common: add database/sql support for Hash and Address (#15541)

common/types.go

@@ -17,6 +17,7 @@
 package common
 
 import (
+	"database/sql/driver"
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
@@ -31,7 +32,9 @@ import (
 
 // Lengths of hashes and addresses in bytes.
 const (
-	HashLength    = 32
+	// HashLength is the expected length of the hash
+	HashLength = 32
+	// AddressLength is the expected length of the adddress
 	AddressLength = 20
 )
 
@@ -120,6 +123,24 @@ func (h Hash) Generate(rand *rand.Rand, size int) reflect.Value {
 	return reflect.ValueOf(h)
 }
 
+// Scan implements Scanner for database/sql.
+func (h *Hash) Scan(src interface{}) error {
+	srcB, ok := src.([]byte)
+	if !ok {
+		return fmt.Errorf("can't scan %T into Hash", src)
+	}
+	if len(srcB) != HashLength {
+		return fmt.Errorf("can't scan []byte of len %d into Hash, want %d", len(srcB), HashLength)
+	}
+	copy(h[:], srcB)
+	return nil
+}
+
+// Value implements valuer for database/sql.
+func (h Hash) Value() (driver.Value, error) {
+	return h[:], nil
+}
+
 // UnprefixedHash allows marshaling a Hash without 0x prefix.
 type UnprefixedHash Hash
 
@@ -229,6 +250,24 @@ func (a *Address) UnmarshalJSON(input []byte) error {
 	return hexutil.UnmarshalFixedJSON(addressT, input, a[:])
 }
 
+// Scan implements Scanner for database/sql.
+func (a *Address) Scan(src interface{}) error {
+	srcB, ok := src.([]byte)
+	if !ok {
+		return fmt.Errorf("can't scan %T into Address", src)
+	}
+	if len(srcB) != AddressLength {
+		return fmt.Errorf("can't scan []byte of len %d into Address, want %d", len(srcB), AddressLength)
+	}
+	copy(a[:], srcB)
+	return nil
+}
+
+// Value implements valuer for database/sql.
+func (a Address) Value() (driver.Value, error) {
+	return a[:], nil
+}
+
 // UnprefixedAddress allows marshaling an Address without 0x prefix.
 type UnprefixedAddress Address