Changes for feature parity with tiny-cid

Cargo.toml

@@ -14,19 +14,24 @@ pre-release-commit-message = "Release {{version}} 🎉🎉"
 no-dev-version = true
 
 [features]
-default = ["std"]
+default = ["std", "multihash/default"]
 std = ["multibase", "multihash/std", "unsigned-varint/std"]
 arb = ["quickcheck", "rand", "multihash/arb"]
+scale-codec = ["parity-scale-codec", "multihash/scale-codec"]
+serde-codec = ["serde", "multihash/serde-codec"]
 
 [dependencies]
 multihash = { version = "0.12", default-features = false }
 unsigned-varint = { version = "0.5.1", default-features = false }
 
 multibase = { version = "0.8.0", optional = true }
+parity-scale-codec = { version = "1.3.5", optional = true, default-features = false, features = ["derive"] }
 quickcheck = { version = "0.9.2", optional = true }
 rand = { version = "0.7.3", optional = true }
+serde = { version = "1.0.116", optional = true }
 
 [dev-dependencies]
 quickcheck = "0.9.2"
 rand = "0.7.3"
 multihash = { version = "0.12", default-features = false, features = ["arb", "multihash-impl"] }
+serde_json = "1.0.59"

src/cid.rs

@@ -26,6 +26,11 @@ const SHA2_256: u64 = 0x12;
 ///
 /// The generic is about the allocated size of the multihash.
 #[derive(PartialEq, Eq, Clone, Debug, PartialOrd, Ord)]
+#[cfg_attr(feature = "scale-codec", derive(parity_scale_codec::Decode))]
+#[cfg_attr(feature = "scale-codec", derive(parity_scale_codec::Encode))]
+#[cfg_attr(feature = "serde-codec", derive(serde::Deserialize))]
+#[cfg_attr(feature = "serde-codec", derive(serde::Serialize))]
+#[cfg_attr(feature = "serde-codec", serde(bound = "S: Size"))]
 pub struct Cid<S: Size> {
     /// The version of CID.
     version: Version,
@@ -177,6 +182,16 @@ impl<S: Size> Cid<S> {
     }
 }
 
+impl<S: Size> Default for Cid<S> {
+    fn default() -> Self {
+        Self {
+            version: Version::V1,
+            codec: 0,
+            hash: Multihash::<S>::default(),
+        }
+    }
+}
+
 #[cfg(feature = "std")]
 #[allow(clippy::derive_hash_xor_eq)]
 impl<S: Size> std::hash::Hash for Cid<S> {
@@ -281,3 +296,45 @@ impl<S: Size> From<Cid<S>> for String {
         cid.to_string()
     }
 }
+
+#[cfg(feature = "std")]
+impl<'a, S: Size> From<Cid<S>> for std::borrow::Cow<'a, Cid<S>> {
+    fn from(from: Cid<S>) -> Self {
+        std::borrow::Cow::Owned(from)
+    }
+}
+
+#[cfg(feature = "std")]
+impl<'a, S: Size> From<&'a Cid<S>> for std::borrow::Cow<'a, Cid<S>> {
+    fn from(from: &'a Cid<S>) -> Self {
+        std::borrow::Cow::Borrowed(from)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    #[cfg(feature = "scale-codec")]
+    fn test_cid_scale_codec() {
+        use super::Cid;
+        use multihash::U64;
+        use parity_scale_codec::{Decode, Encode};
+
+        let cid = Cid::<U64>::default();
+        let bytes = cid.encode();
+        let cid2 = Cid::decode(&mut &bytes[..]).unwrap();
+        assert_eq!(cid, cid2);
+    }
+
+    #[test]
+    #[cfg(feature = "serde-codec")]
+    fn test_cid_serde() {
+        use super::Cid;
+        use multihash::U64;
+
+        let cid = Cid::<U64>::default();
+        let bytes = serde_json::to_string(&cid).unwrap();
+        let cid2 = serde_json::from_str(&bytes).unwrap();
+        assert_eq!(cid, cid2);
+    }
+}

src/version.rs

@@ -4,6 +4,10 @@ use crate::error::{Error, Result};
 
 /// The version of the CID.
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Copy, Debug)]
+#[cfg_attr(feature = "scale-codec", derive(parity_scale_codec::Decode))]
+#[cfg_attr(feature = "scale-codec", derive(parity_scale_codec::Encode))]
+#[cfg_attr(feature = "serde-codec", derive(serde::Deserialize))]
+#[cfg_attr(feature = "serde-codec", derive(serde::Serialize))]
 pub enum Version {
     /// CID version 0.
     V0,