From e03bc675d37337767108993c9397b92ec6ad8f8a Mon Sep 17 00:00:00 2001
From: "Collin M. Barrett" <collinbarrett@users.noreply.github.com>
Date: Sun, 12 Aug 2018 17:23:26 -0500
Subject: [PATCH] add 4-hr in-memory cache for key endpoints

ref #332
---
 .../Extensions/ConfigureServicesCollection.cs |  1 +
 .../V1/Controllers/BaseController.cs          | 12 +++++++++++-
 .../V1/Controllers/ListsController.cs         | 19 +++++++++++++++----
 3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/src/FilterLists.Api/DependencyInjection/Extensions/ConfigureServicesCollection.cs b/src/FilterLists.Api/DependencyInjection/Extensions/ConfigureServicesCollection.cs
index bbb244100..221ec482f 100644
--- a/src/FilterLists.Api/DependencyInjection/Extensions/ConfigureServicesCollection.cs
+++ b/src/FilterLists.Api/DependencyInjection/Extensions/ConfigureServicesCollection.cs
@@ -15,6 +15,7 @@ public static class ConfigureServicesCollection
         public static void AddFilterListsApi(this IServiceCollection services)
         {
             services.ConfigureCookiePolicy();
+            services.AddMemoryCache();
             services.AddMvcCustom();
             services.AddRoutingCustom();
             services.AddApiVersioning();
diff --git a/src/FilterLists.Api/V1/Controllers/BaseController.cs b/src/FilterLists.Api/V1/Controllers/BaseController.cs
index ff2f3ad3e..802749eb7 100644
--- a/src/FilterLists.Api/V1/Controllers/BaseController.cs
+++ b/src/FilterLists.Api/V1/Controllers/BaseController.cs
@@ -1,5 +1,7 @@
-using FilterLists.Services.Seed;
+using System;
+using FilterLists.Services.Seed;
 using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Caching.Memory;
 
 namespace FilterLists.Api.V1.Controllers
 {
@@ -8,6 +10,8 @@ namespace FilterLists.Api.V1.Controllers
     [Route("v{version:apiVersion}/[controller]")]
     public class BaseController : Controller
     {
+        protected readonly TimeSpan AbsoluteExpirationRelativeToNow = TimeSpan.FromHours(4);
+        protected readonly IMemoryCache MemoryCache;
         protected readonly SeedService SeedService;
 
         public BaseController()
@@ -15,5 +19,11 @@ public BaseController()
         }
 
         protected BaseController(SeedService seedService) => SeedService = seedService;
+
+        protected BaseController(IMemoryCache memoryCache, SeedService seedService)
+        {
+            MemoryCache = memoryCache;
+            SeedService = seedService;
+        }
     }
 }
\ No newline at end of file
diff --git a/src/FilterLists.Api/V1/Controllers/ListsController.cs b/src/FilterLists.Api/V1/Controllers/ListsController.cs
index 4d7c40841..85052babd 100644
--- a/src/FilterLists.Api/V1/Controllers/ListsController.cs
+++ b/src/FilterLists.Api/V1/Controllers/ListsController.cs
@@ -4,6 +4,7 @@
 using FilterLists.Services.Seed;
 using FilterLists.Services.Seed.Models;
 using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Caching.Memory;
 
 namespace FilterLists.Api.V1.Controllers
 {
@@ -11,16 +12,26 @@ public class ListsController : BaseController
     {
         private readonly FilterListService filterListService;
 
-        public ListsController(SeedService seedService, FilterListService filterListService) : base(seedService) =>
-            this.filterListService = filterListService;
+        public ListsController(IMemoryCache memoryCache, SeedService seedService, FilterListService filterListService) :
+            base(memoryCache, seedService) => this.filterListService = filterListService;
 
         [HttpGet]
-        public async Task<IActionResult> Index() => Json(await filterListService.GetAllSummariesAsync());
+        public async Task<IActionResult> Index() =>
+            Json(await MemoryCache.GetOrCreate("ListsController_Index", entry =>
+            {
+                entry.AbsoluteExpirationRelativeToNow = AbsoluteExpirationRelativeToNow;
+                return filterListService.GetAllSummariesAsync();
+            }));
 
         [HttpGet]
         [Route("{id}")]
         //TODO: respond with appropriate exception if negative id queried
-        public async Task<IActionResult> GetById(int id) => Json(await filterListService.GetDetailsAsync((uint) id));
+        public async Task<IActionResult> GetById(int id) =>
+            Json(await MemoryCache.GetOrCreate("ListsController_GetById_" + id, entry =>
+            {
+                entry.AbsoluteExpirationRelativeToNow = AbsoluteExpirationRelativeToNow;
+                return filterListService.GetDetailsAsync((uint)id);
+            }));
 
         [HttpGet("seed")]
         public async Task<IActionResult> Seed() => Json(await SeedService.GetAllAsync<FilterList, FilterListSeedDto>());