feat: with base envelope

Signed-off-by: kjuulh <contact@kjuulh.io>

crates/crunch-envelope/src/lib.rs

@@ -0,0 +1,92 @@
+mod envelope_capnp;
+
+#[cfg(feature = "json")]
+mod json_envelope;
+
+#[cfg(feature = "json")]
+pub mod json {
+    pub use crate::json_envelope::*;
+}
+
+use capnp::message::{Builder, ReaderOptions};
+use capnp::serialize;
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum EnvelopeError {
+    #[error("capnp failed to serialize or deserialize code")]
+    CapnpError(#[source] capnp::Error),
+    #[cfg(feature = "json")]
+    #[error("serde_json failed to serialize or deserialize code")]
+    JsonError(#[source] serde_json::Error),
+    #[cfg(feature = "json")]
+    #[error("base64 failed to serialize or deserialize code")]
+    Base64Error(#[source] base64::DecodeError),
+}
+
+pub fn wrap<'a>(domain: &'a str, entity: &'a str, content: &'a [u8]) -> Vec<u8> {
+    let mut builder = Builder::new_default();
+    let mut envelope = builder.init_root::<envelope_capnp::envelope::Builder>();
+    envelope.set_content(content);
+
+    let mut metadata = envelope.init_metadata();
+    metadata.set_domain(domain);
+    metadata.set_entity(entity);
+
+    let output = serialize::write_message_to_words(&builder);
+
+    return output;
+}
+
+#[allow(dead_code)]
+#[derive(Debug, Clone)]
+pub struct Metadata {
+    domain: String,
+    entity: String,
+}
+
+pub fn unwrap<'a>(message: &'a [u8]) -> Result<(Vec<u8>, Metadata), EnvelopeError> {
+    let mut message = message;
+    let message_builder =
+        serialize::read_message_from_flat_slice(&mut message, ReaderOptions::new())
+            .map_err(EnvelopeError::CapnpError)?;
+
+    let envelope = message_builder
+        .get_root::<envelope_capnp::envelope::Reader>()
+        .map_err(EnvelopeError::CapnpError)?;
+    let content = envelope.get_content().map_err(EnvelopeError::CapnpError)?;
+    let metadata = envelope.get_metadata().map_err(EnvelopeError::CapnpError)?;
+
+    Ok((
+        content.to_vec(),
+        Metadata {
+            domain: metadata
+                .get_domain()
+                .map_err(EnvelopeError::CapnpError)?
+                .to_string(),
+            entity: metadata
+                .get_entity()
+                .map_err(EnvelopeError::CapnpError)?
+                .to_string(),
+        },
+    ))
+}
+
+#[cfg(test)]
+mod test {
+    use crate::{unwrap, wrap};
+
+    #[test]
+    fn test_can_serialize() {
+        let domain = "some-domain";
+        let entity = "some-entity";
+        let message = b"some-content";
+        let out = wrap(domain, entity, message);
+
+        let original = unwrap(&out).expect("to be able to unwrap capnp message");
+
+        assert_eq!(domain, original.1.domain);
+        assert_eq!(entity, original.1.entity);
+        assert_eq!(message, original.0.as_slice());
+    }
+}