From 1904a5fc1bb5dfcfe9bd2cd4bf060f53ecf80655 Mon Sep 17 00:00:00 2001
From: Koushik Dutta <koushd@gmail.com>
Date: Fri, 10 Dec 2021 12:20:42 -0800
Subject: [PATCH] server: better mixin invalidation to prevent weird bugs like
 settings not loading, etc

---
 server/src/plugin/plugin-device.ts |  5 ++-
 server/src/plugin/plugin-host.ts   | 17 +--------
 server/src/runtime.ts              | 60 +++++++++++++++++++++---------
 3 files changed, 48 insertions(+), 34 deletions(-)

diff --git a/server/src/plugin/plugin-device.ts b/server/src/plugin/plugin-device.ts
index 83cf6aa4b..005403ae2 100644
--- a/server/src/plugin/plugin-device.ts
+++ b/server/src/plugin/plugin-device.ts
@@ -35,7 +35,7 @@ export class PluginDeviceProxyHandler implements ProxyHandler<any>, ScryptedDevi
     }
 
     invalidateEntry(mixinEntry: MixinTable) {
-        if (!mixinEntry.mixinProviderId)
+        if (!mixinEntry?.mixinProviderId)
             return;
         (async () => {
             const mixinProvider = this.scrypted.getDevice(mixinEntry.mixinProviderId) as ScryptedDevice & MixinProvider;
@@ -53,6 +53,9 @@ export class PluginDeviceProxyHandler implements ProxyHandler<any>, ScryptedDevi
         }
     }
 
+    /**
+     * Rebuild the mixin table with any currently missing mixins.
+     */
     rebuildMixinTable() {
         if (!this.mixinTable)
             return this.invalidate();
diff --git a/server/src/plugin/plugin-host.ts b/server/src/plugin/plugin-host.ts
index dcfd6dd1e..628715d3a 100644
--- a/server/src/plugin/plugin-host.ts
+++ b/server/src/plugin/plugin-host.ts
@@ -60,21 +60,8 @@ export class PluginHost {
         }
         this.ws = {};
 
-        // const pluginDevices = new Set<string>(Object.values(this.scrypted.pluginDevices).filter(d => d.pluginId === this.pluginId).map(d => d._id));
-        // this.scrypted.invalidateMixins(pluginDevices);
-
-        for (const device of Object.values(this.scrypted.devices)) {
-            const pluginDevice = this.scrypted.pluginDevices[device.handler.id];
-            if (!pluginDevice) {
-                console.warn('PluginDevice missing?', device.handler.id);
-                continue;
-            }
-            for (const mixin of getState(pluginDevice, ScryptedInterfaceProperty.mixins) || []) {
-                if (this.scrypted.findPluginDeviceById(mixin)?.pluginId === this.pluginId) {
-                    device.handler.invalidate();
-                }
-            }
-        }
+        const deviceIds = new Set<string>(Object.values(this.scrypted.pluginDevices).filter(d => d.pluginId === this.pluginId).map(d => d._id));
+        this.scrypted.invalidateMixins(deviceIds);
 
         this.consoleServer?.then(server => {
             server.readServer.close();
diff --git a/server/src/runtime.ts b/server/src/runtime.ts
index f476a4b2f..3d7583a2b 100644
--- a/server/src/runtime.ts
+++ b/server/src/runtime.ts
@@ -27,7 +27,7 @@ import { ServiceControl } from './services/service-control';
 import { Alerts } from './services/alerts';
 import { Info } from './services/info';
 import io from 'engine.io';
-import {spawn as ptySpawn} from 'node-pty';
+import { spawn as ptySpawn } from 'node-pty';
 import rimraf from 'rimraf';
 import { getPluginVolume } from './plugin/plugin-volume';
 
@@ -435,25 +435,49 @@ export class ScryptedRuntime {
         return proxyPair;
     }
 
-    invalidateMixins(mixinIds: Set<string>) {
-        // const ret = new Set(mixinIds);
+    invalidateMixins(ids: Set<string>) {
+        const ret = new Set<string>();
+        const remaining = [...ids];
 
-        // for (const device of Object.values(this.devices)) {
-        //     const pluginDevice = this.pluginDevices[device.handler.id];
-        //     if (ret.has(pluginDevice._id))
-        //         continue;
-        //     if (!pluginDevice) {
-        //         console.warn('PluginDevice missing?', device.handler.id);
-        //         continue;
-        //     }
-        //     for (const mixin of getState(pluginDevice, ScryptedInterfaceProperty.mixins) || []) {
-        //         if (this.scrypted.findPluginDeviceById(mixin)?.pluginId === this.pluginId) {
-        //             device.handler.invalidate();
-        //         }
-        //     }
-        // }
+        // first pass:
+        // for every id, find anything it is acting as a mixin, and clear out the entry.
+        while (remaining.length) {
+            const id = remaining.pop();
 
-        // return ret;
+            for (const device of Object.values(this.devices)) {
+                const foundIndex = device.handler?.mixinTable?.findIndex(mt => mt.mixinProviderId === id);
+                if (foundIndex === -1 || foundIndex === undefined)
+                    continue;
+
+                const did = device.handler.id;
+                if (!ret.has(did)) {
+                    // add this to the list of mixin providers that need to be rebuilt
+                    ret.add(did);
+                    remaining.push(did);
+                }
+
+                // if it is the last entry, that means it is the device itself.
+                // can this happen? i don't think it is possible. mixin provider id would be undefined.
+                if (foundIndex === device.handler.mixinTable.length - 1) {
+                    console.warn('attempt to invalidate mixin on actual device?');
+                    continue;
+                }
+
+                const removed = device.handler.mixinTable.splice(0, foundIndex + 1);
+                for (const entry of removed) {
+                    device.handler.invalidateEntry(entry);
+                }
+            }
+        }
+
+        // second pass:
+        // rebuild the mixin tables.
+        for (const id of ret) {
+            const device = this.devices[id];
+            device.handler.rebuildMixinTable();
+        }
+
+        return ret;
     }
 
     async installNpm(pkg: string, version?: string): Promise<PluginHost> {