basic filewatcher using websocket

src/shims/fs/echo-guard.js

@@ -0,0 +1,31 @@
+// Shared echo suppression for file watcher.
+// fs operations mark paths as "locally modified" so the watcher client
+// can skip events that originated from this client.
+
+const ECHO_SUPPRESS_MS = 1500;
+const recentOps = new Map(); // normalized path -> timestamp
+
+function normalize(p) {
+  return (p || "")
+    .replace(/\\/g, "/")
+    .replace(/^\/+/, "")
+    .replace(/\/+$/, "");
+}
+
+export function markLocalOp(path) {
+  recentOps.set(normalize(path), Date.now());
+}
+
+export function isRecentLocalOp(path) {
+  const norm = normalize(path);
+  const ts = recentOps.get(norm);
+
+  if (!ts) return false;
+
+  if (Date.now() - ts < ECHO_SUPPRESS_MS) {
+    return true;
+  }
+
+  recentOps.delete(norm);
+  return false;
+}

src/shims/fs/index.js

@@ -4,6 +4,7 @@ import { transport } from "./transport.js";
 import { createFsPromises } from "./promises.js";
 import { createFsSync } from "./sync.js";
 import { createFsWatch } from "./watch.js";
+import { createWatcherClient } from "./watcher-client.js";
 import { constants } from "./constants.js";
 
 const metadataCache = new MetadataCache();
@@ -12,6 +13,7 @@ const contentCache = new ContentCache();
 const fsPromises = createFsPromises(metadataCache, contentCache, transport);
 const fsSync = createFsSync(metadataCache, contentCache, transport);
 const fsWatch = createFsWatch(transport);
+const watcherClient = createWatcherClient(metadataCache, contentCache, fsWatch);
 
 export const fsShim = {
   promises: fsPromises,
@@ -29,6 +31,7 @@ export const fsShim = {
 
   _metadataCache: metadataCache,
   _contentCache: contentCache,
+  _watcherClient: watcherClient,
 
   async _init(basePath) {
     const tree = await transport.fetchTree(basePath);

src/shims/fs/promises.js

@@ -1,3 +1,5 @@
+import { markLocalOp } from "./echo-guard.js";
+
 export function createFsPromises(metadataCache, contentCache, transport) {
   return {
     async stat(path) {
@@ -85,6 +87,7 @@ export function createFsPromises(metadataCache, contentCache, transport) {
         encoding = encoding?.encoding;
       }
 
+      markLocalOp(path);
       contentCache.set(path, data);
 
       const size =
@@ -110,6 +113,7 @@ export function createFsPromises(metadataCache, contentCache, transport) {
     },
 
     async appendFile(path, data, encoding) {
+      markLocalOp(path);
       contentCache.invalidate(path);
 
       await transport.appendFile(path, data);
@@ -119,6 +123,7 @@ export function createFsPromises(metadataCache, contentCache, transport) {
     },
 
     async unlink(path) {
+      markLocalOp(path);
       contentCache.delete(path);
       metadataCache.delete(path);
 
@@ -126,6 +131,8 @@ export function createFsPromises(metadataCache, contentCache, transport) {
     },
 
     async rename(oldPath, newPath) {
+      markLocalOp(oldPath);
+      markLocalOp(newPath);
       const content = contentCache.get(oldPath);
 
       if (content !== null) {
@@ -142,12 +149,14 @@ export function createFsPromises(metadataCache, contentCache, transport) {
       const recursive =
         typeof options === "object" ? !!options.recursive : !!options;
 
+      markLocalOp(path);
       metadataCache.set(path, { type: "directory" });
 
       await transport.mkdir(path, recursive);
     },
 
     async rmdir(path) {
+      markLocalOp(path);
       metadataCache.delete(path);
       await transport.rmdir(path);
     },
@@ -156,6 +165,7 @@ export function createFsPromises(metadataCache, contentCache, transport) {
       const recursive =
         typeof options === "object" ? !!options.recursive : false;
 
+      markLocalOp(path);
       metadataCache.delete(path);
       contentCache.delete(path);
 
@@ -163,6 +173,7 @@ export function createFsPromises(metadataCache, contentCache, transport) {
     },
 
     async copyFile(src, dest) {
+      markLocalOp(dest);
       await transport.copyFile(src, dest);
 
       const meta = await transport.stat(dest);

src/shims/fs/sync.js

@@ -1,3 +1,5 @@
+import { markLocalOp } from "./echo-guard.js";
+
 export function createFsSync(metadataCache, contentCache, transport) {
   return {
     existsSync(path) {
@@ -64,6 +66,7 @@ export function createFsSync(metadataCache, contentCache, transport) {
         encoding = encoding?.encoding;
       }
 
+      markLocalOp(path);
       contentCache.set(path, data);
 
       const size =
@@ -87,6 +90,7 @@ export function createFsSync(metadataCache, contentCache, transport) {
     },
 
     unlinkSync(path) {
+      markLocalOp(path);
       contentCache.delete(path);
       metadataCache.delete(path);
 

src/shims/fs/watcher-client.js

@@ -0,0 +1,141 @@
+// Client-side WebSocket file watcher.
+// Connects to the server's /ws endpoint, receives file change events,
+// updates the metadata/content caches, and dispatches to fs.watch listeners
+// so Obsidian's vault picks them up automatically.
+
+import { isRecentLocalOp } from "./echo-guard.js";
+
+const RECONNECT_DELAY = 2000;
+
+export function createWatcherClient(metadataCache, contentCache, fsWatch) {
+  let ws = null;
+  let vaultId = null;
+  let reconnectTimer = null;
+
+  function connect(vault) {
+    vaultId = vault;
+
+    if (!vaultId) {
+      console.warn("[watcher] No vault ID, skipping WebSocket connection");
+      return;
+    }
+
+    const protocol = window.location.protocol === "https:" ? "wss:" : "ws:";
+    const url = `${protocol}//${window.location.host}/ws?vault=${encodeURIComponent(vaultId)}`;
+
+    try {
+      ws = new WebSocket(url);
+    } catch (e) {
+      console.error("[watcher] Failed to create WebSocket:", e);
+      scheduleReconnect();
+      return;
+    }
+
+    ws.onopen = () => {
+      console.log("[watcher] Connected to file watcher");
+    };
+
+    ws.onmessage = (event) => {
+      try {
+        const msg = JSON.parse(event.data);
+        handleEvent(msg);
+      } catch (e) {
+        console.error("[watcher] Failed to parse message:", e);
+      }
+    };
+
+    ws.onclose = () => {
+      console.log("[watcher] Disconnected");
+      ws = null;
+      scheduleReconnect();
+    };
+
+    ws.onerror = (e) => {
+      console.error("[watcher] WebSocket error:", e);
+    };
+  }
+
+  function scheduleReconnect() {
+    if (reconnectTimer) return;
+
+    reconnectTimer = setTimeout(() => {
+      reconnectTimer = null;
+
+      if (vaultId) {
+        console.log("[watcher] Reconnecting...");
+        connect(vaultId);
+      }
+    }, RECONNECT_DELAY);
+  }
+
+  function handleEvent(msg) {
+    const { type, path, stat } = msg;
+
+    if (!type || !path) return;
+
+    // Suppress echo from our own operations
+    if (isRecentLocalOp(path)) {
+      return;
+    }
+
+    switch (type) {
+      case "created":
+        if (stat) {
+          metadataCache.set(path, {
+            type: "file",
+            size: stat.size,
+            mtime: stat.mtime,
+            ctime: stat.ctime,
+          });
+        }
+        contentCache.invalidate(path);
+        fsWatch._dispatch("created", path);
+        break;
+
+      case "folder-created":
+        metadataCache.set(path, { type: "directory" });
+        fsWatch._dispatch("folder-created", path);
+        break;
+
+      case "modified":
+        if (stat) {
+          metadataCache.set(path, {
+            type: "file",
+            size: stat.size,
+            mtime: stat.mtime,
+            ctime: stat.ctime,
+          });
+        }
+        contentCache.invalidate(path);
+        fsWatch._dispatch("modified", path);
+        break;
+
+      case "deleted":
+        metadataCache.delete(path);
+        contentCache.invalidate(path);
+        fsWatch._dispatch("deleted", path);
+        break;
+
+      default:
+        console.warn("[watcher] Unknown event type:", type);
+    }
+  }
+
+  function disconnect() {
+    if (reconnectTimer) {
+      clearTimeout(reconnectTimer);
+      reconnectTimer = null;
+    }
+
+    if (ws) {
+      ws.onclose = null; // prevent reconnect
+      ws.close();
+      ws = null;
+    }
+  }
+
+  return {
+    connect,
+    disconnect,
+  };
+}

src/shims/loader.js

@@ -259,4 +259,9 @@ window.__currentVaultId =
 
 installRequestUrlShim();
 
+// Connect file watcher WebSocket after everything is initialized
+if (window.__currentVaultId) {
+  fsShim._watcherClient.connect(window.__currentVaultId);
+}
+
 console.log("[ignis] Shim loader initialized");