
page.pending.pop()!(transformedUpdates);
}
return true;
}
}
);
onCall(
"pullUpdates",
async (pageName: string, version: number): Promise<Update[]> => {
let page = this.openPages.get(pageName);
// console.log("Pulling updates for", pageName);
if (!page) {
console.error("Fetching updates for not open page");
return [];
}
if (version < page.updates.length) {
return page.updates.slice(version);
} else {
return new Promise((resolve) => {
page.pending.push(resolve);
});
}
}
);
socket.on("disconnect", () => {
console.log("Disconnected", socket.id);
socketOpenPages.forEach((page) => {
this.disconnectSocket(socket, page);
});
});
});
}
}
app.use("/", express.static(distDir));
let fsRouter = express.Router();
// let diskFS = new DiskFS(pagesPath);
let filesystem = new RealtimeEditFS(pagesPath, io);
let filesystem = new RealtimeStorage(pagesPath, io);
// Page list
fsRouter.route("/").get(async (req, res) => {
@@ -371,11 +55,11 @@ fsRouter
res.send("");
}
})
.put(async (req, res) => {
.put(bodyParser.text({ type: "*/*" }), async (req, res) => {
let reqPath = req.params[0];
try {
let meta = await filesystem.writePage(reqPath, req);
let meta = await filesystem.writePage(reqPath, req.body);
res.status(200);
res.header("Last-Modified", "" + meta.lastModified);
res.send("OK");
+58
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@@ -0,0 +1,58 @@
import { Update } from "@codemirror/collab";
import { Text } from "@codemirror/state";
import { Socket } from "socket.io";
import { Cursor } from "../../webapp/src/cursorEffect";
import { PageMeta } from "./server";
export class Client {
constructor(public socket: Socket, public version: number) {}
}
export class Page {
versionOffset = 0;
updates: Update[] = [];
cursors = new Map<string, Cursor>();
clients = new Set<Client>();
pending: ((value: any) => void)[] = [];
text: Text;
meta: PageMeta;
saveTimer: NodeJS.Timeout | undefined;
name: string;
constructor(name: string, text: string, meta: PageMeta) {
this.name = name;
this.text = Text.of(text.split("\n"));
this.meta = meta;
}
updatesSince(version: number): Update[] {
return this.updates.slice(version - this.versionOffset);
}
get version(): number {
return this.updates.length + this.versionOffset;
}
flushUpdates(version: number) {
if (this.versionOffset > version) {
throw Error("This should never happen");
}
if (this.versionOffset === version) {
return;
}
this.updates = this.updates.slice(version - this.versionOffset);
this.versionOffset = version;
// console.log("Flushed updates, now got", this.updates.length, "updates");
}
toJSON() {
return {
text: this.text,
version: this.version,
cursors: Object.fromEntries(this.cursors.entries()),
};
}
}
+5
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@@ -0,0 +1,5 @@
export function safeRun(fn: () => Promise<void>) {
fn().catch((e) => {
console.error(e);
});
}
+1 -11
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@@ -670,11 +670,6 @@
"@types/qs" "*"
"@types/serve-static" "*"
"@types/lodash@^4.14.179":
version "4.14.179"
resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.14.179.tgz#490ec3288088c91295780237d2497a3aa9dfb5c5"
integrity sha512-uwc1x90yCKqGcIOAT6DwOSuxnrAbpkdPsUOZtwrXb4D/6wZs+6qG7QnIawDuZWg0sWpxl+ltIKCaLoMlna678w==
"@types/mime@^1":
version "1.3.2"
resolved "https://registry.yarnpkg.com/@types/mime/-/mime-1.3.2.tgz#93e25bf9ee75fe0fd80b594bc4feb0e862111b5a"
@@ -792,7 +787,7 @@ binary-extensions@^2.0.0:
resolved "https://registry.yarnpkg.com/binary-extensions/-/binary-extensions-2.2.0.tgz#75f502eeaf9ffde42fc98829645be4ea76bd9e2d"
integrity sha512-jDctJ/IVQbZoJykoeHbhXpOlNBqGNcwXJKJog42E5HDPUwQTSdjCHdihjj0DlnheQ7blbT6dHOafNAiS8ooQKA==
body-parser@1.19.2:
body-parser@1.19.2, body-parser@^1.19.2:
version "1.19.2"
resolved "https://registry.yarnpkg.com/body-parser/-/body-parser-1.19.2.tgz#4714ccd9c157d44797b8b5607d72c0b89952f26e"
integrity sha512-SAAwOxgoCKMGs9uUAUFHygfLAyaniaoun6I8mFY9pRAJL9+Kec34aU+oIjDhTycub1jozEfEwx1W1IuOYxVSFw==
@@ -1740,11 +1735,6 @@ lodash.uniq@^4.5.0:
resolved "https://registry.yarnpkg.com/lodash.uniq/-/lodash.uniq-4.5.0.tgz#d0225373aeb652adc1bc82e4945339a842754773"
integrity sha1-0CJTc662Uq3BvILklFM5qEJ1R3M=
lodash@^4.17.21:
version "4.17.21"
resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
lowercase-keys@^1.0.0, lowercase-keys@^1.0.1:
version "1.0.1"
resolved "https://registry.yarnpkg.com/lowercase-keys/-/lowercase-keys-1.0.1.tgz#6f9e30b47084d971a7c820ff15a6c5167b74c26f"