feat: integrate MLCChat module for on-device LLM functionality

.gitignore

@@ -4,3 +4,4 @@ SwiftiDate/GlobalVariables.swift
 firebase_chat_sorter.py
 swiftidate-cdff0-firebase-adminsdk-e2p44-7c5e06ebfc.json
 SwiftiDate.xcodeproj/project.pbxproj
+mlc-llm

MLCSwift/.swiftpm/xcode/xcuserdata/youzhewei.xcuserdatad/xcschemes/xcschememanagement.plist

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>SchemeUserState</key>
+	<dict>
+		<key>MLCSwift.xcscheme_^#shared#^_</key>
+		<dict>
+			<key>orderHint</key>
+			<integer>3</integer>
+		</dict>
+	</dict>
+</dict>
+</plist>

MLCSwift/Package.swift

@@ -0,0 +1,32 @@
+// swift-tools-version:5.5
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "MLCSwift",
+    products: [
+        .library(
+            name: "MLCSwift",
+            targets: ["MLCEngineObjC", "MLCSwift"]
+        )
+    ],
+    dependencies: [],
+    targets: [
+        .target(
+            name: "MLCEngineObjC",
+            path: "Sources/ObjC",
+            cxxSettings: [
+                .headerSearchPath("../../tvm_home/include"),
+                .headerSearchPath("../../tvm_home/3rdparty/dmlc-core/include"),
+                .headerSearchPath("../../tvm_home/3rdparty/dlpack/include")
+            ]
+        ),
+        .target(
+            name: "MLCSwift",
+            dependencies: ["MLCEngineObjC"],
+            path: "Sources/Swift"
+        )
+    ],
+    cxxLanguageStandard: .cxx17
+)

MLCSwift/README.md

@@ -0,0 +1,4 @@
+# MLCSwift
+
+This is a simple swift package that exposes the chat module to swift.
+Checkout our [documentation](https://llm.mlc.ai/docs/) for more examples.

MLCSwift/Sources/ObjC/LLMEngine.mm

@@ -0,0 +1,110 @@
+//
+//  LLMEngine.mm
+//  LLMEngine
+//
+#import <Foundation/Foundation.h>
+#import <UIKit/UIKit.h>
+#include <os/proc.h>
+
+#include "LLMEngine.h"
+
+#define TVM_USE_LIBBACKTRACE 0
+#define DMLC_USE_LOGGING_LIBRARY <tvm/runtime/logging.h>
+
+#include <tvm/runtime/packed_func.h>
+#include <tvm/runtime/registry.h>
+
+using namespace tvm::runtime;
+
+@implementation JSONFFIEngine {
+  // Internal c++ classes
+  // internal module backed by JSON FFI
+  Module json_ffi_engine_;
+  // member functions
+  PackedFunc init_background_engine_func_;
+  PackedFunc unload_func_;
+  PackedFunc reload_func_;
+  PackedFunc reset_func_;
+  PackedFunc chat_completion_func_;
+  PackedFunc abort_func_;
+  PackedFunc run_background_loop_func_;
+  PackedFunc run_background_stream_back_loop_func_;
+  PackedFunc exit_background_loop_func_;
+}
+
+- (instancetype)init {
+  if (self = [super init]) {
+    // load chat module
+    const PackedFunc* f_json_ffi_create = Registry::Get("mlc.json_ffi.CreateJSONFFIEngine");
+    ICHECK(f_json_ffi_create) << "Cannot find mlc.json_ffi.CreateJSONFFIEngine";
+    json_ffi_engine_ = (*f_json_ffi_create)();
+    init_background_engine_func_ = json_ffi_engine_->GetFunction("init_background_engine");
+    reload_func_ = json_ffi_engine_->GetFunction("reload");
+    unload_func_ = json_ffi_engine_->GetFunction("unload");
+    reset_func_ = json_ffi_engine_->GetFunction("reset");
+    chat_completion_func_ = json_ffi_engine_->GetFunction("chat_completion");
+    abort_func_ = json_ffi_engine_->GetFunction("abort");
+    run_background_loop_func_ = json_ffi_engine_->GetFunction("run_background_loop");
+    run_background_stream_back_loop_func_ =
+        json_ffi_engine_->GetFunction("run_background_stream_back_loop");
+    exit_background_loop_func_ = json_ffi_engine_->GetFunction("exit_background_loop");
+
+    ICHECK(init_background_engine_func_ != nullptr);
+    ICHECK(reload_func_ != nullptr);
+    ICHECK(unload_func_ != nullptr);
+    ICHECK(reset_func_ != nullptr);
+    ICHECK(chat_completion_func_ != nullptr);
+    ICHECK(abort_func_ != nullptr);
+    ICHECK(run_background_loop_func_ != nullptr);
+    ICHECK(run_background_stream_back_loop_func_ != nullptr);
+    ICHECK(exit_background_loop_func_ != nullptr);
+  }
+  return self;
+}
+
+- (void)initBackgroundEngine:(void (^)(NSString*))streamCallback {
+  TypedPackedFunc<void(String)> internal_stream_callback([streamCallback](String value) {
+    streamCallback([NSString stringWithUTF8String:value.c_str()]);
+  });
+  int device_type = kDLMetal;
+  int device_id = 0;
+  init_background_engine_func_(device_type, device_id, internal_stream_callback);
+}
+
+- (void)reload:(NSString*)engineConfigJson {
+  std::string engine_config = engineConfigJson.UTF8String;
+  reload_func_(engine_config);
+}
+
+- (void)unload {
+  unload_func_();
+}
+
+- (void)reset {
+  reset_func_();
+}
+
+- (void)chatCompletion:(NSString*)requestJSON requestID:(NSString*)requestID {
+  std::string request_json = requestJSON.UTF8String;
+  std::string request_id = requestID.UTF8String;
+  chat_completion_func_(request_json, request_id);
+}
+
+- (void)abort:(NSString*)requestID {
+  std::string request_id = requestID.UTF8String;
+  abort_func_(request_id);
+}
+
+- (void)runBackgroundLoop {
+  run_background_loop_func_();
+}
+
+- (void)runBackgroundStreamBackLoop {
+  run_background_stream_back_loop_func_();
+}
+
+- (void)exitBackgroundLoop {
+  exit_background_loop_func_();
+}
+
+@end

MLCSwift/Sources/ObjC/include/LLMEngine.h

@@ -0,0 +1,32 @@
+//
+//  Use this file to import your target's public headers that you would like to expose to Swift.
+//  LLM Chat Module
+//
+// Exposed interface of Object-C, enables swift binding.
+#import <Foundation/Foundation.h>
+#import <UIKit/UIKit.h>
+
+/**
+ * This is an internal Raw JSON FFI Engine that redirects request to internal JSON FFI Engine in C++
+ */
+@interface JSONFFIEngine : NSObject
+
+- (void)initBackgroundEngine:(void (^)(NSString*))streamCallback;
+
+- (void)reload:(NSString*)engineConfig;
+
+- (void)unload;
+
+- (void)reset;
+
+- (void)chatCompletion:(NSString*)requestJSON requestID:(NSString*)requestID;
+
+- (void)abort:(NSString*)requestID;
+
+- (void)runBackgroundLoop;
+
+- (void)runBackgroundStreamBackLoop;
+
+- (void)exitBackgroundLoop;
+
+@end