Added snapshot tx

Author: Илья

CHANGELOG.md

@@ -1,3 +1,5 @@
+* added snapshot tx
+
 ## 1.12.0
 * added StaticAuthentication
 * added query timeout and canceled params

README.md

@@ -542,6 +542,7 @@ Methods of the query builder:
     - online
     - online_inconsistent
     - serializable
+    - snapshot
 - `txControl(\Ydb\Table\TransactionControl $tx_control)` - transaction control with custom settings
 
 You can chain these methods for convenience.

src/YdbQuery.php

@@ -4,6 +4,7 @@
 
 use Ydb\Table\Query;
 use Ydb\Table\QueryCachePolicy;
+use Ydb\Table\SnapshotModeSettings;
 use Ydb\Table\StaleModeSettings;
 use Ydb\Table\OnlineModeSettings;
 use Ydb\Table\TransactionControl;
@@ -170,6 +171,11 @@ public function beginTx($mode)
                 ]);
                 break;
 
+            case 'snapshot':
+            case 'snapshot_read_only':
+                $tx_settings['snapshot_read_only'] = new SnapshotModeSettings;
+                break;
+
             case 'serializable':
             case 'serializable_read_write':
             default:

tests/CheckTxSettingsTest.php

@@ -0,0 +1,73 @@
+<?php
+
+namespace YdbPlatform\Ydb\Test;
+
+use PHPUnit\Framework\TestCase;
+use YdbPlatform\Ydb\Auth\Implement\AnonymousAuthentication;
+use YdbPlatform\Ydb\Logger\SimpleStdLogger;
+use YdbPlatform\Ydb\Ydb;
+use YdbPlatform\Ydb\YdbQuery;
+
+class CheckTxSettingsTest extends TestCase
+{
+
+    /**
+     * @var Ydb
+     */
+    protected $ydb;
+    /**
+     * @var \YdbPlatform\Ydb\Table
+     */
+    protected $table;
+    /**
+     * @var \YdbPlatform\Ydb\Session|null
+     */
+    protected $session;
+    protected $yql = "SELECT 1;";
+
+    public function __construct(?string $name = null, array $data = [], $dataName = '')
+    {
+        parent::__construct($name, $data, $dataName);
+        $config = [
+
+            // Database path
+            'database'    => '/local',
+
+            // Database endpoint
+            'endpoint'    => 'localhost:2136',
+
+            // Auto discovery (dedicated server only)
+            'discovery'   => false,
+
+            // IAM config
+            'iam_config'  => [
+                'insecure' => true,
+            ],
+            'credentials' => new AnonymousAuthentication()
+        ];
+        $this->ydb = new Ydb($config, new SimpleStdLogger(SimpleStdLogger::DEBUG));
+        $this->table = $this->ydb->table();
+        $this->session = $this->table->session();
+    }
+
+    public function testSerializableTxConfig(){
+        $this->checkTx('serializable', 'serializable_read_write');
+    }
+
+    public function testSnapshotTxConfig(){
+        $this->checkTx('snapshot', 'snapshot_read_only');
+    }
+    public function testStaleTxConfig(){
+        $this->checkTx('stale', 'stale_read_only');
+    }
+    public function testOnlineTxConfig(){
+        $this->checkTx('online', 'online_read_only');
+    }
+
+    protected function checkTx(string $mode, string $value)
+    {
+        $query= $this->session->newQuery($this->yql)
+            ->beginTx($mode);
+        self::assertEquals($value, $query->getRequestData()['tx_control']->getBeginTx()->getTxMode());
+    }
+}