feat: implement Decode,Encode,Type for Box,Arc,Cow

Author: joeydewaal

sqlx-core/src/decode.rs

@@ -1,5 +1,8 @@
 //! Provides [`Decode`] for decoding values from the database.
 
+use std::borrow::Cow;
+use std::sync::Arc;
+
 use crate::database::Database;
 use crate::error::BoxDynError;
 
@@ -77,3 +80,37 @@ where
         }
     }
 }
+
+// implement `Decode` for Arc<T> for all SQL types
+impl<'r, DB, T> Decode<'r, DB> for Arc<T>
+where
+    DB: Database,
+    T: Decode<'r, DB>,
+{
+    fn decode(value: <DB as Database>::ValueRef<'r>) -> Result<Self, BoxDynError> {
+        Ok(Arc::new(T::decode(value)?))
+    }
+}
+
+// implement `Decode` for Cow<T> for all SQL types
+impl<'r, DB, T> Decode<'r, DB> for Cow<'_, T>
+where
+    DB: Database,
+    T: Decode<'r, DB>,
+    T: ToOwned<Owned = T>,
+{
+    fn decode(value: <DB as Database>::ValueRef<'r>) -> Result<Self, BoxDynError> {
+        Ok(Cow::Owned(T::decode(value)?))
+    }
+}
+
+// implement `Decode` for Box<T> for all SQL types
+impl<'r, DB, T> Decode<'r, DB> for Box<T>
+where
+    DB: Database,
+    T: Decode<'r, DB>,
+{
+    fn decode(value: <DB as Database>::ValueRef<'r>) -> Result<Self, BoxDynError> {
+        Ok(Box::new(T::decode(value)?))
+    }
+}

sqlx-core/src/encode.rs

@@ -1,6 +1,8 @@
 //! Provides [`Encode`] for encoding values for the database.
 
+use std::borrow::Cow;
 use std::mem;
+use std::sync::Arc;
 
 use crate::database::Database;
 use crate::error::BoxDynError;
@@ -129,3 +131,88 @@ macro_rules! impl_encode_for_option {
         }
     };
 }
+
+impl<'q, T, DB: Database> Encode<'q, DB> for Arc<T>
+where
+    T: Encode<'q, DB>,
+{
+    #[inline]
+    fn encode(self, buf: &mut <DB as Database>::ArgumentBuffer<'q>) -> Result<IsNull, BoxDynError> {
+        <T as Encode<DB>>::encode_by_ref(self.as_ref(), buf)
+    }
+
+    #[inline]
+    fn encode_by_ref(
+        &self,
+        buf: &mut <DB as Database>::ArgumentBuffer<'q>,
+    ) -> Result<IsNull, BoxDynError> {
+        <&T as Encode<DB>>::encode(self, buf)
+    }
+
+    #[inline]
+    fn produces(&self) -> Option<DB::TypeInfo> {
+        (**self).produces()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> usize {
+        (**self).size_hint()
+    }
+}
+
+impl<'q, T, DB: Database> Encode<'q, DB> for Cow<'_, T>
+where
+    T: Encode<'q, DB>,
+    T: ToOwned<Owned = T>,
+{
+    #[inline]
+    fn encode(self, buf: &mut <DB as Database>::ArgumentBuffer<'q>) -> Result<IsNull, BoxDynError> {
+        <T as Encode<DB>>::encode_by_ref(self.as_ref(), buf)
+    }
+
+    #[inline]
+    fn encode_by_ref(
+        &self,
+        buf: &mut <DB as Database>::ArgumentBuffer<'q>,
+    ) -> Result<IsNull, BoxDynError> {
+        <&T as Encode<DB>>::encode(self, buf)
+    }
+
+    #[inline]
+    fn produces(&self) -> Option<DB::TypeInfo> {
+        (**self).produces()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> usize {
+        (**self).size_hint()
+    }
+}
+
+impl<'q, T, DB: Database> Encode<'q, DB> for Box<T>
+where
+    T: Encode<'q, DB>,
+{
+    #[inline]
+    fn encode(self, buf: &mut <DB as Database>::ArgumentBuffer<'q>) -> Result<IsNull, BoxDynError> {
+        <T as Encode<DB>>::encode_by_ref(self.as_ref(), buf)
+    }
+
+    #[inline]
+    fn encode_by_ref(
+        &self,
+        buf: &mut <DB as Database>::ArgumentBuffer<'q>,
+    ) -> Result<IsNull, BoxDynError> {
+        <&T as Encode<DB>>::encode(self, buf)
+    }
+
+    #[inline]
+    fn produces(&self) -> Option<DB::TypeInfo> {
+        (**self).produces()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> usize {
+        (**self).size_hint()
+    }
+}

sqlx-core/src/types/mod.rs

@@ -17,6 +17,8 @@
 //! To represent nullable SQL types, `Option<T>` is supported where `T` implements `Type`.
 //! An `Option<T>` represents a potentially `NULL` value from SQL.
 
+use std::{borrow::Cow, sync::Arc};
+
 use crate::database::Database;
 use crate::type_info::TypeInfo;
 
@@ -238,3 +240,41 @@ impl<T: Type<DB>, DB: Database> Type<DB> for Option<T> {
         ty.is_null() || <T as Type<DB>>::compatible(ty)
     }
 }
+
+impl<T, DB: Database> Type<DB> for Arc<T>
+where
+    T: Type<DB>,
+    T: ?Sized,
+{
+    fn type_info() -> DB::TypeInfo {
+        <T as Type<DB>>::type_info()
+    }
+
+    fn compatible(ty: &DB::TypeInfo) -> bool {
+        ty.is_null() || <T as Type<DB>>::compatible(ty)
+    }
+}
+
+impl<T, DB: Database> Type<DB> for Cow<'_, T>
+where
+    T: Type<DB>,
+    T: ToOwned<Owned = T>,
+{
+    fn type_info() -> DB::TypeInfo {
+        <T as Type<DB>>::type_info()
+    }
+
+    fn compatible(ty: &DB::TypeInfo) -> bool {
+        ty.is_null() || <T as Type<DB>>::compatible(ty)
+    }
+}
+
+impl<T: Type<DB>, DB: Database> Type<DB> for Box<T> {
+    fn type_info() -> DB::TypeInfo {
+        <T as Type<DB>>::type_info()
+    }
+
+    fn compatible(ty: &DB::TypeInfo) -> bool {
+        ty.is_null() || <T as Type<DB>>::compatible(ty)
+    }
+}

tests/postgres/types.rs

@@ -1,7 +1,9 @@
 extern crate time_ as time;
 
+use std::borrow::Cow;
 use std::net::SocketAddr;
 use std::ops::Bound;
+use std::sync::Arc;
 
 use sqlx::postgres::types::{Oid, PgCiText, PgInterval, PgMoney, PgRange};
 use sqlx::postgres::Postgres;
@@ -657,3 +659,43 @@ CREATE TEMPORARY TABLE user_login (
 
     Ok(())
 }
+
+#[sqlx_macros::test]
+async fn test_arc() -> anyhow::Result<()> {
+    let mut conn = new::<Postgres>().await?;
+
+    let user_age: Arc<i32> = sqlx::query_scalar("select $1 as age ")
+        .bind(Arc::new(1i32))
+        .fetch_one(&mut conn)
+        .await?;
+    assert!(user_age.as_ref() == &1);
+    Ok(())
+}
+
+#[sqlx_macros::test]
+async fn test_cow() -> anyhow::Result<()> {
+    let mut conn = new::<Postgres>().await?;
+
+    let age: Cow<'_, i32> = Cow::Owned(1i32);
+
+    let user_age: Cow<'static, i32> = sqlx::query_scalar("select $1 as age ")
+        .bind(age)
+        .fetch_one(&mut conn)
+        .await?;
+
+    assert!(user_age.as_ref() == &1);
+    Ok(())
+}
+
+#[sqlx_macros::test]
+async fn test_box() -> anyhow::Result<()> {
+    let mut conn = new::<Postgres>().await?;
+
+    let user_age: Box<i32> = sqlx::query_scalar("select $1 as age ")
+        .bind(Box::new(1))
+        .fetch_one(&mut conn)
+        .await?;
+
+    assert!(user_age.as_ref() == &1);
+    Ok(())
+}