Support per-key locking for concurrent write serialization

Author: ekkolon

Cargo.lock

@@ -17,3 +17,5 @@ categories = ["database", "network-programming"]
 thiserror = "2"
 base64 = "0.22"
 blake3 = "1.8"
+dashmap = "6.1"
+tokio = { version = "1.49", default-features = false }

Cargo.toml

@@ -14,3 +14,7 @@ categories.workspace = true
 thiserror.workspace = true
 base64 = { workspace = true }
 blake3 = { workspace = true }
+dashmap = { workspace = true }
+
+[dev-dependencies]
+tokio = { workspace = true, features = ["full"] }

minikv-core/Cargo.toml

@@ -1,2 +1,3 @@
 pub mod hashing;
+pub mod locking;
 pub mod volumes;