[Prototype] Add partition-aware cache serializer

src/client/Microsoft.Identity.Client/Cache/TokenCacheJsonSerializer.cs

@@ -23,24 +23,29 @@ public TokenCacheJsonSerializer(ITokenCacheAccessor accessor)
         }
 
         public byte[] Serialize(IDictionary<string, JToken> unknownNodes)
+        {
+            return Serialize(null, unknownNodes);
+        }
+
+        public byte[] Serialize(string cacheKey, IDictionary<string, JToken> unknownNodes)
         {
             var cache = new CacheSerializationContract(unknownNodes);
-            foreach (var token in _accessor.GetAllAccessTokens())
+            foreach (var token in _accessor.GetAllAccessTokens(cacheKey))
             {
                 cache.AccessTokens[token.CacheKey] = token;
             }
 
-            foreach (var token in _accessor.GetAllRefreshTokens())
+            foreach (var token in _accessor.GetAllRefreshTokens(cacheKey))
             {
                 cache.RefreshTokens[token.CacheKey] = token;
             }
 
-            foreach (var token in _accessor.GetAllIdTokens())
+            foreach (var token in _accessor.GetAllIdTokens(cacheKey))
             {
                 cache.IdTokens[token.CacheKey] = token;
             }
 
-            foreach (var accountItem in _accessor.GetAllAccounts())
+            foreach (var accountItem in _accessor.GetAllAccounts(cacheKey))
             {
                 cache.Accounts[accountItem.CacheKey] = accountItem;
             }

src/client/Microsoft.Identity.Client/ITokenCacheInternal.cs

@@ -12,7 +12,7 @@
 
 namespace Microsoft.Identity.Client
 {
-    internal interface ITokenCacheInternal : ITokenCache, ITokenCacheSerializer
+    internal interface ITokenCacheInternal : ITokenCache, ITokenCacheSerializer, IPartitionedTokenCacheSerializer
     {
         OptionalSemaphoreSlim Semaphore { get; }
         ILegacyCachePersistence LegacyPersistence { get; }

src/client/Microsoft.Identity.Client/ITokenCacheSerializer.cs

@@ -110,4 +110,23 @@ public interface ITokenCacheSerializer
         [EditorBrowsable(EditorBrowsableState.Never)]
         void DeserializeMsalV2(byte[] msalV2State);
     }
+
+    /// <summary>
+    /// Similar to <see cref="ITokenCacheSerializer"/> except accepts a cache partition to serialize into.
+    /// </summary>
+    public interface IPartitionedTokenCacheSerializer
+    {
+        /// <summary>
+        /// Similar to <see cref="ITokenCacheSerializer.SerializeMsalV3"/> except serializes only the specified partition.
+        /// </summary>
+        /// <param name="cacheKey"></param>
+        byte[] SerializeMsal(string cacheKey);
+
+        /// <summary>
+        /// Similar to <see cref="ITokenCacheSerializer.DeserializeMsalV3(byte[], bool)"/> except doesn't clear the existing cache data.
+        /// </summary>
+        /// <param name="msalState"></param>
+
+        void DeserializeMsal(byte[] msalState);
+    }
 }

src/client/Microsoft.Identity.Client/TokenCache.Serialization.cs

@@ -53,5 +53,19 @@ void ITokenCacheSerializer.DeserializeMsalV3(byte[] msalV3State, bool shouldClea
             }
             _unknownNodes = new TokenCacheJsonSerializer(Accessor).Deserialize(msalV3State, shouldClearExistingCache);
         }
+
+        byte[] IPartitionedTokenCacheSerializer.SerializeMsal(string cacheKey)
+        {
+            return new TokenCacheJsonSerializer(Accessor).Serialize(cacheKey, _unknownNodes);
+        }
+
+        void IPartitionedTokenCacheSerializer.DeserializeMsal(byte[] msalState)
+        {
+            if (msalState == null || msalState.Length == 0)
+            {
+                return;
+            }
+            _unknownNodes = new TokenCacheJsonSerializer(Accessor).Deserialize(msalState, false);
+        }
     }
 }