remove rmp-serde (#1057)

* remove rmp-serde

* use version info

3 files changed, 81 insertions, 27 deletions

diff --git a/Cargo.lock b/Cargo.lock
index cd2556e7..d6846dd7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -155,7 +155,6 @@ dependencies = [
  "regex",
  "reqwest",
  "rmp",
- "rmp-serde",
  "semver",
  "serde",
  "serde_json",
@@ -1759,17 +1758,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "rmp-serde"
-version = "1.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c5b13be192e0220b8afb7222aa5813cb62cc269ebb5cac346ca6487681d2913e"
-dependencies = [
- "byteorder",
- "rmp",
- "serde",
-]
-
-[[package]]
 name = "rpassword"
 version = "7.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/atuin-client/Cargo.toml b/atuin-client/Cargo.toml
index e00dc910..8147ddca 100644
--- a/atuin-client/Cargo.toml
+++ b/atuin-client/Cargo.toml
@@ -51,7 +51,6 @@ sql-builder = "3"
 lazy_static = "1"
 memchr = "2.5"
 rmp = { version = "0.8.11" }
-rmp-serde = { version = "1.1.1" }
 typed-builder = "0.14.0"
 
 # sync
diff --git a/atuin-client/src/kv.rs b/atuin-client/src/kv.rs
index 35e8852e..1fe90b6c 100644
--- a/atuin-client/src/kv.rs
+++ b/atuin-client/src/kv.rs
@@ -1,5 +1,4 @@
-use eyre::Result;
-use serde::{Deserialize, Serialize};
+use eyre::{bail, ensure, eyre, Result};
 
 use crate::record::store::Store;
 use crate::settings::Settings;
@@ -7,7 +6,7 @@ use crate::settings::Settings;
 const KV_VERSION: &str = "v0";
 const KV_TAG: &str = "kv";
 
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct KvRecord {
     pub namespace: String,
     pub key: String,
@@ -16,9 +15,55 @@ pub struct KvRecord {
 
 impl KvRecord {
     pub fn serialize(&self) -> Result<Vec<u8>> {
-        let buf = rmp_serde::to_vec(self)?;
+        use rmp::encode;
 
-        Ok(buf)
+        let mut output = vec![];
+
+        // INFO: ensure this is updated when adding new fields
+        encode::write_array_len(&mut output, 3)?;
+
+        encode::write_str(&mut output, &self.namespace)?;
+        encode::write_str(&mut output, &self.key)?;
+        encode::write_str(&mut output, &self.value)?;
+
+        Ok(output)
+    }
+
+    pub fn deserialize(data: &[u8], version: &str) -> Result<Self> {
+        use rmp::decode;
+
+        fn error_report<E: std::fmt::Debug>(err: E) -> eyre::Report {
+            eyre!("{err:?}")
+        }
+
+        match version {
+            KV_VERSION => {
+                let mut bytes = decode::Bytes::new(data);
+
+                let nfields = decode::read_array_len(&mut bytes).map_err(error_report)?;
+                ensure!(nfields == 3, "too many entries in v0 kv record");
+
+                let bytes = bytes.remaining_slice();
+
+                let (namespace, bytes) =
+                    decode::read_str_from_slice(bytes).map_err(error_report)?;
+                let (key, bytes) = decode::read_str_from_slice(bytes).map_err(error_report)?;
+                let (value, bytes) = decode::read_str_from_slice(bytes).map_err(error_report)?;
+
+                if !bytes.is_empty() {
+                    bail!("trailing bytes in encoded kvrecord. malformed")
+                }
+
+                Ok(KvRecord {
+                    namespace: namespace.to_owned(),
+                    key: key.to_owned(),
+                    value: value.to_owned(),
+                })
+            }
+            _ => {
+                bail!("unknown version {version:?}")
+            }
+        }
     }
 }
 
@@ -90,22 +135,44 @@ impl KvStore {
         let Some(mut record) = store.last(host_id.as_str(), KV_TAG).await? else {
             return Ok(None);
         };
-        let kv: KvRecord = rmp_serde::from_slice(&record.data)?;
-
-        if kv.key == key && kv.namespace == namespace {
-            return Ok(Some(kv));
-        }
-
-        while let Some(parent) = record.parent {
-            record = store.get(parent.as_str()).await?;
-            let kv: KvRecord = rmp_serde::from_slice(&record.data)?;
 
+        loop {
+            let kv = KvRecord::deserialize(&record.data, &record.version)?;
             if kv.key == key && kv.namespace == namespace {
                 return Ok(Some(kv));
             }
+
+            if let Some(parent) = record.parent {
+                record = store.get(parent.as_str()).await?;
+            } else {
+                break;
+            }
         }
 
         // if we get here, then... we didn't find the record with that key :(
         Ok(None)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::{KvRecord, KV_VERSION};
+
+    #[test]
+    fn encode_decode() {
+        let kv = KvRecord {
+            namespace: "foo".to_owned(),
+            key: "bar".to_owned(),
+            value: "baz".to_owned(),
+        };
+        let snapshot = [
+            0x93, 0xa3, b'f', b'o', b'o', 0xa3, b'b', b'a', b'r', 0xa3, b'b', b'a', b'z',
+        ];
+
+        let encoded = kv.serialize().unwrap();
+        let decoded = KvRecord::deserialize(&encoded, KV_VERSION).unwrap();
+
+        assert_eq!(encoded, &snapshot);
+        assert_eq!(decoded, kv);
+    }
+}