From 1956441d520153144c47f4ff1f885dffc07548a0 Mon Sep 17 00:00:00 2001
From: Zaid Abdulla <zaid@genieacs.com>
Date: Mon, 28 Sep 2020 12:47:15 -0700
Subject: [PATCH] Limit number of tasks in queue

---
 ui/components/summon-button.ts |  3 ++-
 ui/devices-page.ts             | 26 +++++++++++-------------
 ui/drawer-component.ts         |  2 +-
 ui/task-queue.ts               | 37 ++++++++++++++++++++++++++++++----
 4 files changed, 48 insertions(+), 20 deletions(-)

diff --git a/ui/components/summon-button.ts b/ui/components/summon-button.ts
index 79a5566..0b66310 100644
--- a/ui/components/summon-button.ts
+++ b/ui/components/summon-button.ts
@@ -81,7 +81,8 @@ const component: ClosureComponent = (): Component => {
                 store.fulfill(0, Date.now());
               })
               .catch((err) => {
-                throw err;
+                e.target.disabled = false;
+                notifications.push("error", err.message);
               });
           },
         },
diff --git a/ui/devices-page.ts b/ui/devices-page.ts
index 3b7ddc5..ac06308 100644
--- a/ui/devices-page.ts
+++ b/ui/devices-page.ts
@@ -23,7 +23,7 @@ import config from "./config";
 import indexTableComponent from "./index-table-component";
 import filterComponent from "./filter-component";
 import * as store from "./store";
-import * as taskQueue from "./task-queue";
+import { queueTask, stageDownload } from "./task-queue";
 import * as notifications from "./notifications";
 import { parse, stringify } from "../lib/common/expression-parser";
 import { evaluate, extractParams } from "../lib/common/expression";
@@ -91,12 +91,11 @@ function renderActions(selected: Set<string>): Children {
         title: "Reboot selected devices",
         disabled: !selected.size,
         onclick: () => {
-          for (const d of selected) {
-            taskQueue.queueTask({
-              name: "reboot",
-              device: d,
-            });
-          }
+          const tasks = [...selected].map((s) => ({
+            name: "reboot",
+            device: s,
+          }));
+          queueTask(...tasks);
         },
       },
       "Reboot"
@@ -110,12 +109,11 @@ function renderActions(selected: Set<string>): Children {
         title: "Factory reset selected devices",
         disabled: !selected.size,
         onclick: () => {
-          for (const d of selected) {
-            taskQueue.queueTask({
-              name: "factoryReset",
-              device: d,
-            });
-          }
+          const tasks = [...selected].map((s) => ({
+            name: "factoryReset",
+            device: s,
+          }));
+          queueTask(...tasks);
         },
       },
       "Reset"
@@ -129,7 +127,7 @@ function renderActions(selected: Set<string>): Children {
         title: "Push a firmware or a config file",
         disabled: !selected.size,
         onclick: () => {
-          taskQueue.stageDownload({
+          stageDownload({
             name: "download",
             devices: [...selected],
           });
diff --git a/ui/drawer-component.ts b/ui/drawer-component.ts
index a1ae879..4e75f9d 100644
--- a/ui/drawer-component.ts
+++ b/ui/drawer-component.ts
@@ -468,7 +468,7 @@ const component: ClosureComponent = (): Component => {
                     store.fulfill(0, Date.now());
                   })
                   .catch((err) => {
-                    throw err;
+                    notifications.push("error", err.message);
                   });
               },
             },
diff --git a/ui/task-queue.ts b/ui/task-queue.ts
index 0f3800b..bcb2a7c 100644
--- a/ui/task-queue.ts
+++ b/ui/task-queue.ts
@@ -19,6 +19,7 @@
 
 import * as store from "./store";
 import { Task } from "../lib/types";
+import * as notifications from "./notifications";
 
 export interface QueueTask extends Task {
   status?: string;
@@ -29,12 +30,27 @@ export interface StageTask extends Task {
   devices: string[];
 }
 
+const MAX_QUEUE = 100;
+
 const queue: Set<QueueTask> = new Set();
 const staging: Set<StageTask> = new Set();
 
-export function queueTask(task: QueueTask): void {
-  task.status = "queued";
-  queue.add(task);
+function canQueue(tasks: QueueTask[]): boolean {
+  let count = queue.size;
+  for (const task of tasks) if (!queue.has(task)) ++count;
+  return count <= MAX_QUEUE;
+}
+
+export function queueTask(...tasks: QueueTask[]): void {
+  if (!canQueue(tasks)) {
+    notifications.push("error", "Too many tasks in queue");
+    return;
+  }
+
+  for (const task of tasks) {
+    task.status = "queued";
+    queue.add(task);
+  }
 }
 
 export function deleteTask(task: QueueTask): void {
@@ -58,10 +74,18 @@ export function clearStaging(): void {
 }
 
 export function stageSpv(task: StageTask): void {
+  if (queue.size + task.devices.length > MAX_QUEUE) {
+    notifications.push("error", "Too many tasks in queue");
+    return;
+  }
   staging.add(task);
 }
 
 export function stageDownload(task: StageTask): void {
+  if (queue.size + task.devices.length > MAX_QUEUE) {
+    notifications.push("error", "Too many tasks in queue");
+    return;
+  }
   staging.add(task);
 }
 
@@ -75,10 +99,15 @@ export function commit(
   ) => void
 ): Promise<void> {
   const devices: { [deviceId: string]: any[] } = {};
+
+  if (!canQueue(tasks))
+    return Promise.reject(new Error("Too many tasks in queue"));
+
   for (const t of tasks) {
     devices[t.device] = devices[t.device] || [];
     devices[t.device].push(t);
-    queueTask(t);
+    t.status = "queued";
+    queue.add(t);
   }
 
   return new Promise((resolve) => {