Add borsh serialization support to primitive types

primitive-types/Cargo.toml

@@ -12,6 +12,7 @@ rust-version = "1.60.0"
 fixed-hash = { version = "0.8", path = "../fixed-hash", default-features = false }
 uint = { version = "0.9.0", path = "../uint", default-features = false }
 impl-serde = { version = "0.4.0", path = "impls/serde", default-features = false, optional = true }
+impl-borsh = { version = "0.1.0", path = "impls/borsh", default-features = false, optional = true }
 impl-codec = { version = "0.6.0", path = "impls/codec", default-features = false, optional = true }
 impl-num-traits = { version = "0.1.0", path = "impls/num-traits", default-features = false, optional = true }
 impl-rlp = { version = "0.3", path = "impls/rlp", default-features = false, optional = true }
@@ -30,6 +31,7 @@ rlp = ["impl-rlp"]
 arbitrary = ["fixed-hash/arbitrary", "uint/arbitrary"]
 fp-conversion = ["std"]
 num-traits = ["impl-num-traits"]
+borsh = ["impl-borsh"]
 
 [[test]]
 name = "scale_info"

primitive-types/impls/borsh/CHANGELOG.md

@@ -0,0 +1,5 @@
+# Changelog
+
+The format is based on [Keep a Changelog].
+
+[Keep a Changelog]: http://keepachangelog.com/en/1.0.0/

primitive-types/impls/borsh/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "impl-borsh"
+version = "0.1.0"
+authors = ["Steven Sloboda <steven@eclipse.builders>"]
+license = "MIT OR Apache-2.0"
+homepage = "https://github.com/paritytech/parity-common"
+description = "Borsh serialization support for uint and fixed hash."
+edition = "2021"
+rust-version = "1.56.1"
+
+[features]
+default = ["std",]
+std = ["borsh/std"]
+
+[dependencies]
+borsh = { version = "0.9.3", default-features = false, features = ["std"] }

primitive-types/impls/borsh/src/lib.rs

@@ -0,0 +1,56 @@
+// Copyright 2022 Parity Technologies
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Serde serialization support for uint and fixed hash.
+
+#![no_std]
+
+#[macro_use]
+extern crate alloc;
+
+#[cfg(feature = "std")]
+extern crate std;
+
+#[doc(hidden)]
+pub use borsh;
+
+/// Add Borsh serialization support to an integer created by `construct_uint!`.
+#[macro_export]
+macro_rules! impl_uint_borsh {
+    ($name: ident, $len: expr) => {
+        impl $crate::borsh::BorshSerialize for $name {
+            fn serialize<W: std::io::Write>(&self, writer: &mut W) -> Result<(), std::io::Error> {
+                self.0.serialize(writer)
+            }
+        }
+
+        impl $crate::borsh::BorshDeserialize for $name {
+            fn deserialize(buf: &mut &[u8]) -> Result<Self, std::io::Error> {
+                <[u64; $len]>::deserialize(buf).map(|bytes| Self(bytes))
+            }
+        }
+    };
+}
+
+/// Add Borsh serialization support to a fixed-sized hash type created by `construct_fixed_hash!`.
+#[macro_export]
+macro_rules! impl_fixed_hash_borsh {
+    ($name: ident, $len: expr) => {
+        impl $crate::borsh::BorshSerialize for $name {
+            fn serialize<W: std::io::Write>(&self, writer: &mut W) -> Result<(), std::io::Error> {
+                self.0.serialize(writer)
+            }
+        }
+
+        impl $crate::borsh::BorshDeserialize for $name {
+            fn deserialize(buf: &mut &[u8]) -> Result<Self, std::io::Error> {
+                <[u8; $len]>::deserialize(buf).map(|bytes| Self(bytes))
+            }
+        }
+    };
+}

primitive-types/src/lib.rs

@@ -139,6 +139,21 @@ mod rlp {
 	impl_fixed_hash_rlp!(H768, 96);
 }
 
+#[cfg(feature = "impl-borsh")]
+mod borsh {
+	use super::*;
+	use impl_borsh::{impl_fixed_hash_borsh, impl_uint_borsh};
+
+	impl_uint_borsh!(U128, 2);
+	impl_uint_borsh!(U256, 4);
+	impl_uint_borsh!(U512, 8);
+
+	impl_fixed_hash_borsh!(H128, 16);
+	impl_fixed_hash_borsh!(H160, 20);
+	impl_fixed_hash_borsh!(H256, 32);
+	impl_fixed_hash_borsh!(H512, 64);
+}
+
 impl_fixed_hash_conversions!(H256, H160);
 
 impl U128 {