Added serde feature

piecrust-uplink/Cargo.toml

@@ -16,10 +16,18 @@ license = "MPL-2.0"
 rkyv = { version = "0.7", default-features = false, features = ["size_32", "alloc", "validation"] }
 bytecheck = { version = "0.6", default-features = false }
 dlmalloc = { version = "0.2", optional = true, features = ["global"] }
+serde = { version = "1.0", optional = true }
+hex = { version = "0.4" , optional = true }
+base64 = { version = "0.22", optional = true }
+serde_json = { version = "1.0", optional = true }
+
+[dev-dependencies]
+rand = "0.8"
 
 [features]
 abi = []
 debug = []
+serde = ["dep:serde", "serde_json", "hex", "base64"]
 
 [package.metadata.docs.rs]
 all-features = true

piecrust-uplink/src/lib.rs

@@ -78,6 +78,9 @@ pub use types::*;
 mod error;
 pub use error::*;
 
+#[cfg(feature = "serde")]
+mod serde_support;
+
 /// How many bytes to use for scratch space when serializing
 pub const SCRATCH_BUF_BYTES: usize = 1024;
 

piecrust-uplink/src/serde_support.rs

@@ -0,0 +1,137 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+//
+// Copyright (c) DUSK NETWORK. All rights reserved.
+
+use alloc::format;
+use alloc::string::String;
+
+use base64::{engine::general_purpose::STANDARD as BASE64_STANDARD, Engine};
+use serde::{
+    de::{self, Error, MapAccess, Visitor},
+    ser::SerializeStruct,
+    Deserialize, Deserializer, Serialize, Serializer,
+};
+
+use crate::{ContractId, Event, CONTRACT_ID_BYTES};
+
+impl Serialize for ContractId {
+    fn serialize<S: Serializer>(
+        &self,
+        serializer: S,
+    ) -> Result<S::Ok, S::Error> {
+        let s = hex::encode(self.to_bytes());
+        serializer.serialize_str(&s)
+    }
+}
+
+impl<'de> Deserialize<'de> for ContractId {
+    fn deserialize<D: Deserializer<'de>>(
+        deserializer: D,
+    ) -> Result<Self, D::Error> {
+        let s = String::deserialize(deserializer)?;
+        match hex::decode(s) {
+            Ok(bytes) => {
+                let bytes: [u8; CONTRACT_ID_BYTES] = bytes.try_into().map_err(|_| Error::custom("Failed to deserialize ContractId: invalid byte length"))?;
+                Ok(bytes.into())
+            }
+            Err(e) => Err(Error::custom(format!(
+                "Failed to deserialize ContractId: {e}"
+            ))),
+        }
+    }
+}
+
+impl Serialize for Event {
+    fn serialize<S: Serializer>(
+        &self,
+        serializer: S,
+    ) -> Result<S::Ok, S::Error> {
+        let mut struct_ser = serializer.serialize_struct("Event", 3)?;
+        struct_ser.serialize_field("source", &self.source)?;
+        struct_ser.serialize_field("topic", &self.topic)?;
+        struct_ser
+            .serialize_field("data", &BASE64_STANDARD.encode(&self.data))?;
+        struct_ser.end()
+    }
+}
+
+impl<'de> Deserialize<'de> for Event {
+    fn deserialize<D: Deserializer<'de>>(
+        deserializer: D,
+    ) -> Result<Self, D::Error> {
+        struct StructVisitor;
+
+        impl<'de> Visitor<'de> for StructVisitor {
+            type Value = Event;
+
+            fn expecting(
+                &self,
+                formatter: &mut alloc::fmt::Formatter,
+            ) -> alloc::fmt::Result {
+                formatter
+                    .write_str("a struct with fields: source, topic, and data")
+            }
+
+            fn visit_map<A: MapAccess<'de>>(
+                self,
+                mut map: A,
+            ) -> Result<Self::Value, A::Error> {
+                let (mut source, mut topic, mut data) = (None, None, None);
+                while let Some(key) = map.next_key()? {
+                    match key {
+                        "source" => {
+                            if source.is_some() {
+                                return Err(de::Error::duplicate_field(
+                                    "source",
+                                ));
+                            }
+                            source = Some(map.next_value()?);
+                        }
+                        "topic" => {
+                            if topic.is_some() {
+                                return Err(de::Error::duplicate_field(
+                                    "topic",
+                                ));
+                            }
+                            topic = Some(map.next_value()?);
+                        }
+                        "data" => {
+                            if data.is_some() {
+                                return Err(de::Error::duplicate_field("data"));
+                            }
+                            data = Some(map.next_value()?);
+                        }
+                        field => {
+                            return Err(de::Error::unknown_field(
+                                field,
+                                &["source", "topic", "data"],
+                            ))
+                        }
+                    };
+                }
+                let data: String =
+                    data.ok_or_else(|| de::Error::missing_field("data"))?;
+                let data = BASE64_STANDARD.decode(data).map_err(|e| {
+                    de::Error::custom(format!(
+                        "failed to base64 decode Event data: {e}"
+                    ))
+                })?;
+                Ok(Event {
+                    source: source
+                        .ok_or_else(|| de::Error::missing_field("source"))?,
+                    topic: topic
+                        .ok_or_else(|| de::Error::missing_field("topic"))?,
+                    data,
+                })
+            }
+        }
+
+        deserializer.deserialize_struct(
+            "Event",
+            &["source", "topic", "data"],
+            StructVisitor,
+        )
+    }
+}

piecrust-uplink/tests/serde.rs

@@ -0,0 +1,45 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+//
+// Copyright (c) DUSK NETWORK. All rights reserved.
+
+#[cfg(feature = "serde")]
+mod serde {
+    use piecrust_uplink::{ContractId, Event, CONTRACT_ID_BYTES};
+    use rand::{rngs::StdRng, RngCore, SeedableRng};
+
+    fn rand_contract_id(rng: &mut StdRng) -> ContractId {
+        let mut bytes = [0; CONTRACT_ID_BYTES];
+        rng.fill_bytes(&mut bytes);
+        bytes.into()
+    }
+
+    fn rand_event(rng: &mut StdRng) -> Event {
+        let mut data = [0; 50];
+        rng.fill_bytes(&mut data);
+        Event {
+            source: rand_contract_id(rng),
+            topic: "a-contract-topic".into(),
+            data: data.into(),
+        }
+    }
+
+    #[test]
+    fn contract_id() {
+        let mut rng = StdRng::seed_from_u64(0xdead);
+        let id: ContractId = rand_contract_id(&mut rng);
+        let ser = serde_json::to_string(&id).unwrap();
+        let deser: ContractId = serde_json::from_str(&ser).unwrap();
+        assert_eq!(id, deser);
+    }
+
+    #[test]
+    fn event() {
+        let mut rng = StdRng::seed_from_u64(0xbeef);
+        let event = rand_event(&mut rng);
+        let ser = serde_json::to_string(&event).unwrap();
+        let deser: Event = serde_json::from_str(&ser).unwrap();
+        assert_eq!(event, deser);
+    }
+}