Merge pull request #47 from crupest/avatar-enhance

Use etag for avatar cache.

12 files changed, 400 insertions, 27 deletions

diff --git a/Timeline/Controllers/UserAvatarController.cs b/Timeline/Controllers/UserAvatarController.cs
index ffadcb86..964c9b98 100644
--- a/Timeline/Controllers/UserAvatarController.cs
+++ b/Timeline/Controllers/UserAvatarController.cs
@@ -2,7 +2,9 @@
 using Microsoft.AspNetCore.Http;

 using Microsoft.AspNetCore.Mvc;

 using Microsoft.Extensions.Logging;

+using Microsoft.Net.Http.Headers;

 using System;

+using System.Linq;

 using System.Threading.Tasks;

 using Timeline.Authenticate;

 using Timeline.Filters;

@@ -61,22 +63,23 @@ namespace Timeline.Controllers
         [Authorize]

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

         {

-            const string IfModifiedSinceHeaderKey = "If-Modified-Since";

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

             try

             {

-                var avatarInfo = await _service.GetAvatar(username);

-                var avatar = avatarInfo.Avatar;

-                if (Request.Headers.TryGetValue(IfModifiedSinceHeaderKey, out var value))

+                var eTag = new EntityTagHeaderValue($"\"{await _service.GetAvatarETag(username)}\"");

+

+                if (Request.Headers.TryGetValue(IfNonMatchHeaderKey, out var value))

                 {

-                    var t = DateTime.Parse(value);

-                    if (t > avatarInfo.LastModified)

-                    {

-                        Response.Headers.Add(IfModifiedSinceHeaderKey, avatarInfo.LastModified.ToString("r"));

+                    if (!EntityTagHeaderValue.TryParseStrictList(value, out var eTagList))

+                        return BadRequest(CommonResponse.BadIfNonMatch());

+

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

                         return StatusCode(StatusCodes.Status304NotModified);

-                    }

                 }

 

-                return File(avatar.Data, avatar.Type, new DateTimeOffset(avatarInfo.LastModified), null);

+                var avatarInfo = await _service.GetAvatar(username);

+                var avatar = avatarInfo.Avatar;

+                return File(avatar.Data, avatar.Type, new DateTimeOffset(avatarInfo.LastModified), eTag);

             }

             catch (UserNotExistException e)

             {

diff --git a/Timeline/Entities/DatabaseContext.cs b/Timeline/Entities/DatabaseContext.cs
index bc06b9df..6e1fc638 100644
--- a/Timeline/Entities/DatabaseContext.cs
+++ b/Timeline/Entities/DatabaseContext.cs
@@ -43,7 +43,7 @@ namespace Timeline.Entities
         protected override void OnModelCreating(ModelBuilder modelBuilder)

         {

             modelBuilder.Entity<User>().Property(e => e.Version).HasDefaultValue(0);

-            modelBuilder.Entity<User>().HasIndex(e => e.Name);

+            modelBuilder.Entity<User>().HasIndex(e => e.Name).IsUnique();

         }

 

         public DbSet<User> Users { get; set; }

diff --git a/Timeline/Entities/UserAvatar.cs b/Timeline/Entities/UserAvatar.cs
index b941445d..d549aea5 100644
--- a/Timeline/Entities/UserAvatar.cs
+++ b/Timeline/Entities/UserAvatar.cs
@@ -16,6 +16,9 @@ namespace Timeline.Entities
         [Column("type")]

         public string Type { get; set; }

 

+        [Column("etag"), MaxLength(30)]

+        public string ETag { get; set; }

+

         [Column("last_modified"), Required]

         public DateTime LastModified { get; set; }

 

@@ -28,6 +31,7 @@ namespace Timeline.Entities
                 Id = 0,

                 Data = null,

                 Type = null,

+                ETag = null,

                 LastModified = lastModified

             };

         }

diff --git a/Timeline/Migrations/20190820155221_AddAvatarETag.Designer.cs b/Timeline/Migrations/20190820155221_AddAvatarETag.Designer.cs
new file mode 100644
index 00000000..e7c7cb2f
--- /dev/null
+++ b/Timeline/Migrations/20190820155221_AddAvatarETag.Designer.cs
@@ -0,0 +1,92 @@
+// <auto-generated />

+using System;

+using Microsoft.EntityFrameworkCore;

+using Microsoft.EntityFrameworkCore.Infrastructure;

+using Microsoft.EntityFrameworkCore.Migrations;

+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;

+using Timeline.Entities;

+

+namespace Timeline.Migrations

+{

+    [DbContext(typeof(DatabaseContext))]

+    [Migration("20190820155221_AddAvatarETag")]

+    partial class AddAvatarETag

+    {

+        protected override void BuildTargetModel(ModelBuilder modelBuilder)

+        {

+#pragma warning disable 612, 618

+            modelBuilder

+                .HasAnnotation("ProductVersion", "2.2.6-servicing-10079")

+                .HasAnnotation("Relational:MaxIdentifierLength", 64);

+

+            modelBuilder.Entity("Timeline.Entities.User", b =>

+                {

+                    b.Property<long>("Id")

+                        .ValueGeneratedOnAdd()

+                        .HasColumnName("id");

+

+                    b.Property<string>("EncryptedPassword")

+                        .IsRequired()

+                        .HasColumnName("password");

+

+                    b.Property<string>("Name")

+                        .IsRequired()

+                        .HasColumnName("name")

+                        .HasMaxLength(26);

+

+                    b.Property<string>("RoleString")

+                        .IsRequired()

+                        .HasColumnName("roles");

+

+                    b.Property<long>("Version")

+                        .ValueGeneratedOnAdd()

+                        .HasColumnName("version")

+                        .HasDefaultValue(0L);

+

+                    b.HasKey("Id");

+

+                    b.HasIndex("Name");

+

+                    b.ToTable("users");

+                });

+

+            modelBuilder.Entity("Timeline.Entities.UserAvatar", b =>

+                {

+                    b.Property<long>("Id")

+                        .ValueGeneratedOnAdd()

+                        .HasColumnName("id");

+

+                    b.Property<byte[]>("Data")

+                        .HasColumnName("data");

+

+                    b.Property<string>("ETag")

+                        .HasColumnName("etag")

+                        .HasMaxLength(30);

+

+                    b.Property<DateTime>("LastModified")

+                        .HasColumnName("last_modified");

+

+                    b.Property<string>("Type")

+                        .HasColumnName("type");

+

+                    b.Property<long>("UserId");

+

+                    b.HasKey("Id");

+

+                    b.HasIndex("UserId")

+                        .IsUnique();

+

+                    b.ToTable("user_avatars");

+                });

+

+            modelBuilder.Entity("Timeline.Entities.UserAvatar", b =>

+                {

+                    b.HasOne("Timeline.Entities.User")

+                        .WithOne("Avatar")

+                        .HasForeignKey("Timeline.Entities.UserAvatar", "UserId")

+                        .OnDelete(DeleteBehavior.Cascade);

+                });

+#pragma warning restore 612, 618

+        }

+    }

+}

diff --git a/Timeline/Migrations/20190820155221_AddAvatarETag.cs b/Timeline/Migrations/20190820155221_AddAvatarETag.cs
new file mode 100644
index 00000000..db352b5d
--- /dev/null
+++ b/Timeline/Migrations/20190820155221_AddAvatarETag.cs
@@ -0,0 +1,23 @@
+using Microsoft.EntityFrameworkCore.Migrations;

+

+namespace Timeline.Migrations

+{

+    public partial class AddAvatarETag : Migration

+    {

+        protected override void Up(MigrationBuilder migrationBuilder)

+        {

+            migrationBuilder.AddColumn<string>(

+                name: "etag",

+                table: "user_avatars",

+                maxLength: 30,

+                nullable: true);

+        }

+

+        protected override void Down(MigrationBuilder migrationBuilder)

+        {

+            migrationBuilder.DropColumn(

+                name: "etag",

+                table: "user_avatars");

+        }

+    }

+}

diff --git a/Timeline/Migrations/20190820155354_MakeUserNameIndexUnique.Designer.cs b/Timeline/Migrations/20190820155354_MakeUserNameIndexUnique.Designer.cs
new file mode 100644
index 00000000..420cd41c
--- /dev/null
+++ b/Timeline/Migrations/20190820155354_MakeUserNameIndexUnique.Designer.cs
@@ -0,0 +1,93 @@
+// <auto-generated />

+using System;

+using Microsoft.EntityFrameworkCore;

+using Microsoft.EntityFrameworkCore.Infrastructure;

+using Microsoft.EntityFrameworkCore.Migrations;

+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;

+using Timeline.Entities;

+

+namespace Timeline.Migrations

+{

+    [DbContext(typeof(DatabaseContext))]

+    [Migration("20190820155354_MakeUserNameIndexUnique")]

+    partial class MakeUserNameIndexUnique

+    {

+        protected override void BuildTargetModel(ModelBuilder modelBuilder)

+        {

+#pragma warning disable 612, 618

+            modelBuilder

+                .HasAnnotation("ProductVersion", "2.2.6-servicing-10079")

+                .HasAnnotation("Relational:MaxIdentifierLength", 64);

+

+            modelBuilder.Entity("Timeline.Entities.User", b =>

+                {

+                    b.Property<long>("Id")

+                        .ValueGeneratedOnAdd()

+                        .HasColumnName("id");

+

+                    b.Property<string>("EncryptedPassword")

+                        .IsRequired()

+                        .HasColumnName("password");

+

+                    b.Property<string>("Name")

+                        .IsRequired()

+                        .HasColumnName("name")

+                        .HasMaxLength(26);

+

+                    b.Property<string>("RoleString")

+                        .IsRequired()

+                        .HasColumnName("roles");

+

+                    b.Property<long>("Version")

+                        .ValueGeneratedOnAdd()

+                        .HasColumnName("version")

+                        .HasDefaultValue(0L);

+

+                    b.HasKey("Id");

+

+                    b.HasIndex("Name")

+                        .IsUnique();

+

+                    b.ToTable("users");

+                });

+

+            modelBuilder.Entity("Timeline.Entities.UserAvatar", b =>

+                {

+                    b.Property<long>("Id")

+                        .ValueGeneratedOnAdd()

+                        .HasColumnName("id");

+

+                    b.Property<byte[]>("Data")

+                        .HasColumnName("data");

+

+                    b.Property<string>("ETag")

+                        .HasColumnName("etag")

+                        .HasMaxLength(30);

+

+                    b.Property<DateTime>("LastModified")

+                        .HasColumnName("last_modified");

+

+                    b.Property<string>("Type")

+                        .HasColumnName("type");

+

+                    b.Property<long>("UserId");

+

+                    b.HasKey("Id");

+

+                    b.HasIndex("UserId")

+                        .IsUnique();

+

+                    b.ToTable("user_avatars");

+                });

+

+            modelBuilder.Entity("Timeline.Entities.UserAvatar", b =>

+                {

+                    b.HasOne("Timeline.Entities.User")

+                        .WithOne("Avatar")

+                        .HasForeignKey("Timeline.Entities.UserAvatar", "UserId")

+                        .OnDelete(DeleteBehavior.Cascade);

+                });

+#pragma warning restore 612, 618

+        }

+    }

+}

diff --git a/Timeline/Migrations/20190820155354_MakeUserNameIndexUnique.cs b/Timeline/Migrations/20190820155354_MakeUserNameIndexUnique.cs
new file mode 100644
index 00000000..01d72450
--- /dev/null
+++ b/Timeline/Migrations/20190820155354_MakeUserNameIndexUnique.cs
@@ -0,0 +1,32 @@
+using Microsoft.EntityFrameworkCore.Migrations;

+

+namespace Timeline.Migrations

+{

+    public partial class MakeUserNameIndexUnique : Migration

+    {

+        protected override void Up(MigrationBuilder migrationBuilder)

+        {

+            migrationBuilder.DropIndex(

+                name: "IX_users_name",

+                table: "users");

+

+            migrationBuilder.CreateIndex(

+                name: "IX_users_name",

+                table: "users",

+                column: "name",

+                unique: true);

+        }

+

+        protected override void Down(MigrationBuilder migrationBuilder)

+        {

+            migrationBuilder.DropIndex(

+                name: "IX_users_name",

+                table: "users");

+

+            migrationBuilder.CreateIndex(

+                name: "IX_users_name",

+                table: "users",

+                column: "name");

+        }

+    }

+}

diff --git a/Timeline/Migrations/DatabaseContextModelSnapshot.cs b/Timeline/Migrations/DatabaseContextModelSnapshot.cs
index 0eb85997..4941321c 100644
--- a/Timeline/Migrations/DatabaseContextModelSnapshot.cs
+++ b/Timeline/Migrations/DatabaseContextModelSnapshot.cs
@@ -43,7 +43,8 @@ namespace Timeline.Migrations
 

                     b.HasKey("Id");

 

-                    b.HasIndex("Name");

+                    b.HasIndex("Name")

+                        .IsUnique();

 

                     b.ToTable("users");

                 });

@@ -57,6 +58,10 @@ namespace Timeline.Migrations
                     b.Property<byte[]>("Data")

                         .HasColumnName("data");

 

+                    b.Property<string>("ETag")

+                        .HasColumnName("etag")

+                        .HasMaxLength(30);

+

                     b.Property<DateTime>("LastModified")

                         .HasColumnName("last_modified");

 

diff --git a/Timeline/Models/Http/Common.cs b/Timeline/Models/Http/Common.cs
index 50f6836e..a72f187c 100644
--- a/Timeline/Models/Http/Common.cs
+++ b/Timeline/Models/Http/Common.cs
@@ -13,6 +13,7 @@ namespace Timeline.Models.Http
             public const int Header_Missing_ContentType = -111;

             public const int Header_Missing_ContentLength = -112;

             public const int Header_Zero_ContentLength = -113;

+            public const int Header_BadFormat_IfNonMatch = -114;

         }

 

         public static CommonResponse InvalidModel(string message)

@@ -35,6 +36,11 @@ namespace Timeline.Models.Http
             return new CommonResponse(ErrorCodes.Header_Zero_ContentLength, "Header Content-Length must not be 0.");

         }

 

+        public static CommonResponse BadIfNonMatch()

+        {

+            return new CommonResponse(ErrorCodes.Header_BadFormat_IfNonMatch, "Header If-Non-Match is of bad format.");

+        }

+

         public CommonResponse()

         {

 

diff --git a/Timeline/Services/DatabaseCorruptedException.cs b/Timeline/Services/DatabaseCorruptedException.cs
new file mode 100644
index 00000000..9988e0ad
--- /dev/null
+++ b/Timeline/Services/DatabaseCorruptedException.cs
@@ -0,0 +1,15 @@
+using System;

+

+namespace Timeline.Services

+{

+    [Serializable]

+    public class DatabaseCorruptedException : Exception

+    {

+        public DatabaseCorruptedException() { }

+        public DatabaseCorruptedException(string message) : base(message) { }

+        public DatabaseCorruptedException(string message, Exception inner) : base(message, inner) { }

+        protected DatabaseCorruptedException(

+          System.Runtime.Serialization.SerializationInfo info,

+          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

+    }

+}

diff --git a/Timeline/Services/ETagGenerator.cs b/Timeline/Services/ETagGenerator.cs
new file mode 100644
index 00000000..e2abebdc
--- /dev/null
+++ b/Timeline/Services/ETagGenerator.cs
@@ -0,0 +1,33 @@
+using System;

+using System.Security.Cryptography;

+

+namespace Timeline.Services

+{

+    public interface IETagGenerator

+    {

+        string Generate(byte[] source);

+    }

+

+    public class ETagGenerator : IETagGenerator, IDisposable

+    {

+        private readonly SHA1 _sha1;

+

+        public ETagGenerator()

+        {

+            _sha1 = SHA1.Create();

+        }

+

+        public string Generate(byte[] source)

+        {

+            if (source == null || source.Length == 0)

+                throw new ArgumentException("Source is null or empty.", nameof(source));

+

+            return Convert.ToBase64String(_sha1.ComputeHash(source));

+        }

+

+        public void Dispose()

+        {

+            _sha1.Dispose();

+        }

+    }

+}

diff --git a/Timeline/Services/UserAvatarService.cs b/Timeline/Services/UserAvatarService.cs
index a83b8a52..7b1f405c 100644
--- a/Timeline/Services/UserAvatarService.cs
+++ b/Timeline/Services/UserAvatarService.cs
@@ -1,6 +1,7 @@
 using Microsoft.AspNetCore.Hosting;

 using Microsoft.EntityFrameworkCore;

 using Microsoft.Extensions.DependencyInjection;

+using Microsoft.Extensions.DependencyInjection.Extensions;

 using Microsoft.Extensions.Logging;

 using SixLabors.ImageSharp;

 using SixLabors.ImageSharp.Formats;

@@ -65,6 +66,12 @@ namespace Timeline.Services
     public interface IDefaultUserAvatarProvider

     {

         /// <summary>

+        /// Get the etag of default avatar.

+        /// </summary>

+        /// <returns></returns>

+        Task<string> GetDefaultAvatarETag();

+

+        /// <summary>

         /// Get the default avatar.

         /// </summary>

         Task<AvatarInfo> GetDefaultAvatar();

@@ -83,6 +90,15 @@ namespace Timeline.Services
     public interface IUserAvatarService

     {

         /// <summary>

+        /// Get the etag of a user's avatar.

+        /// </summary>

+        /// <param name="username">The username of the user to get avatar etag of.</param>

+        /// <returns>The etag.</returns>

+        /// <exception cref="ArgumentException">Thrown if <paramref name="username"/> is null or empty.</exception>

+        /// <exception cref="UserNotExistException">Thrown if the user does not exist.</exception>

+        Task<string> GetAvatarETag(string username);

+

+        /// <summary>

         /// Get avatar of a user. If the user has no avatar, a default one is returned.

         /// </summary>

         /// <param name="username">The username of the user to get avatar of.</param>

@@ -107,22 +123,46 @@ namespace Timeline.Services
     {

         private readonly IHostingEnvironment _environment;

 

-        public DefaultUserAvatarProvider(IHostingEnvironment environment)

+        private readonly IETagGenerator _eTagGenerator;

+

+        private byte[] _cacheData;

+        private DateTime _cacheLastModified;

+        private string _cacheETag;

+

+        public DefaultUserAvatarProvider(IHostingEnvironment environment, IETagGenerator eTagGenerator)

         {

             _environment = environment;

+            _eTagGenerator = eTagGenerator;

         }

 

-        public async Task<AvatarInfo> GetDefaultAvatar()

+        private async Task CheckAndInit()

         {

+            if (_cacheData != null)

+                return;

+

             var path = Path.Combine(_environment.ContentRootPath, "default-avatar.png");

+            _cacheData = await File.ReadAllBytesAsync(path);

+            _cacheLastModified = File.GetLastWriteTime(path);

+            _cacheETag = _eTagGenerator.Generate(_cacheData);

+        }

+

+        public async Task<string> GetDefaultAvatarETag()

+        {

+            await CheckAndInit();

+            return _cacheETag;

+        }

+

+        public async Task<AvatarInfo> GetDefaultAvatar()

+        {

+            await CheckAndInit();

             return new AvatarInfo

             {

                 Avatar = new Avatar

                 {

                     Type = "image/png",

-                    Data = await File.ReadAllBytesAsync(path)

+                    Data = _cacheData

                 },

-                LastModified = File.GetLastWriteTime(path)

+                LastModified = _cacheLastModified

             };

         }

     }

@@ -161,12 +201,36 @@ namespace Timeline.Services
         private readonly IDefaultUserAvatarProvider _defaultUserAvatarProvider;

         private readonly IUserAvatarValidator _avatarValidator;

 

-        public UserAvatarService(ILogger<UserAvatarService> logger, DatabaseContext database, IDefaultUserAvatarProvider defaultUserAvatarProvider, IUserAvatarValidator avatarValidator)

+        private readonly IETagGenerator _eTagGenerator;

+

+        public UserAvatarService(

+            ILogger<UserAvatarService> logger,

+            DatabaseContext database,

+            IDefaultUserAvatarProvider defaultUserAvatarProvider,

+            IUserAvatarValidator avatarValidator,

+            IETagGenerator eTagGenerator)

         {

             _logger = logger;

             _database = database;

             _defaultUserAvatarProvider = defaultUserAvatarProvider;

             _avatarValidator = avatarValidator;

+            _eTagGenerator = eTagGenerator;

+        }

+

+        public async Task<string> GetAvatarETag(string username)

+        {

+            if (string.IsNullOrEmpty(username))

+                throw new ArgumentException("Username is null or empty.", nameof(username));

+

+            var userId = await _database.Users.Where(u => u.Name == username).Select(u => u.Id).SingleOrDefaultAsync();

+            if (userId == 0)

+                throw new UserNotExistException(username);

+

+            var eTag = (await _database.UserAvatars.Where(a => a.UserId == userId).Select(a => new { a.ETag }).SingleAsync()).ETag;

+            if (eTag == null)

+                return await _defaultUserAvatarProvider.GetDefaultAvatarETag();

+            else

+                return eTag;

         }

 

         public async Task<AvatarInfo> GetAvatar(string username)

@@ -174,16 +238,17 @@ namespace Timeline.Services
             if (string.IsNullOrEmpty(username))

                 throw new ArgumentException("Username is null or empty.", nameof(username));

 

-            var user = await _database.Users.Where(u => u.Name == username).SingleOrDefaultAsync();

-            if (user == null)

+            var userId = await _database.Users.Where(u => u.Name == username).Select(u => u.Id).SingleOrDefaultAsync();

+            if (userId == 0)

                 throw new UserNotExistException(username);

 

-            await _database.Entry(user).Reference(u => u.Avatar).LoadAsync();

-            var avatar = user.Avatar;

+            var avatar = await _database.UserAvatars.Where(a => a.UserId == userId).Select(a => new { a.Type, a.Data, a.LastModified }).SingleAsync();

 

-            if ((avatar.Type == null) == (avatar.Data == null))

+            if ((avatar.Type == null) != (avatar.Data == null))

+            {

                 _logger.LogCritical("Database corupted! One of type and data of a avatar is null but the other is not.");

-                // TODO: Throw an exception to indicate this.

+                throw new DatabaseCorruptedException();

+            }

 

             if (avatar.Data == null)

             {

@@ -218,12 +283,11 @@ namespace Timeline.Services
                     throw new ArgumentException("Data of avatar is null.", nameof(avatar));

             }

 

-            var user = await _database.Users.Where(u => u.Name == username).SingleOrDefaultAsync();

-            if (user == null)

+            var userId = await _database.Users.Where(u => u.Name == username).Select(u => u.Id).SingleOrDefaultAsync();

+            if (userId == 0)

                 throw new UserNotExistException(username);

 

-            await _database.Entry(user).Reference(u => u.Avatar).LoadAsync();

-            var avatarEntity = user.Avatar;

+            var avatarEntity = await _database.UserAvatars.Where(a => a.UserId == userId).SingleAsync();

 

             if (avatar == null)

             {

@@ -233,6 +297,7 @@ namespace Timeline.Services
                 {

                     avatarEntity.Data = null;

                     avatarEntity.Type = null;

+                    avatarEntity.ETag = null;

                     avatarEntity.LastModified = DateTime.Now;

                     await _database.SaveChangesAsync();

                     _logger.LogInformation("Updated an entry in user_avatars.");

@@ -243,6 +308,7 @@ namespace Timeline.Services
                 await _avatarValidator.Validate(avatar);

                 avatarEntity.Type = avatar.Type;

                 avatarEntity.Data = avatar.Data;

+                avatarEntity.ETag = _eTagGenerator.Generate(avatar.Data);

                 avatarEntity.LastModified = DateTime.Now;

                 await _database.SaveChangesAsync();

                 _logger.LogInformation("Updated an entry in user_avatars.");

@@ -254,6 +320,7 @@ namespace Timeline.Services
     {

         public static void AddUserAvatarService(this IServiceCollection services)

         {

+            services.TryAddTransient<IETagGenerator, ETagGenerator>();

             services.AddScoped<IUserAvatarService, UserAvatarService>();

             services.AddSingleton<IDefaultUserAvatarProvider, DefaultUserAvatarProvider>();

             services.AddSingleton<IUserAvatarValidator, UserAvatarValidator>();