Merge pull request #39 from xbotter/webapi-example

update webapi example

LLama.WebAPI/Controllers/ChatController.cs

@@ -1,3 +1,4 @@
+using LLama.Common;
 using LLama.WebAPI.Models;
 using LLama.WebAPI.Services;
 using Microsoft.AspNetCore.Mvc;
@@ -9,20 +10,44 @@ namespace LLama.WebAPI.Controllers
     [Route("[controller]")]
     public class ChatController : ControllerBase
     {
-        private readonly ChatService _service;
         private readonly ILogger<ChatController> _logger;
 
-        public ChatController(ILogger<ChatController> logger,
-            ChatService service)
+        public ChatController(ILogger<ChatController> logger)
         {
             _logger = logger;
-            _service = service;
         }
 
         [HttpPost("Send")]
-        public string SendMessage([FromBody] SendMessageInput input)
+        public string SendMessage([FromBody] SendMessageInput input, [FromServices] StatefulChatService _service)
         {
             return _service.Send(input);
         }
+
+        [HttpPost("Send/Stream")]
+        public async Task SendMessageStream([FromBody] SendMessageInput input, [FromServices] StatefulChatService _service, CancellationToken cancellationToken)
+        {
+
+            Response.ContentType = "text/event-stream";
+
+            await foreach (var r in _service.SendStream(input))
+            {
+                await Response.WriteAsync("data:" + r + "\n\n", cancellationToken);
+                await Response.Body.FlushAsync(cancellationToken);
+            }
+
+            await Response.CompleteAsync();
+        }
+
+        [HttpPost("History")]
+        public async Task<string> SendHistory([FromBody] HistoryInput input, [FromServices] StatelessChatService _service)
+        {
+            var history = new ChatHistory();
+
+            var messages = input.Messages.Select(m => new ChatHistory.Message(Enum.Parse<AuthorRole>(m.Role), m.Content));
+
+            history.Messages.AddRange(messages);
+
+            return await _service.SendAsync(history);
+        }
     }
 }

LLama.WebAPI/LLama.WebAPI.csproj

@@ -7,6 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.VisualStudio.Validation" Version="17.6.11" />
     <PackageReference Include="Swashbuckle.AspNetCore" Version="6.2.3" />
   </ItemGroup>
 

LLama.WebAPI/Models/SendMessageInput.cs

@@ -4,3 +4,13 @@ public class SendMessageInput
 {
     public string Text { get; set; }
 }
+
+public class HistoryInput
+{
+    public List<HistoryItem> Messages { get; set; }
+    public class HistoryItem
+    {
+        public string Role { get; set; }
+        public string Content { get; set; }
+    }
+}

LLama.WebAPI/Program.cs

@@ -9,7 +9,8 @@ builder.Services.AddControllers();
 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen();
 
-builder.Services.AddSingleton<ChatService>();
+builder.Services.AddSingleton<StatefulChatService>();
+builder.Services.AddScoped<StatelessChatService>();
 
 var app = builder.Build();
 

LLama.WebAPI/Services/ChatService.cs

@@ -1,34 +0,0 @@
-using LLama.OldVersion;
-using LLama.WebAPI.Models;
-
-namespace LLama.WebAPI.Services;
-
-public class ChatService
-{
-    private readonly ChatSession<LLamaModel> _session;
-
-    public ChatService()
-    {
-        LLamaModel model = new(new LLamaParams(model: @"ggml-model-q4_0.bin", n_ctx: 512, interactive: true, repeat_penalty: 1.0f, verbose_prompt: false));
-        _session = new ChatSession<LLamaModel>(model)
-            .WithPromptFile(@"Assets\chat-with-bob.txt")
-            .WithAntiprompt(new string[] { "User:" });
-    }
-
-    public string Send(SendMessageInput input)
-    {
-        Console.ForegroundColor = ConsoleColor.Green;
-        Console.WriteLine(input.Text);
-
-        Console.ForegroundColor = ConsoleColor.White;
-        var outputs = _session.Chat(input.Text);
-        var result = "";
-        foreach (var output in outputs)
-        {
-            Console.Write(output);
-            result += output;
-        }
-
-        return result;
-    }
-}

LLama.WebAPI/Services/StatefulChatService.cs

@@ -0,0 +1,82 @@
+
+using LLama.WebAPI.Models;
+using Microsoft;
+using System.Runtime.CompilerServices;
+
+namespace LLama.WebAPI.Services;
+
+public class StatefulChatService : IDisposable
+{
+    private readonly ChatSession _session;
+    private readonly LLamaModel _model;
+    private bool _continue = false;
+
+    private const string SystemPrompt = "Transcript of a dialog, where the User interacts with an Assistant. Assistant is helpful, kind, honest, good at writing, and never fails to answer the User's requests immediately and with precision.\n\n"
+                                       + "User: ";
+
+    public StatefulChatService(IConfiguration configuration)
+    {
+        _model = new LLamaModel(new Common.ModelParams(configuration["ModelPath"], contextSize: 512));
+        _session = new ChatSession(new InteractiveExecutor(_model));
+    }
+
+    public void Dispose()
+    {
+        _model?.Dispose();
+    }
+
+    public string Send(SendMessageInput input)
+    {
+        var userInput = input.Text;
+        if (!_continue)
+        {
+            userInput = SystemPrompt + userInput;
+            Console.Write(SystemPrompt);
+            _continue = true;
+        }
+
+        Console.ForegroundColor = ConsoleColor.Green;
+        Console.Write(input.Text);
+
+        Console.ForegroundColor = ConsoleColor.White;
+        var outputs = _session.Chat(userInput, new Common.InferenceParams()
+        {
+            RepeatPenalty = 1.0f,
+            AntiPrompts = new string[] { "User:" },
+        });
+        var result = "";
+        foreach (var output in outputs)
+        {
+            Console.Write(output);
+            result += output;
+        }
+
+        return result;
+    }
+
+    public async IAsyncEnumerable<string> SendStream(SendMessageInput input)
+    {
+        var userInput = input.Text;
+        if (!_continue)
+        {
+            userInput = SystemPrompt + userInput;
+            Console.Write(SystemPrompt);
+            _continue = true;
+        }
+
+        Console.ForegroundColor = ConsoleColor.Green;
+        Console.Write(input.Text);
+
+        Console.ForegroundColor = ConsoleColor.White;
+        var outputs = _session.ChatAsync(userInput, new Common.InferenceParams()
+        {
+            RepeatPenalty = 1.0f,
+            AntiPrompts = new string[] { "User:" },
+        });
+        await foreach (var output in outputs)
+        {
+            Console.Write(output);
+            yield return output;
+        }
+    }
+}

LLama.WebAPI/Services/StatelessChatService.cs

@@ -0,0 +1,48 @@
+using LLama.Common;
+using Microsoft.AspNetCore.Http;
+using System.Text;
+using static LLama.LLamaTransforms;
+
+namespace LLama.WebAPI.Services
+{
+    public class StatelessChatService
+    {
+        private readonly LLamaModel _model;
+        private readonly ChatSession _session;
+
+        public StatelessChatService(IConfiguration configuration)
+        {
+            _model = new LLamaModel(new ModelParams(configuration["ModelPath"], contextSize: 512));
+            // TODO: replace with a stateless executor
+            _session = new ChatSession(new InteractiveExecutor(_model))
+                        .WithOutputTransform(new LLamaTransforms.KeywordTextOutputStreamTransform(new string[] { "User:", "Assistant:" }, redundancyLength: 8))
+                        .WithHistoryTransform(new HistoryTransform());
+        }
+
+        public async Task<string> SendAsync(ChatHistory history)
+        {
+            var result = _session.ChatAsync(history, new InferenceParams()
+            {
+                AntiPrompts = new string[] { "User:" },
+            });
+
+            var sb = new StringBuilder();
+            await foreach (var r in result)
+            {
+                Console.Write(r);
+                sb.Append(r);
+            }
+
+            return sb.ToString();
+
+        }
+    }
+    public class HistoryTransform : DefaultHistoryTransform
+    {
+        public override string HistoryToText(ChatHistory history)
+        {
+            return base.HistoryToText(history) + "\n Assistant:";
+        }
+
+    }
+}

LLama.WebAPI/appsettings.json

@@ -5,5 +5,6 @@
       "Microsoft.AspNetCore": "Warning"
     }
   },
-  "AllowedHosts": "*"
+  "AllowedHosts": "*",
+  "ModelPath": "..\\..\\LLamaModel\\ggml-model-f32-q4_0.bin"
 }