feat(IDBConnection): Add getTransactionIsolation and setTransactionIsolation

Signed-off-by: provokateurin <[email protected]>

Author: provokateurin

lib/private/DB/ConnectionAdapter.php

@@ -26,6 +26,13 @@ class ConnectionAdapter implements IDBConnection {
 	/** @var Connection */
 	private $inner;
 
+	/**
+	 * The currently active transaction isolation level or NULL before it has been determined.
+	 *
+	 * @var \Doctrine\DBAL\TransactionIsolationLevel::*|null
+	 */
+	private ?int $transactionIsolationLevel = null;
+
 	public function __construct(Connection $inner) {
 		$this->inner = $inner;
 	}
@@ -262,4 +269,14 @@ public function getShardDefinition(string $name): ?ShardDefinition {
 	public function getCrossShardMoveHelper(): CrossShardMoveHelper {
 		return $this->inner->getCrossShardMoveHelper();
 	}
+
+	public function setTransactionIsolation(int $level): int {
+		$this->transactionIsolationLevel = $level;
+
+		return $this->executeStatement($this->getDatabasePlatform()->getSetTransactionIsolationSQL($level));
+	}
+
+	public function getTransactionIsolation(): int {
+		return $this->transactionIsolationLevel ??= $this->getDatabasePlatform()->getDefaultTransactionIsolationLevel();
+	}
 }

lib/public/IDBConnection.php

@@ -388,4 +388,26 @@ public function getShardDefinition(string $name): ?ShardDefinition;
 	 * @since 30.0.0
 	 */
 	public function getCrossShardMoveHelper(): CrossShardMoveHelper;
+
+	/**
+	 * Sets the transaction isolation level.
+	 *
+	 * @param \Doctrine\DBAL\TransactionIsolationLevel::* $level The level to set.
+	 *
+	 * @throws \Doctrine\DBAL\Exception
+	 *
+	 * @since 33.0.0
+	 */
+	public function setTransactionIsolation(int $level): int;
+
+	/**
+	 * Gets the currently active transaction isolation level.
+	 *
+	 * @return \Doctrine\DBAL\TransactionIsolationLevel::* The current transaction isolation level.
+	 *
+	 * @throws \Doctrine\DBAL\Exception
+	 *
+	 * @since 33.0.0
+	 */
+	public function getTransactionIsolation(): int;
 }