Chore: refactoring to not reinvent the wheel—or Cow as it were

Author: robsdedude

neo4j/src/driver/io/bolt/bolt_handler/hello_5x0.rs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::borrow::Cow;
 use std::collections::HashMap;
 use std::io::{Read, Write};
 use std::mem;
@@ -34,7 +35,6 @@ use super::super::{
 };
 use super::common::{check_no_notification_filter, write_auth_entries, write_str_entry};
 use crate::error_::Result;
-use crate::util::RefContainer;
 use crate::value::{ValueReceive, ValueSend};
 
 pub(super) const SERVER_AGENT_KEY: &str = "server";
@@ -184,14 +184,14 @@ impl HelloHandler5x0 {
 
     pub(super) fn extract_connection_hints(
         meta: &BoltMeta,
-    ) -> RefContainer<'_, HashMap<String, ValueReceive>> {
+    ) -> Cow<'_, HashMap<String, ValueReceive>> {
         match meta.get(HINTS_KEY) {
-            Some(ValueReceive::Map(hints)) => RefContainer::Borrowed(hints),
+            Some(ValueReceive::Map(hints)) => Cow::Borrowed(hints),
             Some(value) => {
                 warn!("Server sent unexpected {HINTS_KEY} type {:?}", value);
-                RefContainer::Owned(HashMap::new())
+                Cow::Owned(HashMap::new())
             }
-            None => RefContainer::Owned(HashMap::new()),
+            None => Cow::Owned(HashMap::new()),
         }
     }
 

neo4j/src/driver/io/pool/single_pool.rs

@@ -12,12 +12,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use log::{info, log_enabled, Level};
+use std::borrow::Cow;
 use std::collections::{HashSet, VecDeque};
 use std::ops::{Deref, DerefMut};
 use std::sync::Arc;
 use std::time::Duration;
 
+use log::{info, log_enabled, Level};
 use parking_lot::lock_api::MutexGuard;
 use parking_lot::{Condvar, Mutex, RawMutex};
 
@@ -30,7 +31,6 @@ use crate::driver::config::auth::{auth_managers, AuthToken};
 use crate::driver::config::AuthConfig;
 use crate::error_::{Neo4jError, Result};
 use crate::time::Instant;
-use crate::util::RefContainer;
 
 type PoolElement = TcpBolt;
 
@@ -95,13 +95,13 @@ impl InnerPool {
     ) -> Result<PoolElement> {
         let auth = match session_auth {
             SessionAuth::None => match &self.config.auth {
-                AuthConfig::Static(auth) => RefContainer::Borrowed(auth),
+                AuthConfig::Static(auth) => Cow::Borrowed(auth),
                 AuthConfig::Manager(manager) => {
-                    RefContainer::Owned(auth_managers::get_auth(manager.as_ref())?)
+                    Cow::Owned(auth_managers::get_auth(manager.as_ref())?)
                 }
             },
-            SessionAuth::Reauth(auth) => RefContainer::Borrowed(auth),
-            SessionAuth::Forced(auth) => RefContainer::Borrowed(auth),
+            SessionAuth::Reauth(auth) => Cow::Borrowed(auth),
+            SessionAuth::Forced(auth) => Cow::Borrowed(auth),
         };
 
         let address = Arc::clone(&self.address);
@@ -386,9 +386,9 @@ impl UnpreparedSinglePooledBolt {
         match session_auth {
             SessionAuth::None => {
                 let new_auth = match &self.pool.config.auth {
-                    AuthConfig::Static(auth) => RefContainer::Borrowed(auth),
+                    AuthConfig::Static(auth) => Cow::Borrowed(auth),
                     AuthConfig::Manager(manager) => {
-                        RefContainer::Owned(auth_managers::get_auth(manager.as_ref())?)
+                        Cow::Owned(auth_managers::get_auth(manager.as_ref())?)
                     }
                 };
                 let reauth_params = ReauthParameters::new(new_auth.as_ref(), false);

neo4j/src/util.rs

@@ -12,8 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::ops::Deref;
-
 pub(crate) fn truncate_string(string: &str, start: usize, end: usize) -> &str {
     let mut chars = string.chars();
     for _ in 0..start {
@@ -29,28 +27,6 @@ pub(crate) fn truncate_string(string: &str, start: usize, end: usize) -> &str {
     chars.as_str()
 }
 
-pub(crate) enum RefContainer<'a, T> {
-    Owned(T),
-    Borrowed(&'a T),
-}
-
-impl<T> AsRef<T> for RefContainer<'_, T> {
-    fn as_ref(&self) -> &T {
-        match self {
-            RefContainer::Owned(t) => t,
-            RefContainer::Borrowed(t) => t,
-        }
-    }
-}
-
-impl<T> Deref for RefContainer<'_, T> {
-    type Target = T;
-
-    fn deref(&self) -> &Self::Target {
-        self.as_ref()
-    }
-}
-
 macro_rules! concat_str {
     ($a:expr, $b:expr) => {{
         const A: &str = $a;