Reset POOLS_HASH when reloading config to avoid duplications

Before, when configuration was reloaded, we checked whether a given pool
configuration was changed by adding it to a HashSet and checking whether it was
inserted or ignored. This behavior has a undesired effect when changing existing
pools, as the new one will be added, even though the old will still exist
in the HashSet.

With this change, the HashSet is always recreated with current configuration, leaving
intact the rest of the logic.

Author: magec

src/pool.rs

@@ -160,9 +160,11 @@ impl ConnectionPool {
         let mut address_id = 0;
 
         let mut pools_hash = (*(*POOLS_HASH.load())).clone();
+        let mut new_pools_hash = HashSet::<crate::config::Pool>::default();
 
         for (pool_name, pool_config) in &config.pools {
             let changed = pools_hash.insert(pool_config.clone());
+            new_pools_hash.insert(pool_config.clone());
 
             // There is one pool per database/user pair.
             for user in pool_config.users.values() {
@@ -332,7 +334,7 @@ impl ConnectionPool {
         }
 
         POOLS.store(Arc::new(new_pools.clone()));
-        POOLS_HASH.store(Arc::new(pools_hash.clone()));
+        POOLS_HASH.store(Arc::new(new_pools_hash.clone()));
 
         Ok(())
     }