Add attributes for serialization hints (#1)

Author: josesimoes

nanoFramework.System.Runtime.Serialization/FieldNoReflectionAttribute.cs

@@ -0,0 +1,16 @@
+//
+// Copyright (c) .NET Foundation and Contributors
+// Portions Copyright (c) Microsoft Corporation.  All rights reserved.
+// See LICENSE file in the project root for full license information.
+//
+
+namespace System.Runtime.Serialization
+{
+    /// <summary>
+    /// Indicates that this field doesn't allow reflection.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Field, Inherited = false)]
+    sealed public class FieldNoReflectionAttribute : Attribute
+    {
+    }
+}

nanoFramework.System.Runtime.Serialization/SerializationHintsAttribute.cs

@@ -0,0 +1,70 @@
+//
+// Copyright (c) .NET Foundation and Contributors
+// Portions Copyright (c) Microsoft Corporation.  All rights reserved.
+// See LICENSE file in the project root for full license information.
+//
+
+namespace System.Runtime.Serialization
+{
+    /// <summary>
+    /// Provides hints to the binary serializer on how to improve serialization and decrease the size of the serialialized representation.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Class, Inherited = true)]
+    public class SerializationHintsAttribute : Attribute
+    {
+        //
+        // Keep in sync with Microsoft.SPOT.Debugger.SerializationHintsAttribute!!!!
+        //
+
+#pragma warning disable S1104 // intended use in .NET nanoFramework for native usage
+
+        /// <summary>
+        /// Serialization options for the current object.
+        /// </summary>
+        public SerializationOptions Options;
+
+        /// <summary>
+        /// Specifies the size of an array.
+        /// </summary>
+        /// <remarks>
+        /// If an array's size is fixed and known, it can be stated using the <see cref="ArraySize"/> option. A value of -1 can be used if the class being serialized only has one array of simple data types and no other fields.
+        /// </remarks>
+        //// -1 == extend to the end of the stream.
+        public int ArraySize;
+
+        /// <summary>
+        /// Specifies the number of bits in which the current object is bit-packed.
+        /// </summary>
+        /// <remarks>
+        /// This can be applied only to ordinal types, <see cref="DateTime"/> and <see cref="TimeSpan"/>.
+        /// This indicates how many bits should be kept for an ordinal type. If <see cref="BitPacked"/> is 0, a data type's default size is applied (for example, 2 bytes for an <see cref="short"/> and 1 byte for the <see cref="byte"/> type). 
+        /// Decorating a <see cref="bool"/> field with <see cref="BitPacked"/> attribute set to 1, only one bit - which is enough to represent true or false - is kept for the <see cref="bool"/> value.
+        /// </remarks>
+        //// bits count
+        public int BitPacked;
+
+        /// <summary>
+        /// Specifies the range bias adjustment for a particular serialized value.
+        /// </summary>
+        /// <remarks>
+        /// This can be applied to ordinal types, <see cref="DateTime"/> and <see cref="TimeSpan"/>.
+        /// It can't be applied to <see cref="bool"/> type objects.
+        /// With the exception of <see cref="bool"/>, all ordinal types can use <see cref="RangeBias"/>. It allows to store a value using fewer bits. Before saving the ordinal value, the range bias value is subtracted from it. For instance, a 16 bit data type has to used to store values that range between 1000 and 1500. The required bits can be decreased from 16 to 6 if the range is known in advance. When <see cref="RangeBias"/> is set to 1000, the number 1000 is subtracted from the original value before it's serialized.
+        /// </remarks>
+        public long RangeBias;
+
+        /// <summary>
+        /// Specifies the range bias adjustment for a particular serialized value.
+        /// </summary>
+        /// <remarks>
+        /// This can be applied to ordinal types, <see cref="DateTime"/> and <see cref="TimeSpan"/>.
+        /// It can't be applied to <see cref="bool"/> type objects.
+        /// When serializing a value, <see cref="Scale"/> helps save storage bits similar to <see cref="RangeBias"/>. The value to be serialized is divided by <see cref="Scale"/>. Defining a <see cref="Scale"/> of two, the range of values can be cut in half if a field only contains odd or even values. It's also possible to combine <see cref="RangeBias"/> with <see cref="Scale"/>. However, the order of operations must be taken into account here. The value will be first subtracted by <see cref="RangeBias"/> and then divided by <see cref="Scale"/>.
+        /// </remarks>
+        //// this will be ticks for DateTime objects
+        public ulong Scale;
+
+#pragma warning restore S1104 // Fields should not have public accessibility
+
+    }
+}

nanoFramework.System.Runtime.Serialization/SerializationOptions.cs

@@ -0,0 +1,30 @@
+//
+// Copyright (c) .NET Foundation and Contributors
+// Portions Copyright (c) Microsoft Corporation.  All rights reserved.
+// See LICENSE file in the project root for full license information.
+//
+
+namespace System.Runtime.Serialization
+{
+    /// <summary>
+    /// Options for serialization and deserialization.
+    /// </summary>
+    [Flags()]
+    public enum SerializationOptions
+    {
+        /// <summary>
+        /// A value indicating that the pointer to the serialized object is never <see langword="null"/>.
+        /// </summary>
+        PointerNeverNull = 0x00000010,
+
+        /// <summary>
+        /// A value indicating that the elements in the serialized object are never <see langword="null"/>.
+        /// </summary>
+        ElementsNeverNull = 0x00000020,
+
+        /// <summary>
+        /// A value indicating that the serialized object can only be an instance of the specified class, and not an instance of a derived class.
+        /// </summary>
+        FixedType = 0x00000100,
+    }
+}

nanoFramework.System.Runtime.Serialization/System.Runtime.Serialization.nfproj

@@ -40,8 +40,14 @@
     <NFMDP_PE_ExcludeClassByName Include="ThisAssembly">
       <InProject>false</InProject>
     </NFMDP_PE_ExcludeClassByName>
+    <NFMDP_PE_ExcludeClassByName Include="System.Runtime.Serialization.FieldNoReflectionAttribute">
+      <InProject>false</InProject>
+    </NFMDP_PE_ExcludeClassByName>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="FieldNoReflectionAttribute.cs" />
+    <Compile Include="SerializationHintsAttribute.cs" />
+    <Compile Include="SerializationOptions.cs" />
     <Compile Include="SerializationException.cs" />
     <Compile Include="BinaryFormatter.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />