[pbs-devel] [PATCH proxmox 2/2] product-config: use inner mutability for PRODUCT_CONFIG

[Shannon Sterz]

with edition 2024 `static mut` references will be disallowed [1]. the
recommended way to work around this is to use inner mutability, so use a
`OnceLock` for the `PRODUCT_CONFIG` as that should not change throughout
the run time of an application.

[1]:
https://doc.rust-lang.org/nightly/edition-guide/rust-2024/static-mut-references.html

Signed-off-by: Shannon Sterz <s.sterz at proxmox.com>
---
 proxmox-product-config/src/init.rs | 33 +++++++++++++++---------------
 1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/proxmox-product-config/src/init.rs b/proxmox-product-config/src/init.rs
index a244559a..1bc47110 100644
--- a/proxmox-product-config/src/init.rs
+++ b/proxmox-product-config/src/init.rs
@@ -1,18 +1,21 @@
+use std::sync::OnceLock;
+
+#[derive(Debug)]
 struct ProxmoxProductConfig {
     api_user: nix::unistd::User,
     priv_user: nix::unistd::User,
 }
 
-static mut PRODUCT_CONFIG: Option<ProxmoxProductConfig> = None;
+static PRODUCT_CONFIG: OnceLock<ProxmoxProductConfig> = OnceLock::new();
 
 /// Initialize the global product configuration.
 pub fn init(api_user: nix::unistd::User, priv_user: nix::unistd::User) {
-    unsafe {
-        PRODUCT_CONFIG = Some(ProxmoxProductConfig {
+    PRODUCT_CONFIG
+        .set(ProxmoxProductConfig {
             api_user,
             priv_user,
-        });
-    }
+        })
+        .expect("cannot init proxmox product config twice");
 }
 
 /// Returns the global api user set with [init].
@@ -21,12 +24,10 @@ pub fn init(api_user: nix::unistd::User, priv_user: nix::unistd::User) {
 ///
 /// Panics if [init] wasn't called before.
 pub fn get_api_user() -> &'static nix::unistd::User {
-    unsafe {
-        &PRODUCT_CONFIG
-            .as_ref()
-            .expect("ProxmoxProductConfig is not initialized!")
-            .api_user
-    }
+    &PRODUCT_CONFIG
+        .get()
+        .expect("ProxmoxProductConfig is not initialized!")
+        .api_user
 }
 
 // Returns the global privileged user set with [init].
@@ -35,10 +36,8 @@ pub fn get_api_user() -> &'static nix::unistd::User {
 ///
 /// Panics if [init] wasn't called before.
 pub fn get_priv_user() -> &'static nix::unistd::User {
-    unsafe {
-        &PRODUCT_CONFIG
-            .as_ref()
-            .expect("ProxmoxProductConfig is not initialized!")
-            .priv_user
-    }
+    &PRODUCT_CONFIG
+        .get()
+        .expect("ProxmoxProductConfig is not initialized!")
+        .priv_user
 }
-- 
2.39.5