Caching methods in Connection

sqlx-core/src/common/statement_cache.rs

@@ -49,6 +49,7 @@ impl<T> StatementCache<T> {
     }
 
     /// Clear all cached statements from the cache.
+    #[cfg(any(feature = "postgres", feature = "sqlite"))]
     pub fn clear(&mut self) {
         self.inner.clear();
     }

sqlx-core/src/connection.rs

@@ -3,7 +3,7 @@ use std::str::FromStr;
 use futures_core::future::BoxFuture;
 use futures_core::Future;
 
-use crate::database::Database;
+use crate::database::{Database, HasStatementCache};
 use crate::error::{BoxDynError, Error};
 use crate::transaction::Transaction;
 
@@ -64,6 +64,23 @@ pub trait Connection: Send {
         })
     }
 
+    /// The number of statements currently cached in the connection.
+    fn cached_statements_size(&self) -> usize
+    where
+        Self::Database: HasStatementCache,
+    {
+        0
+    }
+
+    /// Removes all statements from the cache, closing them on the server if
+    /// needed.
+    fn clear_cached_statements(&mut self) -> BoxFuture<'_, Result<(), Error>>
+    where
+        Self::Database: HasStatementCache,
+    {
+        Box::pin(async move { Ok(()) })
+    }
+
     #[doc(hidden)]
     fn flush(&mut self) -> BoxFuture<'_, Result<(), Error>>;
 

sqlx-core/src/database.rs

@@ -74,3 +74,5 @@ pub trait HasArguments<'q> {
     /// The concrete type used as a buffer for arguments while encoding.
     type ArgumentBuffer: Default;
 }
+
+pub trait HasStatementCache {}

sqlx-core/src/lib.rs

@@ -29,7 +29,6 @@ pub mod arguments;
 #[macro_use]
 pub mod pool;
 
-pub mod caching_connection;
 pub mod connection;
 
 #[macro_use]

sqlx-core/src/mysql/connection/mod.rs

@@ -6,7 +6,6 @@ use futures_core::future::BoxFuture;
 use futures_util::FutureExt;
 use hashbrown::HashMap;
 
-use crate::caching_connection::CachingConnection;
 use crate::common::StatementCache;
 use crate::connection::{Connect, Connection};
 use crate::error::Error;
@@ -46,22 +45,6 @@ pub struct MySqlConnection {
     scratch_row_column_names: Arc<HashMap<UStr, usize>>,
 }
 
-impl CachingConnection for MySqlConnection {
-    fn cached_statements_count(&self) -> usize {
-        self.cache_statement.len()
-    }
-
-    fn clear_cached_statements(&mut self) -> BoxFuture<'_, Result<(), Error>> {
-        Box::pin(async move {
-            while let Some(statement) = self.cache_statement.remove_lru() {
-                self.stream.send_packet(StmtClose { statement }).await?;
-            }
-
-            Ok(())
-        })
-    }
-}
-
 impl Debug for MySqlConnection {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         f.debug_struct("MySqlConnection").finish()
@@ -94,6 +77,20 @@ impl Connection for MySqlConnection {
         self.stream.wait_until_ready().boxed()
     }
 
+    fn cached_statements_size(&self) -> usize {
+        self.cache_statement.len()
+    }
+
+    fn clear_cached_statements(&mut self) -> BoxFuture<'_, Result<(), Error>> {
+        Box::pin(async move {
+            while let Some(statement) = self.cache_statement.remove_lru() {
+                self.stream.send_packet(StmtClose { statement }).await?;
+            }
+
+            Ok(())
+        })
+    }
+
     #[doc(hidden)]
     fn should_flush(&self) -> bool {
         !self.stream.wbuf.is_empty()

sqlx-core/src/mysql/database.rs

@@ -1,4 +1,4 @@
-use crate::database::{Database, HasArguments, HasValueRef};
+use crate::database::{Database, HasArguments, HasStatementCache, HasValueRef};
 use crate::mysql::value::{MySqlValue, MySqlValueRef};
 use crate::mysql::{
     MySqlArguments, MySqlConnection, MySqlRow, MySqlTransactionManager, MySqlTypeInfo,
@@ -33,3 +33,5 @@ impl HasArguments<'_> for MySql {
 
     type ArgumentBuffer = Vec<u8>;
 }
+
+impl HasStatementCache for MySql {}

sqlx-core/src/postgres/connection/mod.rs

@@ -5,7 +5,6 @@ use futures_core::future::BoxFuture;
 use futures_util::{FutureExt, TryFutureExt};
 use hashbrown::HashMap;
 
-use crate::caching_connection::CachingConnection;
 use crate::common::StatementCache;
 use crate::connection::{Connect, Connection};
 use crate::error::Error;
@@ -98,19 +97,6 @@ impl Debug for PgConnection {
     }
 }
 
-impl CachingConnection for PgConnection {
-    fn cached_statements_count(&self) -> usize {
-        self.cache_statement.len()
-    }
-
-    fn clear_cached_statements(&mut self) -> BoxFuture<'_, Result<(), Error>> {
-        Box::pin(async move {
-            self.cache_statement.clear();
-            Ok(())
-        })
-    }
-}
-
 impl Connection for PgConnection {
     type Database = Postgres;
 
@@ -134,6 +120,17 @@ impl Connection for PgConnection {
         self.execute("/* SQLx ping */").map_ok(|_| ()).boxed()
     }
 
+    fn cached_statements_size(&self) -> usize {
+        self.cache_statement.len()
+    }
+
+    fn clear_cached_statements(&mut self) -> BoxFuture<'_, Result<(), Error>> {
+        Box::pin(async move {
+            self.cache_statement.clear();
+            Ok(())
+        })
+    }
+
     #[doc(hidden)]
     fn flush(&mut self) -> BoxFuture<'_, Result<(), Error>> {
         self.wait_until_ready().boxed()

sqlx-core/src/postgres/database.rs

@@ -1,4 +1,4 @@
-use crate::database::{Database, HasArguments, HasValueRef};
+use crate::database::{Database, HasArguments, HasStatementCache, HasValueRef};
 use crate::postgres::arguments::PgArgumentBuffer;
 use crate::postgres::value::{PgValue, PgValueRef};
 use crate::postgres::{PgArguments, PgConnection, PgRow, PgTransactionManager, PgTypeInfo};
@@ -32,3 +32,5 @@ impl HasArguments<'_> for Postgres {
 
     type ArgumentBuffer = PgArgumentBuffer;
 }
+
+impl HasStatementCache for Postgres {}

sqlx-core/src/sqlite/connection/mod.rs

@@ -6,7 +6,6 @@ use futures_util::future;
 use hashbrown::HashMap;
 use libsqlite3_sys::sqlite3;
 
-use crate::caching_connection::CachingConnection;
 use crate::common::StatementCache;
 use crate::connection::{Connect, Connection};
 use crate::error::Error;
@@ -49,19 +48,6 @@ impl Debug for SqliteConnection {
     }
 }
 
-impl CachingConnection for SqliteConnection {
-    fn cached_statements_count(&self) -> usize {
-        self.statements.len()
-    }
-
-    fn clear_cached_statements(&mut self) -> BoxFuture<'_, Result<(), Error>> {
-        Box::pin(async move {
-            self.statements.clear();
-            Ok(())
-        })
-    }
-}
-
 impl Connection for SqliteConnection {
     type Database = Sqlite;
 
@@ -75,6 +61,17 @@ impl Connection for SqliteConnection {
         Box::pin(future::ok(()))
     }
 
+    fn cached_statements_size(&self) -> usize {
+        self.statements.len()
+    }
+
+    fn clear_cached_statements(&mut self) -> BoxFuture<'_, Result<(), Error>> {
+        Box::pin(async move {
+            self.statements.clear();
+            Ok(())
+        })
+    }
+
     #[doc(hidden)]
     fn flush(&mut self) -> BoxFuture<'_, Result<(), Error>> {
         // For SQLite, FLUSH does effectively nothing

sqlx-core/src/sqlite/database.rs

@@ -1,4 +1,4 @@
-use crate::database::{Database, HasArguments, HasValueRef};
+use crate::database::{Database, HasArguments, HasStatementCache, HasValueRef};
 use crate::sqlite::{
     SqliteArgumentValue, SqliteArguments, SqliteConnection, SqliteRow, SqliteTransactionManager,
     SqliteTypeInfo, SqliteValue, SqliteValueRef,
@@ -33,3 +33,5 @@ impl<'q> HasArguments<'q> for Sqlite {
 
     type ArgumentBuffer = Vec<SqliteArgumentValue<'q>>;
 }
+
+impl HasStatementCache for Sqlite {}

src/lib.rs

@@ -1,7 +1,6 @@
 #![cfg_attr(docsrs, feature(doc_cfg))]
 
 pub use sqlx_core::arguments::{Arguments, IntoArguments};
-pub use sqlx_core::caching_connection::CachingConnection;
 pub use sqlx_core::connection::{Connect, Connection};
 pub use sqlx_core::database::{self, Database};
 pub use sqlx_core::executor::{Execute, Executor};

tests/mysql/mysql.rs

@@ -1,6 +1,6 @@
 use futures::TryStreamExt;
 use sqlx::mysql::{MySql, MySqlPool, MySqlRow};
-use sqlx::{CachingConnection, Connection, Executor, Row};
+use sqlx::{Connection, Executor, Row};
 use sqlx_test::new;
 
 #[sqlx_macros::test]
@@ -193,9 +193,9 @@ async fn it_caches_statements() -> anyhow::Result<()> {
         assert_eq!(i, val);
     }
 
-    assert_eq!(1, conn.cached_statements_count());
+    assert_eq!(1, conn.cached_statements_size());
     conn.clear_cached_statements().await?;
-    assert_eq!(0, conn.cached_statements_count());
+    assert_eq!(0, conn.cached_statements_size());
 
     Ok(())
 }

tests/postgres/postgres.rs

@@ -1,7 +1,6 @@
 use futures::TryStreamExt;
 use sqlx::postgres::PgRow;
 use sqlx::postgres::{PgDatabaseError, PgErrorPosition, PgSeverity};
-use sqlx::CachingConnection;
 use sqlx::{postgres::Postgres, Connection, Executor, PgPool, Row};
 use sqlx_test::new;
 use std::time::Duration;
@@ -504,9 +503,9 @@ async fn it_caches_statements() -> anyhow::Result<()> {
         assert_eq!(i, val);
     }
 
-    assert_eq!(1, conn.cached_statements_count());
+    assert_eq!(1, conn.cached_statements_size());
     conn.clear_cached_statements().await?;
-    assert_eq!(0, conn.cached_statements_count());
+    assert_eq!(0, conn.cached_statements_size());
 
     Ok(())
 }

tests/sqlite/sqlite.rs

@@ -1,6 +1,6 @@
 use futures::TryStreamExt;
 use sqlx::{
-    query, sqlite::Sqlite, CachingConnection, Connect, Connection, Executor, Row, SqliteConnection,
+    query, sqlite::Sqlite, Connect, Connection, Executor, Row, SqliteConnection,
     SqlitePool,
 };
 use sqlx_test::new;
@@ -286,9 +286,9 @@ async fn it_caches_statements() -> anyhow::Result<()> {
         assert_eq!(i, val);
     }
 
-    assert_eq!(1, conn.cached_statements_count());
+    assert_eq!(1, conn.cached_statements_size());
     conn.clear_cached_statements().await?;
-    assert_eq!(0, conn.cached_statements_count());
+    assert_eq!(0, conn.cached_statements_size());
 
     Ok(())
 }