add utils::BincodeVecWriter

lib/src/util.rs

@@ -12,3 +12,46 @@ where
         self.map_err(|e| e.to_string())
     }
 }
+
+#[cfg(any(feature = "sync", feature = "async"))]
+mod bincode_utils {
+    use std::ops::{Deref, DerefMut};
+
+    use bincode::enc::write::Writer;
+    use bincode::error::EncodeError;
+
+    /// struct that allows [`Vec<u8>`] to implement [bincode::enc::write::Writer] trait
+    pub struct BincodeVecWriter {
+        vec: Vec<u8>,
+    }
+
+    impl BincodeVecWriter {
+        pub fn new(vec: Vec<u8>) -> BincodeVecWriter {
+            BincodeVecWriter { vec }
+        }
+    }
+
+    impl Deref for BincodeVecWriter {
+        type Target = Vec<u8>;
+
+        fn deref(&self) -> &Self::Target {
+            &self.vec
+        }
+    }
+
+    impl DerefMut for BincodeVecWriter {
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            &mut self.vec
+        }
+    }
+
+    impl Writer for BincodeVecWriter {
+        fn write(&mut self, bytes: &[u8]) -> Result<(), EncodeError> {
+            self.vec.extend_from_slice(bytes);
+            Ok(())
+        }
+    }
+}
+
+#[cfg(any(feature = "sync", feature = "async"))]
+pub use bincode_utils::BincodeVecWriter;