From: Michael Wallner <mike@php.net>
Date: Sat, 13 Apr 2013 11:47:42 +0000 (+0200)
Subject: add identity and lock
X-Git-Tag: v1.0.0~5
X-Git-Url: https://git.m6w6.name/?p=m6w6%2Fpq-gateway;a=commitdiff_plain;h=580991717f5e8bb237403757e2111a8d04aca616

add identity and lock
---

diff --git a/composer.json b/composer.json
index 84d86e1..8d6d33c 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,10 @@
     "autoload": {
         "psr-0": {
             "pq\\Gateway": "lib",
-			"pq\\Query": "lib"
+												"pq\\Query": "lib"
         }
-    }
+    },
+				"suggest": {
+								"reactphp/promise": "1.0.*"
+				}
 }
diff --git a/lib/pq/Gateway/Row.php b/lib/pq/Gateway/Row.php
index 2493373..bba7c09 100644
--- a/lib/pq/Gateway/Row.php
+++ b/lib/pq/Gateway/Row.php
@@ -2,6 +2,8 @@
 
 namespace pq\Gateway;
 
+use \pq\Query\Expr as QueryExpr;
+
 class Row implements \JsonSerializable
 {
 	/**
@@ -93,6 +95,30 @@ class Row implements \JsonSerializable
 		return $this->data;
 	}
 	
+	/**
+	 * Get all column/value pairs to possibly uniquely identify this row
+	 * @return array
+	 * @throws \OutOfBoundsException if any primary key column is not present in the row
+	 */
+	function getIdentity() {
+		$cols = array();
+		if (count($identity = $this->getTable()->getIdentity())) {
+			foreach ($identity as $col) {
+				if (!array_key_exists($col, $this->data)) {
+					throw new \OutOfBoundsException(
+						sprintf("Column '%s' does not exist in row of table '%s'",
+							$col, $this->getTable()->getName()
+						)
+					);
+				}
+				$cols[$col] = $this->data[$col];
+			}
+		} else {
+			$cols = $this->data;
+		}
+		return $cols;
+	}
+	
 	/**
 	 * Check whether the row contains modifications
 	 * @return boolean
@@ -106,6 +132,10 @@ class Row implements \JsonSerializable
 		return false;
 	}
 	
+	/**
+	 * Refresh the rows data
+	 * @return \pq\Gateway\Row
+	 */
 	function refresh() {
 		$this->data = $this->table->find($this->criteria(), null, 1, 0)->current()->data;
 		$this->cell = array();
@@ -125,13 +155,21 @@ class Row implements \JsonSerializable
 	}
 	
 	/**
-	 * Transform data array to where criteria
+	 * Transform the row's identity to where criteria
 	 * @return array
 	 */
 	protected function criteria() {
 		$where = array();
-		foreach($this->data as $k => $v) {
-			$where["$k="] = $v;
+		foreach ($this->getIdentity() as $col => $val) {
+			if (isset($val)) {
+				$where["$col="] = $val;
+			} else {
+				$where["$col IS"] = new QueryExpr("NULL");
+			}
+		}
+		
+		if (($lock = $this->getTable()->getLock())) {
+			$lock->criteria($this, $where);
 		}
 		return $where;
 	}
@@ -210,7 +248,11 @@ class Row implements \JsonSerializable
 	 * @return \pq\Gateway\Row
 	 */
 	function create() {
-		$this->data = $this->table->create($this->changes())->current()->data;
+		$rowset = $this->table->create($this->changes());
+		if (!count($rowset)) {
+			throw new \UnexpectedValueException("No row created");
+		}
+		$this->data = $rowset->current()->data;
 		$this->cell = array();
 		return $this;
 	}
@@ -220,7 +262,11 @@ class Row implements \JsonSerializable
 	 * @return \pq\Gateway\Row
 	 */
 	function update() {
-		$this->data = $this->table->update($this->criteria(), $this->changes())->current()->data;
+		$rowset = $this->table->update($this->criteria(), $this->changes());
+		if (!count($rowset)) {
+			throw new \UnexpectedValueException("No row updated");
+		}
+		$this->data = $rowset->current()->data;
 		$this->cell = array();
 		return $this;
 	}
@@ -230,7 +276,11 @@ class Row implements \JsonSerializable
 	 * @return \pq\Gateway\Row
 	 */
 	function delete() {
-		$this->data = $this->table->delete($this->criteria(), "*")->current()->data;
+		$rowset = $this->table->delete($this->criteria(), "*");
+		if (!count($rowset)) {
+			throw new \UnexpectedValueException("No row deleted");
+		}
+		$this->data = $rowset->current()->data;
 		return $this->prime();
 	}
 }
diff --git a/lib/pq/Gateway/Table.php b/lib/pq/Gateway/Table.php
index 8fc85d7..fe5efbd 100644
--- a/lib/pq/Gateway/Table.php
+++ b/lib/pq/Gateway/Table.php
@@ -47,6 +47,11 @@ class Table
 	 */
 	protected $exec;
 	
+	/**
+	 * @var \pq\Gateway\Table\Identity
+	 */
+	protected $identity;
+	
 	/**
 	 * @var \pq\Gateway\Table\Relations
 	 */
@@ -57,6 +62,11 @@ class Table
 	 */
 	protected $metadataCache;
 	
+	/**
+	 * @var \pq\Gateway\Table\LockInterface
+	 */
+	protected $lock;
+	
 	/**
 	 * @param string $table
 	 * @return \pq\Gateway\Table
@@ -179,6 +189,17 @@ class Table
 		return $this;
 	}
 	
+	/**
+	 * Get the primary key
+	 * @return \pq\Gateway\Table\Identity
+	 */
+	function getIdentity() {
+		if (!isset($this->identity)) {
+			$this->identity = new Table\Identity($this);
+		}
+		return $this->identity;
+	}
+	
 	/**
 	 * Get foreign key relations
 	 * @param string $to fkey
@@ -227,6 +248,24 @@ class Table
 		return $this->name;
 	}
 
+	/**
+	 * Set a lock provider
+	 * @param \pq\Gateway\Table\LockInterface $lock
+	 * @return \pq\Gateway\Table
+	 */
+	function setLock(Table\LockInterface $lock) {
+		$this->lock = $lock;
+		return $this;
+	}
+	
+	/**
+	 * Get any set lock provider
+	 * @return \pq\Gateway\Table\LockIntferace
+	 */
+	function getLock() {
+		return $this->lock;
+	}
+	
 	/**
 	 * Execute the query
 	 * @param \pq\Query\WriterInterface $query
@@ -262,9 +301,10 @@ class Table
 	 * @param array|string $order
 	 * @param int $limit
 	 * @param int $offset
+	 * @param string $lock
 	 * @return mixed
 	 */
-	function find(array $where = null, $order = null, $limit = 0, $offset = 0) {
+	function find(array $where = null, $order = null, $limit = 0, $offset = 0, $lock = null) {
 		$query = $this->getQueryWriter()->reset();
 		$query->write("SELECT * FROM", $this->conn->quoteName($this->name));
 		if ($where) {
@@ -276,7 +316,12 @@ class Table
 		if ($limit) {
 			$query->write("LIMIT", $limit);
 		}
-		$query->write("OFFSET", $offset);
+		if ($offset) {
+			$query->write("OFFSET", $offset);
+		}
+		if ($lock) {
+			$query->write("FOR", $lock);
+		}
 		return $this->execute($query);
 	}
 	
@@ -293,7 +338,7 @@ class Table
 		// select * from $this where $this->$foreignColumn = $foreign->$referencedColumn
 		
 		if (!isset($name)) {
-			$name = $this->getName();
+			$name = $foreign->getTable()->getName();
 		}
 		
 		if (!$foreign->getTable()->hasRelation($name, $this->getName())) {
diff --git a/lib/pq/Gateway/Table/CacheInterface.php b/lib/pq/Gateway/Table/CacheInterface.php
index c06b11b..5e30fac 100644
--- a/lib/pq/Gateway/Table/CacheInterface.php
+++ b/lib/pq/Gateway/Table/CacheInterface.php
@@ -2,6 +2,9 @@
 
 namespace pq\Gateway\Table;
 
+/**
+ * @codeCoverageIgnore
+ */
 interface CacheInterface
 {
 	/**
diff --git a/lib/pq/Gateway/Table/Identity.php b/lib/pq/Gateway/Table/Identity.php
new file mode 100644
index 0000000..fcc133b
--- /dev/null
+++ b/lib/pq/Gateway/Table/Identity.php
@@ -0,0 +1,70 @@
+<?php
+
+namespace pq\Gateway\Table;
+
+use \pq\Gateway\Table;
+
+const IDENTITY_SQL = <<<SQL
+select
+ a.attname as column
+from  pg_class     c
+ join pg_index     i  on c.oid    = i.indrelid
+ join pg_attribute a  on c.oid    = a.attrelid
+where 
+     c.relname = \$1
+ and a.attnum  = any(i.indkey)
+ and i.indisprimary
+order by 
+ a.attnum
+SQL;
+
+/**
+ * A primary key implementation
+ */
+class Identity implements \Countable, \IteratorAggregate
+{
+	/**
+	 * @var array
+	 */
+	protected $columns = array();
+	
+	/**
+	 * @param \pq\Gateway\Table $table
+	 */
+	function __construct(Table $table) {
+		$cache = $table->getMetadataCache();
+		if (!($this->columns = $cache->get("$table#identity"))) {
+			$table->getQueryExecutor()->execute(
+				new \pq\Query\Writer(IDENTITY_SQL, array($table->getName())), 
+				function($result) use($table, $cache) {
+					$this->columns = array_map("current", $result->fetchAll(\pq\Result::FETCH_ARRAY));
+					$cache->set("$table#identity", $this->columns);
+				}
+			);
+		}
+	}
+	
+	/**
+	 * @implements \Countable
+	 * @return int
+	 */
+	function count() {
+		return count($this->columns);
+	}
+	
+	/**
+	 * @implements \IteratorAggregate
+	 * @return \ArrayIterator
+	 */
+	function getIterator() {
+		return new \ArrayIterator($this->columns);
+	}
+	
+	/**
+	 * Get the column names which the primary key contains
+	 * @return array
+	 */
+	function getColumns() {
+		return $this->columns;
+	}
+}
diff --git a/lib/pq/Gateway/Table/LockInterface.php b/lib/pq/Gateway/Table/LockInterface.php
new file mode 100644
index 0000000..ff8e858
--- /dev/null
+++ b/lib/pq/Gateway/Table/LockInterface.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace pq\Gateway\Table;
+
+use \pq\Gateway\Row;
+
+interface LockInterface
+{
+	function criteria(Row $row, array &$where);
+}
diff --git a/lib/pq/Gateway/Table/OptimisticLock.php b/lib/pq/Gateway/Table/OptimisticLock.php
new file mode 100644
index 0000000..08e5ae3
--- /dev/null
+++ b/lib/pq/Gateway/Table/OptimisticLock.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace pq\Gateway\Table;
+
+use \pq\Gateway\Row;
+
+/**
+ * An optimistic row lock implementation using a versioning column
+ */
+class OptimisticLock implements LockInterface
+{
+	/**
+	 * The name of the versioning column
+	 * @var string
+	 */
+	protected $column;
+	
+	/**
+	 * @param string $column
+	 */
+	function __construct($column = "version") {
+		$this->column = $column;
+	}
+	
+	/**
+	 * @implements LockInterface
+	 * @param \pq\Gateway\Row $row
+	 * @param array $where reference to the criteria
+	 */
+	function criteria(Row $row, array &$where) {
+		$where["{$this->column}="] = $row->getData()[$this->column];
+		$row->{$this->column}->mod(+1);
+	}
+}
diff --git a/lib/pq/Gateway/Table/PessimisticLock.php b/lib/pq/Gateway/Table/PessimisticLock.php
new file mode 100644
index 0000000..e711b46
--- /dev/null
+++ b/lib/pq/Gateway/Table/PessimisticLock.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace pq\Gateway\Table;
+
+use \pq\Gateway\Row;
+
+/**
+ * A pessimistic row lock implementation using an additional SELECT FOR UPDATE
+ */
+class PessimisticLock implements LockInterface
+{
+	/**
+	 * @inheritdoc
+	 * @param \pq\Gateway\Row $row
+	 * @param array $ignore
+	 * @throws \UnexpectedValueException if the row has already been modified
+	 */
+	function criteria(Row $row, array &$ignore) {
+		$where = array();
+		foreach ($row->getIdentity() as $col => $val) {
+			if (isset($val)) {
+				$where["$col="] = $val;
+			} else {
+				$where["$col IS"] = new QueryExpr("NULL");
+			}
+		}
+		
+		if (1 != count($rowset = $row->getTable()->find($where, null, 0, 0, "update nowait"))) {
+			throw new \UnexpectedValueException("Failed to select a single row");
+		}
+		if ($rowset->current()->getData() != $row->getData()) {
+			throw new \UnexpectedValueException("Row has already been modified");
+		}
+	}
+}
\ No newline at end of file
diff --git a/lib/pq/Gateway/Table/Relations.php b/lib/pq/Gateway/Table/Relations.php
index 128dca7..ab74d40 100644
--- a/lib/pq/Gateway/Table/Relations.php
+++ b/lib/pq/Gateway/Table/Relations.php
@@ -30,17 +30,26 @@ order by
 	,att1.attnum
 SQL;
 
+/**
+ * A foreighn key implementation
+ */
 class Relations
 {
-	public $references;
+	/**
+	 * @var array
+	 */
+	protected $references;
 	
 	function __construct(Table $table) {
 		$cache = $table->getMetadataCache();
-		if (!($this->references = $cache->get("$table:references"))) {
-			$this->references = $table->getConnection()
-				->execParams(RELATION_SQL, array($table->getName()))
-				->map(array(0,1), array(2,3,4), \pq\Result::FETCH_OBJECT);
-			$cache->set("$table:references", $this->references);
+		if (!($this->references = $cache->get("$table#relations"))) {
+			$table->getQueryExecutor()->execute(
+				new \pq\Query\Writer(RELATION_SQL, array($table->getName())),
+				function($result) use($table, $cache) {
+					$this->references = $result->map(array(0,1), array(2,3,4), \pq\Result::FETCH_OBJECT);
+					$cache->set("$table#relations", $this->references);
+				}
+			);
 		}
 	}
 	
diff --git a/lib/pq/Query/AsyncExecutor.php b/lib/pq/Query/AsyncExecutor.php
new file mode 100644
index 0000000..737c0eb
--- /dev/null
+++ b/lib/pq/Query/AsyncExecutor.php
@@ -0,0 +1,38 @@
+<?php
+
+namespace pq\Query\Executor;
+
+use \pq\Query\Executor;
+use \pq\Query\WriterInterface;
+
+/**
+ * @requires \React\Promise
+ */
+use \React\Promise\Deferred;
+
+/**
+ * An asynchronous query executor
+ */
+class Async extends Executor
+{
+	/**
+	 * Execute the query asynchronously through \pq\Connection::execParamsAsync()
+	 * @param \pq\Query\WriterInterface $query
+	 * @param callable $callback
+	 * @return \React\Promise\DeferredPromise
+	 */
+	function execute(WriterInterface $query, callable $callback) {
+		$this->result = null;
+		$this->query = $query;
+		$this->notify();
+		
+		$deferred = new Deferred;
+		$this->getConnection()->execParamsAsync($query, $query->getParams(), $query->getTypes(), 
+			array($deferred->resolver(), "resolve"));
+		
+		return $deferred->then(function($result) {
+			$this->result = $result;
+			$this->notify();
+		})->then($callback);
+	}
+}
diff --git a/lib/pq/Query/Executor.php b/lib/pq/Query/Executor.php
index a01580a..d1c7521 100644
--- a/lib/pq/Query/Executor.php
+++ b/lib/pq/Query/Executor.php
@@ -12,12 +12,28 @@ class Executor implements ExecutorInterface
 	 */
 	protected $conn;
 	
+	/**
+	 * @var \SplObjectStorage
+	 */
+	protected $observers;
+	
+	/**
+	 * @var WriterInterface
+	 */
+	protected $query;
+	
+	/**
+	 * @var \pq\Result
+	 */
+	protected $result;
+	
 	/**
 	 * Create a synchronous query executor
 	 * @param \pq\Connection $conn
 	 */
 	function __construct(\pq\Connection $conn) {
 		$this->conn = $conn;
+		$this->observers = new \SplObjectStorage;
 	}
 	
 	/**
@@ -38,6 +54,22 @@ class Executor implements ExecutorInterface
 		return $this;
 	}
 	
+	/**
+	 * @inheritdoc
+	 * @return WriterInterface
+	 */
+	function getQuery() {
+		return $this->query;
+	}
+	
+	/**
+	 * @inheritdoc
+	 * @return \pq\Result
+	 */
+	function getResult() {
+		return $this->result;
+	}
+	
 	/**
 	 * Execute the query synchronously through \pq\Connection::execParams()
 	 * @param \pq\Query\WriterInterface $query
@@ -45,6 +77,36 @@ class Executor implements ExecutorInterface
 	 * @return mixed
 	 */
 	function execute(WriterInterface $query, callable $callback) {
-		return $callback($this->getConnection()->execParams($query, $query->getParams(), $query->getTypes()));
+		$this->result = null;
+		$this->query = $query;
+		$this->notify();
+		$this->result = $this->getConnection()->execParams($query, $query->getParams(), $query->getTypes());
+		$this->notify();
+		return $callback($this->result);
+	}
+	
+	/**
+	 * @implements \SplSubject
+	 * @param \SplObserver $observer
+	 */
+	function attach(\SplObserver $observer) {
+		$this->observers->attach($observer);
+	}
+	
+	/**
+	 * @implements \SplSubject
+	 * @param \SplObserver $observer
+	 */
+	function detach(\SplObserver $observer) {
+		$this->observers->detach($observer);
+	}
+	
+	/**
+	 * @implements \SplSubject
+	 */
+	function notify() {
+		foreach ($this->observers as $observer){
+			$observer->update($this);
+		}
 	}
 }
diff --git a/lib/pq/Query/Executor/Async.php b/lib/pq/Query/Executor/Async.php
deleted file mode 100644
index d41f53e..0000000
--- a/lib/pq/Query/Executor/Async.php
+++ /dev/null
@@ -1,55 +0,0 @@
-<?php
-
-namespace pq\Query\Executor;
-
-use \pq\Query\ExecutorInterface;
-use \pq\Query\WriterInterface;
-
-use \React\Promise\Deferred;
-
-/**
- * An asynchronous query executor
- */
-class Async implements ExecutorInterface
-{
-	protected $conn;
-	
-	/**
-	 * Create a asynchronous query exectuor
-	 * @param \pq\Connection $conn
-	 */
-	function __construct(\pq\Connection $conn) {
-		$this->conn = $conn;
-	}
-	
-	/**
-	 * Get the connection
-	 * @return \pq\Connection
-	 */
-	function getConnection() {
-		return $this->conn;
-	}
-	
-	/**
-	 * Set the connection
-	 * @param \pq\Connection $conn
-	 * @return \pq\Query\Executor\Async
-	 */
-	function setConnection(\pq\Connection $conn) {
-		$this->conn = $conn;
-		return $this;
-	}
-	
-	/**
-	 * Execute the query asynchronously through \pq\Connection::execParamsAsync()
-	 * @param \pq\Query\WriterInterface $query
-	 * @param callable $callback
-	 * @return \React\Promise\DeferredPromise
-	 */
-	function execute(WriterInterface $query, callable $callback) {
-		$deferred = new Deferred; // FIXME
-		$this->getConnection()->execParamsAsync($query, $query->getParams(), $query->getTypes(), 
-			array($deferred->resolver(), "resolve"));
-		return $deferred->then($callback);
-	}
-}
diff --git a/lib/pq/Query/ExecutorInterface.php b/lib/pq/Query/ExecutorInterface.php
index 141ac23..906404f 100644
--- a/lib/pq/Query/ExecutorInterface.php
+++ b/lib/pq/Query/ExecutorInterface.php
@@ -4,8 +4,9 @@ namespace pq\Query;
 
 /**
  * An executor of \pq\Query\Writer queries
+ * @codeCoverageIgnore
  */
-interface ExecutorInterface
+interface ExecutorInterface extends \SplSubject
 {
 	/**
 	 * Get the connection
@@ -27,4 +28,15 @@ interface ExecutorInterface
 	 * @return mixed the result of the callback
 	 */
 	function execute(WriterInterface $query, callable $callback);
+	
+	/**
+	 * @return WriterInterface
+	 */
+	function getQuery();
+	
+	/**
+	 * @return \pq\Result
+	 */
+	function getResult();
+	
 }
diff --git a/lib/pq/Query/ExpressibleInterface.php b/lib/pq/Query/ExpressibleInterface.php
index 1009583..a1c2ffe 100644
--- a/lib/pq/Query/ExpressibleInterface.php
+++ b/lib/pq/Query/ExpressibleInterface.php
@@ -2,6 +2,9 @@
 
 namespace pq\Query;
 
+/**
+ * @codeCoverageIgnore
+ */
 interface ExpressibleInterface
 {
 	/**
diff --git a/lib/pq/Query/Writer.php b/lib/pq/Query/Writer.php
index 6e06945..b5f3ab2 100644
--- a/lib/pq/Query/Writer.php
+++ b/lib/pq/Query/Writer.php
@@ -48,7 +48,13 @@ class Writer implements WriterInterface
 	 * @return string
 	 */
 	protected function reduce($q, $v) {
-		return $q . " " . (is_array($v) ? implode(", ", $v) : $v);
+		if (is_array($v)) {
+			$v = implode(", ", $v);
+		}
+		if (strlen($q)) {
+			$q .= " ";
+		}
+		return $q . $v;
 	}
 
 	/**
@@ -83,6 +89,9 @@ class Writer implements WriterInterface
 	 * @return \pq\Query\Writer
 	 */
 	function write() {
+		if (strlen($this->query)) {
+			$this->query .= " ";
+		}
 		$this->query .= array_reduce(func_get_args(), array($this, "reduce"));
 		return $this;
 	}
diff --git a/lib/pq/Query/WriterInterface.php b/lib/pq/Query/WriterInterface.php
index 885d4ca..35b6c48 100644
--- a/lib/pq/Query/WriterInterface.php
+++ b/lib/pq/Query/WriterInterface.php
@@ -4,6 +4,7 @@ namespace pq\Query;
 
 /**
  * A query writer which supports easily constructing queries for \pq\Connection::execParams()
+ * @codeCoverageIgnore
  */
 interface WriterInterface
 {
diff --git a/tests/lib/pq/Gateway/CellTest.php b/tests/lib/pq/Gateway/CellTest.php
index d7a8fc6..9dc9680 100644
--- a/tests/lib/pq/Gateway/CellTest.php
+++ b/tests/lib/pq/Gateway/CellTest.php
@@ -23,6 +23,7 @@ class CellTest extends \PHPUnit_Framework_TestCase {
 		$this->conn->exec(PQ_TEST_DATA);
 		Table::$defaultConnection = $this->conn;
 		$this->table = new Table("test");
+		$this->table->getQueryExecutor()->attach(new \QueryLogger());
 	}
 
 	protected function tearDown() {
diff --git a/tests/lib/pq/Gateway/RowTest.php b/tests/lib/pq/Gateway/RowTest.php
index fc08094..00dbbbb 100644
--- a/tests/lib/pq/Gateway/RowTest.php
+++ b/tests/lib/pq/Gateway/RowTest.php
@@ -23,6 +23,7 @@ class RowTest extends \PHPUnit_Framework_TestCase {
 		$this->conn->exec(PQ_TEST_DATA);
 		Table::$defaultConnection = $this->conn;
 		$this->table = new Table("test");
+		$this->table->getQueryExecutor()->attach(new \QueryLogger());
 	}
 
 	protected function tearDown() {
@@ -51,4 +52,59 @@ class RowTest extends \PHPUnit_Framework_TestCase {
 		$row = new Row($this->table);
 		$this->assertSame($this->table, $row->getTable());
 	}
+	
+	function testPessimisticLock() {
+		$this->table->setLock(new Table\PessimisticLock);
+		$txn = $this->table->getConnection()->startTransaction();
+		$row = $this->table->find(null, null, 1)->current();
+		$row->data = "foo";
+		$row->update();
+		$txn->commit();
+		$this->assertSame("foo", $row->data->get());
+	}
+	
+	function testPessimisticLockFail() {
+		$this->table->setLock(new Table\PessimisticLock);
+		$txn = $this->table->getConnection()->startTransaction();
+		$row = $this->table->find(null, null, 1)->current();
+		$row->data = "foo";
+		executeInConcurrentTransaction(
+			$this->table->getQueryExecutor(),
+			"UPDATE {$this->table->getName()} SET data='bar' WHERE id=\$1", 
+			array($row->id->get()));
+		$this->setExpectedException("\\UnexpectedValueException", "Row has already been modified");
+		$row->update();
+		$txn->commit();
+	}
+	
+	function testOptimisticLock() {
+		$this->table->setLock(new Table\OptimisticLock("counter"));
+		$row = $this->table->find(null, null, 1)->current();
+		$cnt = $row->counter->get();
+		$row->data = "foo";
+		$row->update();
+		$this->assertEquals("foo", $row->data->get());
+		$this->assertEquals($cnt +1, $row->counter->get());
+	}
+	
+	function testOptimisticLockFail() {
+		$this->table->setLock(new Table\OptimisticLock("counter"));
+		$row = $this->table->find(null, null, 1)->current();
+		$cnt = $row->counter->get();
+		$row->data = "foo";
+		executeInConcurrentTransaction(
+			$this->table->getQueryExecutor(), 
+			"UPDATE {$this->table->getName()} SET counter = 10 WHERE id=\$1", 
+			array($row->id->get()));
+		$this->setExpectedException("\\UnexpectedValueException", "No row updated");
+		$row->update();
+	}
+	
+	function testRef() {
+		foreach ($this->table->find() as $row) {
+			foreach ($row->reftest() as $ref) {
+				$this->assertEquals($row->id->get(), $ref->test->id->get());
+			}
+		}
+	}
 }
diff --git a/tests/lib/pq/Gateway/RowsetTest.php b/tests/lib/pq/Gateway/RowsetTest.php
index 48ac624..037192a 100644
--- a/tests/lib/pq/Gateway/RowsetTest.php
+++ b/tests/lib/pq/Gateway/RowsetTest.php
@@ -23,6 +23,7 @@ class RowsetTest extends \PHPUnit_Framework_TestCase {
 		$this->conn->exec(PQ_TEST_DATA);
 		Table::$defaultConnection = $this->conn;
 		$this->table = new Table("test");
+		$this->table->getQueryExecutor()->attach(new \QueryLogger());
 	}
 
 	protected function tearDown() {
@@ -107,7 +108,7 @@ class RowsetTest extends \PHPUnit_Framework_TestCase {
 	}
 
 	public function testDeleteFail() {
-		$this->setExpectedException("pq\\Exception");
+		$this->setExpectedException("Exception");
 		$rowset = new Rowset($this->table);
 		$rowset->append(new Row($this->table, array("xx" => 0)))->delete();
 	}
diff --git a/tests/lib/pq/Gateway/TableTest.php b/tests/lib/pq/Gateway/TableTest.php
index a5fb56f..e1b6687 100644
--- a/tests/lib/pq/Gateway/TableTest.php
+++ b/tests/lib/pq/Gateway/TableTest.php
@@ -23,6 +23,7 @@ class TableTest extends \PHPUnit_Framework_TestCase {
 		$this->conn->exec(PQ_TEST_DATA);
 		Table::$defaultConnection = $this->conn;
 		$this->table = new Table("test");
+		$this->table->getQueryExecutor()->attach(new \QueryLogger());
 	}
 
 	protected function tearDown() {
diff --git a/tests/setup.inc b/tests/setup.inc
index ee9733c..bec6c71 100644
--- a/tests/setup.inc
+++ b/tests/setup.inc
@@ -42,3 +42,49 @@ SQL;
 spl_autoload_register(function($c) {
 	if (substr($c,0,3) == "pq\\") return require_once sprintf("%s/../lib/%s.php", __DIR__, strtr($c, "\\", "/"));
 });
+
+function executeInConcurrentTransaction(\pq\Query\ExecutorInterface $exec, $sql, array $params = null) {
+	$conn = $exec->getConnection();
+	$exec->setConnection(new pq\Connection(PQ_TEST_DSN));
+	$exec->execute(new \pq\Query\Writer($sql, $params), function(){});
+	$exec->setConnection($conn);
+}
+
+class QueryLogger implements \SplObserver
+{
+	protected $fp;
+	
+	function __construct($logfile = null) {
+		if (!isset($logfile)) {
+			$logfile = __DIR__."/query.log";
+		}
+		if (!$this->fp = @fopen($logfile, "a")) {
+			throw new \RuntimeException(error_get_last()["message"]);
+		}
+	}
+	
+	function __destruct() {
+		if (is_resource($this->fp)) {
+			fclose($this->fp);
+		}
+	}
+	
+	function update(\SplSubject $executor) {
+		$result = $executor->getResult();
+		if (isset($result)) {
+			fprintf($this->fp, "[%s] R %s\n", 
+				date_create()->format("Y-m-d H:i:s"),
+				json_encode([
+					"S" => $result->statusMessage, 
+					"N" => $result->numRows, 
+					"C" => $result->numCols,
+					"A" => $result->affectedRows
+				]));
+		} elseif (($query = $executor->getQuery())) {
+			fprintf($this->fp, "[%s] Q %s %% %s\n", 
+				date_create()->format("Y-m-d H:i:s"),
+				preg_replace("/\s+/", " ", $query), 
+				json_encode($query->getParams()));
+		}
+	}
+}