From 15905fd282b7c144a7526256fda23a09d93b750b Mon Sep 17 00:00:00 2001
From: Mark Story <mark@mark-story.com>
Date: Sun, 5 May 2013 00:00:37 -0400
Subject: [PATCH] Shift connection logic into the drivers.

This allows classes that only access the driver (like schema platforms)
to have access to lazy connection features. I think this also makes the
drivers better encapsulate their behavior. Before some of the
connected/connection logic was in the connection class which I think
will slowly become the datasource class, or a wrapper for the various
SQL based datasources at the very least.
---
 lib/Cake/Database/Connection.php              | 42 ++---------
 lib/Cake/Database/Driver.php                  | 69 +++++++++++++++----
 lib/Cake/Database/Driver/Mysql.php            |  8 ++-
 lib/Cake/Database/Driver/PDODriverTrait.php   | 28 ++++++--
 lib/Cake/Database/Driver/Postgres.php         | 19 ++---
 lib/Cake/Database/Driver/Sqlite.php           | 14 ++--
 .../TestCase/Database/Driver/MysqlTest.php    |  9 ++-
 .../TestCase/Database/Driver/PostgresTest.php | 12 +++-
 .../TestCase/Database/Driver/SqliteTest.php   |  6 +-
 9 files changed, 128 insertions(+), 79 deletions(-)

diff --git a/lib/Cake/Database/Connection.php b/lib/Cake/Database/Connection.php
index 38d3850a12c..cff91794010 100644
--- a/lib/Cake/Database/Connection.php
+++ b/lib/Cake/Database/Connection.php
@@ -46,13 +46,6 @@ class Connection {
  */
 	protected $_driver;
 
-/**
- * Whether connection was established or not
- *
- * @var boolean
- */
-	protected $_connected = false;
-
 /**
  * Contains how many nested transactions have been started
  *
@@ -103,7 +96,7 @@ public function __construct($config) {
 			throw new MissingDriverException(['driver' => $config['datasource']]);
 		}
 
-		$this->driver($config['datasource']);
+		$this->driver($config['datasource'], $config);
 		if (!$this->_driver->enabled()) {
 			throw new MissingExtensionException(['driver' => get_class($this->_driver)]);
 		}
@@ -121,9 +114,6 @@ public function __construct($config) {
  * @return void
  */
 	public function __destruct() {
-		if ($this->_connected) {
-			$this->_driver->disconnect();
-		}
 		unset($this->_driver);
 	}
 
@@ -143,14 +133,15 @@ public function config() {
  * If no params are passed it will return the current driver instance
  *
  * @param string|Driver $driver
+ * @param array|null $config Either config for a new driver or null.
  * @return Driver
  */
-	public function driver($driver = null) {
+	public function driver($driver = null, $config = null) {
 		if ($driver === null) {
 			return $this->_driver;
 		}
 		if (is_string($driver)) {
-			$driver = new $driver;
+			$driver = new $driver($config);
 		}
 		return $this->_driver = $driver;
 	}
@@ -162,11 +153,9 @@ public function driver($driver = null) {
  * @return boolean true on success or false if already connected.
  */
 	public function connect() {
-		if ($this->_connected) {
-			return false;
-		}
 		try {
-			return $this->_connected = $this->_driver->connect($this->_config);
+			$this->_driver->connect();
+			return true;
 		} catch(\Exception $e) {
 			throw new MissingConnectionException(['reason' => $e->getMessage()]);
 		}
@@ -179,7 +168,6 @@ public function connect() {
  */
 	public function disconnect() {
 		$this->_driver->disconnect();
-		$this->_connected = false;
 	}
 
 /**
@@ -188,7 +176,7 @@ public function disconnect() {
  * @return boolean
  */
 	public function isConnected() {
-		return $this->_connected;
+		return $this->_driver->isConnected();
 	}
 
 /**
@@ -198,7 +186,6 @@ public function isConnected() {
  * @return \Cake\Database\Statement
  */
 	public function prepare($sql) {
-		$this->connect();
 		$statement = $this->_driver->prepare($sql);
 
 		if ($this->_logQueries) {
@@ -218,7 +205,6 @@ public function prepare($sql) {
  * @return \Cake\Database\Statement executed statement
  */
 	public function execute($query, array $params = [], array $types = []) {
-		$this->connect();
 		if ($params) {
 			$statement = $this->prepare($query);
 			$statement->bind($params, $types);
@@ -236,7 +222,6 @@ public function execute($query, array $params = [], array $types = []) {
  * @return \Cake\Database\Statement
  */
 	public function query($sql) {
-		$this->connect();
 		$statement = $this->prepare($sql);
 		$statement->execute();
 		return $statement;
@@ -260,8 +245,6 @@ public function newQuery() {
  * @return \Cake\Database\Statement
  */
 	public function insert($table, array $data, array $types = []) {
-		$this->connect();
-
 		$columns = array_keys($data);
 		return $this->newQuery()->insert($table, $columns, $types)
 			->values($data)
@@ -278,7 +261,6 @@ public function insert($table, array $data, array $types = []) {
  * @return \Cake\Database\Statement
  */
 	public function update($table, array $data, array $conditions = [], $types = []) {
-		$this->connect();
 		$columns = array_keys($data);
 
 		return $this->newQuery()->update($table)
@@ -296,7 +278,6 @@ public function update($table, array $data, array $conditions = [], $types = [])
  * @return \Cake\Database\Statement
  */
 	public function delete($table, $conditions = [], $types = []) {
-		$this->connect();
 		return $this->newQuery()->delete($table)
 			->where($conditions, $types)
 			->execute();
@@ -308,7 +289,6 @@ public function delete($table, $conditions = [], $types = []) {
  * @return void
  */
 	public function begin() {
-		$this->connect();
 		if (!$this->_transactionStarted) {
 			if ($this->_logQueries) {
 				$this->log('BEGIN');
@@ -334,7 +314,6 @@ public function commit() {
 		if (!$this->_transactionStarted) {
 			return false;
 		}
-		$this->connect();
 
 		if ($this->_transactionLevel === 0) {
 			$this->_transactionStarted = false;
@@ -360,7 +339,6 @@ public function rollback() {
 		if (!$this->_transactionStarted) {
 			return false;
 		}
-		$this->connect();
 
 		$useSavePoint = $this->useSavePoints();
 		if ($this->_transactionLevel === 0 || !$useSavePoint) {
@@ -414,7 +392,6 @@ public function useSavePoints($enable = null) {
  * @return void
  */
 	public function createSavePoint($name) {
-		$this->connect();
 		$this->execute($this->_driver->savePointSQL($name));
 	}
 
@@ -425,7 +402,6 @@ public function createSavePoint($name) {
  * @return void
  */
 	public function releaseSavePoint($name) {
-		$this->connect();
 		$this->execute($this->_driver->releaseSavePointSQL($name));
 	}
 
@@ -436,7 +412,6 @@ public function releaseSavePoint($name) {
  * @return void
  */
 	public function rollbackSavepoint($name) {
-		$this->connect();
 		$this->execute($this->_driver->rollbackSavePointSQL($name));
 	}
 
@@ -448,7 +423,6 @@ public function rollbackSavepoint($name) {
  * @return mixed quoted value
  */
 	public function quote($value, $type = null) {
-		$this->connect();
 		list($value, $type) = $this->cast($value, $type);
 		return $this->_driver->quote($value, $type);
 	}
@@ -459,7 +433,6 @@ public function quote($value, $type = null) {
  * @return boolean
  */
 	public function supportsQuoting() {
-		$this->connect();
 		return $this->_driver->supportsQuoting();
 	}
 
@@ -481,7 +454,6 @@ public function quoteIdentifier($identifier) {
  * @return string|integer
  */
 	public function lastInsertId($table) {
-		$this->connect();
 		return $this->_driver->lastInsertId($table);
 	}
 
diff --git a/lib/Cake/Database/Driver.php b/lib/Cake/Database/Driver.php
index 66f1e120897..42d7fed5066 100644
--- a/lib/Cake/Database/Driver.php
+++ b/lib/Cake/Database/Driver.php
@@ -23,22 +23,47 @@
  * Represents a database diver containing all specificities for
  * a database engine including its SQL dialect
  *
- **/
+ */
 abstract class Driver {
 
+/**
+ * Configuration data.
+ *
+ * @var array
+ */
+	protected $_config;
+
+/**
+ * Base configuration that is merged into the user
+ * supplied configuration data.
+ *
+ * @var array
+ */
+	protected $_baseConfig = [];
+
+/**
+ * Constructor
+ *
+ * @param array $config The configuration for the driver.
+ * @return void
+ */
+	public function __construct($config = []) {
+		$config += $this->_baseConfig;
+		$this->_config = $config;
+	}
+
 /**
  * Establishes a connection to the database server
  *
- * @param array $config configuration to be used for creating connection
  * @return boolean true con success
- **/
-	public abstract function connect(array $config);
+ */
+	public abstract function connect();
 
 /**
  * Disconnects from database server
  *
  * @return void
- **/
+ */
 	public abstract function disconnect();
 
 /**
@@ -46,14 +71,14 @@ public abstract function disconnect();
  * If first argument is passed,
  *
  * @return void
- **/
+ */
 	public abstract function connection($connection = null);
 
 /**
  * Returns whether php is able to use this driver for connecting to database
  *
  * @return boolean true if it is valid to use this driver
- **/
+ */
 	public abstract function enabled();
 
 /**
@@ -61,28 +86,28 @@ public abstract function enabled();
  *
  * @param string $sql
  * @return Cake\Database\Statement
- **/
+ */
 	public abstract function prepare($sql);
 
 /**
  * Starts a transaction
  *
  * @return boolean true on success, false otherwise
- **/
+ */
 	public abstract function beginTransaction();
 
 /**
  * Commits a transaction
  *
  * @return boolean true on success, false otherwise
- **/
+ */
 	public abstract function commitTransaction();
 
 /**
  * Rollsback a transaction
  *
  * @return boolean true on success, false otherwise
- **/
+ */
 	public abstract function rollbackTransaction();
 
 /**
@@ -105,7 +130,7 @@ public abstract function quote($value, $type);
  * Checks if the driver supports quoting
  *
  * @return boolean
- **/
+ */
 	public function supportsQuoting() {
 		return true;
 	}
@@ -115,9 +140,27 @@ public function supportsQuoting() {
  *
  * @param string $table table name or sequence to get last insert value from
  * @return string|integer
- **/
+ */
 	public function lastInsertId($table = null) {
 		return $this->_connection->lastInsertId($table);
 	}
 
+/**
+ * Check whether or not the driver is connected.
+ *
+ * @return boolean
+ */
+	public function isConnected() {
+		return $this->_connection !== null;
+	}
+
+/**
+ * Destructor
+ *
+ * @return void
+ */
+	public function __destruct() {
+		$this->_connection = null;
+	}
+
 }
diff --git a/lib/Cake/Database/Driver/Mysql.php b/lib/Cake/Database/Driver/Mysql.php
index 35941f27fe1..77941bf799a 100644
--- a/lib/Cake/Database/Driver/Mysql.php
+++ b/lib/Cake/Database/Driver/Mysql.php
@@ -46,11 +46,13 @@ class Mysql extends \Cake\Database\Driver {
 /**
  * Establishes a connection to the database server
  *
- * @param array $config configuration to be used for creating connection
  * @return boolean true on success
  */
-	public function connect(array $config) {
-		$config += $this->_baseConfig;
+	public function connect() {
+		if ($this->_connection) {
+			return true;
+		}
+		$config = $this->_config;
 
 		if ($config['timezone'] === 'UTC') {
 			$config['timezone'] = '+0:00';
diff --git a/lib/Cake/Database/Driver/PDODriverTrait.php b/lib/Cake/Database/Driver/PDODriverTrait.php
index 368f05f434e..3d15126991a 100644
--- a/lib/Cake/Database/Driver/PDODriverTrait.php
+++ b/lib/Cake/Database/Driver/PDODriverTrait.php
@@ -22,6 +22,13 @@
 
 trait PDODriverTrait {
 
+/**
+ * Instance of PDO.
+ *
+ * @var \PDO
+ */
+	protected $_connection;
+
 /**
  * Establishes a connection to the databse server
  *
@@ -69,7 +76,8 @@ public function disconnect() {
  * @return Cake\Database\Statement
  */
 	public function prepare($sql) {
-		$statement = $this->connection()->prepare($sql);
+		$this->connect();
+		$statement = $this->_connection->prepare($sql);
 		return new PDOStatement($statement, $this);
 	}
 
@@ -79,7 +87,8 @@ public function prepare($sql) {
  * @return boolean true on success, false otherwise
  */
 	public function beginTransaction() {
-		return $this->connection()->beginTransaction();
+		$this->connect();
+		return $this->_connection->beginTransaction();
 	}
 
 /**
@@ -88,7 +97,8 @@ public function beginTransaction() {
  * @return boolean true on success, false otherwise
  */
 	public function commitTransaction() {
-		return $this->connection()->commit();
+		$this->connect();
+		return $this->_connection->commit();
 	}
 
 /**
@@ -97,7 +107,8 @@ public function commitTransaction() {
  * @return boolean true on success, false otherwise
  */
 	public function rollbackTransaction() {
-		return $this->connection()->rollback();
+		$this->connect();
+		return $this->_connection->rollback();
 	}
 
 /**
@@ -106,7 +117,8 @@ public function rollbackTransaction() {
  * @return string
  */
 	public function quote($value, $type) {
-		return $this->connection()->quote($value, $type);
+		$this->connect();
+		return $this->_connection->quote($value, $type);
 	}
 
 /**
@@ -116,7 +128,8 @@ public function quote($value, $type) {
  * @return string|integer
  */
 	public function lastInsertId($table = null) {
-		return $this->connection()->lastInsertId();
+		$this->connect();
+		return $this->_connection->lastInsertId();
 	}
 
 /**
@@ -125,7 +138,8 @@ public function lastInsertId($table = null) {
  * @return boolean
  */
 	public function supportsQuoting() {
-		return $this->connection()->getAttribute(PDO::ATTR_DRIVER_NAME) !== 'odbc';
+		$this->connect();
+		return $this->_connection->getAttribute(PDO::ATTR_DRIVER_NAME) !== 'odbc';
 	}
 
 }
diff --git a/lib/Cake/Database/Driver/Postgres.php b/lib/Cake/Database/Driver/Postgres.php
index 200977faddb..bb18d4401fc 100644
--- a/lib/Cake/Database/Driver/Postgres.php
+++ b/lib/Cake/Database/Driver/Postgres.php
@@ -49,11 +49,13 @@ class Postgres extends \Cake\Database\Driver {
 /**
  * Establishes a connection to the databse server
  *
- * @param array $config configuration to be used for creating connection
  * @return boolean true on success
  */
-	public function connect(array $config) {
-		$config += $this->_baseConfig;
+	public function connect() {
+		if ($this->_connection) {
+			return true;
+		}
+		$config = $this->_config;
 		$config['flags'] += [
 			PDO::ATTR_PERSISTENT => $config['persistent'],
 			PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
@@ -64,7 +66,7 @@ public function connect(array $config) {
 		}
 
 		$this->_connect($config);
-		$connection = $this->connection();
+		$this->_connection = $connection = $this->connection();
 		if (!empty($config['encoding'])) {
 			$this->setEncoding($config['encoding']);
 		}
@@ -88,7 +90,6 @@ public function connect(array $config) {
  *
  * @return boolean true if it is valid to use this driver
  */
-
 	public function enabled() {
 		return in_array('pgsql', PDO::getAvailableDrivers());
 	}
@@ -99,8 +100,8 @@ public function enabled() {
  * @return void
  */
 	public function setEncoding($encoding) {
-		$connection = $this->connection();
-		$connection->exec('SET NAMES ' . $connection->quote($encoding));
+		$this->connect();
+		$this->_connection->exec('SET NAMES ' . $this->_connection->quote($encoding));
 	}
 
 /**
@@ -110,8 +111,8 @@ public function setEncoding($encoding) {
  * @return void
  */
 	public function setSchema($schema) {
-		$connection = $this->connection();
-		$connection->exec('SET search_path TO ' . $connection->quote($schema));
+		$this->connect();
+		$this->_connection->exec('SET search_path TO ' . $this->_connection->quote($schema));
 	}
 
 }
diff --git a/lib/Cake/Database/Driver/Sqlite.php b/lib/Cake/Database/Driver/Sqlite.php
index e7ea8addf9e..522751af5da 100644
--- a/lib/Cake/Database/Driver/Sqlite.php
+++ b/lib/Cake/Database/Driver/Sqlite.php
@@ -33,6 +33,8 @@ class Sqlite extends \Cake\Database\Driver {
  */
 	protected $_baseConfig = [
 		'persistent' => false,
+		'login' => null,
+		'password' => null,
 		'database' => ':memory:',
 		'encoding' => 'utf8',
 		'flags' => [],
@@ -43,11 +45,13 @@ class Sqlite extends \Cake\Database\Driver {
 /**
  * Establishes a connection to the databse server
  *
- * @param array $config configuration to be used for creating connection
  * @return boolean true on success
  */
-	public function connect(array $config) {
-		$config += $this->_baseConfig + ['login' => null, 'password' => null];
+	public function connect() {
+		if ($this->_connection) {
+			return true;
+		}
+		$config = $this->_config;
 		$config['flags'] += [
 			PDO::ATTR_PERSISTENT => $config['persistent'],
 			PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
@@ -64,7 +68,6 @@ public function connect(array $config) {
 				$this->connection()->exec($command);
 			}
 		}
-
 		return true;
 	}
 
@@ -85,7 +88,8 @@ public function enabled() {
  * @return Cake\Database\Statement
  */
 	public function prepare($sql) {
-		$statement = $this->connection()->prepare($sql);
+		$this->connect();
+		$statement = $this->_connection->prepare($sql);
 		return new SqliteStatement(new PDOStatement($statement, $this), $this);
 	}
 
diff --git a/lib/Cake/Test/TestCase/Database/Driver/MysqlTest.php b/lib/Cake/Test/TestCase/Database/Driver/MysqlTest.php
index 68b5b3f7570..8e8ed14c37b 100644
--- a/lib/Cake/Test/TestCase/Database/Driver/MysqlTest.php
+++ b/lib/Cake/Test/TestCase/Database/Driver/MysqlTest.php
@@ -77,7 +77,6 @@ public function testConnectionConfigDefault() {
  * @return void
  */
 	public function testConnectionConfigCustom() {
-		$driver = $this->getMock('Cake\Database\Driver\Mysql', ['_connect']);
 		$config = [
 			'persistent' => false,
 			'host' => 'foo',
@@ -90,7 +89,11 @@ public function testConnectionConfigCustom() {
 			'timezone' => 'Antartica',
 			'init' => ['Execute this', 'this too']
 		];
-
+		$driver = $this->getMock(
+			'Cake\Database\Driver\Mysql',
+			['_connect'],
+			[$config]
+		);
 		$expected = $config;
 		$expected['dsn'] = 'mysql:host=foo;port=3440;dbname=bar;charset=a-language';
 		$expected['init'][] = "SET time_zone = 'Antartica'";
@@ -102,7 +105,7 @@ public function testConnectionConfigCustom() {
 		];
 		$driver->expects($this->once())->method('_connect')
 			->with($expected);
-		$driver->connect($config);
+		$driver->connect();
 	}
 
 }
diff --git a/lib/Cake/Test/TestCase/Database/Driver/PostgresTest.php b/lib/Cake/Test/TestCase/Database/Driver/PostgresTest.php
index 04059f45f38..afa31f5f7f7 100644
--- a/lib/Cake/Test/TestCase/Database/Driver/PostgresTest.php
+++ b/lib/Cake/Test/TestCase/Database/Driver/PostgresTest.php
@@ -74,7 +74,7 @@ public function testConnectionConfigDefault() {
 		$driver->expects($this->any())->method('connection')
 			->will($this->returnValue($connection));
 
-		$driver->connect([]);
+		$driver->connect();
 	}
 
 /**
@@ -83,7 +83,6 @@ public function testConnectionConfigDefault() {
  * @return void
  */
 	public function testConnectionConfigCustom() {
-		$driver = $this->getMock('Cake\Database\driver\Postgres', ['_connect', 'connection']);
 		$config = [
 			'persistent' => false,
 			'host' => 'foo',
@@ -97,6 +96,11 @@ public function testConnectionConfigCustom() {
 			'schema' => 'fooblic',
 			'init' => ['Execute this', 'this too']
 		];
+		$driver = $this->getMock(
+			'Cake\Database\driver\Postgres',
+			['_connect', 'connection'],
+			[$config]
+		);
 
 		$expected = $config;
 		$expected['dsn'] = 'pgsql:host=foo;port=3440;dbname=bar';
@@ -121,12 +125,14 @@ public function testConnectionConfigCustom() {
 		$connection->expects($this->at(7))->method('exec')->with('SET timezone = Antartica');
 		$connection->expects($this->exactly(5))->method('exec');
 
+		$driver->connection($connection);
 		$driver->expects($this->once())->method('_connect')
 			->with($expected);
+
 		$driver->expects($this->any())->method('connection')
 			->will($this->returnValue($connection));
 
-		$driver->connect($config);
+		$driver->connect();
 	}
 
 }
diff --git a/lib/Cake/Test/TestCase/Database/Driver/SqliteTest.php b/lib/Cake/Test/TestCase/Database/Driver/SqliteTest.php
index 440d88d6980..38a080d8a0a 100644
--- a/lib/Cake/Test/TestCase/Database/Driver/SqliteTest.php
+++ b/lib/Cake/Test/TestCase/Database/Driver/SqliteTest.php
@@ -61,7 +61,6 @@ public function testConnectionConfigDefault() {
  * @return void
  */
 	public function testConnectionConfigCustom() {
-		$driver = $this->getMock('Cake\Database\driver\Sqlite', ['_connect', 'connection']);
 		$config = [
 			'persistent' => true,
 			'host' => 'foo',
@@ -70,6 +69,11 @@ public function testConnectionConfigCustom() {
 			'encoding' => 'a-language',
 			'init' => ['Execute this', 'this too']
 		];
+		$driver = $this->getMock(
+			'Cake\Database\driver\Sqlite',
+			['_connect', 'connection'],
+			[$config]
+		);
 
 		$expected = $config;
 		$expected += ['login' => null, 'password' => null];