feat: append versionstamp to key (#40)

This adds a new `M_SET_SUFFIX_VERSIONSTAMPED_KEY` mutation type that is
same as `M_SET` except that the hex-encoded versionstamp of the current
atomic operation is appended to the key.

Author: losfair

Cargo.lock

@@ -148,6 +148,11 @@ impl TryFrom<pb::AtomicWrite> for AtomicWrite {
             .ok_or(ConvertError::DecodeError)?;
           MutationKind::Max(value)
         }
+        (pb::MutationType::MSetSuffixVersionstampedKey, Some(value)) => {
+          let value = decode_value(value.data, value.encoding as i64)
+            .ok_or(ConvertError::DecodeError)?;
+          MutationKind::SetSuffixVersionstampedKey(value)
+        }
         _ => return Err(ConvertError::InvalidMutationKind),
       };
       let expire_at = match mutation.expire_at_ms {

proto/convert.rs

@@ -323,6 +323,7 @@ pub enum MutationKind {
   Sum(KvValue),
   Min(KvValue),
   Max(KvValue),
+  SetSuffixVersionstampedKey(KvValue),
 }
 
 impl MutationKind {
@@ -332,6 +333,7 @@ impl MutationKind {
       MutationKind::Sum(value) => Some(value),
       MutationKind::Min(value) => Some(value),
       MutationKind::Max(value) => Some(value),
+      MutationKind::SetSuffixVersionstampedKey(value) => Some(value),
       MutationKind::Delete => None,
     }
   }

proto/interface.rs

@@ -135,6 +135,8 @@ enum MutationType {
   M_MAX = 4;
   // Max the stored value with the new value. Both values must be LE64 encoded.
   M_MIN = 5;
+  // Set the value, with the versionstamp appended to the end of the key as a string.
+  M_SET_SUFFIX_VERSIONSTAMPED_KEY = 9;
 }
 
 // The encoding of a value.

proto/schema/datapath.proto

@@ -614,6 +614,14 @@ impl<P: RemotePermissions> Database for Remote<P> {
             expire_at_ms,
           });
         }
+        denokv_proto::MutationKind::SetSuffixVersionstampedKey(value) => {
+          mutations.push(pb::Mutation {
+            key: mutation.key,
+            value: Some(encode_value_to_pb(value)),
+            mutation_type: pb::MutationType::MSetSuffixVersionstampedKey as _,
+            expire_at_ms,
+          });
+        }
       }
     }
 

remote/lib.rs

@@ -21,6 +21,7 @@ async-trait.workspace = true
 chrono.workspace = true
 denokv_proto.workspace = true
 futures.workspace = true
+hex.workspace = true
 log.workspace = true
 num-bigint.workspace = true
 rand.workspace = true

sqlite/Cargo.toml

@@ -287,6 +287,7 @@ impl SqliteBackend {
       let version: i64 = tx
         .prepare_cached(STATEMENT_INC_AND_GET_DATA_VERSION)?
         .query_row([incrementer_count], |row| row.get(0))?;
+      let new_versionstamp = version_to_versionstamp(version);
 
       for mutation in &write.mutations {
         match &mutation.kind {
@@ -326,6 +327,31 @@ impl SqliteBackend {
               a.max(b)
             })?;
           }
+          MutationKind::SetSuffixVersionstampedKey(value) => {
+            let mut versionstamp_suffix = [0u8; 22];
+            versionstamp_suffix[0] = 0x02;
+            hex::encode_to_slice(
+              new_versionstamp,
+              &mut versionstamp_suffix[1..21],
+            )
+            .unwrap();
+
+            let key = [&mutation.key[..], &versionstamp_suffix[..]].concat();
+
+            let (value, encoding) = encode_value(value);
+            let changed =
+              tx.prepare_cached(STATEMENT_KV_POINT_SET)?.execute(params![
+                key,
+                value,
+                &encoding,
+                &version,
+                mutation
+                  .expire_at
+                  .map(|time| time.timestamp_millis())
+                  .unwrap_or(-1i64)
+              ])?;
+            assert_eq!(changed, 1)
+          }
         }
       }
 
@@ -355,8 +381,6 @@ impl SqliteBackend {
         assert_eq!(changed, 1)
       }
 
-      let new_versionstamp = version_to_versionstamp(version);
-
       Ok((
         has_enqueues,
         Some(CommitResult {