#1403: Simplify ApiDescriptionCache

framework/src/Volo.Abp.Core/Volo/Abp/DependencyInjection/ISingletonDependency.cs

@@ -2,5 +2,6 @@
 {
     public interface ISingletonDependency
     {
+
     }
 }

framework/src/Volo.Abp.Http.Client/Volo/Abp/Http/Client/DynamicProxying/ApiDescriptionCache.cs

@@ -2,8 +2,6 @@
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Serialization;
 using Nito.AsyncEx;
 using Volo.Abp.DependencyInjection;
 using Volo.Abp.Http.Modeling;
@@ -12,55 +10,29 @@ namespace Volo.Abp.Http.Client.DynamicProxying
 {
     public class ApiDescriptionCache : IApiDescriptionCache, ISingletonDependency
     {
-        private readonly IDynamicProxyHttpClientFactory _httpClientFactory;
-
         private readonly Dictionary<string, ApplicationApiDescriptionModel> _cache;
-        private readonly AsyncLock _asyncLock;
+        private readonly SemaphoreSlim _semaphoreSlim;
 
-        public ApiDescriptionCache(IDynamicProxyHttpClientFactory httpClientFactory)
+        public ApiDescriptionCache()
         {
-            _httpClientFactory = httpClientFactory;
-
             _cache = new Dictionary<string, ApplicationApiDescriptionModel>();
-            _asyncLock = new AsyncLock();
+            _semaphoreSlim = new SemaphoreSlim(1, 1);
         }
 
-        public async Task<ApplicationApiDescriptionModel> GetAsync(string baseUrl, CancellationToken cancellationToken = default)
+        public async Task<ApplicationApiDescriptionModel> GetAsync(
+            string baseUrl, 
+            Func<Task<ApplicationApiDescriptionModel>> factory)
         {
-            using (await _asyncLock.LockAsync(cancellationToken))
+            using (await _semaphoreSlim.LockAsync())
             {
                 var model = _cache.GetOrDefault(baseUrl);
                 if (model == null)
                 {
-                    _cache[baseUrl] = model = await GetFromServerAsync(baseUrl);
+                    _cache[baseUrl] = model = await factory();
                 }
 
                 return model;
             }
         }
-
-        private async Task<ApplicationApiDescriptionModel> GetFromServerAsync(string baseUrl)
-        {
-            using (var client = _httpClientFactory.Create())
-            {
-                var response = await client.GetAsync(baseUrl.EnsureEndsWith('/') + "api/abp/api-definition");
-                if (!response.IsSuccessStatusCode)
-                {
-                    throw new AbpException("Remote service returns error!");
-                }
-
-                var content = await response.Content.ReadAsStringAsync();
-
-                var result = JsonConvert.DeserializeObject(
-                    content,
-                    typeof(ApplicationApiDescriptionModel),
-                    new JsonSerializerSettings
-                    {
-                        ContractResolver = new CamelCasePropertyNamesContractResolver()
-                    });
-
-                return (ApplicationApiDescriptionModel)result;
-            }
-        }
     }
 }

framework/src/Volo.Abp.Http.Client/Volo/Abp/Http/Client/DynamicProxying/ApiDescriptionFinder.cs

@@ -2,23 +2,34 @@
 using System.Linq;
 using System.Reflection;
 using System.Threading.Tasks;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Serialization;
 using Volo.Abp.DependencyInjection;
 using Volo.Abp.Http.Modeling;
+using Volo.Abp.Threading;
 
 namespace Volo.Abp.Http.Client.DynamicProxying
 {
     public class ApiDescriptionFinder : IApiDescriptionFinder, ISingletonDependency
     {
-        private readonly IApiDescriptionCache _descriptionCache;
+        public ICancellationTokenProvider CancellationTokenProvider { get; set; }
 
-        public ApiDescriptionFinder(IApiDescriptionCache descriptionCache)
+        protected IDynamicProxyHttpClientFactory HttpClientFactory { get; }
+
+        protected IApiDescriptionCache Cache { get; }
+
+        public ApiDescriptionFinder(
+            IApiDescriptionCache cache, 
+            IDynamicProxyHttpClientFactory httpClientFactory)
         {
-            _descriptionCache = descriptionCache;
+            Cache = cache;
+            HttpClientFactory = httpClientFactory;
+            CancellationTokenProvider = NullCancellationTokenProvider.Instance;
         }
 
         public async Task<ActionApiDescriptionModel> FindActionAsync(string baseUrl, Type serviceType, MethodInfo method)
         {
-            var apiDescription = await _descriptionCache.GetAsync(baseUrl);
+            var apiDescription = await GetApiDescriptionAsync(baseUrl);
 
             //TODO: Cache finding?
 
@@ -57,7 +68,40 @@ namespace Volo.Abp.Http.Client.DynamicProxying
                 }
             }
 
-            throw new AbpException("Could not found remote action for method: " + method);
+            throw new AbpException($"Could not found remote action for method: {method} on the URL: {baseUrl}");
+        }
+
+        public virtual async Task<ApplicationApiDescriptionModel> GetApiDescriptionAsync(string baseUrl)
+        {
+            return await Cache.GetAsync(baseUrl, () => GetApiDescriptionFromServerAsync(baseUrl));
+        }
+
+        protected virtual async Task<ApplicationApiDescriptionModel> GetApiDescriptionFromServerAsync(string baseUrl)
+        {
+            using (var client = HttpClientFactory.Create())
+            {
+                var response = await client.GetAsync(
+                    baseUrl.EnsureEndsWith('/') + "api/abp/api-definition",
+                    CancellationTokenProvider.Token
+                );
+
+                if (!response.IsSuccessStatusCode)
+                {
+                    throw new AbpException("Remote service returns error!");
+                }
+
+                var content = await response.Content.ReadAsStringAsync();
+
+                var result = JsonConvert.DeserializeObject(
+                    content,
+                    typeof(ApplicationApiDescriptionModel),
+                    new JsonSerializerSettings
+                    {
+                        ContractResolver = new CamelCasePropertyNamesContractResolver()
+                    });
+
+                return (ApplicationApiDescriptionModel)result;
+            }
         }
     }
 }

framework/src/Volo.Abp.Http.Client/Volo/Abp/Http/Client/DynamicProxying/IApiDescriptionCache.cs

@@ -1,4 +1,4 @@
-using System.Threading;
+using System;
 using System.Threading.Tasks;
 using Volo.Abp.Http.Modeling;
 
@@ -6,6 +6,9 @@ namespace Volo.Abp.Http.Client.DynamicProxying
 {
     public interface IApiDescriptionCache
     {
-        Task<ApplicationApiDescriptionModel> GetAsync(string baseUrl, CancellationToken cancellationToken = default);
+        Task<ApplicationApiDescriptionModel> GetAsync(
+            string baseUrl,
+            Func<Task<ApplicationApiDescriptionModel>> factory
+        );
     }
 }

framework/src/Volo.Abp.Http.Client/Volo/Abp/Http/Client/DynamicProxying/IApiDescriptionFinder.cs

@@ -8,5 +8,7 @@ namespace Volo.Abp.Http.Client.DynamicProxying
     public interface IApiDescriptionFinder
     {
         Task<ActionApiDescriptionModel> FindActionAsync(string baseUrl, Type serviceType, MethodInfo invocationMethod);
+
+        Task<ApplicationApiDescriptionModel> GetApiDescriptionAsync(string baseUrl);
     }
 }

framework/src/Volo.Abp.Uow/Volo/Abp/Uow/IAmbientUnitOfWork.cs

@@ -2,5 +2,6 @@
 {
     public interface IAmbientUnitOfWork : IUnitOfWorkAccessor
     {
+
     }
 }