feat(ext/kv): return versionstamp from set/commit (#18512)

This commit updates the `Deno.Kv` API to return the new commited
versionstamp for the mutated data from `db.set` and `ao.commit`. This is
returned in the form of a `Deno.KvCommitResult` object that has a
`versionstamp` property.

4 files changed, 30 insertions, 11 deletions

diff --git a/ext/kv/01_db.ts b/ext/kv/01_db.ts
index 70e4c7fca..e0c5335e6 100644
--- a/ext/kv/01_db.ts
+++ b/ext/kv/01_db.ts
@@ -111,14 +111,15 @@ class Kv {
       [key, "set", value],
     ];
 
-    const result = await core.opAsync(
+    const versionstamp = await core.opAsync(
       "op_kv_atomic_write",
       this.#rid,
       checks,
       mutations,
       [],
     );
-    if (!result) throw new TypeError("Failed to set value");
+    if (versionstamp === null) throw new TypeError("Failed to set value");
+    return { versionstamp };
   }
 
   async delete(key: Deno.KvKey) {
@@ -255,15 +256,16 @@ class AtomicOperation {
     return this;
   }
 
-  async commit(): Promise<boolean> {
-    const result = await core.opAsync(
+  async commit(): Promise<Deno.KvCommitResult | null> {
+    const versionstamp = await core.opAsync(
       "op_kv_atomic_write",
       this.#rid,
       this.#checks,
       this.#mutations,
       [], // TODO(@losfair): enqueue
     );
-    return result;
+    if (versionstamp === null) return null;
+    return { versionstamp };
   }
 
   then() {
diff --git a/ext/kv/interface.rs b/ext/kv/interface.rs
index 6e520b9c5..31b7638b4 100644
--- a/ext/kv/interface.rs
+++ b/ext/kv/interface.rs
@@ -31,7 +31,10 @@ pub trait Database {
     options: SnapshotReadOptions,
   ) -> Result<Vec<ReadRangeOutput>, AnyError>;
 
-  async fn atomic_write(&self, write: AtomicWrite) -> Result<bool, AnyError>;
+  async fn atomic_write(
+    &self,
+    write: AtomicWrite,
+  ) -> Result<Option<CommitResult>, AnyError>;
 }
 
 /// Options for a snapshot read.
@@ -304,3 +307,9 @@ impl MutationKind {
     }
   }
 }
+
+/// The result of a successful commit of an atomic write operation.
+pub struct CommitResult {
+  /// The new versionstamp of the data that was committed.
+  pub versionstamp: Versionstamp,
+}
diff --git a/ext/kv/lib.rs b/ext/kv/lib.rs
index 8782fbec6..f17ed55e3 100644
--- a/ext/kv/lib.rs
+++ b/ext/kv/lib.rs
@@ -519,7 +519,7 @@ async fn op_kv_atomic_write<DBH>(
   checks: Vec<V8KvCheck>,
   mutations: Vec<V8KvMutation>,
   enqueues: Vec<V8Enqueue>,
-) -> Result<bool, AnyError>
+) -> Result<Option<String>, AnyError>
 where
   DBH: DatabaseHandler + 'static,
 {
@@ -585,7 +585,7 @@ where
 
   let result = db.atomic_write(atomic_write).await?;
 
-  Ok(result)
+  Ok(result.map(|res| hex::encode(res.versionstamp)))
 }
 
 // (prefix, start, end)
diff --git a/ext/kv/sqlite.rs b/ext/kv/sqlite.rs
index 17634127f..63be1281b 100644
--- a/ext/kv/sqlite.rs
+++ b/ext/kv/sqlite.rs
@@ -17,6 +17,7 @@ use rusqlite::OptionalExtension;
 use rusqlite::Transaction;
 
 use crate::AtomicWrite;
+use crate::CommitResult;
 use crate::Database;
 use crate::DatabaseHandler;
 use crate::KvEntry;
@@ -216,7 +217,10 @@ impl Database for SqliteDb {
     Ok(responses)
   }
 
-  async fn atomic_write(&self, write: AtomicWrite) -> Result<bool, AnyError> {
+  async fn atomic_write(
+    &self,
+    write: AtomicWrite,
+  ) -> Result<Option<CommitResult>, AnyError> {
     let mut db = self.0.borrow_mut();
 
     let tx = db.transaction()?;
@@ -228,7 +232,7 @@ impl Database for SqliteDb {
         .optional()?
         .map(version_to_versionstamp);
       if real_versionstamp != check.versionstamp {
-        return Ok(false);
+        return Ok(None);
       }
     }
 
@@ -273,7 +277,11 @@ impl Database for SqliteDb {
 
     tx.commit()?;
 
-    Ok(true)
+    let new_vesionstamp = version_to_versionstamp(version);
+
+    Ok(Some(CommitResult {
+      versionstamp: new_vesionstamp,
+    }))
   }
 }