Merge pull request #693 from siningma/u8_array

Add serialize/deserialize support for [u8; N]

Author: piodul

scylla-cql/src/frame/response/cql_to_rust.rs

@@ -137,6 +137,13 @@ impl_from_cql_value_from_method!(BigDecimal, into_decimal); // BigDecimal::from_
 impl_from_cql_value_from_method!(Duration, as_duration); // Duration::from_cql<CqlValue>
 impl_from_cql_value_from_method!(CqlDuration, as_cql_duration); // CqlDuration::from_cql<CqlValue>
 
+impl<const N: usize> FromCqlVal<CqlValue> for [u8; N] {
+    fn from_cql(cql_val: CqlValue) -> Result<Self, FromCqlValError> {
+        let val = cql_val.into_blob().ok_or(FromCqlValError::BadCqlType)?;
+        val.try_into().map_err(|_| FromCqlValError::BadVal)
+    }
+}
+
 impl FromCqlVal<CqlValue> for crate::frame::value::Date {
     fn from_cql(cql_val: CqlValue) -> Result<Self, FromCqlValError> {
         match cql_val {
@@ -409,6 +416,12 @@ mod tests {
         );
     }
 
+    #[test]
+    fn u8_array_from_cql() {
+        let val = [1u8; 4];
+        assert_eq!(Ok(val), <[u8; 4]>::from_cql(CqlValue::Blob(val.to_vec())));
+    }
+
     #[test]
     fn ip_addr_from_cql() {
         let ip_addr = IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1));

scylla-cql/src/frame/value.rs

@@ -470,6 +470,17 @@ impl Value for Vec<u8> {
     }
 }
 
+impl<const N: usize> Value for [u8; N] {
+    fn serialize(&self, buf: &mut Vec<u8>) -> Result<(), ValueTooBig> {
+        let val_len: i32 = self.len().try_into().map_err(|_| ValueTooBig)?;
+        buf.put_i32(val_len);
+
+        buf.extend_from_slice(self);
+
+        Ok(())
+    }
+}
+
 impl Value for IpAddr {
     fn serialize(&self, buf: &mut Vec<u8>) -> Result<(), ValueTooBig> {
         match self {

scylla-cql/src/frame/value_tests.rs

@@ -29,6 +29,12 @@ fn basic_serialization() {
     assert_eq!(serialized("abc".to_string()), vec![0, 0, 0, 3, 97, 98, 99]);
 }
 
+#[test]
+fn u8_array_serialization() {
+    let val = [1u8; 4];
+    assert_eq!(serialized(val), vec![0, 0, 0, 4, 1, 1, 1, 1]);
+}
+
 #[test]
 fn naive_date_serialization() {
     // 1970-01-31 is 2^31