Make use of C#7.2 readonly struct and in modifier to keep assigment by ref in methods

Author: bahusoid

src/NHibernate.DomainModel/NHibernate.DomainModel.csproj

@@ -5,6 +5,7 @@
     <TargetFrameworks>$(NhLibTargetFrameworks)</TargetFrameworks>
     <IsTestProject>true</IsTestProject>
     <NoWarn>$(NoWarn);3001;3002;3003;3005</NoWarn>
+    <LangVersion>7.2</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition="'$(TargetFramework)' == 'net461'">
     <DefineConstants>NETFX;$(DefineConstants)</DefineConstants>

src/NHibernate.Test/NHibernate.Test.csproj

@@ -6,6 +6,7 @@
     <IsTestProject>true</IsTestProject>
     <NoWarn>$(NoWarn);3001;3002;3003;3005</NoWarn>
     <ContentSQLiteInteropFiles>true</ContentSQLiteInteropFiles>
+    <LangVersion>7.2</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition="'$(TargetFramework)' == 'net461'">
     <DefineConstants>NETFX;$(DefineConstants)</DefineConstants>

src/NHibernate.TestDatabaseSetup/NHibernate.TestDatabaseSetup.csproj

@@ -6,6 +6,7 @@
     <TargetFrameworks>$(NhAppTargetFrameworks)</TargetFrameworks>
     <IsTestProject>true</IsTestProject>
     <NoWarn>$(NoWarn);3001;3002;3003;3005</NoWarn>
+    <LangVersion>7.2</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition="'$(TargetFramework)' == 'net461'">
     <DefineConstants>NETFX;$(DefineConstants)</DefineConstants>

src/NHibernate/Engine/EntityKey.cs

@@ -12,7 +12,7 @@ namespace NHibernate.Engine
 	/// and the identifier space (eg. tablename)
 	/// </summary>
 	[Serializable]
-	public struct EntityKey : ISerializable, IEquatable<EntityKey>
+	public readonly struct EntityKey : ISerializable, IEquatable<EntityKey>
 	{
 		public static EntityKey Null { get; } = new EntityKey();
 

src/NHibernate/Engine/IPersistenceContext.cs

@@ -113,7 +113,7 @@ public partial interface IPersistenceContext
 		/// <item><description>an entry of NO_ROW here is interpreted as an exception</description></item>
 		/// </list>
 		/// </remarks>
-		object[] GetCachedDatabaseSnapshot(EntityKey key);
+		object[] GetCachedDatabaseSnapshot(in EntityKey key);
 
 		/// <summary>
 		/// Get the values of the natural id fields as known to the underlying
@@ -123,22 +123,22 @@ public partial interface IPersistenceContext
 		object[] GetNaturalIdSnapshot(object id, IEntityPersister persister);
 
 		/// <summary> Add a canonical mapping from entity key to entity instance</summary>
-		void AddEntity(EntityKey key, object entity);
+		void AddEntity(in EntityKey key, object entity);
 
 		/// <summary>
 		/// Get the entity instance associated with the given <tt>EntityKey</tt>
 		/// </summary>
-		object GetEntity(EntityKey key);
+		object GetEntity(in EntityKey key);
 
 		/// <summary> Is there an entity with the given key in the persistence context</summary>
-		bool ContainsEntity(EntityKey key);
+		bool ContainsEntity(in EntityKey key);
 
 		/// <summary>
 		/// Remove an entity from the session cache, also clear
 		/// up other state associated with the entity, all except
 		/// for the <tt>EntityEntry</tt>
 		/// </summary>
-		object RemoveEntity(EntityKey key);
+		object RemoveEntity(in EntityKey key);
 
 		/// <summary> Get an entity cached by unique key</summary>
 		object GetEntity(EntityUniqueKey euk);
@@ -216,9 +216,9 @@ EntityEntry AddEntry(object entity, Status status, object[] loadedState, object
 		/// Attempts to check whether the given key represents an entity already loaded within the
 		/// current session.
 		/// </summary>
-		/// <param name="obj">The entity reference against which to perform the uniqueness check.</param>
 		/// <param name="key">The entity key.</param>
-		void CheckUniqueness(EntityKey key, object obj);
+		/// <param name="obj">The entity reference against which to perform the uniqueness check.</param>
+		void CheckUniqueness(in EntityKey key, object obj);
 
 		/// <summary>
 		/// If the existing proxy is insufficiently "narrow" (derived), instantiate a new proxy
@@ -231,14 +231,14 @@ EntityEntry AddEntry(object entity, Status status, object[] loadedState, object
 		/// <param name="key">The internal cache key for the proxied entity. </param>
 		/// <param name="obj">(optional) the actual proxied entity instance. </param>
 		/// <returns> An appropriately narrowed instance. </returns>
-		object NarrowProxy(INHibernateProxy proxy, IEntityPersister persister, EntityKey key, object obj);
+		object NarrowProxy(INHibernateProxy proxy, IEntityPersister persister, in EntityKey key, object obj);
 
 		/// <summary>
 		/// Return the existing proxy associated with the given <tt>EntityKey</tt>, or the
 		/// third argument (the entity associated with the key) if no proxy exists. Init
 		/// the proxy to the target implementation, if necessary.
 		/// </summary>
-		object ProxyFor(IEntityPersister persister, EntityKey key, object impl);
+		object ProxyFor(IEntityPersister persister,in EntityKey key, object impl);
 
 		/// <summary>
 		/// Return the existing proxy associated with the given <tt>EntityKey</tt>, or the
@@ -326,13 +326,13 @@ EntityEntry AddEntry(object entity, Status status, object[] loadedState, object
 		CollectionEntry GetCollectionEntryOrNull(object collection);
 
 		/// <summary> Get an existing proxy by key</summary>
-		object GetProxy(EntityKey key);
+		object GetProxy(in EntityKey key);
 
 		/// <summary> Add a proxy to the session cache</summary>
-		void AddProxy(EntityKey key, INHibernateProxy proxy);
+		void AddProxy(in EntityKey key, INHibernateProxy proxy);
 
 		/// <summary> Remove a proxy from the session cache</summary>
-		object RemoveProxy(EntityKey key);
+		object RemoveProxy(in EntityKey key);
 
 		/// <summary> Called before cascading</summary>
 		int IncrementCascadeLevel();
@@ -360,10 +360,10 @@ EntityEntry AddEntry(object entity, Status status, object[] loadedState, object
 		/// <summary>
 		/// Record the fact that the association belonging to the keyed entity is null.
 		/// </summary>
-		void AddNullProperty(EntityKey ownerKey, string propertyName);
+		void AddNullProperty(in EntityKey ownerKey, string propertyName);
 
 		/// <summary> Is the association property belonging to the keyed entity null?</summary>
-		bool IsPropertyNull(EntityKey ownerKey, string propertyName);
+		bool IsPropertyNull(in EntityKey ownerKey, string propertyName);
 
 		/// <summary>
 		/// Change the read-only status of an entity (or proxy).
@@ -398,7 +398,7 @@ EntityEntry AddEntry(object entity, Status status, object[] loadedState, object
 		/// <seealso cref="IPersistenceContext.SetReadOnly(object, bool)" />
 		bool IsReadOnly(object entityOrProxy);
 
-		void ReplaceDelayedEntityIdentityInsertKeys(EntityKey oldKey, object generatedId);
+		void ReplaceDelayedEntityIdentityInsertKeys(in EntityKey oldKey, object generatedId);
 
 		/// <summary>Is in a two-phase load? </summary>
 		bool IsLoadFinished { get; }

src/NHibernate/Engine/StatefulPersistenceContext.cs

@@ -355,7 +355,7 @@ public object[] GetDatabaseSnapshot(object id, IEntityPersister persister)
 		/// <item><description>an entry of NO_ROW here is interpreted as an exception</description></item>
 		/// </list>
 		/// </remarks>
-		public object[] GetCachedDatabaseSnapshot(EntityKey key)
+		public object[] GetCachedDatabaseSnapshot(in EntityKey key)
 		{
 			object snapshot;
 			if (!entitySnapshotsByKey.TryGetValue(key, out snapshot))
@@ -418,7 +418,7 @@ public object[] GetNaturalIdSnapshot(object id, IEntityPersister persister)
 		}
 
 		/// <summary> Add a canonical mapping from entity key to entity instance</summary>
-		public void AddEntity(EntityKey key, object entity)
+		public void AddEntity(in EntityKey key, object entity)
 		{
 			entitiesByKey[key] = entity;
 			BatchFetchQueue.RemoveBatchLoadableEntityKey(key);
@@ -427,15 +427,15 @@ public void AddEntity(EntityKey key, object entity)
 		/// <summary>
 		/// Get the entity instance associated with the given <tt>EntityKey</tt>
 		/// </summary>
-		public object GetEntity(EntityKey key)
+		public object GetEntity(in EntityKey key)
 		{
 			object result;
 			entitiesByKey.TryGetValue(key, out result);
 			return result;
 		}
 
 		/// <summary> Is there an entity with the given key in the persistence context</summary>
-		public bool ContainsEntity(EntityKey key)
+		public bool ContainsEntity(in EntityKey key)
 		{
 			return entitiesByKey.ContainsKey(key);
 		}
@@ -445,7 +445,7 @@ public bool ContainsEntity(EntityKey key)
 		/// up other state associated with the entity, all except
 		/// for the <tt>EntityEntry</tt>
 		/// </summary>
-		public object RemoveEntity(EntityKey key)
+		public object RemoveEntity(in EntityKey key)
 		{
 			object tempObject = entitiesByKey[key];
 			entitiesByKey.Remove(key);
@@ -525,7 +525,7 @@ public EntityEntry AddEntity(object entity, Status status, object[] loadedState,
 		}
 
 		/// <summary> Adds an entity to the internal caches.</summary>
-		public EntityEntry AddEntity(object entity, Status status, object[] loadedState, EntityKey entityKey, object version,
+		public EntityEntry AddEntity(object entity, Status status, object[] loadedState, in EntityKey entityKey, object version,
 		                             LockMode lockMode, bool existsInDatabase, IEntityPersister persister,
 		                             bool disableVersionIncrement)
 		{
@@ -712,9 +712,9 @@ public object UnproxyAndReassociate(object maybeProxy)
 		/// Attempts to check whether the given key represents an entity already loaded within the
 		/// current session.
 		/// </summary>
-		/// <param name="obj">The entity reference against which to perform the uniqueness check.</param>
 		/// <param name="key">The entity key.</param>
-		public void CheckUniqueness(EntityKey key, object obj)
+		/// <param name="obj">The entity reference against which to perform the uniqueness check.</param>
+		public void CheckUniqueness(in EntityKey key, object obj)
 		{
 			object entity = GetEntity(key);
 			if (entity == obj)
@@ -738,7 +738,7 @@ public void CheckUniqueness(EntityKey key, object obj)
 		/// <param name="key">The internal cache key for the proxied entity. </param>
 		/// <param name="obj">(optional) the actual proxied entity instance. </param>
 		/// <returns> An appropriately narrowed instance. </returns>
-		public object NarrowProxy(INHibernateProxy proxy, IEntityPersister persister, EntityKey key, object obj)
+		public object NarrowProxy(INHibernateProxy proxy, IEntityPersister persister, in EntityKey key, object obj)
 		{
 			bool alreadyNarrow = persister.ConcreteProxyClass.IsInstanceOfType(proxy);
 
@@ -782,7 +782,7 @@ public object NarrowProxy(INHibernateProxy proxy, IEntityPersister persister, En
 		/// third argument (the entity associated with the key) if no proxy exists. Init
 		/// the proxy to the target implementation, if necessary.
 		/// </summary>
-		public object ProxyFor(IEntityPersister persister, EntityKey key, object impl)
+		public object ProxyFor(IEntityPersister persister, in EntityKey key, object impl)
 		{
 			if (!persister.HasProxy || key.IsNull)
 				return impl;
@@ -1076,7 +1076,7 @@ public CollectionEntry GetCollectionEntryOrNull(object collection)
 		}
 
 		/// <summary> Get an existing proxy by key</summary>
-		public object GetProxy(EntityKey key)
+		public object GetProxy(in EntityKey key)
 		{
 			INHibernateProxy result;
 			if (proxiesByKey.TryGetValue(key, out result))
@@ -1086,13 +1086,13 @@ public object GetProxy(EntityKey key)
 		}
 
 		/// <summary> Add a proxy to the session cache</summary>
-		public void AddProxy(EntityKey key, INHibernateProxy proxy)
+		public void AddProxy(in EntityKey key, INHibernateProxy proxy)
 		{
 			proxiesByKey[key] = proxy;
 		}
 
 		/// <summary> Remove a proxy from the session cache</summary>
-		public object RemoveProxy(EntityKey key)
+		public object RemoveProxy(in EntityKey key)
 		{
 			if (batchFetchQueue != null)
 			{
@@ -1295,13 +1295,13 @@ private object GetIndexInParent(string property, object childEntity, IEntityPers
 		/// <summary>
 		/// Record the fact that the association belonging to the keyed entity is null.
 		/// </summary>
-		public void AddNullProperty(EntityKey ownerKey, string propertyName)
+		public void AddNullProperty(in EntityKey ownerKey, string propertyName)
 		{
 			nullAssociations.Add(new AssociationKey(ownerKey, propertyName));
 		}
 
 		/// <summary> Is the association property belonging to the keyed entity null?</summary>
-		public bool IsPropertyNull(EntityKey ownerKey, string propertyName)
+		public bool IsPropertyNull(in EntityKey ownerKey, string propertyName)
 		{
 			return nullAssociations.Contains(new AssociationKey(ownerKey, propertyName));
 		}
@@ -1382,7 +1382,7 @@ public bool IsReadOnly(object entityOrProxy)
 			return isReadOnly;
 		}
 
-		public void ReplaceDelayedEntityIdentityInsertKeys(EntityKey oldKey, object generatedId)
+		public void ReplaceDelayedEntityIdentityInsertKeys(in EntityKey oldKey, object generatedId)
 		{
 			object tempObject = entitiesByKey[oldKey];
 			entitiesByKey.Remove(oldKey);

src/NHibernate/NHibernate.csproj

@@ -12,6 +12,7 @@
 
     <PackageDescription>NHibernate is a mature, open source object-relational mapper for the .NET framework. It is actively developed, fully featured and used in thousands of successful projects.</PackageDescription>
     <PackageTags>ORM; O/RM; DataBase; DAL; ObjectRelationalMapping; NHibernate; ADO.Net; Core</PackageTags>
+    <LangVersion>7.3</LangVersion>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(TargetFramework)' == 'net461'">