use reference counting for healtcheck_query

Author: kvch

pgdog/src/backend/pool/config.rs

@@ -1,5 +1,6 @@
 //! Pool configuration.
 
+use std::sync::Arc;
 use std::time::Duration;
 
 use serde::{Deserialize, Serialize};
@@ -24,7 +25,7 @@ pub struct Config {
     /// Can this pool be banned from serving traffic?
     pub bannable: bool,
     /// Healtcheck query.
-    pub healthcheck_query: String,
+    pub healthcheck_query: Arc<String>,
     /// Healtheck timeout.
     pub healthcheck_timeout: Duration, // ms
     /// Healtcheck interval.
@@ -73,8 +74,8 @@ impl Config {
     }
 
     /// Healthcheck query.
-    pub fn healthcheck_query(&self) -> &String {
-        &self.healthcheck_query
+    pub fn healthcheck_query(&self) -> Arc<String> {
+        self.healthcheck_query.clone()
     }
 
     /// Healthcheck timeout.
@@ -177,7 +178,7 @@ impl Default for Config {
             connect_timeout: Duration::from_millis(5_000),
             max_age: Duration::from_millis(24 * 3600 * 1000),
             bannable: true,
-            healthcheck_query: ";".into(),
+            healthcheck_query: Arc::new(";".into()),
             healthcheck_timeout: Duration::from_millis(5_000),
             healthcheck_interval: Duration::from_millis(30_000),
             idle_healthcheck_interval: Duration::from_millis(5_000),

pgdog/src/backend/pool/healthcheck.rs

@@ -1,5 +1,6 @@
 //! Healtcheck a connection.
 
+use std::sync::Arc;
 use std::time::{Duration, Instant};
 
 use tokio::time::timeout;
@@ -12,7 +13,7 @@ use crate::backend::Server;
 pub struct Healtcheck<'a> {
     conn: &'a mut Server,
     pool: Pool,
-    healthcheck_query: String,
+    healthcheck_query: Arc<String>,
     healthcheck_interval: Duration,
     healthcheck_timeout: Duration,
 }
@@ -22,7 +23,7 @@ impl<'a> Healtcheck<'a> {
     pub fn conditional(
         conn: &'a mut Server,
         pool: Pool,
-        healthcheck_query: String,
+        healthcheck_query: Arc<String>,
         healthcheck_interval: Duration,
         healthcheck_timeout: Duration,
     ) -> Self {
@@ -39,7 +40,7 @@ impl<'a> Healtcheck<'a> {
     pub fn mandatory(
         conn: &'a mut Server,
         pool: Pool,
-        healthcheck_query: String,
+        healthcheck_query: Arc<String>,
         healthcheck_timeout: Duration,
     ) -> Self {
         Self::conditional(

pgdog/src/backend/pool/monitor.rs

@@ -280,7 +280,7 @@ impl Monitor {
             }
             (
                 guard.take(&Request::default()),
-                guard.config.healthcheck_query().to_owned(),
+                guard.config.healthcheck_query().clone(),
                 guard.config.healthcheck_timeout(),
                 guard.config.connect_timeout(),
             )

pgdog/src/backend/pool/pool_impl.rs

@@ -129,7 +129,7 @@ impl Pool {
                     } else {
                         guard.config.checkout_timeout
                     },
-                    guard.config.healthcheck_query.to_string(),
+                    guard.config.healthcheck_query.clone(),
                     guard.config.healthcheck_timeout,
                     guard.config.healthcheck_interval,
                     conn,
@@ -177,7 +177,7 @@ impl Pool {
     async fn maybe_healthcheck(
         &self,
         mut conn: Guard,
-        healthcheck_query: String,
+        healthcheck_query: Arc<String>,
         healthcheck_timeout: Duration,
         healthcheck_interval: Duration,
     ) -> Result<Guard, Error> {
@@ -357,8 +357,8 @@ impl Pool {
     }
 
     #[inline]
-    pub fn healthcheck_query(&self) -> String {
-        self.lock().config.clone().healthcheck_query
+    pub fn healthcheck_query(&self) -> Arc<String> {
+        self.lock().config.clone().healthcheck_query.clone()
     }
 
     /// Get startup parameters for new server connections.
@@ -374,7 +374,7 @@ impl Pool {
             },
         ];
 
-        let config = { *self.lock().config() };
+        let config = { self.lock().config().clone() };
 
         if let Some(statement_timeout) = config.statement_timeout {
             params.push(Parameter {

pgdog/src/config/mod.rs

@@ -272,7 +272,7 @@ pub struct General {
     pub pooler_mode: PoolerMode,
     /// Query to check a connection.
     #[serde(default = "General::healthcheck_query")]
-    pub healthcheck_query: String,
+    pub healthcheck_query: Arc<String>,
     /// How often to check a connection.
     #[serde(default = "General::healthcheck_interval")]
     pub healthcheck_interval: u64,
@@ -413,8 +413,8 @@ impl General {
         1
     }
 
-    fn healthcheck_query() -> String {
-        ";".into()
+    fn healthcheck_query() -> Arc<String> {
+        Arc::new(";".into())
     }
 
     fn healthcheck_interval() -> u64 {