add rkyv support

Cargo.toml

@@ -31,6 +31,7 @@ diesel = { default-features = false, optional = true, version = "1.4" }
 num-traits = { default-features = false, features = ["i128"], version = "0.2" }
 postgres = { default-features = false, optional = true, version = "0.19" }
 rand = { default-features = false, optional = true, version = "0.8" }
+rkyv = {default-features = false, version = "0.7", optional = true}
 rocket = { default-features = false, optional = true, version = "0.5.0-rc.1" }
 serde = { default-features = false, optional = true, version = "1.0" }
 serde_json = { default-features = false, optional = true, version = "1.0" }
@@ -59,6 +60,7 @@ default = ["serde", "std"]
 legacy-ops = []
 maths = []
 maths-nopanic = ["maths"]
+rkyv = ["rkyv/size_32"]
 rocket-traits = ["rocket"]
 rust-fuzz = ["arbitrary"]
 serde-arbitrary-precision = ["serde-with-arbitrary-precision"]
@@ -68,7 +70,7 @@ serde-str = ["serde-with-str"]
 serde-with-arbitrary-precision = ["serde", "serde_json/arbitrary_precision", "serde_json/std"]
 serde-with-float = ["serde"]
 serde-with-str = ["serde"]
-std = []
+std = ["rkyv/std"]
 tokio-pg = ["db-tokio-postgres"] # Backwards compatability
 
 [workspace]

Makefile.toml

@@ -176,7 +176,8 @@ args = ["test", "--workspace", "--no-default-features", "--features=maths-nopani
 [tasks.test-misc]
 dependencies = [
     "test-rust-fuzz",
-    "test-borsh"
+    "test-borsh",
+    "test-rkyv"
 ]
 
 [tasks.test-rust-fuzz]
@@ -251,6 +252,10 @@ args = ["test", "--workspace", "--tests", "--features=serde-with-str", "serde",
 command = "cargo"
 args = ["test", "--workspace", "--features=borsh"]
 
+[tasks.test-rkyv]
+command = "cargo"
+args = ["test", "--workspace", "--features=rkyv"]
+
 [tasks.test-rand]
 command = "cargo"
 args = ["test", "--workspace", "--features=rand"]

README.md

@@ -79,6 +79,7 @@ assert_eq!(total.to_string(), "27.26");
 * [c-repr](#c-repr)
 * [legacy-ops](#legacy-ops)
 * [maths](#maths)
+* [rkyv](#rkyv)
 * [rocket-traits](#rocket-traits)
 * [rust-fuzz](#rust-fuzz)
 * [std](#std)
@@ -144,6 +145,9 @@ non-panicking behavior, please use the feature: `maths-nopanic`.
 
 Implements `rand::distributions::Distribution<Decimal>` to allow the creation of random instances.
 
+### `rkyv`
+Enables [rkyv](https://github.com/rkyv/rkyv) serialization for `Decimal`.
+
 ### `rocket-traits`
 
 Enable support for Rocket forms by implementing the `FromFormField` trait.

src/decimal.rs

@@ -19,6 +19,8 @@ use diesel::sql_types::Numeric;
 #[cfg(not(feature = "std"))]
 use num_traits::float::FloatCore;
 use num_traits::{FromPrimitive, Num, One, Signed, ToPrimitive, Zero};
+#[cfg(feature = "rkyv")]
+use rkyv::{Archive, Deserialize, Serialize};
 
 /// The smallest value that can be represented by this decimal type.
 const MIN: Decimal = Decimal {
@@ -101,6 +103,12 @@ pub struct UnpackedDecimal {
     feature = "borsh",
     derive(borsh::BorshDeserialize, borsh::BorshSerialize, borsh::BorshSchema)
 )]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(Archive, Deserialize, Serialize),
+    archive(compare(PartialEq)),
+    archive_attr(derive(Debug))
+)]
 pub struct Decimal {
     // Bits 0-15: unused
     // Bits 16-23: Contains "e", a value between 0-28 that indicates the scale

tests/decimal_tests.rs

@@ -152,6 +152,27 @@ fn it_can_serialize_deserialize_borsh() {
     }
 }
 
+#[test]
+#[cfg(feature = "rkyv")]
+fn it_can_serialize_deserialize_rkyv() {
+    use rkyv::Deserialize;
+    let tests = [
+        "12.3456789",
+        "5233.9008808150288439427720175",
+        "-5233.9008808150288439427720175",
+    ];
+    for test in &tests {
+        let a = Decimal::from_str(test).unwrap();
+        let bytes = rkyv::to_bytes::<_, 256>(&a).unwrap();
+
+        let archived = unsafe { rkyv::archived_root::<Decimal>(&bytes[..]) };
+        assert_eq!(archived, &a);
+
+        let deserialized: Decimal = archived.deserialize(&mut rkyv::Infallible).unwrap();
+        assert_eq!(deserialized, a);
+    }
+}
+
 #[test]
 fn it_can_deserialize_unbounded_values() {
     // Mantissa for these: 19393111376951473493673267553
@@ -2556,14 +2577,14 @@ fn it_can_return_the_min_value() {
 #[test]
 fn it_can_go_from_and_into() {
     let d = Decimal::from_str("5").unwrap();
-    let di8 = 5u8.into();
-    let di32 = 5i32.into();
-    let disize = 5isize.into();
-    let di64 = 5i64.into();
-    let du8 = 5u8.into();
-    let du32 = 5u32.into();
-    let dusize = 5usize.into();
-    let du64 = 5u64.into();
+    let di8: Decimal = 5u8.into();
+    let di32: Decimal = 5i32.into();
+    let disize: Decimal = 5isize.into();
+    let di64: Decimal = 5i64.into();
+    let du8: Decimal = 5u8.into();
+    let du32: Decimal = 5u32.into();
+    let dusize: Decimal = 5usize.into();
+    let du64: Decimal = 5u64.into();
 
     assert_eq!(d, di8);
     assert_eq!(di8, di32);