Abstract out data cache helper.

8 files changed, 345 insertions, 63 deletions

diff --git a/Timeline/Controllers/UserAvatarController.cs b/Timeline/Controllers/UserAvatarController.cs
index f4f3db3e..f78dcb08 100644
--- a/Timeline/Controllers/UserAvatarController.cs
+++ b/Timeline/Controllers/UserAvatarController.cs
@@ -46,34 +46,11 @@ namespace Timeline.Controllers
                 return NotFound(ErrorResponse.UserCommon.NotExist());

             }

 

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

-

-            var eTagValue = $"\"{await _service.GetAvatarETag(id)}\"";

-            var eTag = new EntityTagHeaderValue(eTagValue);

-

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

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

             {

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

-                {

-                    _logger.LogInformation(Log.Format(LogGetBadIfNoneMatch,

-                        ("Username", username), ("If-None-Match", value)));

-                    return BadRequest(ErrorResponse.Common.Header.IfNonMatch_BadFormat());

-                }

-

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

-                {

-                    Response.Headers.Add("ETag", eTagValue);

-                    _logger.LogInformation(Log.Format(LogGetReturnNotModify, ("Username", username)));

-                    return StatusCode(StatusCodes.Status304NotModified);

-                }

-            }

-

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

-            var avatar = avatarInfo.Avatar;

-

-            _logger.LogInformation(Log.Format(LogGetReturnData, ("Username", username)));

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

-

+                var avatar = await _service.GetAvatar(id);

+                return avatar.ToCacheableData();

+            });

         }

 

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

diff --git a/Timeline/Helpers/DataCacheHelper.cs b/Timeline/Helpers/DataCacheHelper.cs
new file mode 100644
index 00000000..c13aaddb
--- /dev/null
+++ b/Timeline/Helpers/DataCacheHelper.cs
@@ -0,0 +1,108 @@
+using Microsoft.AspNetCore.Http;

+using Microsoft.AspNetCore.Mvc;

+using Microsoft.Extensions.DependencyInjection;

+using Microsoft.Extensions.Logging;

+using Microsoft.Net.Http.Headers;

+using System;

+using System.Linq;

+using System.Threading.Tasks;

+using Timeline.Models.Http;

+using static Timeline.Resources.Helper.DataCacheHelper;

+

+namespace Timeline.Helpers

+{

+    public interface ICacheableData

+    {

+        string Type { get; }

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

+        byte[] Data { get; }

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

+        DateTime? LastModified { get; }

+    }

+

+    public class CacheableData : ICacheableData

+    {

+        public CacheableData(string type, byte[] data, DateTime? lastModified)

+        {

+            Type = type;

+            Data = data;

+            LastModified = lastModified;

+        }

+

+        public string Type { get; set; }

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

+        public byte[] Data { get; set; }

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

+        public DateTime? LastModified { get; set; }

+    }

+

+    public interface ICacheableDataProvider

+    {

+        Task<string> GetDataETag();

+        Task<ICacheableData> GetData();

+    }

+

+    public class DelegateCacheableDataProvider : ICacheableDataProvider

+    {

+        private readonly Func<Task<string>> _getDataETagDelegate;

+        private readonly Func<Task<ICacheableData>> _getDataDelegate;

+

+        public DelegateCacheableDataProvider(Func<Task<string>> getDataETagDelegate, Func<Task<ICacheableData>> getDataDelegate)

+        {

+            _getDataETagDelegate = getDataETagDelegate;

+            _getDataDelegate = getDataDelegate;

+        }

+

+        public Task<ICacheableData> GetData()

+        {

+            return _getDataDelegate();

+        }

+

+        public Task<string> GetDataETag()

+        {

+            return _getDataETagDelegate();

+        }

+    }

+

+    public static class DataCacheHelper

+    {

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

+        {

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

+            const string ETagHeaderKey = "ETag";

+

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

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

+

+            var eTagValue = await provider.GetDataETag();

+            eTagValue = '"' + eTagValue + '"';

+            var eTag = new EntityTagHeaderValue(eTagValue);

+

+

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

+            {

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

+                {

+                    logger.LogInformation(Log.Format(LogBadIfNoneMatch, ("Header Value", value)));

+                    return controller.BadRequest(ErrorResponse.Common.Header.IfNonMatch_BadFormat());

+                }

+

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

+                {

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

+                    logger.LogInformation(LogResultNotModified);

+                    return controller.StatusCode(StatusCodes.Status304NotModified);

+                }

+            }

+

+            var data = await provider.GetData();

+            logger.LogInformation(LogResultData);

+            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)

+        {

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

+        }

+    }

+}

diff --git a/Timeline/Resources/Controllers/UserAvatarController.Designer.cs b/Timeline/Resources/Controllers/UserAvatarController.Designer.cs
index e6eeb1e8..b0c35ff9 100644
--- a/Timeline/Resources/Controllers/UserAvatarController.Designer.cs
+++ b/Timeline/Resources/Controllers/UserAvatarController.Designer.cs
@@ -97,33 +97,6 @@ namespace Timeline.Resources.Controllers {
         }

         

         /// <summary>

-        ///   Looks up a localized string similar to Attempt to get a avatar with If-None-Match in bad format..

-        /// </summary>

-        internal static string LogGetBadIfNoneMatch {

-            get {

-                return ResourceManager.GetString("LogGetBadIfNoneMatch", resourceCulture);

-            }

-        }

-        

-        /// <summary>

-        ///   Looks up a localized string similar to Returned full data for a get avatar attempt..

-        /// </summary>

-        internal static string LogGetReturnData {

-            get {

-                return ResourceManager.GetString("LogGetReturnData", resourceCulture);

-            }

-        }

-        

-        /// <summary>

-        ///   Looks up a localized string similar to Returned NotModify for a get avatar attempt..

-        /// </summary>

-        internal static string LogGetReturnNotModify {

-            get {

-                return ResourceManager.GetString("LogGetReturnNotModify", resourceCulture);

-            }

-        }

-        

-        /// <summary>

         ///   Looks up a localized string similar to Attempt to get a avatar of a non-existent user failed..

         /// </summary>

         internal static string LogGetUserNotExist {

diff --git a/Timeline/Resources/Controllers/UserAvatarController.resx b/Timeline/Resources/Controllers/UserAvatarController.resx
index 58860c83..864d96c0 100644
--- a/Timeline/Resources/Controllers/UserAvatarController.resx
+++ b/Timeline/Resources/Controllers/UserAvatarController.resx
@@ -129,15 +129,6 @@
   <data name="LogDeleteSuccess" xml:space="preserve">

     <value>Succeed to delete a avatar of a user.</value>

   </data>

-  <data name="LogGetBadIfNoneMatch" xml:space="preserve">

-    <value>Attempt to get a avatar with If-None-Match in bad format.</value>

-  </data>

-  <data name="LogGetReturnData" xml:space="preserve">

-    <value>Returned full data for a get avatar attempt.</value>

-  </data>

-  <data name="LogGetReturnNotModify" xml:space="preserve">

-    <value>Returned NotModify for a get avatar attempt.</value>

-  </data>

   <data name="LogGetUserNotExist" xml:space="preserve">

     <value>Attempt to get a avatar of a non-existent user failed.</value>

   </data>

diff --git a/Timeline/Resources/Helper/DataCacheHelper.Designer.cs b/Timeline/Resources/Helper/DataCacheHelper.Designer.cs
new file mode 100644
index 00000000..acf56d13
--- /dev/null
+++ b/Timeline/Resources/Helper/DataCacheHelper.Designer.cs
@@ -0,0 +1,90 @@
+//------------------------------------------------------------------------------

+// <auto-generated>

+//     This code was generated by a tool.

+//     Runtime Version:4.0.30319.42000

+//

+//     Changes to this file may cause incorrect behavior and will be lost if

+//     the code is regenerated.

+// </auto-generated>

+//------------------------------------------------------------------------------

+

+namespace Timeline.Resources.Helper {

+    using System;

+    

+    

+    /// <summary>

+    ///   A strongly-typed resource class, for looking up localized strings, etc.

+    /// </summary>

+    // This class was auto-generated by the StronglyTypedResourceBuilder

+    // class via a tool like ResGen or Visual Studio.

+    // To add or remove a member, edit your .ResX file then rerun ResGen

+    // with the /str option, or rebuild your VS project.

+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "16.0.0.0")]

+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

+    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

+    internal class DataCacheHelper {

+        

+        private static global::System.Resources.ResourceManager resourceMan;

+        

+        private static global::System.Globalization.CultureInfo resourceCulture;

+        

+        [global::System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]

+        internal DataCacheHelper() {

+        }

+        

+        /// <summary>

+        ///   Returns the cached ResourceManager instance used by this class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Resources.ResourceManager ResourceManager {

+            get {

+                if (object.ReferenceEquals(resourceMan, null)) {

+                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("Timeline.Resources.Helper.DataCacheHelper", typeof(DataCacheHelper).Assembly);

+                    resourceMan = temp;

+                }

+                return resourceMan;

+            }

+        }

+        

+        /// <summary>

+        ///   Overrides the current thread's CurrentUICulture property for all

+        ///   resource lookups using this strongly typed resource class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Globalization.CultureInfo Culture {

+            get {

+                return resourceCulture;

+            }

+            set {

+                resourceCulture = value;

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Header If-None-Match is of bad format..

+        /// </summary>

+        internal static string LogBadIfNoneMatch {

+            get {

+                return ResourceManager.GetString("LogBadIfNoneMatch", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Cache is invalid and data is returned..

+        /// </summary>

+        internal static string LogResultData {

+            get {

+                return ResourceManager.GetString("LogResultData", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Cache is valid and 304 Not Modified is returned..

+        /// </summary>

+        internal static string LogResultNotModified {

+            get {

+                return ResourceManager.GetString("LogResultNotModified", resourceCulture);

+            }

+        }

+    }

+}

diff --git a/Timeline/Resources/Helper/DataCacheHelper.resx b/Timeline/Resources/Helper/DataCacheHelper.resx
new file mode 100644
index 00000000..515cfa9b
--- /dev/null
+++ b/Timeline/Resources/Helper/DataCacheHelper.resx
@@ -0,0 +1,129 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="LogBadIfNoneMatch" xml:space="preserve">

+    <value>Header If-None-Match is of bad format.</value>

+  </data>

+  <data name="LogResultData" xml:space="preserve">

+    <value>Cache is invalid and data is returned.</value>

+  </data>

+  <data name="LogResultNotModified" xml:space="preserve">

+    <value>Cache is valid and 304 Not Modified is returned.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Services/UserAvatarService.cs b/Timeline/Services/UserAvatarService.cs
index 1b1be698..3ab8f14d 100644
--- a/Timeline/Services/UserAvatarService.cs
+++ b/Timeline/Services/UserAvatarService.cs
@@ -22,6 +22,11 @@ namespace Timeline.Services
     {

         public Avatar Avatar { get; set; } = default!;

         public DateTime LastModified { get; set; }

+

+        public CacheableData ToCacheableData()

+        {

+            return new CacheableData(Avatar.Type, Avatar.Data, LastModified);

+        }

     }

 

     /// <summary>

diff --git a/Timeline/Timeline.csproj b/Timeline/Timeline.csproj
index 245ff3e7..739f79dd 100644
--- a/Timeline/Timeline.csproj
+++ b/Timeline/Timeline.csproj
@@ -72,6 +72,11 @@
             <AutoGen>True</AutoGen>

             <DependentUpon>Filters.resx</DependentUpon>

         </Compile>

+        <Compile Update="Resources\Helper\DataCacheHelper.Designer.cs">

+          <DesignTime>True</DesignTime>

+          <AutoGen>True</AutoGen>

+          <DependentUpon>DataCacheHelper.resx</DependentUpon>

+        </Compile>

         <Compile Update="Resources\Messages.Designer.cs">

             <DesignTime>True</DesignTime>

             <AutoGen>True</AutoGen>

@@ -159,6 +164,10 @@
             <Generator>ResXFileCodeGenerator</Generator>

             <LastGenOutput>Filters.Designer.cs</LastGenOutput>

         </EmbeddedResource>

+        <EmbeddedResource Update="Resources\Helper\DataCacheHelper.resx">

+          <Generator>ResXFileCodeGenerator</Generator>

+          <LastGenOutput>DataCacheHelper.Designer.cs</LastGenOutput>

+        </EmbeddedResource>

         <EmbeddedResource Update="Resources\Messages.resx">

             <Generator>ResXFileCodeGenerator</Generator>

             <LastGenOutput>Messages.Designer.cs</LastGenOutput>