Collab work

.gitignore

@@ -9,3 +9,4 @@ website_build
 deno.lock
 fly.toml
 env.sh
+node_modules

build_bundle.ts

@@ -13,12 +13,23 @@ await esbuild.build({
   sourcemap: false,
   minify: false,
   plugins: [
+    // ESBuild plugin to make npm modules external
+    {
+      name: "npm-external",
+      setup(build: any) {
+        build.onResolve({ filter: /^npm:/ }, (args: any) => {
+          return {
+            path: args.path,
+            external: true,
+          };
+        });
+      },
+    },
     {
       name: "json",
       setup: (build) =>
         build.onLoad({ filter: /\.json$/ }, () => ({ loader: "json" })),
     },
-
     ...denoPlugins({
       importMapURL: new URL("./import_map.json", import.meta.url)
         .toString(),

plug-api/silverbullet-syscall/collab.ts

@@ -7,3 +7,7 @@ export function start(serverUrl: string, token: string, username: string) {
 export function stop() {
   return syscall("collab.stop");
 }
+
+export function ping(clientId: string, currentPage: string) {
+  return syscall("collab.ping", clientId, currentPage);
+}

plugs/collab/collab.ts

@@ -110,6 +110,7 @@ export async function detectPage() {
       console.error("Error parsing YAML", e);
     }
   }
+  await ping();
 }
 
 export function shareNoop() {
@@ -160,3 +161,48 @@ export function writeFileCollab(name: string): FileMeta {
     perm: "rw",
   };
 }
+
+const clientId = nanoid();
+let currentCollabId: string | undefined;
+
+const localCollabServer = location.protocol === "http:"
+  ? `ws://${location.host}/.ws-collab`
+  : `wss://${location.host}/.ws-collab`;
+
+async function ping() {
+  try {
+    const currentPage = await editor.getCurrentPage();
+    const { collabId } = await collab.ping(
+      clientId,
+      currentPage,
+    );
+    console.log("Collab ID", collabId);
+    if (!collabId && currentCollabId) {
+      // Stop collab
+      console.log("Stopping collab");
+      // editor.flashNotification("Closing real-time collaboration mode.");
+      currentCollabId = undefined;
+      await collab.stop();
+    } else if (collabId && collabId !== currentCollabId) {
+      // Start collab
+      console.log("Starting collab");
+      editor.flashNotification("Opening page in real-time collaboration mode.");
+      currentCollabId = collabId;
+      await collab.start(
+        localCollabServer,
+        `${collabId}/${currentPage}`,
+        "you",
+      );
+    }
+  } catch (e: any) {
+    // console.error("Ping error", e);
+    if (e.message.includes("Failed to fetch") && currentCollabId) {
+      console.log("Offline, stopping collab");
+      currentCollabId = undefined;
+      await collab.stop();
+    }
+  }
+}
+setInterval(() => {
+  ping().catch(console.error);
+}, 5000);

server/collab.test.ts

@@ -0,0 +1,39 @@
+import { assert, assertEquals } from "../test_deps.ts";
+import { CollabServer } from "./collab.ts";
+
+Deno.test("Collab server", async () => {
+  const collabServer = new CollabServer(null as any);
+  console.log("Client 1 joins page 1");
+  assertEquals(collabServer.ping("client1", "page1"), {});
+  assertEquals(collabServer.clients.size, 1);
+  assertEquals(collabServer.pages.size, 1);
+  console.log("Client 1 joins page 2");
+  assertEquals(collabServer.ping("client1", "page2"), {});
+  assertEquals(collabServer.clients.size, 1);
+  assertEquals(collabServer.pages.size, 1);
+  console.log("Client 2 joins to page 2, collab id created");
+  const collabId = collabServer.ping("client2", "page2").collabId;
+  assertEquals(collabServer.clients.size, 2);
+  assert(collabId !== undefined);
+  console.log("Client 2 moves to page 1, collab id destroyed");
+  assertEquals(collabServer.ping("client2", "page1"), {});
+  assertEquals(collabServer.ping("client1", "page2"), {});
+  console.log("Going to cleanup, which should have no effect");
+  collabServer.cleanup(50);
+  assertEquals(collabServer.clients.size, 2);
+  collabServer.ping("client2", "page2");
+  console.log("Going to sleep 20ms");
+  await sleep(20);
+  console.log("Then client 1 pings, but client 2 does not");
+  assertEquals(collabServer.ping("client1", "page2"), {});
+  await sleep(20);
+  console.log("Going to cleanup, which should clean client 2");
+  collabServer.cleanup(35);
+  assertEquals(collabServer.clients.size, 1);
+  assertEquals(collabServer.pages.get("page2")!.collabId, undefined);
+  console.log(collabServer);
+});
+
+function sleep(ms: number) {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}

server/collab.ts

@@ -0,0 +1,191 @@
+import { Hocuspocus } from "npm:@hocuspocus/server@2.0.6";
+import { getAvailablePortSync } from "https://deno.land/x/port@1.0.0/mod.ts";
+import { nanoid } from "https://esm.sh/nanoid@4.0.0";
+import { race, timeout } from "../common/async_util.ts";
+import { Application } from "./deps.ts";
+import { SpacePrimitives } from "../common/spaces/space_primitives.ts";
+
+type CollabPage = {
+  clients: Set<string>; // clientIds
+  collabId?: string;
+};
+
+const pingInterval = 5000;
+
+export class CollabServer {
+  clients: Map<string, { openPage: string; lastPing: number }> = new Map();
+  pages: Map<string, CollabPage> = new Map();
+
+  constructor(private spacePrimitives: SpacePrimitives) {
+  }
+
+  start() {
+    setInterval(() => {
+      this.cleanup(3 * pingInterval);
+    }, pingInterval);
+  }
+
+  ping(clientId: string, currentPage: string): { collabId?: string } {
+    let clientState = this.clients.get(clientId);
+    let collabId: string | undefined;
+    if (!clientState) {
+      clientState = {
+        openPage: "",
+        lastPing: Date.now(),
+      };
+    } else {
+      clientState.lastPing = Date.now();
+    }
+    if (currentPage !== clientState.openPage) {
+      // Client switched pages
+      // Update last page record
+      const lastCollabPage = this.pages.get(clientState.openPage);
+      if (lastCollabPage) {
+        lastCollabPage.clients.delete(clientId);
+        if (lastCollabPage.clients.size === 0) {
+          // Cleanup
+          this.pages.delete(clientState.openPage);
+        } else {
+          if (lastCollabPage.clients.size === 1) {
+            delete lastCollabPage.collabId;
+          }
+          this.pages.set(clientState.openPage, lastCollabPage);
+        }
+      }
+      // Update new page
+      let nextCollabPage = this.pages.get(currentPage);
+      if (!nextCollabPage) {
+        nextCollabPage = {
+          clients: new Set(),
+        };
+      }
+      nextCollabPage.clients.add(clientId);
+      if (nextCollabPage.clients.size === 2) {
+        // Create a new collabId
+        nextCollabPage.collabId = nanoid();
+      }
+      clientState.openPage = currentPage;
+      this.pages.set(currentPage, nextCollabPage);
+      collabId = nextCollabPage.collabId;
+    } else {
+      // Page didn't change
+      collabId = this.pages.get(currentPage)?.collabId;
+    }
+    this.clients.set(clientId, clientState);
+    if (collabId) {
+      return { collabId };
+    } else {
+      return {};
+    }
+  }
+
+  cleanup(timeout: number) {
+    // Clean up clients that haven't pinged for some time
+    for (const [clientId, clientState] of this.clients) {
+      if (Date.now() - clientState.lastPing > timeout) {
+        console.log("[Collab]", "Ejecting client", clientId);
+        this.clients.delete(clientId);
+        const collabPage = this.pages.get(clientState.openPage);
+        if (collabPage) {
+          collabPage.clients.delete(clientId);
+          if (collabPage.clients.size === 0) {
+            this.pages.delete(clientState.openPage);
+          } else {
+            if (collabPage.clients.size === 1) {
+              delete collabPage.collabId;
+            }
+            this.pages.set(clientState.openPage, collabPage);
+          }
+        }
+      }
+    }
+  }
+
+  route(app: Application) {
+    // The way this works is that we spin up a separate WS server locally and then proxy requests to it
+    // This is the only way I could get Hocuspocus to work with Deno
+    const internalPort = getAvailablePortSync();
+    const hocuspocus = new Hocuspocus({
+      port: internalPort,
+      address: "localhost",
+      quiet: true,
+      onLoadDocument: async (doc) => {
+        console.log("[Hocuspocus]", "Requesting doc load", doc.documentName);
+        const pageName = doc.documentName.split("/").slice(1).join("/");
+        try {
+          const yText = doc.document.getText("codemirror");
+          const { data } = await this.spacePrimitives.readFile(
+            `${pageName}.md`,
+          );
+
+          yText.insert(0, new TextDecoder().decode(data));
+          console.log("[Hocuspocus]", "Loaded document from space");
+          return doc.document;
+        } catch (e) {
+          console.error("Error loading doc", e);
+        }
+      },
+      onDisconnect: (client) => {
+        console.log("[Hocuspocus]", "Client disconnected", client.clientsCount);
+        if (client.clientsCount === 0) {
+          console.log(
+            "[Hocuspocus]",
+            "Last client disconnected from",
+            client.documentName,
+            "purging from memory",
+          );
+          hocuspocus.documents.delete(client.documentName);
+        }
+        return Promise.resolve();
+      },
+    });
+
+    hocuspocus.listen();
+    app.use((ctx) => {
+      if (ctx.request.url.pathname === "/.ws") {
+        const sock = ctx.upgrade();
+        sock.onmessage = (e) => {
+          console.log("WS: Got message", e.data);
+        };
+      }
+      // Websocket proxy to hocuspocus
+      if (ctx.request.url.pathname === "/.ws-collab") {
+        const sock = ctx.upgrade();
+
+        const ws = new WebSocket(`ws://localhost:${internalPort}`);
+        const wsReady = race([
+          new Promise<void>((resolve) => {
+            ws.onopen = () => {
+              resolve();
+            };
+          }),
+          timeout(1000),
+        ]).catch(() => {
+          console.error("Timeout waiting for collab to open websocket");
+          sock.close();
+        });
+        sock.onmessage = (e) => {
+          // console.log("Got message", e);
+          wsReady.then(() => ws.send(e.data)).catch(console.error);
+        };
+        sock.onclose = () => {
+          if (ws.OPEN) {
+            ws.close();
+          }
+        };
+        ws.onmessage = (e) => {
+          if (sock.OPEN) {
+            sock.send(e.data);
+          } else {
+            console.error("Got message from websocket but socket is not open");
+          }
+        };
+        ws.onclose = () => {
+          if (sock.OPEN) {
+            sock.close();
+          }
+        };
+      }
+    });
+  }
+}

server/http_server.ts

@@ -7,6 +7,7 @@ import { performLocalFetch } from "../common/proxy_fetch.ts";
 import { BuiltinSettings } from "../web/types.ts";
 import { gitIgnoreCompiler } from "./deps.ts";
 import { FilteredSpacePrimitives } from "../common/spaces/filtered_space_primitives.ts";
+import { CollabServer } from "./collab.ts";
 
 export type ServerOptions = {
   hostname: string;
@@ -29,6 +30,7 @@ export class HttpServer {
   clientAssetBundle: AssetBundle;
   settings?: BuiltinSettings;
   spacePrimitives: SpacePrimitives;
+  collab: CollabServer;
 
   constructor(
     spacePrimitives: SpacePrimitives,
@@ -62,6 +64,8 @@ export class HttpServer {
         }
       },
     );
+    this.collab = new CollabServer(this.spacePrimitives);
+    this.collab.start();
   }
 
   // Replaces some template variables in index.html in a rather ad-hoc manner, but YOLO
@@ -123,7 +127,8 @@ export class HttpServer {
     this.app.use(({ request, response }, next) => {
       if (
         !request.url.pathname.startsWith("/.fs") &&
-        request.url.pathname !== "/.auth"
+        request.url.pathname !== "/.auth" &&
+        !request.url.pathname.startsWith("/.ws")
       ) {
         response.headers.set("Content-type", "text/html");
         response.body = this.renderIndexHtml();
@@ -138,6 +143,8 @@ export class HttpServer {
     this.app.use(fsRouter.routes());
     this.app.use(fsRouter.allowedMethods());
 
+    this.collab.route(this.app);
+
     this.abortController = new AbortController();
     const listenOptions: any = {
       hostname: this.hostname,
@@ -273,6 +280,15 @@ export class HttpServer {
             });
             return;
           }
+          case "ping": {
+            response.headers.set("Content-Type", "application/json");
+            // console.log("Got ping", body);
+            response.body = JSON.stringify(
+              this.collab.ping(body.clientId, body.page),
+            );
+            // console.log(this.collab);
+            return;
+          }
           default:
             response.headers.set("Content-Type", "text/plain");
             response.status = 400;

web/cm_plugins/collab.ts

@@ -1,4 +1,4 @@
-import { Extension, WebsocketProvider, Y, yCollab } from "../deps.ts";
+import { Extension, HocuspocusProvider, Y, yCollab } from "../deps.ts";
 
 const userColors = [
   { color: "#30bced", light: "#30bced33" },
@@ -12,27 +12,27 @@ const userColors = [
 ];
 
 export class CollabState {
-  ydoc: Y.Doc;
-  collabProvider: WebsocketProvider;
-  ytext: Y.Text;
-  yundoManager: Y.UndoManager;
+  public ytext: Y.Text;
+  private collabProvider: HocuspocusProvider;
+  private yundoManager: Y.UndoManager;
 
-  constructor(serverUrl: string, token: string, username: string) {
-    this.ydoc = new Y.Doc();
-    this.collabProvider = new WebsocketProvider(
-      serverUrl,
-      token,
-      this.ydoc,
-    );
+  constructor(serverUrl: string, name: string, username: string) {
+    this.collabProvider = new HocuspocusProvider({
+      url: serverUrl,
+      name: name,
+    });
 
     this.collabProvider.on("status", (e: any) => {
       console.log("Collab status change", e);
     });
-    this.collabProvider.on("sync", (e: any) => {
-      console.log("Sync status", e);
-    });
+    // this.collabProvider.on("sync", (e: any) => {
+    //   console.log("Sync status", e);
+    // });
+    // this.collabProvider.on("synced", (e: any) => {
+    //   console.log("Synced status", e);
+    // });
 
-    this.ytext = this.ydoc.getText("codemirror");
+    this.ytext = this.collabProvider.document.getText("codemirror");
     this.yundoManager = new Y.UndoManager(this.ytext);
 
     const randomColor =
@@ -46,6 +46,7 @@ export class CollabState {
   }
 
   stop() {
+    this.collabProvider.disconnect();
     this.collabProvider.destroy();
   }
 

web/deps.ts

@@ -21,7 +21,7 @@ export {
   yCollab,
   yUndoManagerKeymap,
 } from "https://esm.sh/y-codemirror.next@0.3.2?external=yjs,@codemirror/state,@codemirror/commands,@codemirror/history,@codemirror/view";
-export { WebsocketProvider } from "https://esm.sh/y-websocket@1.4.5?external=yjs";
+export { HocuspocusProvider } from "https://esm.sh/@hocuspocus/provider@2.0.6?external=yjs,ws";
 
 // Vim mode
 export {

web/editor.tsx

@@ -389,7 +389,8 @@ export class Editor {
 
     this.space.on({
       pageChanged: (meta) => {
-        if (this.currentPage === meta.name) {
+        // Only reload when watching the current page (to avoid reloading when switching pages and in collab mode)
+        if (this.space.watchInterval && this.currentPage === meta.name) {
           console.log("Page changed elsewhere, reloading");
           this.flashNotification("Page changed elsewhere, reloading");
           this.reloadPage();
@@ -1144,8 +1145,7 @@ export class Editor {
         await this.save(true);
         // And stop the collab session
         if (this.collabState) {
-          this.collabState.stop();
-          this.collabState = undefined;
+          this.stopCollab();
         }
       }
     }
@@ -1226,10 +1226,18 @@ export class Editor {
     if (pageState) {
       // Restore state
       editorView.scrollDOM.scrollTop = pageState!.scrollTop;
-      editorView.dispatch({
-        selection: pageState.selection,
-        scrollIntoView: true,
-      });
+      try {
+        editorView.dispatch({
+          selection: pageState.selection,
+          scrollIntoView: true,
+        });
+      } catch {
+        // This is fine, just go to the top
+        editorView.dispatch({
+          selection: { anchor: 0 },
+          scrollIntoView: true,
+        });
+      }
     } else {
       editorView.scrollDOM.scrollTop = 0;
       editorView.dispatch({
@@ -1508,12 +1516,24 @@ export class Editor {
     }
     const initialText = this.editorView!.state.sliceDoc();
     this.collabState = new CollabState(serverUrl, token, username);
-    this.collabState.collabProvider.once("sync", (synced: boolean) => {
-      if (this.collabState?.ytext.toString() === "") {
-        console.log("Synced value is empty, putting back original text");
-        this.collabState?.ytext.insert(0, initialText);
-      }
-    });
+    // this.collabState.collabProvider.on("synced", () => {
+    //   if (this.collabState?.ytext.toString() === "") {
+    //     console.error("Synced value is empty, putting back original text");
+    //     this.collabState?.ytext.insert(0, initialText);
+    //   }
+    // });
     this.rebuildEditorState();
+    // Don't watch for local changes in this mode
+    this.space.unwatch();
+  }
+
+  stopCollab() {
+    if (this.collabState) {
+      this.collabState.stop();
+      this.collabState = undefined;
+      this.rebuildEditorState();
+    }
+    // Start file watching again
+    this.space.watch();
   }
 }

web/space.ts

@@ -51,7 +51,7 @@ export class Space extends EventEmitter<SpaceEvents> {
     super();
     this.kvStore.get("imageHeightCache").then((cache) => {
       if (cache) {
-        console.log("Loaded image height cache from KV store", cache);
+        // console.log("Loaded image height cache from KV store", cache);
         this.imageHeightCache = cache;
       }
     });

web/syscalls/collab.ts

@@ -14,7 +14,25 @@ export function collabSyscalls(editor: Editor): SysCallMapping {
     "collab.stop": (
       _ctx,
     ) => {
-      editor.collabState?.stop();
+      editor.stopCollab();
+    },
+    "collab.ping": async (
+      _ctx,
+      clientId: string,
+      currentPage: string,
+    ) => {
+      const resp = await editor.remoteSpacePrimitives.authenticatedFetch(
+        editor.remoteSpacePrimitives.url,
+        {
+          method: "POST",
+          body: JSON.stringify({
+            operation: "ping",
+            clientId,
+            page: currentPage,
+          }),
+        },
+      );
+      return resp.json();
     },
   };
 }