fix locking logic

patch-db-derive-internals/src/lib.rs

@@ -0,0 +1,42 @@
+use proc_macro2::TokenStream;
+use quote::quote;
+
+pub fn build_model(input: &syn::DeriveInput) -> TokenStream {
+    match &input.data {
+        syn::Data::Struct(struct_ast) => build_model_struct(input, struct_ast),
+        syn::Data::Enum(enum_ast) => build_model_enum(enum_ast),
+        syn::Data::Union(_) => panic!("Unions are not supported"),
+    }
+}
+
+fn build_model_struct(input: &syn::DeriveInput, ast: &syn::DataStruct) -> TokenStream {
+    let model_name = syn::Ident::new(
+        &format!("{}Model", input.ident),
+        proc_macro2::Span::call_site(),
+    );
+    let base_name = &input.ident;
+    let model_vis = &input.vis;
+    quote! {
+        #model_vis struct #model_name<Tx: patch_db::Checkpoint> {
+            data: Option<Box<#base_name>>,
+            ptr: json_ptr::JsonPointer,
+            tx: Tx,
+        }
+        impl<Tx: patch_db::Checkpoint> #model_name<Tx> {
+            pub fn get(&mut self, lock: patch_db::LockType) -> Result<&#base_name, patch_db::Error> {
+                if let Some(data) = self.data.as_ref() {
+                    match lock {
+                        patch_db::LockType::None => Ok(data),
+
+                    }
+                } else {
+                    self.tx.get(&self.ptr, lock)
+                }
+            }
+        }
+    }
+}
+
+fn build_model_enum(ast: &syn::DataEnum) -> TokenStream {
+    todo!()
+}