Changes to compile in VS Mac + change model to llama2

This commit includes changes to compile en VS Mac + changest to use llama2 not codellama.

It includes MacOS binaries in memory and metal

LLama.Unittest/BasicTest.cs

@@ -25,7 +25,7 @@ namespace LLama.Unittest
         [Fact]
         public void BasicModelProperties()
         {
-            Assert.Equal(32016, _model.VocabCount);
+            Assert.Equal(32000, _model.VocabCount);
             Assert.Equal(2048, _model.ContextSize);
             Assert.Equal(4096, _model.EmbeddingSize);
         }

LLama.Unittest/Constants.cs

@@ -2,6 +2,6 @@
 {
     internal static class Constants
     {
-        public static string ModelPath = "Models/codellama-7b.Q3_K_S.gguf";
+        public static string ModelPath = "Models/llama-2-7b.q4_0.gguf";
     }
 }

LLama.Unittest/LLama.Unittest.csproj

@@ -24,7 +24,7 @@
   </ItemGroup>
 
   <Target Name="DownloadContentFiles" BeforeTargets="Build">
-      <DownloadFile SourceUrl="https://huggingface.co/TheBloke/CodeLlama-7B-GGUF/resolve/main/codellama-7b.Q3_K_S.gguf" DestinationFolder="Models" DestinationFileName="codellama-7b.Q3_K_S.gguf" SkipUnchangedFiles="true">
+      <DownloadFile SourceUrl="https://huggingface.co/narrative-bi/Llama-2-7B-GGUF/resolve/main/llama-2-7b.q4_0.gguf" DestinationFolder="Models" DestinationFileName="llama-2-7b.q4_0.gguf" SkipUnchangedFiles="true">
     </DownloadFile>
   </Target>
 
@@ -37,7 +37,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <None Update="Models\codellama-7b.Q3_K_S.gguf">
+    <None Update="Models\llama-2-7b.q4_0.gguf">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
   </ItemGroup>

LLama.Unittest/LLamaContextTests.cs

@@ -29,7 +29,7 @@ namespace LLama.Unittest
         {
             Assert.Equal(768, _context.ContextSize);
             Assert.Equal(4096, _context.EmbeddingSize);
-            Assert.Equal(32016, _context.VocabCount);
+            Assert.Equal(32000, _context.VocabCount);
         }
     }
 }

LLama.Unittest/ModelsParamsTests.cs

@@ -45,21 +45,26 @@ namespace LLama.Unittest
             Assert.Equal(expected, actual);
         }
 
-        private class NewtsonsoftEncodingConverter
-            : Newtonsoft.Json.JsonConverter<Encoding>
+
+
+        public class NewtsonsoftEncodingConverter : JsonConverter
         {
-            public override void WriteJson(JsonWriter writer, Encoding? value, JsonSerializer serializer)
+            public override bool CanConvert(Type objectType)
             {
-                writer.WriteValue((string?)value?.WebName);
+                return typeof(Encoding).IsAssignableFrom(objectType);
             }
 
-            public override Encoding? ReadJson(JsonReader reader, Type objectType, Encoding? existingValue, bool hasExistingValue, JsonSerializer serializer)
+            public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
             {
-                var name = (string?)reader.Value;
-                if (name == null)
-                    return null;
-                return Encoding.GetEncoding(name);
+                writer.WriteValue(((Encoding)value).WebName);
+            }
+
+            public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+            {
+                return Encoding.GetEncoding((string)reader.Value);
             }
         }
+
+
     }
 }