bug fixes, and performance improvements, and drawer

server/api/topic/[topicId]/index.get.ts

@@ -1,95 +1,60 @@
-import { db } from "~~/server/lib/db";
-import { topicEvents } from "~~/server/utils/events";
+import { db } from '~~/server/lib/db';
+import { topicEvents } from '~~/server/utils/events';
+import { createTopicSnapshotStream } from '~~/server/utils/topic-snapshot-stream';
 
 export default defineEventHandler(async (event) => {
     await protectRoute(event);
 
     const topicId = getRouterParam(event, 'topicId')!;
-    const isSSE = getHeader(event, 'accept')?.includes('text/event-stream') ?? false;
-
     const userId = event.context.user!.id as string;
-
-    const topic = await db.query.topics.findFirst({
-        where: {
-            id: topicId,
-            userId,
-        },
+    const isSSE = getHeader(event, 'accept')?.includes('text/event-stream') ?? false;
+    const readTopic = () => db.query.topics.findFirst({
+        where: { id: topicId, userId },
         with: {
             messages: {
-                orderBy: {
-                    createdAt: 'asc',
-                },
+                orderBy: { createdAt: 'asc' },
                 with: {
                     parts: {
-                        orderBy: {
-                            createdAt: 'asc',
-                        },
-                        with: {
-                            toolCall: true,
-                        }
-                    },
-                    attachments: {
-                        with: {
-                            file: true,
-                        }
+                        orderBy: { createdAt: 'asc' },
+                        with: { toolCall: true },
                     },
+                    attachments: { with: { file: true } },
                     generation: true,
-                }
+                },
             },
         },
     });
 
-    if (!topic) {
-        console.log("topic not found");
-        throw createError({
-            statusCode: 404,
-            statusMessage: 'Not Found',
-        });
-    }
-
-    if (isSSE === false) {
+    if (!isSSE) {
+        const topic = await readTopic();
+        if (!topic) {
+            setResponseStatus(event, 404);
+            return { ok: false, error: 'Topic not found' };
+        }
+        topicEvents.applyLiveText(topicId, topic.messages);
         return topic;
     }
 
+    // Authorize before subscribing; no topic data is exposed before this check.
+    const ownedTopic = await db.query.topics.findFirst({
+        where: { id: topicId, userId },
+        columns: { id: true },
+    });
+    if (!ownedTopic) {
+        setResponseStatus(event, 404);
+        return { ok: false, error: 'Topic not found' };
+    }
+
+    const subscription = createTopicSnapshotStream(topicId, getQuery(event).snapshot);
+    event.node.res.once('close', subscription.close);
+    const stream = await subscription.open(readTopic);
+    if (!stream.ok) {
+        setResponseStatus(event, stream.error === 'read-failed' ? 500 : 404);
+        return { ok: false, error: stream.error };
+    }
     setHeader(event, 'Content-Type', 'text/event-stream');
     setHeader(event, 'Cache-Control', 'no-cache');
-    setHeader(event, 'Connection', 'keep-alive');
+    setHeader(event, 'X-Accel-Buffering', 'no');
 
-    const { lastUpdate, count } = getQuery(event);
-    const serverLastUpdate = topic.messages.at(-1)?.updatedAt;
-    const serverCount = topic.messages.length;
-
-    // TODO: there is potentially a race condition here where the client could 
-    // connect at milisecond 87, and the last database write was at 0 (there
-    // is a write every 100ms for some operations), if there were tokens sent
-    // at 20 40 and 60, those tokens are lost to the client.
-    let streamController: ReadableStreamDefaultController;
-    let interval: NodeJS.Timeout;
-    const stream = new ReadableStream({
-        start(controller) {
-            streamController = controller;
-            controller.enqueue(`:connected\n\n`);
-
-            if ((lastUpdate && count) && (lastUpdate === serverLastUpdate?.toISOString() && count === serverCount)) {
-                controller.enqueue(':already_synced\n\n')
-            } else {
-                controller.enqueue(`data: ${JSON.stringify({
-                    type: 'initial_state',
-                    payload: topic
-                })}\n\n`);
-            }
-
-            interval = setInterval(() => {
-                controller.enqueue(`:heartbeat\n\n`);
-            }, 15000);
-
-            topicEvents.subscribe(topicId, streamController);
-        },
-        cancel() {
-            topicEvents.unsubscribe(topicId, streamController);
-            clearInterval(interval);
-        }
-    });
-
-    return sendStream(event, stream);
+    return sendStream(event, stream.data);
 });