more borrowing, less owning

Author: domZippilli

lightning/src/util/persist.rs

@@ -199,26 +199,26 @@ where
 	Ok(res)
 }
 
-enum KVStoreUpdatingPersisterError {
+enum KVStoreUpdatingPersisterError<'a> {
     /// The monitor name was improperly formatted.
-    BadMonitorName { reason: String, context: String },
+    BadMonitorName { reason: &'a str, context: &'a str },
     /// The monitor could not be decoded.
     MonitorDecodeFailed {
         reason: DecodeError,
-        context: String,
+        context: &'a str,
     },
     /// The update could not be decoded.
     UpdateDecodeFailed {
         reason: DecodeError,
-        context: String,
+        context: &'a str,
     },
     /// Storage could not be read.
-    StorageReadFailed { reason: io::Error, context: String },
+    StorageReadFailed { reason: io::Error, context: &'a str },
     /// An update could not be applied to a monitor.
-    UpdateFailed { reason: String, context: String },
+    UpdateFailed { reason: &'a str, context: &'a str },
 }
 
-impl From<KVStoreUpdatingPersisterError> for io::Error {
+impl<'a> From<KVStoreUpdatingPersisterError<'a>> for io::Error {
     fn from(value: KVStoreUpdatingPersisterError) -> Self {
         match value {
             KVStoreUpdatingPersisterError::BadMonitorName { reason, context } => io::Error::new(
@@ -255,8 +255,8 @@ pub struct MonitorName(String);
 
 impl MonitorName {
     /// The key to store this monitor with.
-    fn storage_key(&self) -> String {
-        self.0.clone()
+    fn storage_key(&self) -> &str {
+        &self.0
     }
 }
 
@@ -269,25 +269,25 @@ impl TryFrom<MonitorName> for OutPoint {
             parts
                 .next()
                 .ok_or_else(|| KVStoreUpdatingPersisterError::BadMonitorName {
-                    reason: "no txid found, maybe there is no underscore".to_string(),
-                    context: value.0.clone(),
+                    reason: "no txid found, maybe there is no underscore",
+                    context: &value.0,
                 })?;
         let index = parts
             .next()
             .ok_or_else(|| KVStoreUpdatingPersisterError::BadMonitorName {
-                reason: "no index value found after underscore".to_string(),
-                context: value.0.clone(),
+                reason: "no index value found after underscore",
+                context: &value.0,
             })?;
         let index = index
             .parse()
-            .map_err(|e| KVStoreUpdatingPersisterError::BadMonitorName {
-                reason: format!("bad index value, caused by {}", e),
-                context: value.0.clone(),
+            .map_err(|_| KVStoreUpdatingPersisterError::BadMonitorName {
+                reason: "could not parse index value in monitor name",
+                context: &value.0,
             })?;
-        let txid = Txid::from_hex(txid_hex).map_err(|e| {
+        let txid = Txid::from_hex(txid_hex).map_err(|_| {
             KVStoreUpdatingPersisterError::BadMonitorName {
-                reason: format!("bad txid, caused by: {}", e),
-                context: value.0.clone(),
+                reason: "bad txid in monitor name",
+                context: &value.0,
             }
         })?;
         Ok(OutPoint { txid, index })
@@ -306,8 +306,8 @@ pub struct UpdateName(String);
 
 impl UpdateName {
     /// The key to store this update with.
-    fn storage_key(&self) -> String {
-        self.0.clone()
+    fn storage_key(&self) -> &str {
+        &self.0
     }
 }
 
@@ -356,7 +356,7 @@ where
             let (bh, monitor) = self.deserialize_monitor(
                 entropy_source.clone(),
                 signer_provider.clone(),
-                monitor_name.clone(),
+                &monitor_name,
             )?;
             // ...parse and apply the updates with an id higher than the monitor.
             for update_name in self.list_update_names(&monitor_name)? {
@@ -367,8 +367,8 @@ where
                     monitor
                         .update_monitor(&update, broadcaster, fee_estimator.clone(), &self.logger)
                         .map_err(|_| KVStoreUpdatingPersisterError::UpdateFailed {
-                            reason: "update_monitor returned Err(())".to_string(),
-                            context: format!("monitor: {:?}", monitor_name),
+                            reason: "update_monitor returned Err(())",
+                            context: &monitor_name.0,
                         })?;
                 }
             }
@@ -382,7 +382,7 @@ where
     fn monitor_update_namespace(&self, monitor_name: &MonitorName) -> String {
         // Append the monitor name to the namespace with an underscore.
         [
-            CHANNEL_MONITOR_UPDATE_PERSISTENCE_NAMESPACE.to_owned(),
+            CHANNEL_MONITOR_UPDATE_PERSISTENCE_NAMESPACE,
             monitor_name.storage_key(),
         ]
         .join("_")
@@ -407,7 +407,7 @@ where
         &self,
         entropy_source: ES,
         signer_provider: SP,
-        monitor_name: MonitorName,
+        monitor_name: &MonitorName,
     ) -> io::Result<(
         BlockHash,
         ChannelMonitor<<SP::Target as SignerProvider>::Signer>,
@@ -417,17 +417,17 @@ where
         SP::Target: SignerProvider + Sized,
     {
         let key = monitor_name.storage_key();
-        let outpoint: OutPoint = monitor_name.try_into()?;
+        let outpoint: OutPoint = monitor_name.to_owned().try_into()?;
         match <(
             BlockHash,
             ChannelMonitor<<SP::Target as SignerProvider>::Signer>,
         )>::read(
             &mut self
                 .kv
-                .read(CHANNEL_MONITOR_PERSISTENCE_NAMESPACE, &key)
+                .read(CHANNEL_MONITOR_PERSISTENCE_NAMESPACE, key)
                 .map_err(|e| KVStoreUpdatingPersisterError::StorageReadFailed {
                     reason: e,
-                    context: key.clone(),
+                    context: key,
                 })?,
             (&*entropy_source, &*signer_provider),
         ) {
@@ -465,7 +465,7 @@ where
             ChannelMonitorUpdate::read(&mut self.kv.read(&ns, &key).map_err(|e| {
                 KVStoreUpdatingPersisterError::StorageReadFailed {
                     reason: e,
-                    context: key.clone(),
+                    context: key,
                 }
             })?)
             .map_err(|e| KVStoreUpdatingPersisterError::UpdateDecodeFailed {
@@ -490,7 +490,7 @@ where
             {
                 let ns = self.monitor_update_namespace(&monitor_name);
                 let key = update_name.storage_key();
-                self.kv.remove(&ns, &key)?;
+                self.kv.remove(&ns, key)?;
             }
         }
         Ok(())