gpt4all-backend: Add llmodel create and destroy functions (#554)

* Add llmodel create and destroy functions

* Fix capitalization

* Fix capitalization

* Fix capitalization

* Update CMakeLists.txt

---------

Co-authored-by: kuvaus <kuvaus@users.noreply.github.com>

gpt4all-backend/CMakeLists.txt

@@ -17,7 +17,7 @@ include_directories("${CMAKE_CURRENT_BINARY_DIR}")
 
 set(LLMODEL_VERSION_MAJOR 0)
 set(LLMODEL_VERSION_MINOR 1)
-set(LLMODEL_VERSION_PATCH 0)
+set(LLMODEL_VERSION_PATCH 1)
 set(LLMODEL_VERSION "${LLMODEL_VERSION_MAJOR}.${LLMODEL_VERSION_MINOR}.${LLMODEL_VERSION_PATCH}")
 project(llmodel VERSION ${LLMODEL_VERSION} LANGUAGES CXX C)
 

gpt4all-backend/llmodel_c.cpp

@@ -51,6 +51,31 @@ void llmodel_llama_destroy(llmodel_model llama)
     delete wrapper;
 }
 
+llmodel_model llmodel_model_create(const char *model_path) {
+
+    uint32_t magic;
+    llmodel_model model;
+    FILE *f = fopen(model_path, "rb");
+    fread(&magic, sizeof(magic), 1, f);
+
+    if (magic == 0x67676d6c) { model = llmodel_gptj_create();  }
+    if (magic == 0x67676a74) { model = llmodel_llama_create(); }
+    if (magic == 0x67676d6d) { model = llmodel_mpt_create();   }
+    else  {fprintf(stderr, "Invalid model file\n");}
+    fclose(f);
+    return model;
+}
+
+void llmodel_model_destroy(llmodel_model model) {
+
+    LLModelWrapper *wrapper = reinterpret_cast<LLModelWrapper*>(model);
+    const std::type_info &modelTypeInfo = typeid(*wrapper->llModel);
+
+    if (modelTypeInfo == typeid(GPTJ))       { llmodel_gptj_destroy(model);  }
+    if (modelTypeInfo == typeid(LLamaModel)) { llmodel_llama_destroy(model); }
+    if (modelTypeInfo == typeid(MPT))        { llmodel_mpt_destroy(model);   }
+}
+
 bool llmodel_loadModel(llmodel_model model, const char *model_path)
 {
     LLModelWrapper *wrapper = reinterpret_cast<LLModelWrapper*>(model);

gpt4all-backend/llmodel_c.h

@@ -95,6 +95,22 @@ llmodel_model llmodel_llama_create();
  */
 void llmodel_llama_destroy(llmodel_model llama);
 
+/**
+ * Create a llmodel instance.
+ * Recognises correct model type from file at model_path
+ * @param model_path A string representing the path to the model file. 
+ * @return A pointer to the llmodel_model instance.
+ */
+llmodel_model llmodel_model_create(const char *model_path);
+
+/**
+ * Destroy a llmodel instance.
+ * Recognises correct model type using type info
+ * @param model a pointer to a llmodel_model instance.
+ */
+void llmodel_model_destroy(llmodel_model model);
+
+
 /**
  * Load a model from a file.
  * @param model A pointer to the llmodel_model instance.