From b90a32307906d7ffb1b94064fef2dcdc3e5ccb84 Mon Sep 17 00:00:00 2001
From: Nate-Wessel <nate.wessel@toronto.ca>
Date: Thu, 11 Jul 2024 20:12:53 +0000
Subject: [PATCH] implement queue for travel time promises

---
 frontend/package-lock.json  | 32 ++++++++++++++++++++++++++++++++
 frontend/package.json       |  1 +
 frontend/src/spatialData.js |  7 +++++--
 3 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/frontend/package-lock.json b/frontend/package-lock.json
index 3262e35..2c17e81 100644
--- a/frontend/package-lock.json
+++ b/frontend/package-lock.json
@@ -14,6 +14,7 @@
                 "@mui/material": "5.x",
                 "express": "^4.18.2",
                 "leaflet": "^1.9.4",
+                "p-queue": "^8.0.1",
                 "react": "18.x",
                 "react-calendar": "^4.6.1",
                 "react-date-picker": "^8.4.0",
@@ -4447,6 +4448,11 @@
                 "node": ">= 0.6"
             }
         },
+        "node_modules/eventemitter3": {
+            "version": "5.0.1",
+            "resolved": "https://registry.npmjs.org/eventemitter3/-/eventemitter3-5.0.1.tgz",
+            "integrity": "sha512-GWkBvjiSZK87ELrYOSESUYeVIc9mvLLf/nXalMOS5dYrgZq9o5OVkbZAVM06CVxYsCwH9BDZFPlQTlPA1j4ahA=="
+        },
         "node_modules/events": {
             "version": "3.3.0",
             "resolved": "https://registry.npmjs.org/events/-/events-3.3.0.tgz",
@@ -6518,6 +6524,32 @@
                 "node": ">=6"
             }
         },
+        "node_modules/p-queue": {
+            "version": "8.0.1",
+            "resolved": "https://registry.npmjs.org/p-queue/-/p-queue-8.0.1.tgz",
+            "integrity": "sha512-NXzu9aQJTAzbBqOt2hwsR63ea7yvxJc0PwN/zobNAudYfb1B7R08SzB4TsLeSbUCuG467NhnoT0oO6w1qRO+BA==",
+            "dependencies": {
+                "eventemitter3": "^5.0.1",
+                "p-timeout": "^6.1.2"
+            },
+            "engines": {
+                "node": ">=18"
+            },
+            "funding": {
+                "url": "https://github.com/sponsors/sindresorhus"
+            }
+        },
+        "node_modules/p-timeout": {
+            "version": "6.1.2",
+            "resolved": "https://registry.npmjs.org/p-timeout/-/p-timeout-6.1.2.tgz",
+            "integrity": "sha512-UbD77BuZ9Bc9aABo74gfXhNvzC9Tx7SxtHSh1fxvx3jTLLYvmVhiQZZrJzqqU0jKbN32kb5VOKiLEQI/3bIjgQ==",
+            "engines": {
+                "node": ">=14.16"
+            },
+            "funding": {
+                "url": "https://github.com/sponsors/sindresorhus"
+            }
+        },
         "node_modules/p-try": {
             "version": "2.2.0",
             "resolved": "https://registry.npmjs.org/p-try/-/p-try-2.2.0.tgz",
diff --git a/frontend/package.json b/frontend/package.json
index c295608..79e3ae5 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -46,6 +46,7 @@
         "@mui/material": "5.x",
         "express": "^4.18.2",
         "leaflet": "^1.9.4",
+        "p-queue": "^8.0.1",
         "react": "18.x",
         "react-calendar": "^4.6.1",
         "react-date-picker": "^8.4.0",
diff --git a/frontend/src/spatialData.js b/frontend/src/spatialData.js
index 6f45eec..b874547 100644
--- a/frontend/src/spatialData.js
+++ b/frontend/src/spatialData.js
@@ -5,6 +5,9 @@ import { Days } from './days.js'
 import { HolidayOption } from './holidayOption.js'
 import { TravelTimeQuery } from './travelTimeQuery.js'
 import { domain } from './domain.js'
+import PQueue from 'p-queue'
+
+const queue = new PQueue({concurrency: 3})
 
 // instantiated once, this is the data store for all spatial and temporal data
 export class SpatialData {
@@ -116,10 +119,10 @@ export class SpatialData {
         return [...this.#queries.values()].sort((a,b)=> a.URI < b.URI ? -1 : 1)
     }
     fetchAllResults(){
-        return Promise.all(
+        return queue.addAll(
             this.travelTimeQueries
                 .filter( TTQ => ! TTQ.hasData )
-                .map( TTQ => TTQ.fetchData() )
+                .map( TTQ => () => TTQ.fetchData() )
         )
     }
 }