*: Add Serialize and Deserialize to PeerId gossipsub MessageId and kad Key

Cargo.toml

@@ -60,6 +60,7 @@ wasm-ext-websocket = ["wasm-ext", "libp2p-wasm-ext/websocket"]
 websocket = ["libp2p-websocket"]
 yamux = ["libp2p-yamux"]
 secp256k1 = ["libp2p-core/secp256k1"]
+serde = ["libp2p-core/serde"]
 
 [package.metadata.docs.rs]
 all-features = true

core/Cargo.toml

@@ -37,6 +37,7 @@ thiserror = "1.0"
 unsigned-varint = "0.7"
 void = "1"
 zeroize = "1"
+_serde = { package = "serde", version = "1", optional = true, features = ["derive"] }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 ring = { version = "0.16.9", features = ["alloc", "std"], default-features = false }
@@ -59,6 +60,7 @@ prost-build = "0.9"
 default = [ "secp256k1", "ecdsa" ]
 secp256k1 = [ "libsecp256k1" ]
 ecdsa = [ "p256" ]
+serde = ["multihash/serde-codec", "_serde"]
 
 [[bench]]
 name = "peer_id"

core/src/lib.rs

@@ -35,6 +35,9 @@
 //!   define how to upgrade each individual substream to use a protocol.
 //!   See the `upgrade` module.
 
+#[cfg(feature = "serde")]
+extern crate _serde as serde;
+
 mod keys_proto {
     include!(concat!(env!("OUT_DIR"), "/keys_proto.rs"));
 }

core/src/peer_id.rs

@@ -24,13 +24,18 @@ use rand::Rng;
 use std::{convert::TryFrom, fmt, str::FromStr};
 use thiserror::Error;
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 /// Public keys with byte-lengths smaller than `MAX_INLINE_KEY_LENGTH` will be
 /// automatically used as the peer id using an identity multihash.
 const MAX_INLINE_KEY_LENGTH: usize = 42;
 
 /// Identifier of a peer of the network.
 ///
 /// The data is a multihash of the public key of the peer.
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "serde", serde(crate = "_serde"))] 
 #[derive(Clone, Copy, Eq, Hash, Ord, PartialEq, PartialOrd)]
 pub struct PeerId {
     multihash: Multihash,

protocols/gossipsub/Cargo.toml

@@ -30,6 +30,7 @@ regex = "1.4.0"
 futures-timer = "3.0.2"
 pin-project = "1.0.8"
 instant = "0.1.11"
+serde = { version = "1", optional = true, features = ["derive"] }
 # Metrics dependencies
 open-metrics-client = "0.13.0"
 

protocols/gossipsub/src/types.rs

@@ -27,6 +27,9 @@ use prost::Message;
 use std::fmt;
 use std::fmt::Debug;
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 #[derive(Debug)]
 /// Validation kinds from the application for received messages.
 pub enum MessageAcceptance {
@@ -42,6 +45,7 @@ pub enum MessageAcceptance {
 /// Macro for declaring message id types
 macro_rules! declare_message_id_type {
     ($name: ident, $name_string: expr) => {
+        #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
         #[derive(Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
         pub struct $name(pub Vec<u8>);