From cc271ee1545af4c59329402e145a0ea2b9e991f9 Mon Sep 17 00:00:00 2001
From: Kijin Sung <kijin@kijinsung.com>
Date: Mon, 29 Jun 2020 15:45:01 +0900
Subject: [PATCH] Initial implementation of DB class based on PDO MySQL driver

---
 common/framework/db.php                    | 539 +++++++++++++++++++++
 common/framework/exceptions/dberror.php    |  18 +
 common/framework/exceptions/queryerror.php |   2 +-
 common/legacy.php                          |   2 +-
 4 files changed, 559 insertions(+), 2 deletions(-)
 create mode 100644 common/framework/db.php
 create mode 100644 common/framework/exceptions/dberror.php

diff --git a/common/framework/db.php b/common/framework/db.php
new file mode 100644
index 000000000..1743dafb2
--- /dev/null
+++ b/common/framework/db.php
@@ -0,0 +1,539 @@
+<?php
+
+namespace Rhymix\Framework;
+
+/**
+ * The DB class.
+ */
+class DB
+{
+	/**
+	 * Singleton instances.
+	 */
+	protected static $_instances = array();
+	
+	/**
+	 * Connection handle.
+	 */
+	protected $_handle;
+	
+	/**
+	 * Prefix and other connection settings.
+	 */
+	protected $_prefix = '';
+	protected $_charset = 'utf8mb4';
+	protected $_engine = 'innodb';
+	
+	/**
+	 * Information about the last executed statement.
+	 */
+	protected $_last_stmt;
+	
+	/**
+	 * Elapsed time.
+	 */
+	protected $_query_time = 0;
+	protected $_total_time = 0;
+	
+	/**
+	 * Error codes.
+	 */
+	protected $_errno = 0;
+	protected $_errstr = '';
+	
+	/**
+	 * Transaction level.
+	 */
+	protected $_transaction_level = 0;
+	
+	/**
+	 * Properties for backward compatibility.
+	 */
+	public $db_type = 'mysql';
+	public $db_version = '';
+	public $use_prepared_statements = true;
+	
+	/**
+	 * Get a singleton instance of the DB class.
+	 * 
+	 * @param string $type
+	 * @return self
+	 */
+	public static function getInstance(string $type = 'master'): self
+	{
+		// If an instance already exists, return it.
+		if (isset(self::$_instances[$type]))
+		{
+			return self::$_instances[$type];
+		}
+		
+		// Check if configuration exists for the selected DB type.
+		$config = Config::get('db.' . $type) ?: array();
+		if (!count($config))
+		{
+			throw new Exceptions\DBError('DB type \'' . $type . '\' is not configured.');
+		}
+		
+		// Create an instance and return it.
+		return self::$_instances[$type] = new self($config);
+	}
+   
+	/**
+	 * Constructor.
+	 * 
+	 * @param string $type
+	 */
+	public function __construct(array $config)
+	{
+		// Save important config values to the instance.
+		$this->_prefix = $config['prefix'] ?: $this->_prefix;
+		$this->_charset = $config['charset'] ?: $this->_charset;
+		$this->_engine = $config['engine'] ?: $this->_engine;
+		
+		// Connect to the DB.
+		$dsn = 'mysql:host=' . $config['host'];
+		$dsn .= (isset($config['port']) && $config['port'] != 3306) ? (';port=' . $config['port']) : '';
+		$dsn .= ';dbname=' . $config['database'];
+		$dsn .= ';charset=' . $this->_charset;
+		$options = array(
+			\PDO::ATTR_ERRMODE => \PDO::ERRMODE_EXCEPTION,
+			\PDO::ATTR_EMULATE_PREPARES => false,
+			\PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => false,
+		);
+		try
+		{
+			$this->_handle = new \PDO($dsn, $config['user'], $config['pass'], $options);
+		}
+		catch (\PDOException $e)
+		{
+			throw new Exceptions\DBError($e->getMessage(), $e->getCode());
+		}
+		
+		// Get the DB version.
+		$this->db_version = $this->_handle->getAttribute(\PDO::ATTR_SERVER_VERSION);
+	}
+	
+	/**
+	 * Get the raw PDO handle.
+	 * 
+	 * @return PDO
+	 */
+	public function getHandle(): \PDO
+	{
+		return $this->_handle;
+	}
+	
+	/**
+	 * Execute an XML-defined query.
+	 * 
+	 * @param string $query_id
+	 * @param array $args
+	 * @param array $columns
+	 * @param string $type
+	 * @return \BaseObject
+	 */
+	public function executeQuery(string $query_id, $args = [], $column_list = []): \BaseObject
+	{
+		// Validate the args.
+		if (is_object($args))
+		{
+			$args = get_object_vars($args);
+		}
+		if (!is_array($args))
+		{
+			return $this->setError(-1, 'Invalid query arguments.');
+		}
+		
+		// Force the column list to a numerical array.
+		$column_list = is_array($column_list) ? array_values($column_list) : array();
+		
+		// Start measuring elapsed time.
+		$class_start_time = microtime(true);
+		
+		// Get the name of the XML file.
+		$parts = explode('.', $query_id);
+		if (count($parts) === 2)
+		{
+			array_unshift($parts, 'modules');
+		}
+		$filename = \RX_BASEDIR . $parts[0] . '/' . $parts[1] . '/queries/' . $parts[2] . '.xml';
+		if (!Storage::exists($filename))
+		{
+			return $this->setError(-1, 'Query \'' . $query_id . '\' does not exist.');
+		}
+		
+		// Parse and cache the XML file.
+		$cache_key = sprintf('query:%s:%d', $filename, filemtime($filename));
+		$query = Cache::get($cache_key);
+		if (!$query)
+		{
+			$query = Parsers\DBQueryParser::loadXML($filename);
+			if ($query)
+			{
+				Cache::set($cache_key, $query, 0, true);
+			}
+			else
+			{
+				return $this->setError(-1, 'Query \'' . $query_id . '\' cannot be parsed.');
+			}
+		}
+		
+		// Get the query string and parameters.
+		try
+		{
+			$query_string = $query->getQueryString($this->_prefix, $args, $column_list);
+			$query_params = $query->getQueryParams();
+		}
+		catch (Exceptions\QueryError $e)
+		{
+			return $this->setError(-1, $e->getMessage());
+		}
+		
+		// Prepare and execute the query.
+		try
+		{
+			$query_start_time = microtime(true);
+			$this->_last_stmt = $this->_query($query_string, $query_params);
+			$query_elapsed_time = microtime(true) - $query_start_time;
+			$result = $this->_fetch($this->_last_stmt);
+		}
+		catch (\PDOException $e)
+		{
+			return $this->setError(-1, $e->getMessage());
+		}
+		
+		// Compose the result object.
+		$output = new \BaseObject;
+		$output->add('_query', $query_string);
+		$output->add('_elapsed_time', sprintf("%0.5f", $query_elapsed_time));
+		$output->data = $result;
+		
+		// Compose statistics about elapsed time.
+		$class_elapsed_time = microtime(true) - $class_start_time;
+		$this->_query_time += $query_elapsed_time;
+		$this->_total_time += $class_elapsed_time;
+		
+		// Return the complete result.
+		return $output;
+	}
+	
+	/**
+	 * Execute a literal query string.
+	 * 
+	 * This method should not be public, as it starts with an underscore.
+	 * But since there are many legacy apps that rely on it, we will leave it public.
+	 * 
+	 * @param string $query_string
+	 * @param array $query_params
+	 * @return \PDOStatement
+	 */
+	public function _query(string $query_string, array $query_params = []): \PDOStatement
+	{
+		if (count($query_params))
+		{
+			$stmt = $this->_handle->prepare($query_string);
+			$stmt->execute($query_params);
+		}
+		else
+		{
+			$stmt = $this->_handle->query($query_string);
+		}
+		
+		return $stmt;
+	}
+	
+	/**
+	 * Fetch results from a query.
+	 * 
+	 * This method should not be public, as it starts with an underscore.
+	 * But since there are many legacy apps that rely on it, we will leave it public.
+	 * 
+	 * @param \PDOStatement $stmt
+	 * @param int $last_index
+	 * @return array|object
+	 */
+	public function _fetch(\PDOStatement $stmt, int $last_index = 0)
+	{
+		$result = array();
+		$index = $last_index;
+		$step = $last_index !== 0 ? -1 : 1;
+		
+		while ($row = $stmt->fetchObject())
+		{
+			$result[$index] = $row;
+			$index += $step;
+		}
+		
+		$stmt->closeCursor();
+		
+		if ($last_index === 0 && count($result) === 1)
+		{
+			return $result[0];
+		}
+		else
+		{
+			return $result;
+		}
+	}
+	
+	/**
+	 * Begin a transaction.
+	 * 
+	 * @return int
+	 */
+	public function begin(): int
+	{
+		if (!$this->_handle->inTransaction())
+		{
+			$this->_handle->beginTransaction();
+		}
+		$this->_transaction_level++;
+		return $this->_transaction_level;
+	}
+	
+	/**
+	 * Roll back a transaction.
+	 * 
+	 * @return int
+	 */
+	public function rollback(): int
+	{
+		if ($this->_handle->inTransaction() && $this->_transaction_level === 1)
+		{
+			$this->_handle->rollBack();
+		}
+		$this->_transaction_level--;
+		return $this->_transaction_level;
+	}
+	
+	/**
+	 * Commit a transaction.
+	 * 
+	 * @return int
+	 */
+	public function commit(): int
+	{
+		if ($this->_handle->inTransaction() && $this->_transaction_level === 1)
+		{
+			$this->_handle->commit();
+		}
+		$this->_transaction_level--;
+		return $this->_transaction_level;
+	}
+	
+	/**
+	 * Get the number of rows affected by the last statement.
+	 * 
+	 * @return int
+	 */
+	public function getAffectedRows(): int
+	{
+		return $this->_last_stmt ? intval($this->_last_stmt->rowCount()) : 0;
+	}
+	
+	/**
+	 * Get the auto-incremented ID generated by the last statement.
+	 * 
+	 * @return int
+	 */
+	public function getInsertID(): int
+	{
+		return intval($this->_handle->lastInsertId());
+	}
+	
+	/**
+	 * Get the next global sequence value.
+	 */
+	public function getNextSequence()
+	{
+		$this->_query(sprintf('INSERT INTO `%ssequence` (seq) VALUES (0)', $this->_prefix));
+		$sequence = $this->getInsertID();
+		if($sequence % 10000 == 0)
+		{
+			$this->_query(sprintf('DELETE FROM `%ssequence` WHERE seq < %d', $this->_prefix, $sequence));
+		}
+		return $sequence;
+	}
+	
+	/**
+	 * Drop a table.
+	 * 
+	 * @param string $table_name
+	 * @return BaseObject
+	 */
+	public function dropTable(string $table_name): \BaseObject
+	{
+		return new \BaseObject;
+	}
+	
+	/**
+	 * Check if the last statement produced an error.
+	 * 
+	 * @return bool
+	 */
+	public function isError(): bool
+	{
+		return $this->_errno !== 0 ? true : false;
+	}
+	
+	/**
+	 * Get the last error information.
+	 * 
+	 * @return \BaseObject
+	 */
+	public function getError(): \BaseObject
+	{
+		return new \BaseObject($this->_errno, $this->_errstr);
+	}
+	
+	/**
+	 * Set error information to instance properties.
+	 * 
+	 * @param int $errno
+	 * @param string $errstr
+	 * @return BaseObject
+	 */
+	public function setError(int $errno = 0, string $errstr = 'success'): \BaseObject
+	{
+		$this->_errno = $errno;
+		$this->_errstr = $errstr;
+		return new \BaseObject($errno, $errstr);
+	}
+	
+	/**
+	 * Send an entry to the query log for debugging.
+	 * 
+	 * @param array $log
+	 * @return void
+	 */
+	public function setQueryLog(array $log)
+	{
+		Debug::addQuery($log);
+	}
+	
+	/**
+	 * ========================== DEPRECATED METHODS ==========================
+	 * ==================== KEPT FOR COMPATIBILITY WITH XE ====================
+	 */
+	
+	/**
+	 * Old alias to getInstance().
+	 * 
+	 * @deprecated
+	 * @return self
+	 */
+	public static function create(): self
+	{
+		return self::getInstance();
+	}
+	
+	/**
+	 * Get the list of supported database drivers.
+	 * 
+	 * @deprecated
+	 * @return array
+	 */
+	public static function getSupportedList(): array
+	{
+		return array(
+			(object)array(
+				'db_type' => 'mysql',
+				'enable' => extension_loaded('pdo_mysql'),
+			),
+		);
+	}
+   
+	/**
+	 * Get the list of enabled database drivers.
+	 * 
+	 * @deprecated
+	 * @return array
+	 */
+	public static function getEnableList(): array
+	{
+		return array_filter(self::getSupportedList(), function($item) {
+			return $item->enable;
+		});
+	}
+   
+	/**
+	 * Get the list of disabled database drivers.
+	 * 
+	 * @deprecated
+	 * @return array
+	 */
+	public static function getDisableList(): array
+	{
+		return array_filter(self::getSupportedList(), function($item) {
+			return !$item->enable;
+		});
+	}
+	
+	/**
+	 * Check if the current instance is supported.
+	 * 
+	 * @deprecated
+	 * @return bool
+	 */
+	public function isSupported(): bool
+	{
+		return true;
+	}
+	
+	/**
+	 * Check if the current instance is connected.
+	 * 
+	 * @deprecated
+	 * @return bool
+	 */
+	public function isConnected(): bool
+	{
+		return true;
+	}
+	
+	/**
+	 * Close the DB connection.
+	 * 
+	 * @deprecated
+	 * @return bool
+	 */
+	public function close(): bool
+	{
+		return true;
+	}
+	
+	/**
+	 * Methods related to the click count cache feature.
+	 * 
+	 * @deprecated
+	 * @return bool
+	 */
+	public function getCountCache(): bool
+	{
+		return false;
+	}
+	public function putCountCache(): bool
+	{
+		return false;
+	}
+	public function resetCountCache(): bool
+	{
+		return false;
+	}
+	
+	/**
+	 * Other deprecated methods.
+	 */
+	public function _getSlaveConnectionStringIndex(): int
+	{
+		return 0;
+	}
+	public function _getConnection(): \PDO
+	{
+		return $this->getHandle();
+	}
+	public function _dbInfoExists(): bool
+	{
+		return true;
+	}
+}
diff --git a/common/framework/exceptions/dberror.php b/common/framework/exceptions/dberror.php
new file mode 100644
index 000000000..2d7048ef9
--- /dev/null
+++ b/common/framework/exceptions/dberror.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Rhymix\Framework\Exceptions;
+
+/**
+ * The DB Error exception class.
+ */
+class DBError extends \Rhymix\Framework\Exception
+{
+	public function __construct($message = '', $code = 0, $previous = null)
+	{
+		if ($message === '')
+		{
+			$message = 'DB Error';
+		}
+		parent::__construct($message, $code, $previous);
+	}
+}
diff --git a/common/framework/exceptions/queryerror.php b/common/framework/exceptions/queryerror.php
index afc643788..0843f71be 100644
--- a/common/framework/exceptions/queryerror.php
+++ b/common/framework/exceptions/queryerror.php
@@ -5,7 +5,7 @@ namespace Rhymix\Framework\Exceptions;
 /**
  * The Query Error exception class.
  */
-class QueryError extends \Rhymix\Framework\Exception
+class QueryError extends DBError
 {
 	public function __construct($message = '', $code = 0, $previous = null)
 	{
diff --git a/common/legacy.php b/common/legacy.php
index 8098bb1b7..2bb87f44b 100644
--- a/common/legacy.php
+++ b/common/legacy.php
@@ -158,7 +158,7 @@ function executeQueryArray($query_id, $args = NULL, $arg_columns = NULL)
 {
 	$oDB = DB::getInstance();
 	$output = $oDB->executeQuery($query_id, $args, $arg_columns);
-	if(isset($output->data) && !is_array($output->data) && countobj($output->data) > 0)
+	if(isset($output->data) && is_object($output->data))
 	{
 		$output->data = array($output->data);
 	}