fixup! Add protocol compliant PostgresKvStore impl.

Author: G8XSU

rust/impls/src/postgres_store.rs

@@ -27,7 +27,19 @@ const KEY_COLUMN: &str = "key";
 const VALUE_COLUMN: &str = "value";
 const VERSION_COLUMN: &str = "version";
 
-const LIST_KEY_VERSIONS_MAX_PAGE_SIZE: i32 = 100;
+/// The maximum number of key versions that can be returned in a single page.
+///
+/// This constant helps control memory and bandwidth usage for list operations,
+/// preventing overly large payloads. If the number of results exceeds this limit,
+/// the response will be paginated.
+pub const LIST_KEY_VERSIONS_MAX_PAGE_SIZE: i32 = 100;
+
+/// The maximum number of items allowed in a single `PutObjectRequest`.
+///
+/// Setting an upper bound on the number of items helps ensure that
+/// each request stays within acceptable memory and performance limits.
+/// Exceeding this value will result in request rejection through [`VssError::InvalidRequestError`].
+pub const MAX_PUT_REQUEST_ITEM_COUNT: usize = 1000;
 
 /// A [PostgreSQL](https://www.postgresql.org/) based backend implementation for VSS.
 pub struct PostgresBackendImpl {
@@ -47,12 +59,12 @@ impl PostgresBackendImpl {
 		Ok(PostgresBackendImpl { pool })
 	}
 
-	fn build_vss_record(&self, user_token: &str, store_id: &str, kv: &KeyValue) -> VssDbRecord {
+	fn build_vss_record(&self, user_token: String, store_id: String, kv: KeyValue) -> VssDbRecord {
 		let now = Utc::now();
 		VssDbRecord {
-			user_token: user_token.to_string(),
-			store_id: store_id.to_string(),
-			key: kv.key.clone(),
+			user_token,
+			store_id,
+			key: kv.key,
 			value: kv.value.to_vec(),
 			version: kv.version,
 			created_at: now,
@@ -227,28 +239,30 @@ impl KvStore for PostgresBackendImpl {
 		&self, user_token: String, request: PutObjectRequest,
 	) -> Result<PutObjectResponse, VssError> {
 		let store_id = &request.store_id;
-		if request.transaction_items.len() + request.delete_items.len() > 1000 {
-			return Err(VssError::InvalidRequestError(
-				"Number of write items per request should be less than equal to 1000".to_string(),
-			));
+		if request.transaction_items.len() + request.delete_items.len() > MAX_PUT_REQUEST_ITEM_COUNT
+		{
+			return Err(VssError::InvalidRequestError(format!(
+				"Number of write items per request should be less than equal to {}",
+				MAX_PUT_REQUEST_ITEM_COUNT
+			)));
 		}
 		let mut vss_put_records: Vec<VssDbRecord> = request
 			.transaction_items
-			.iter()
-			.map(|kv| self.build_vss_record(&user_token, store_id, kv))
+			.into_iter()
+			.map(|kv| self.build_vss_record(user_token.to_string(), store_id.to_string(), kv))
 			.collect();
 
 		let vss_delete_records: Vec<VssDbRecord> = request
 			.delete_items
-			.iter()
-			.map(|kv| self.build_vss_record(&user_token, store_id, kv))
+			.into_iter()
+			.map(|kv| self.build_vss_record(user_token.to_string(), store_id.to_string(), kv))
 			.collect();
 
 		if let Some(global_version) = request.global_version {
 			let global_version_record = self.build_vss_record(
-				&user_token,
-				store_id,
-				&KeyValue {
+				user_token,
+				store_id.to_string(),
+				KeyValue {
 					key: GLOBAL_VERSION_KEY.to_string(),
 					value: Bytes::new(),
 					version: global_version,
@@ -300,7 +314,10 @@ impl KvStore for PostgresBackendImpl {
 		&self, user_token: String, request: DeleteObjectRequest,
 	) -> Result<DeleteObjectResponse, VssError> {
 		let store_id = &request.store_id;
-		let vss_record = self.build_vss_record(&user_token, store_id, &request.key_value.unwrap());
+		let key_value = request.key_value.ok_or_else(|| {
+			VssError::InvalidRequestError("key_value missing in DeleteObjectRequest".to_string())
+		})?;
+		let vss_record = self.build_vss_record(user_token, store_id.to_string(), key_value);
 
 		let mut conn = self
 			.pool
@@ -362,7 +379,7 @@ impl KvStore for PostgresBackendImpl {
 		let key_like = format!("{}%", key_prefix.as_deref().unwrap_or(""));
 		let page_token_param = page_token.as_deref().unwrap_or("");
 		let params: Vec<&(dyn tokio_postgres::types::ToSql + Sync)> =
-			vec![&user_token, &store_id, &page_token_param, &key_like, &(limit)];
+			vec![&user_token, &store_id, &page_token_param, &key_like, &limit];
 
 		let rows = conn
 			.query(stmt, &params)