Cache servers and repos only for a short time to let the component refresh the token automatically. (#120)

Author: tusmester

src/SenseNet.Client/Authentication/TokenStore.cs

@@ -29,9 +29,11 @@ Task<string> GetTokenAsync(ServerContext server, string clientId, string secret,
     internal class TokenStore : ITokenStore
     {
         private readonly ILogger<TokenStore> _logger;
-        private readonly MemoryCache _cache = new MemoryCache(new MemoryCacheOptions());
+        private readonly MemoryCache _cache = new(new MemoryCacheOptions());
         private readonly ITokenProvider _tokenProvider;
 
+        private const int DefaultCacheDurationInMinutes = 30;
+
         public TokenStore(ITokenProvider tokenProvider, ILogger<TokenStore> logger)
         {
             _tokenProvider = tokenProvider;
@@ -42,12 +44,12 @@ public async Task<string> GetTokenAsync(ServerContext server, string clientId, s
             CancellationToken cancel = default)
         {
             // look for the token in the cache
-            var tokenCacheKey = "TK:" + server.Url;
+            var tokenCacheKey = $"TK-{server.Url}-{clientId}".GetHashCode();
             if (_cache.TryGetValue(tokenCacheKey, out string accessToken))
                 return accessToken;
 
             // look for auth info in the cache
-            var authInfoCacheKey = "AI:" + server.Url;
+            var authInfoCacheKey = $"AI-{server.Url}-{clientId}".GetHashCode();
             if (!_cache.TryGetValue(authInfoCacheKey, out AuthorityInfo authInfo))
             {
                 _logger?.LogTrace($"Getting authority info from {server.Url}.");
@@ -59,7 +61,7 @@ public async Task<string> GetTokenAsync(ServerContext server, string clientId, s
                     authInfo.ClientId = clientId;
 
                 if (!string.IsNullOrEmpty(authInfo.Authority))
-                    _cache.Set(authInfoCacheKey, authInfo, TimeSpan.FromMinutes(30));
+                    _cache.Set(authInfoCacheKey, authInfo, TimeSpan.FromMinutes(DefaultCacheDurationInMinutes));
                 else
                     _logger?.LogTrace($"Authority info is empty for server {server.Url}");
             }
@@ -74,24 +76,28 @@ public async Task<string> GetTokenAsync(ServerContext server, string clientId, s
 
             accessToken = tokenInfo?.AccessToken;
 
-            //TODO: determine access token cache expiration based on the token expiration
-            if (!string.IsNullOrEmpty(accessToken))
+            if (string.IsNullOrEmpty(accessToken)) 
+                return accessToken;
+
+            // Maximize token expiration to the received token expiration (if given) or a fixed short time.
+            var tokenExpiration = tokenInfo.ExpiresIn > 0
+                ? TimeSpan.FromSeconds(Math.Min(tokenInfo.ExpiresIn, DefaultCacheDurationInMinutes * 60))
+                : TimeSpan.FromMinutes(DefaultCacheDurationInMinutes);
+
+            _cache.Set(tokenCacheKey, accessToken, tokenExpiration);
+
+            try
+            {
+                // parse token and log user
+                var handler = new JwtSecurityTokenHandler();
+                var token = handler.ReadJwtToken(accessToken);
+                var sub = token.Claims.FirstOrDefault(c => c.Type == "client_sub")?.Value ?? "unknown";
+
+                _logger?.LogTrace($"Token acquired for user {sub}. Expires in {tokenExpiration}.");
+            }
+            catch (Exception ex)
             {
-                _cache.Set(tokenCacheKey, accessToken, TimeSpan.FromMinutes(10));
-
-                try
-                {
-                    // parse token and log user
-                    var handler = new JwtSecurityTokenHandler();
-                    var token = handler.ReadJwtToken(accessToken);
-                    var sub = token.Claims.FirstOrDefault(c => c.Type == "client_sub")?.Value ?? "unknown";
-
-                    _logger?.LogTrace($"Token acquired for user {sub}.");
-                }
-                catch (Exception ex)
-                {
-                    _logger?.LogWarning(ex, $"Could not read access token: {ex.Message}");
-                }
+                _logger?.LogWarning(ex, $"Could not read access token: {ex.Message}");
             }
 
             return accessToken;

src/SenseNet.Client/Repository/RepositoryCollection.cs

@@ -16,6 +16,8 @@ internal class RepositoryCollection : IRepositoryCollection
         private readonly MemoryCache _repositories = new(new MemoryCacheOptions { SizeLimit = 1024 });
         private readonly SemaphoreSlim _asyncLock = new(1, 1);
 
+        private const int DefaultCacheDurationInMinutes = 30;
+
         public RepositoryCollection(IServiceProvider services, IServerContextFactory serverFactory, ILogger<RepositoryCollection> logger)
         {
             _services = services;
@@ -67,7 +69,7 @@ int GetCacheKey()
 
                 _repositories.Set(cacheKey, repo, new MemoryCacheEntryOptions
                 {
-                    AbsoluteExpiration = new DateTimeOffset(DateTime.UtcNow.AddHours(1)),
+                    AbsoluteExpiration = new DateTimeOffset(DateTime.UtcNow.AddMinutes(DefaultCacheDurationInMinutes)),
                     Size = 1
                 });
 

src/SenseNet.Client/ServerContextFactory.cs

@@ -1,6 +1,8 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.Extensions.Caching.Memory;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using SenseNet.Client.Authentication;
@@ -44,7 +46,9 @@ internal class ServerContextFactory : IServerContextFactory
     private readonly ServerContextOptions _serverContextOptions;
     private readonly RepositoryOptions _repositoryOptions;
     private readonly SemaphoreSlim _asyncLock = new(1, 1);
-    private readonly IDictionary<string, ServerContext> _servers = new Dictionary<string, ServerContext>();
+    private readonly MemoryCache _servers = new(new MemoryCacheOptions());
+
+    private const int DefaultCacheDurationInMinutes = 30;
 
     public ServerContextFactory(ITokenStore tokenStore, IOptions<ServerContextOptions> serverContextOptions,
         IOptions<RepositoryOptions> repositoryOptions, ILogger<ServerContextFactory> logger)
@@ -63,20 +67,20 @@ ServerContext CloneWithToken(ServerContext original)
             var clonedServer = original.Clone();
 
             // set token only if provided, do not overwrite cached value if no token is present
-            if (!string.IsNullOrEmpty(token))
-            {
-                clonedServer.Authentication.AccessToken = token;
+            if (string.IsNullOrEmpty(token)) 
+                return clonedServer;
+
+            clonedServer.Authentication.AccessToken = token;
 
-                // if a token is provided, do NOT use the configured api key to prevent a security issue
-                clonedServer.Authentication.ApiKey = null;
-            }
+            // if a token is provided, do NOT use the configured api key to prevent a security issue
+            clonedServer.Authentication.ApiKey = null;
 
             return clonedServer;
         }
 
         name ??= ServerContextOptions.DefaultServerName;
 
-        if (_servers.TryGetValue(name, out var server))
+        if (_servers.TryGetValue(name, out ServerContext server))
             return CloneWithToken(server);
 
         await _asyncLock.WaitAsync();
@@ -86,11 +90,14 @@ ServerContext CloneWithToken(ServerContext original)
             if (_servers.TryGetValue(name, out server))
                 return CloneWithToken(server);
 
+            _logger.LogTrace("Constructing a new server instance " +
+                             $"for {(string.IsNullOrWhiteSpace(name) ? "the default server" : name)}");
+
             // cache the authenticated server
             server = await GetAuthenticatedServerAsync(name).ConfigureAwait(false);
 
             if (server != null)
-                _servers[name] = server;
+                _servers.Set(name, server, TimeSpan.FromMinutes(DefaultCacheDurationInMinutes));
         }
         finally
         {