Relax Sized bound for Decode, Encode

Author: joeydewaal

sqlx-core/src/decode.rs

@@ -83,8 +83,8 @@ where
 }
 
 macro_rules! impl_decode_for_smartpointer {
-    ($smart_pointer:ty) => {
-        impl<'r, DB, T> Decode<'r, DB> for $smart_pointer
+    ($smart_pointer:tt) => {
+        impl<'r, DB, T> Decode<'r, DB> for $smart_pointer<T>
         where
             DB: Database,
             T: Decode<'r, DB>,
@@ -93,21 +93,66 @@ macro_rules! impl_decode_for_smartpointer {
                 Ok(Self::new(T::decode(value)?))
             }
         }
+
+        impl<'r, DB> Decode<'r, DB> for $smart_pointer<str>
+        where
+            DB: Database,
+            &'r str: Decode<'r, DB>,
+        {
+            fn decode(value: <DB as Database>::ValueRef<'r>) -> Result<Self, BoxDynError> {
+                let ref_str = <&str as Decode<DB>>::decode(value)?;
+                Ok(ref_str.into())
+            }
+        }
+
+        impl<'r, DB> Decode<'r, DB> for $smart_pointer<[u8]>
+        where
+            DB: Database,
+            &'r [u8]: Decode<'r, DB>,
+        {
+            fn decode(value: <DB as Database>::ValueRef<'r>) -> Result<Self, BoxDynError> {
+                let ref_str = <&[u8] as Decode<DB>>::decode(value)?;
+                Ok(ref_str.into())
+            }
+        }
     };
 }
 
-impl_decode_for_smartpointer!(Arc<T>);
-impl_decode_for_smartpointer!(Box<T>);
-impl_decode_for_smartpointer!(Rc<T>);
+impl_decode_for_smartpointer!(Arc);
+impl_decode_for_smartpointer!(Box);
+impl_decode_for_smartpointer!(Rc);
 
 // 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>,
+    T: ToOwned,
+    <T as ToOwned>::Owned: Decode<'r, DB>,
+{
+    fn decode(value: <DB as Database>::ValueRef<'r>) -> Result<Self, BoxDynError> {
+        let owned = <<T as ToOwned>::Owned as Decode<DB>>::decode(value)?;
+        Ok(Cow::Owned(owned))
+    }
+}
+
+impl<'r, DB> Decode<'r, DB> for Cow<'r, str>
+where
+    DB: Database,
+    &'r str: Decode<'r, DB>,
+{
+    fn decode(value: <DB as Database>::ValueRef<'r>) -> Result<Self, BoxDynError> {
+        let borrowed = <&str as Decode<DB>>::decode(value)?;
+        Ok(Cow::Borrowed(borrowed))
+    }
+}
+
+impl<'r, DB> Decode<'r, DB> for Cow<'r, [u8]>
+where
+    DB: Database,
+    &'r [u8]: Decode<'r, DB>,
 {
     fn decode(value: <DB as Database>::ValueRef<'r>) -> Result<Self, BoxDynError> {
-        Ok(Cow::Owned(T::decode(value)?))
+        let borrowed = <&[u8] as Decode<DB>>::decode(value)?;
+        Ok(Cow::Borrowed(borrowed))
     }
 }

sqlx-core/src/encode.rs

@@ -175,28 +175,28 @@ impl_encode_for_smartpointer!(Rc<T>);
 impl<'q, T, DB: Database> Encode<'q, DB> for Cow<'_, T>
 where
     T: Encode<'q, DB>,
-    T: ToOwned<Owned = T>,
+    T: ToOwned,
 {
     #[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)
+        <&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)
+        <&T as Encode<DB>>::encode_by_ref(&self.as_ref(), buf)
     }
 
     #[inline]
     fn produces(&self) -> Option<DB::TypeInfo> {
-        (**self).produces()
+        <&T as Encode<DB>>::produces(&self.as_ref())
     }
 
     #[inline]
     fn size_hint(&self) -> usize {
-        (**self).size_hint()
+        <&T as Encode<DB>>::size_hint(&self.as_ref())
     }
 }

sqlx-core/src/types/mod.rs

@@ -276,7 +276,7 @@ impl_type_for_smartpointer!(Rc<T>);
 impl<T, DB: Database> Type<DB> for Cow<'_, T>
 where
     T: Type<DB>,
-    T: ToOwned<Owned = T>,
+    T: ToOwned,
     T: ?Sized,
 {
     fn type_info() -> DB::TypeInfo {

sqlx-mysql/src/types/bytes.rs

@@ -46,12 +46,6 @@ impl Encode<'_, MySql> for Box<[u8]> {
     }
 }
 
-impl<'r> Decode<'r, MySql> for Box<[u8]> {
-    fn decode(value: MySqlValueRef<'r>) -> Result<Self, BoxDynError> {
-        <&[u8] as Decode<MySql>>::decode(value).map(Box::from)
-    }
-}
-
 impl Type<MySql> for Vec<u8> {
     fn type_info() -> MySqlTypeInfo {
         <[u8] as Type<MySql>>::type_info()

sqlx-mysql/src/types/str.rs

@@ -1,11 +1,12 @@
+use std::borrow::Cow;
+
 use crate::decode::Decode;
 use crate::encode::{Encode, IsNull};
 use crate::error::BoxDynError;
 use crate::io::MySqlBufMutExt;
 use crate::protocol::text::{ColumnFlags, ColumnType};
 use crate::types::Type;
 use crate::{MySql, MySqlTypeInfo, MySqlValueRef};
-use std::borrow::Cow;
 
 impl Type<MySql> for str {
     fn type_info() -> MySqlTypeInfo {
@@ -52,12 +53,6 @@ impl Encode<'_, MySql> for Box<str> {
     }
 }
 
-impl<'r> Decode<'r, MySql> for Box<str> {
-    fn decode(value: MySqlValueRef<'r>) -> Result<Self, BoxDynError> {
-        <&str as Decode<MySql>>::decode(value).map(Box::from)
-    }
-}
-
 impl Type<MySql> for String {
     fn type_info() -> MySqlTypeInfo {
         <str as Type<MySql>>::type_info()
@@ -89,8 +84,8 @@ impl Encode<'_, MySql> for Cow<'_, str> {
     }
 }
 
-impl<'r> Decode<'r, MySql> for Cow<'r, str> {
-    fn decode(value: MySqlValueRef<'r>) -> Result<Self, BoxDynError> {
-        value.as_str().map(Cow::Borrowed)
+impl Encode<'_, MySql> for Cow<'_, [u8]> {
+    fn encode_by_ref(&self, buf: &mut Vec<u8>) -> Result<IsNull, BoxDynError> {
+        <&[u8] as Encode<MySql>>::encode(self.as_ref(), buf)
     }
 }

sqlx-postgres/src/types/bytes.rs

@@ -80,15 +80,6 @@ fn text_hex_decode_input(value: PgValueRef<'_>) -> Result<&[u8], BoxDynError> {
         .map_err(Into::into)
 }
 
-impl Decode<'_, Postgres> for Box<[u8]> {
-    fn decode(value: PgValueRef<'_>) -> Result<Self, BoxDynError> {
-        Ok(match value.format() {
-            PgValueFormat::Binary => Box::from(value.as_bytes()?),
-            PgValueFormat::Text => Box::from(hex::decode(text_hex_decode_input(value)?)?),
-        })
-    }
-}
-
 impl Decode<'_, Postgres> for Vec<u8> {
     fn decode(value: PgValueRef<'_>) -> Result<Self, BoxDynError> {
         Ok(match value.format() {

sqlx-postgres/src/types/str.rs

@@ -82,15 +82,6 @@ impl Encode<'_, Postgres> for &'_ str {
     }
 }
 
-impl Encode<'_, Postgres> for Cow<'_, str> {
-    fn encode_by_ref(&self, buf: &mut PgArgumentBuffer) -> Result<IsNull, BoxDynError> {
-        match self {
-            Cow::Borrowed(str) => <&str as Encode<Postgres>>::encode(*str, buf),
-            Cow::Owned(str) => <&str as Encode<Postgres>>::encode(&**str, buf),
-        }
-    }
-}
-
 impl Encode<'_, Postgres> for Box<str> {
     fn encode_by_ref(&self, buf: &mut PgArgumentBuffer) -> Result<IsNull, BoxDynError> {
         <&str as Encode<Postgres>>::encode(&**self, buf)
@@ -109,20 +100,23 @@ impl<'r> Decode<'r, Postgres> for &'r str {
     }
 }
 
-impl<'r> Decode<'r, Postgres> for Cow<'r, str> {
-    fn decode(value: PgValueRef<'r>) -> Result<Self, BoxDynError> {
-        Ok(Cow::Borrowed(value.as_str()?))
+impl Decode<'_, Postgres> for String {
+    fn decode(value: PgValueRef<'_>) -> Result<Self, BoxDynError> {
+        Ok(value.as_str()?.to_owned())
     }
 }
 
-impl<'r> Decode<'r, Postgres> for Box<str> {
-    fn decode(value: PgValueRef<'r>) -> Result<Self, BoxDynError> {
-        Ok(Box::from(value.as_str()?))
+impl Encode<'_, Postgres> for Cow<'_, str> {
+    fn encode_by_ref(&self, buf: &mut PgArgumentBuffer) -> Result<IsNull, BoxDynError> {
+        match self {
+            Cow::Borrowed(str) => <&str as Encode<Postgres>>::encode(*str, buf),
+            Cow::Owned(str) => <&str as Encode<Postgres>>::encode(&**str, buf),
+        }
     }
 }
 
-impl Decode<'_, Postgres> for String {
-    fn decode(value: PgValueRef<'_>) -> Result<Self, BoxDynError> {
-        Ok(value.as_str()?.to_owned())
+impl Encode<'_, Postgres> for Cow<'_, [u8]> {
+    fn encode_by_ref(&self, buf: &mut PgArgumentBuffer) -> Result<IsNull, BoxDynError> {
+        <&[u8] as Encode<Postgres>>::encode(self.as_ref(), buf)
     }
 }

sqlx-sqlite/src/types/bytes.rs

@@ -53,12 +53,6 @@ impl Encode<'_, Sqlite> for Box<[u8]> {
     }
 }
 
-impl Decode<'_, Sqlite> for Box<[u8]> {
-    fn decode(value: SqliteValueRef<'_>) -> Result<Self, BoxDynError> {
-        Ok(Box::from(value.blob()))
-    }
-}
-
 impl Type<Sqlite> for Vec<u8> {
     fn type_info() -> SqliteTypeInfo {
         <&[u8] as Type<Sqlite>>::type_info()

sqlx-sqlite/src/types/str.rs

@@ -49,12 +49,6 @@ impl Encode<'_, Sqlite> for Box<str> {
     }
 }
 
-impl Decode<'_, Sqlite> for Box<str> {
-    fn decode(value: SqliteValueRef<'_>) -> Result<Self, BoxDynError> {
-        value.text().map(Box::from)
-    }
-}
-
 impl Type<Sqlite> for String {
     fn type_info() -> SqliteTypeInfo {
         <&str as Type<Sqlite>>::type_info()
@@ -101,8 +95,19 @@ impl<'q> Encode<'q, Sqlite> for Cow<'q, str> {
     }
 }
 
-impl<'r> Decode<'r, Sqlite> for Cow<'r, str> {
-    fn decode(value: SqliteValueRef<'r>) -> Result<Self, BoxDynError> {
-        value.text().map(Cow::Borrowed)
+impl<'q> Encode<'q, Sqlite> for Cow<'q, [u8]> {
+    fn encode(self, args: &mut Vec<SqliteArgumentValue<'q>>) -> Result<IsNull, BoxDynError> {
+        args.push(SqliteArgumentValue::Blob(self));
+
+        Ok(IsNull::No)
+    }
+
+    fn encode_by_ref(
+        &self,
+        args: &mut Vec<SqliteArgumentValue<'q>>,
+    ) -> Result<IsNull, BoxDynError> {
+        args.push(SqliteArgumentValue::Blob(self.clone()));
+
+        Ok(IsNull::No)
     }
 }

tests/mysql/types.rs

@@ -1,11 +1,14 @@
 extern crate time_ as time;
 
+use std::borrow::Cow;
 use std::net::SocketAddr;
+use std::rc::Rc;
 #[cfg(feature = "rust_decimal")]
 use std::str::FromStr;
+use std::sync::Arc;
 
 use sqlx::mysql::MySql;
-use sqlx::{Executor, Row};
+use sqlx::{Executor, FromRow, Row};
 
 use sqlx::types::Text;
 
@@ -384,3 +387,49 @@ CREATE TEMPORARY TABLE user_login (
 
     Ok(())
 }
+
+#[sqlx_macros::test]
+async fn test_smartpointers() -> anyhow::Result<()> {
+    let mut conn = new::<MySql>().await?;
+
+    let user_age: (Arc<i32>, Cow<'static, i32>, Box<i32>, i32) =
+        sqlx::query_as("SELECT ?, ?, ?, ?")
+            .bind(Arc::new(1i32))
+            .bind(Cow::<'_, i32>::Borrowed(&2i32))
+            .bind(Box::new(3i32))
+            .bind(Rc::new(4i32))
+            .fetch_one(&mut conn)
+            .await?;
+
+    assert!(user_age.0.as_ref() == &1);
+    assert!(user_age.1.as_ref() == &2);
+    assert!(user_age.2.as_ref() == &3);
+    assert!(user_age.3 == 4);
+    Ok(())
+}
+
+#[sqlx_macros::test]
+async fn test_str_slice() -> anyhow::Result<()> {
+    let mut conn = new::<MySql>().await?;
+
+    let box_str: Box<str> = "John".into();
+    let box_slice: Box<[u8]> = [1, 2, 3, 4].into();
+    let cow_str: Cow<'static, str> = "Phil".into();
+    let cow_slice: Cow<'static, [u8]> = Cow::Borrowed(&[1, 2, 3, 4]);
+
+    let row = sqlx::query("SELECT ?, ?, ?, ?")
+        .bind(&box_str)
+        .bind(&box_slice)
+        .bind(&cow_str)
+        .bind(&cow_slice)
+        .fetch_one(&mut conn)
+        .await?;
+
+    let data: (Box<str>, Box<[u8]>, Cow<'_, str>, Cow<'_, [u8]>) = FromRow::from_row(&row)?;
+
+    assert!(data.0 == box_str);
+    assert!(data.1 == box_slice);
+    assert!(data.2 == cow_str);
+    assert!(data.3 == cow_slice);
+    Ok(())
+}