feat: add get-embedding api to LLamaModel.

LLama.Examples/GetEmbeddings.cs

@@ -0,0 +1,22 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace LLama.Examples
+{
+    public class GetEmbeddings
+    {
+        LLamaEmbedder _embedder;
+        public GetEmbeddings(string modelPath)
+        {
+            _embedder = new LLamaEmbedder(new LLamaParams(model: modelPath));
+        }
+
+        public void Run(string text)
+        {
+            Console.WriteLine(string.Join(", ", _embedder.GetEmbeddings(text)));
+        }
+    }
+}

LLama.Examples/Program.cs

@@ -2,11 +2,11 @@
 using LLama.Examples;
 using LLama.Types;
 
-int choice = 3;
+int choice = 0;
 
 if(choice == 0)
 {
-    ChatSession chat = new(@"C:\Users\haipi\Source\repos\ggml-model-q4_0.bin", @"C:\Users\haipi\Source\repos\SciSharp\LLamaSharp\LLama.Examples\Assets\chat-with-bob.txt", new string[] { "User:" });
+    ChatSession chat = new(@"<Your model file path>", @"<Your prompt file path>", new string[] { "User:" });
     chat.Run();
 }
 else if(choice == 1)
@@ -22,6 +22,11 @@
 else if (choice == 3) // quantization
 {
     Quantize q = new Quantize();
-    q.Run(@"D:\development\llama\weights\LLaMA\7B\ggml-model-f16.bin",
-        @"D:\development\llama\weights\LLaMA\7B\ggml-model-q4_1.bin", "q4_1");
+    q.Run(@"<Your src model file path>",
+        @"<Your dst model file path>", "q4_1");
+}
+else if (choice == 4) // quantization
+{
+    GetEmbeddings em = new GetEmbeddings(@"<Your model file path>");
+    em.Run("Hello, what is python?");
 }

LLama/GptModel.cs

@@ -42,6 +42,7 @@ public class LLamaModel: IChatModel
         bool _first_time_chat = true;
 
         public string Name { get; set; }
+        public SafeLLamaContextHandle NativeHandle => _ctx;
 
         public LLamaModel(string model_path, string model_name, bool echo_input = false, bool verbose = false, int seed = 0, int n_threads = -1, int n_predict = -1,
             int n_parts = -1, int n_ctx = 512, int n_batch = 512, int n_keep = 0,
@@ -70,7 +71,7 @@ public unsafe LLamaModel(LLamaParams @params, string name = "", bool echo_input
             _ctx = Utils.llama_init_from_gpt_params(ref _params);
 
             // Add a space in front of the first character to match OG llama tokenizer behavior
-            _params.prompt.Insert(0, " ");
+            _params.prompt = _params.prompt.Insert(0, " ");
             _session_tokens = new List<llama_token>();
 
             _path_session = @params.path_session;
@@ -223,7 +224,7 @@ public LLamaModel WithPrompt(string prompt)
             _params.prompt = prompt;
             if (!_params.prompt.EndsWith(" "))
             {
-                _params.prompt.Insert(0, " ");
+                _params.prompt = _params.prompt.Insert(0, " ");
             }
             _embed_inp = Utils.llama_tokenize(_ctx, _params.prompt, true);
             if (_embed_inp.Count > _n_ctx - 4)

LLama/LLamaEmbedder.cs

@@ -0,0 +1,64 @@
+using LLama.Native;
+using System;
+using System.Collections.Generic;
+using System.Text;
+using LLama.Exceptions;
+
+namespace LLama
+{
+    public class LLamaEmbedder
+    {
+        SafeLLamaContextHandle _ctx;
+
+        /// <summary>
+        /// Warning: must ensure the original model has params.embedding = true;
+        /// </summary>
+        /// <param name="ctx"></param>
+        internal LLamaEmbedder(SafeLLamaContextHandle ctx)
+        {
+            _ctx = ctx;
+        }
+
+        public LLamaEmbedder(LLamaParams @params)
+        {
+            @params.embedding = true;
+            _ctx = Utils.llama_init_from_gpt_params(ref @params);
+        }
+
+        public unsafe float[] GetEmbeddings(string text, int n_thread = -1, bool add_bos = true)
+        {
+            if(n_thread == -1)
+            {
+                n_thread = Math.Max(Environment.ProcessorCount / 2, 1);
+            }
+            int n_past = 0;
+            if (add_bos)
+            {
+                text = text.Insert(0, " ");
+            }
+            var embed_inp = Utils.llama_tokenize(_ctx, text, add_bos);
+
+            // TODO(Rinne): deal with log of prompt
+
+            if (embed_inp.Count > 0)
+            {
+                var embed_inp_array = embed_inp.ToArray();
+                if (NativeApi.llama_eval(_ctx, embed_inp_array, embed_inp_array.Length, n_past, n_thread) != 0)
+                {
+                    throw new RuntimeError("Failed to eval.");
+                }
+            }
+
+            int n_embed = NativeApi.llama_n_embd(_ctx);
+            var embeddings = NativeApi.llama_get_embeddings(_ctx);
+            if(embeddings == null)
+            {
+                return new float[0];
+            }
+            var span = new Span<float>(embeddings, n_embed);
+            float[] res = new float[n_embed];
+            span.CopyTo(res.AsSpan());
+            return res;
+        }
+    }
+}

LLama/Native/SafeLLamaContextHandle.cs

@@ -5,7 +5,7 @@
 
 namespace LLama.Native
 {
-    internal class SafeLLamaContextHandle: SafeLLamaHandleBase
+    public class SafeLLamaContextHandle: SafeLLamaHandleBase
     {
         protected SafeLLamaContextHandle()
         {

LLama/Native/SafeLLamaHandleBase.cs

@@ -5,7 +5,7 @@
 
 namespace LLama.Native
 {
-    internal abstract class SafeLLamaHandleBase: SafeHandle
+    public abstract class SafeLLamaHandleBase: SafeHandle
     {
         private protected SafeLLamaHandleBase()
             : base(IntPtr.Zero, ownsHandle: true)