- Apply LoRA in `LLamaWeights.LoadFromFile`

- Sanity checking that weights are not disposed when creating a context from them
 - Further simplified `Utils.InitLLamaContextFromModelParams`

LLama/LLamaContext.cs

@@ -74,8 +74,7 @@ namespace LLama
             _ctx = Utils.InitLLamaContextFromModelParams(Params);
         }
 
-        //todo make this internal
-        public LLamaContext(SafeLLamaContextHandle nativeContext, IModelParams @params, Encoding encoding, ILLamaLogger? logger = null)
+        internal LLamaContext(SafeLLamaContextHandle nativeContext, IModelParams @params, Encoding encoding, ILLamaLogger? logger = null)
         {
             Params = @params;
 
@@ -86,6 +85,9 @@ namespace LLama
 
         public LLamaContext(LLamaWeights model, IModelParams @params, Encoding encoding, ILLamaLogger? logger = null)
         {
+            if (model.NativeHandle.IsClosed)
+                throw new ObjectDisposedException("Cannot create context, model weights have been disposed");
+
             Params = @params;
 
             _logger = logger;

LLama/LLamaWeights.cs

@@ -1,6 +1,6 @@
 using System;
 using System.Text;
-using LLama.Common;
+using LLama.Abstractions;
 using LLama.Extensions;
 using LLama.Native;
 
@@ -30,10 +30,14 @@ namespace LLama
         /// </summary>
         /// <param name="params"></param>
         /// <returns></returns>
-        public static LLamaWeights LoadFromFile(ModelParams @params)
+        public static LLamaWeights LoadFromFile(IModelParams @params)
         {
             using var pin = @params.ToLlamaContextParams(out var lparams);
             var weights = SafeLlamaModelHandle.LoadFromFile(@params.ModelPath, lparams);
+
+            if (!string.IsNullOrEmpty(@params.LoraAdapter))
+                weights.ApplyLoraFromFile(@params.LoraAdapter, @params.LoraBase, @params.Threads);
+
             return new LLamaWeights(weights);
         }
 
@@ -47,11 +51,11 @@ namespace LLama
         /// Create a llama_context using this model
         /// </summary>
         /// <param name="params"></param>
-        /// <param name="utf8"></param>
+        /// <param name="encoding"></param>
         /// <returns></returns>
-        public LLamaContext CreateContext(ModelParams @params, Encoding utf8)
+        public LLamaContext CreateContext(IModelParams @params, Encoding encoding)
         {
-            return new LLamaContext(this, @params, Encoding.UTF8);
+            return new LLamaContext(this, @params, encoding);
         }
     }
 }

LLama/Utils.cs

@@ -13,16 +13,10 @@ namespace LLama
     {
         public static SafeLLamaContextHandle InitLLamaContextFromModelParams(IModelParams @params)
         {
-            using (@params.ToLlamaContextParams(out var lparams))
-            {
-                var model = SafeLlamaModelHandle.LoadFromFile(@params.ModelPath, lparams);
-                var ctx = SafeLLamaContextHandle.Create(model, lparams);
-                
-                if (!string.IsNullOrEmpty(@params.LoraAdapter))
-                    model.ApplyLoraFromFile(@params.LoraAdapter, @params.LoraBase, @params.Threads);
+            using var weights = LLamaWeights.LoadFromFile(@params);
 
-                return ctx;
-            }
+            using (@params.ToLlamaContextParams(out var lparams))
+                return SafeLLamaContextHandle.Create(weights.NativeHandle, lparams);
         }
 
         [Obsolete("Use SafeLLamaContextHandle Tokenize method instead")]