[RNET-6] Add support for client resync

Realm/Realm/Configurations/FullSyncConfiguration.cs

@@ -33,6 +33,13 @@ public class FullSyncConfiguration : SyncConfigurationBase
     {
         internal override bool IsFullSync => true;
 
+        internal override ClientResyncMode ResyncMode => ClientResyncMode;
+
+        /// <summary>
+        /// Gets or sets a value controlling the behavior in case of a Client Resync. Default is <see cref="ClientResyncMode.RecoverLocalRealm"/>
+        /// </summary>
+        public ClientResyncMode ClientResyncMode { get; set; } = ClientResyncMode.RecoverLocalRealm;
+
         /// <summary>
         /// Initializes a new instance of the <see cref="FullSyncConfiguration"/> class.
         /// </summary>

Realm/Realm/Configurations/QueryBasedSyncConfiguration.cs

@@ -37,6 +37,8 @@ public class QueryBasedSyncConfiguration : SyncConfigurationBase
     {
         internal override bool IsFullSync => false;
 
+        internal override ClientResyncMode ResyncMode => ClientResyncMode.Manual;
+
         internal static readonly Type[] _queryBasedPermissionTypes =
         {
             typeof(ClassPermission),

Realm/Realm/Configurations/SyncConfigurationBase.cs

@@ -90,6 +90,8 @@ public abstract class SyncConfigurationBase : RealmConfigurationBase
         /// </summary>
         public Action<SyncProgress> OnProgress { get; set; }
 
+        internal abstract ClientResyncMode ResyncMode { get; }
+
         /// <summary>
         /// Gets or sets a value indicating how detailed the sync client's logs will be.
         /// </summary>
@@ -302,7 +304,8 @@ internal Native.SyncConfiguration ToNative()
                 client_validate_ssl = EnableSSLValidation,
                 TrustedCAPath = TrustedCAPath,
                 is_partial = !IsFullSync,
-                PartialSyncIdentifier = null
+                PartialSyncIdentifier = null,
+                client_resync_mode = ResyncMode,
             };
         }
 

Realm/Realm/Native/SyncConfiguration.cs

@@ -38,6 +38,7 @@ internal SyncUserHandle SyncUserHandle
 
         [MarshalAs(UnmanagedType.LPWStr)]
         private string url;
+
         private IntPtr url_len;
 
         internal string Url
@@ -54,6 +55,7 @@ internal string Url
 
         [MarshalAs(UnmanagedType.LPWStr)]
         private string trusted_ca_path;
+
         private IntPtr trusted_ca_path_len;
 
         internal string TrustedCAPath
@@ -70,6 +72,7 @@ internal string TrustedCAPath
 
         [MarshalAs(UnmanagedType.LPWStr)]
         private string partial_sync_identifier;
+
         private IntPtr partial_sync_identifier_len;
 
         internal string PartialSyncIdentifier
@@ -80,5 +83,8 @@ internal string PartialSyncIdentifier
                 partial_sync_identifier_len = (IntPtr)(value?.Length ?? 0);
             }
         }
+
+        [MarshalAs(UnmanagedType.U1)]
+        internal ClientResyncMode client_resync_mode;
     }
 }

Realm/Realm/Sync/ClientResyncMode.cs

@@ -0,0 +1,45 @@
+using Realms.Sync.Exceptions;
+
+namespace Realms.Sync
+{
+    /// <summary>
+    /// Enum describing what should happen in case of a Client Resync.
+    /// </summary>
+    /// <remarks>
+    /// A Client Resync is triggered if the device and server cannot agree on a common shared history
+    /// for the Realm file, thus making it impossible for the device to upload or receive any changes.
+    /// This can happen if the server is rolled back or restored from backup.
+    /// <br/>
+    /// IMPORTANT: Just having the device offline will not trigger a Client Resync.
+    /// </remarks>
+    public enum ClientResyncMode : byte
+    {
+        /// <summary>
+        /// Realm will compare the local Realm with the Realm on the server and automatically transfer
+        /// any changes from the local Realm that makes sense to the Realm provided by the server.
+        /// <br/>
+        /// This is the default mode for fully synchronized Realms. It is not yet supported by
+        /// Query-based Realms.
+        /// </summary>
+        RecoverLocalRealm = 0,
+
+        /// <summary>
+        /// The local Realm will be discarded and replaced with the server side Realm.
+        /// All local changes will be lost.
+        /// <br/>
+        /// This mode is not yet supported by Query-based Realms.
+        /// </summary>
+        DiscardLocalRealm = 1,
+
+        /// <summary>
+        /// A manual Client Resync is also known as a Client Reset.
+        /// <br/>
+        /// A <see cref="ClientResetException"/> will be sent to <see cref="Session.Error"/>,
+        /// triggering a Client Reset. Doing this provides a handle to both the old and new Realm file, enabling
+        /// full control over which changes to move, if any.
+        /// <br/>
+        /// This is the only supported mode for Query-based Realms.
+        /// </summary>
+        Manual = 2,
+    }
+}

wrappers/dependencies.list

@@ -1,3 +1,3 @@
-REALM_CORE_VERSION=5.23.1
-REALM_SYNC_VERSION=4.7.1
+REALM_CORE_VERSION=5.23.3
+REALM_SYNC_VERSION=4.7.5
 ANDROID_OPENSSL_VERSION=1.0.2k

wrappers/src/sync_manager_cs.cpp

@@ -97,6 +97,7 @@ Realm::Config get_shared_realm_config(Configuration configuration, SyncConfigura
     config.sync_config = std::make_shared<SyncConfig>(*sync_configuration.user, realm_url);
     config.sync_config->bind_session_handler = bind_session;
     config.sync_config->error_handler = handle_session_error;
+    config.sync_config->client_resync_mode = sync_configuration.client_resync_mode;
     config.path = Utf16StringAccessor(configuration.path, configuration.path_len);
 
     // by definition the key is only allowed to be 64 bytes long, enforced by C# code

wrappers/src/sync_manager_cs.hpp

@@ -19,6 +19,9 @@
 #pragma once
 
 #include "realm_export_decls.hpp"
+#include "sync/sync_config.hpp"
+
+using namespace realm;
 
 namespace realm {
     class SyncUser;
@@ -38,9 +41,6 @@ namespace realm {
         bool is_partial;
         uint16_t* partial_sync_identifier;
         size_t partial_sync_identifier_len;
+        realm::ClientResyncMode client_resync_mode;
     };
-
-    namespace binding {
-        REALM_EXPORT bool has_feature(StringData feature);
-    }
 }