From 5cfb1bda8967d5e7587136c4b7b45f88931d8890 Mon Sep 17 00:00:00 2001
From: Juuso Alasuutari <juuso.alasuutari@gmail.com>
Date: Mon, 12 Jun 2023 19:41:22 +0300
Subject: [PATCH] llmodel: add model wrapper destructor, fix mem leak in golang
 bindings (#862)

Signed-off-by: Juuso Alasuutari <juuso.alasuutari@gmail.com>
---
 gpt4all-backend/llmodel_c.cpp       | 21 +++++++++++----------
 gpt4all-bindings/golang/binding.cpp |  1 +
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/gpt4all-backend/llmodel_c.cpp b/gpt4all-backend/llmodel_c.cpp
index c5ab5b39..89120507 100644
--- a/gpt4all-backend/llmodel_c.cpp
+++ b/gpt4all-backend/llmodel_c.cpp
@@ -9,6 +9,7 @@
 struct LLModelWrapper {
     LLModel *llModel = nullptr;
     LLModel::PromptContext promptContext;
+    ~LLModelWrapper() { delete llModel; }
 };
 
 
@@ -25,33 +26,33 @@ llmodel_model llmodel_model_create(const char *model_path) {
 
 llmodel_model llmodel_model_create2(const char *model_path, const char *build_variant, llmodel_error *error) {
     auto wrapper = new LLModelWrapper;
-    llmodel_error new_error{};
+    int error_code = 0;
 
     try {
         wrapper->llModel = LLModel::construct(model_path, build_variant);
     } catch (const std::exception& e) {
-        new_error.code = EINVAL;
+        error_code = EINVAL;
         last_error_message = e.what();
     }
 
     if (!wrapper->llModel) {
         delete std::exchange(wrapper, nullptr);
         // Get errno and error message if none
-        if (new_error.code == 0) {
-            new_error.code = errno;
-            last_error_message = strerror(errno);
+        if (error_code == 0) {
+            error_code = errno;
+            last_error_message = std::strerror(error_code);
         }
-        // Set message pointer
-        new_error.message = last_error_message.c_str();
         // Set error argument
-        if (error) *error = new_error;
+        if (error) {
+            error->message = last_error_message.c_str();
+            error->code = error_code;
+        }
     }
     return reinterpret_cast<llmodel_model*>(wrapper);
 }
 
 void llmodel_model_destroy(llmodel_model model) {
-    LLModelWrapper *wrapper = reinterpret_cast<LLModelWrapper*>(model);
-    delete wrapper->llModel;
+    delete reinterpret_cast<LLModelWrapper*>(model);
 }
 
 bool llmodel_loadModel(llmodel_model model, const char *model_path)
diff --git a/gpt4all-bindings/golang/binding.cpp b/gpt4all-bindings/golang/binding.cpp
index a0bc4feb..d626dda1 100644
--- a/gpt4all-bindings/golang/binding.cpp
+++ b/gpt4all-bindings/golang/binding.cpp
@@ -25,6 +25,7 @@ void* load_model(const char *fname, int n_threads) {
         return nullptr;
     }
     if (!llmodel_loadModel(model, fname)) {
+        llmodel_model_destroy(model);
         return nullptr;
     }