Add cache for timeline post data.

4 files changed, 74 insertions, 10 deletions

diff --git a/Timeline/Controllers/TimelineController.cs b/Timeline/Controllers/TimelineController.cs
index 58390c29..8bc0345f 100644
--- a/Timeline/Controllers/TimelineController.cs
+++ b/Timeline/Controllers/TimelineController.cs
@@ -9,6 +9,7 @@ using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;

 using System.Threading.Tasks;

 using Timeline.Filters;

+using Timeline.Helpers;

 using Timeline.Models;

 using Timeline.Models.Http;

 using Timeline.Models.Validation;

@@ -114,7 +115,6 @@ namespace Timeline.Controllers
             return result;

         }

 

-        // TODO: Make cache available.

         [HttpGet("timelines/{name}/posts/{id}/data")]

         public async Task<ActionResult<List<TimelinePostInfo>>> PostDataGet([FromRoute][GeneralTimelineName] string name, [FromRoute] long id)

         {

@@ -125,8 +125,11 @@ namespace Timeline.Controllers
 

             try

             {

-                var data = await _service.GetPostData(name, id);

-                return File(data.Data, data.Type, data.LastModified, new EntityTagHeaderValue($"\"{data.ETag}\""));

+                return await DataCacheHelper.GenerateActionResult(this, () => _service.GetPostDataETag(name, id), async () =>

+                {

+                    var data = await _service.GetPostData(name, id);

+                    return data;

+                });

             }

             catch (TimelinePostNotExistException)

             {

diff --git a/Timeline/Controllers/UserAvatarController.cs b/Timeline/Controllers/UserAvatarController.cs
index f78dcb08..b5f4be1e 100644
--- a/Timeline/Controllers/UserAvatarController.cs
+++ b/Timeline/Controllers/UserAvatarController.cs
@@ -32,7 +32,6 @@ namespace Timeline.Controllers
         }

 

         [HttpGet("users/{username}/avatar")]

-        [ResponseCache(NoStore = false, Location = ResponseCacheLocation.None, Duration = 0)]

         public async Task<IActionResult> Get([FromRoute][Username] string username)

         {

             long id;

diff --git a/Timeline/Helpers/DataCacheHelper.cs b/Timeline/Helpers/DataCacheHelper.cs
index c13aaddb..574d90b4 100644
--- a/Timeline/Helpers/DataCacheHelper.cs
+++ b/Timeline/Helpers/DataCacheHelper.cs
@@ -66,11 +66,25 @@ namespace Timeline.Helpers
 

     public static class DataCacheHelper

     {

-        public static async Task<ActionResult> GenerateActionResult(Controller controller, ICacheableDataProvider provider)

+        public static async Task<ActionResult> GenerateActionResult(Controller controller, ICacheableDataProvider provider, TimeSpan? maxAge = null)

         {

+            const string CacheControlHeaderKey = "Cache-Control";

             const string IfNonMatchHeaderKey = "If-None-Match";

             const string ETagHeaderKey = "ETag";

 

+            string GenerateCacheControlHeaderValue()

+            {

+                var cacheControlHeader = new CacheControlHeaderValue()

+                {

+                    NoCache = true,

+                    NoStore = false,

+                    MaxAge = maxAge ?? TimeSpan.FromDays(14),

+                    Private = true,

+                    MustRevalidate = true

+                };

+                return cacheControlHeader.ToString();

+            }

+

             var loggerFactory = controller.HttpContext.RequestServices.GetRequiredService<ILoggerFactory>();

             var logger = loggerFactory.CreateLogger(typeof(DataCacheHelper));

 

@@ -89,20 +103,23 @@ namespace Timeline.Helpers
 

                 if (eTagList.FirstOrDefault(e => e.Equals(eTag)) != null)

                 {

-                    controller.Response.Headers.Add(ETagHeaderKey, eTagValue);

                     logger.LogInformation(LogResultNotModified);

+                    controller.Response.Headers.Add(ETagHeaderKey, eTagValue);

+                    controller.Response.Headers.Add(CacheControlHeaderKey, GenerateCacheControlHeaderValue());

+

                     return controller.StatusCode(StatusCodes.Status304NotModified);

                 }

             }

 

             var data = await provider.GetData();

             logger.LogInformation(LogResultData);

+            controller.Response.Headers.Add(CacheControlHeaderKey, GenerateCacheControlHeaderValue());

             return controller.File(data.Data, data.Type, data.LastModified, eTag);

         }

 

-        public static Task<ActionResult> GenerateActionResult(Controller controller, Func<Task<string>> getDataETagDelegate, Func<Task<ICacheableData>> getDataDelegate)

+        public static Task<ActionResult> GenerateActionResult(Controller controller, Func<Task<string>> getDataETagDelegate, Func<Task<ICacheableData>> getDataDelegate, TimeSpan? maxAge = null)

         {

-            return GenerateActionResult(controller, new DelegateCacheableDataProvider(getDataETagDelegate, getDataDelegate));

+            return GenerateActionResult(controller, new DelegateCacheableDataProvider(getDataETagDelegate, getDataDelegate), maxAge);

         }

     }

 }

diff --git a/Timeline/Services/TimelineService.cs b/Timeline/Services/TimelineService.cs
index 301a1d97..b26016e5 100644
--- a/Timeline/Services/TimelineService.cs
+++ b/Timeline/Services/TimelineService.cs
@@ -7,6 +7,7 @@ using System.Globalization;
 using System.Linq;

 using System.Threading.Tasks;

 using Timeline.Entities;

+using Timeline.Helpers;

 using Timeline.Models;

 using Timeline.Models.Validation;

 using static Timeline.Resources.Services.TimelineService;

@@ -32,14 +33,14 @@ namespace Timeline.Services
         public long UserId { get; set; }

     }

 

-    public class PostData

+    public class PostData : ICacheableData

     {

 #pragma warning disable CA1819 // Properties should not return arrays

         public byte[] Data { get; set; } = default!;

 #pragma warning restore CA1819 // Properties should not return arrays

         public string Type { get; set; } = default!;

         public string ETag { get; set; } = default!;

-        public DateTime LastModified { get; set; } = default!;

+        public DateTime? LastModified { get; set; }

     }

 

     /// <summary>

@@ -92,6 +93,20 @@ namespace Timeline.Services
         Task<List<TimelinePost>> GetPosts(string name);

 

         /// <summary>

+        /// Get the etag of data of a post.

+        /// </summary>

+        /// <param name="name">See remarks of <see cref="IBaseTimelineService"/>.</param>

+        /// <param name="postId">The id of the post.</param>

+        /// <returns>The etag of the data.</returns>

+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="name"/> is null.</exception>

+        /// <exception cref="ArgumentException">See remarks of <see cref="IBaseTimelineService"/>.</exception>

+        /// <exception cref="TimelineNotExistException">See remarks of <see cref="IBaseTimelineService"/>.</exception>

+        /// <exception cref="TimelinePostNotExistException">Thrown when post of <paramref name="postId"/> does not exist or has been deleted.</exception>

+        /// <exception cref="InvalidOperationException">Thrown when post has no data. See remarks.</exception>

+        /// <seealso cref="GetPostData(string, long)"/>

+        Task<string> GetPostDataETag(string name, long postId);

+

+        /// <summary>

         /// Get the data of a post.

         /// </summary>

         /// <param name="name">See remarks of <see cref="IBaseTimelineService"/>.</param>

@@ -105,6 +120,7 @@ namespace Timeline.Services
         /// <remarks>

         /// Use this method to retrieve the image of image post.

         /// </remarks>

+        /// <seealso cref="GetPostDataETag(string, long)"/>

         Task<PostData> GetPostData(string name, long postId);

 

         /// <summary>

@@ -402,6 +418,29 @@ namespace Timeline.Services
             }

             return posts;

         }

+

+        public async Task<string> GetPostDataETag(string name, long postId)

+        {

+            if (name == null)

+                throw new ArgumentNullException(nameof(name));

+

+            var timelineId = await FindTimelineId(name);

+            var postEntity = await Database.TimelinePosts.Where(p => p.LocalId == postId).SingleOrDefaultAsync();

+

+            if (postEntity == null)

+                throw new TimelinePostNotExistException(name, postId);

+

+            if (postEntity.Content == null)

+                throw new TimelinePostNotExistException(name, postId, true);

+

+            if (postEntity.ContentType != TimelinePostContentTypes.Image)

+                throw new InvalidOperationException(ExceptionGetDataNonImagePost);

+

+            var tag = postEntity.Content;

+

+            return tag;

+        }

+

         public async Task<PostData> GetPostData(string name, long postId)

         {

             if (name == null)

@@ -1014,6 +1053,12 @@ namespace Timeline.Services
             return s.GetPosts(realName);

         }

 

+        public Task<string> GetPostDataETag(string name, long postId)

+        {

+            var s = BranchName(name, out var realName);

+            return s.GetPostDataETag(realName, postId);

+        }

+

         public Task<PostData> GetPostData(string name, long postId)

         {

             var s = BranchName(name, out var realName);