Made codecs object-safe and deal with bytes only

1 files changed, 21 insertions, 19 deletions

diff --git a/src/codec.rs b/src/codec.rs
index 8b38a9b..11fa76e 100644
--- a/src/codec.rs
+++ b/src/codec.rs
@@ -1,26 +1,28 @@
+use thiserror::Error;
+
 /// Codecs enable the concealment of payload data inside the data of a carrier.
 pub trait Codec {
-    /// Data type representing the carrier.
-    type Carrier;
-
-    /// Data type representing the payload.
-    type Payload;
-
-    /// Data type representing encoder output/decoder input (usually the same as the carrier).
-    type Output;
-
-    /// Type of errors produced by this codec.
-    type Error;
-
     /// Embeds payload data inside carrier, returning the result.
-    fn encode<C, P>(&self, carrier: C, payload: P) -> Result<Self::Output, Self::Error>
-    where
-        C: Into<Self::Carrier>,
-        P: Into<Self::Payload>;
+    fn encode(&self, carrier: &[u8], payload: &[u8]) -> Result<Vec<u8>, CodecError>;
 
     /// Extracts payload data from an encoded carrier, returning the carrier with data removed and the
     /// payload data.
-    fn decode<E>(&self, encoded: E) -> Result<(Self::Carrier, Self::Payload), Self::Error>
-    where
-        E: Into<Self::Output>;
+    fn decode(&self, encoded: &[u8]) -> Result<(Vec<u8>, Vec<u8>), CodecError>;
+}
+
+/// Errors produced by a codec
+#[derive(Debug, Error)]
+pub enum CodecError {
+    /// Variant used when data is determined not to be encoded. Note that a codec may have no way
+    /// of knowing this, so this may not be returned even if the data was not encoded
+    #[error("Data was not encoded with this codec")]
+    DataNotEncoded,
+
+    /// Variant used when data is invalid in some way. Allows a message string for further context
+    #[error("Provided data invalid: {0}")]
+    DataInvalid(String),
+
+    /// Variant used when some dependency, such as a file load, fails
+    #[error("Error occured in dependency: {0}")]
+    DependencyError(String),
 }