Numerous improvements to the Oracle (oci8) driver and DB_driver
diff --git a/system/database/drivers/oci8/oci8_result.php b/system/database/drivers/oci8/oci8_result.php
index 0f69fa9..cbf4bec 100644
--- a/system/database/drivers/oci8/oci8_result.php
+++ b/system/database/drivers/oci8/oci8_result.php
@@ -1,13 +1,13 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 5.1.6 or newer
  *
  * NOTICE OF LICENSE
- * 
+ *
  * Licensed under the Open Software License version 3.0
- * 
+ *
  * This source file is subject to the Open Software License (OSL 3.0) that is
  * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
@@ -38,31 +38,40 @@
  */
 class CI_DB_oci8_result extends CI_DB_result {
 
-	var $stmt_id;
-	var $curs_id;
-	var $limit_used;
+	public $stmt_id;
+	public $curs_id;
+	public $limit_used;
+
+	// This will be changed by CI_DB_driver, but it's good to have a default:
+	public $commit_mode = OCI_DEFAULT;
+
+	/* Overwriting the parent here, so we have a way to know if it's
+	 * already called or not:
+	 */
+	public $num_rows;
 
 	/**
 	 * Number of rows in the result set.
 	 *
-	 * Oracle doesn't have a graceful way to retun the number of rows
+	 * Oracle doesn't have a graceful way to return the number of rows
 	 * so we have to use what amounts to a hack.
 	 *
-	 *
-	 * @access  public
 	 * @return  integer
 	 */
 	public function num_rows()
 	{
-		if ($this->num_rows === 0 && count($this->result_array()) > 0)
+		if ( ! is_int($this->num_rows))
 		{
-			$this->num_rows = count($this->result_array());
-			@oci_execute($this->stmt_id, OCI_DEFAULT);
-
-			if ($this->curs_id)
+			if (count($this->result_array) > 0)
 			{
-				@oci_execute($this->curs_id, OCI_DEFAULT);
+				return $this->num_rows = count($this->result_array);
 			}
+			elseif (count($this->result_object) > 0)
+			{
+				return $this->num_rows = count($this->result_array);
+			}
+
+			return $this->num_rows = count($this->result_array());
 		}
 
 		return $this->num_rows;
@@ -73,7 +82,6 @@
 	/**
 	 * Number of fields in the result set
 	 *
-	 * @access  public
 	 * @return  integer
 	 */
 	public function num_fields()
@@ -83,7 +91,7 @@
 		// if we used a limit we subtract it
 		if ($this->limit_used)
 		{
-			$count = $count - 1;
+			return $count - 1;
 		}
 
 		return $count;
@@ -96,7 +104,6 @@
 	 *
 	 * Generates an array of column names
 	 *
-	 * @access	public
 	 * @return	array
 	 */
 	public function list_fields()
@@ -116,7 +123,6 @@
 	 *
 	 * Generates an array of objects containing field meta-data
 	 *
-	 * @access  public
 	 * @return  array
 	 */
 	public function field_data()
@@ -140,7 +146,7 @@
 	/**
 	 * Free the result
 	 *
-	 * @return	null
+	 * @return	void
 	 */
 	public function free_result()
 	{
@@ -149,6 +155,17 @@
 			oci_free_statement($this->result_id);
 			$this->result_id = FALSE;
 		}
+
+		if (is_resource($this->stmt_id))
+		{
+			oci_free_statement($this->stmt_id);
+		}
+
+		if (is_resource($this->curs_id))
+		{
+			oci_cancel($this->curs_id);
+			$this->curs_id = NULL;
+		}
 	}
 
 	// --------------------------------------------------------------------
@@ -158,7 +175,6 @@
 	 *
 	 * Returns the result set as an array
 	 *
-	 * @access  protected
 	 * @return  array
 	 */
 	protected function _fetch_assoc()
@@ -174,22 +190,47 @@
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @access  protected
 	 * @return  object
 	 */
 	protected function _fetch_object()
 	{
 		$id = ($this->curs_id) ? $this->curs_id : $this->stmt_id;
-		return @oci_fetch_object($id);
+		return oci_fetch_object($id);
+	}
+
+	// --------------------------------------------------------------------
+
+	/* Query result
+	 *
+	 * Acts as a wrapper for result_array(), result_object()
+	 * and custom_result_object().
+	 *
+	 * @param	string	('object', 'array' or a custom class name)
+	 * @return	array
+	 */
+
+	public function result($type = 'object')
+	{
+		if ($type === 'object')
+		{
+			return $this->result_object();
+		}
+		elseif ($type === 'array')
+		{
+			return $this->result_array();
+		}
+		else
+		{
+			return $this->custom_result_object($type);
+		}
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Query result.  "array" version.
+	 * Query result. "array" version.
 	 *
-	 * @access  public
-	 * @return  array
+	 * @return	array
 	 */
 	public function result_array()
 	{
@@ -197,14 +238,488 @@
 		{
 			return $this->result_array;
 		}
+		elseif (count($this->result_object) > 0)
+		{
+			for ($i = 0, $c = count($this->result_object); $i < $c; $i++)
+			{
+				$this->result_array[$i] = (array) $this->result_object[$i];
+			}
+
+			return $this->result_array;
+		}
+		elseif (is_array($this->row_data))
+		{
+			if (count($this->row_data) === 0)
+			{
+				return $this->result_array;
+			}
+			else
+			{
+				$row_index = count($this->row_data);
+			}
+		}
+		else
+		{
+			$row_index = 0;
+			$this->row_data = array();
+		}
 
 		$row = NULL;
 		while ($row = $this->_fetch_assoc())
 		{
-			$this->result_array[] = $row;
+			$this->row_data[$row_index++] = $row;
 		}
 
-		return $this->result_array;
+		// Un-comment the following line, in case it becomes needed
+		// $this->_data_seek();
+		return $this->result_array = $this->row_data;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Query result. "object" version.
+	 *
+	 * @return	array
+	 */
+	public function result_object()
+	{
+		if (count($this->result_object) > 0)
+		{
+			return $this->result_object;
+		}
+		elseif (count($this->result_array) > 0)
+		{
+			for ($i = 0, $c = count($this->result_array); $i < $c; $i++)
+			{
+				$this->result_object[] = (object) $this->result_array[$i];
+			}
+
+			return $this->result_object;
+		}
+		elseif (is_array($this->row_data))
+		{
+			if (count($this->row_data) === 0)
+			{
+				return $this->result_object;
+			}
+			else
+			{
+				$row_index = count($this->row_data);
+				for ($i = 0; $i < $row_index; $i++)
+				{
+					$this->result_object[$i] = (object) $this->row_data[$i];
+				}
+			}
+		}
+		else
+		{
+			$row_index = 0;
+			$this->row_data = array();
+		}
+
+		$row = NULL;
+		while ($row = $this->_fetch_object())
+		{
+			$this->row_data[$row_index] = (array) $row;
+			$this->result_object[$row_index++] = $row;
+		}
+
+		// Un-comment the following line, in case it becomes needed
+		// $this->_data_seek();
+		return $this->result_object;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Query result. Custom object version.
+	 *
+	 * @param	string	class name used to instantiate rows to
+	 * @return	array
+	 */
+	public function custom_result_object($class_name)
+	{
+		if (array_key_exists($class_name, $this->custom_result_object))
+		{
+			return $this->custom_result_object[$class_name];
+		}
+
+		if ( ! class_exists($class_name) OR $this->result_id === FALSE OR $this->num_rows() === 0)
+		{
+			return array();
+		}
+
+		// add the data to the object
+		$result_object = array();
+		$data = NULL;
+
+		/* First check if we don't already have the data.
+		 * If so - pass by reference, as we don't know how
+		 * large it might be and we don't want 1000 row
+		 * sets being copied.
+		 */
+		if (count($this->result_array) > 0)
+		{
+			$data = &$this->result_array;
+		}
+		elseif (count($this->result_object) > 0)
+		{
+			$data = &$this->result_object;
+		}
+
+		if ( ! is_null($data))
+		{
+			for ($i = 0, $c = count($data); $i < $c; $i++)
+			{
+				$result_object[$i] = new $class_name();
+				foreach ($data[$i] as $key => $value)
+				{
+					$result_object[$i]->$key = $value;
+				}
+			}
+		}
+		else
+		{
+			// No prefetched result set
+			if (is_array($this->row_data))
+			{
+				$row_index = count($this->row_data);
+				if ($row_index === 0)
+				{
+					return array();
+				}
+				else
+				{
+					for ($i = 0; $i < $row_index; $i++)
+					{
+						$result_object[$i] = new $class_name();
+						foreach ($this->row_data[$i] as $key => $value)
+						{
+							$result_object[$i]->$key = $value;
+						}
+					}
+				}
+			}
+			else
+			{
+				$row_index = 0;
+				$this->row_data = array();
+			}
+
+			while ($row = $this->_fetch_assoc())
+			{
+				$data = new $class_name();
+				foreach ($row as $key => $value)
+				{
+					$data->$key = $value;
+				}
+
+				$this->row_data[$row_index] = $row;
+				$result_object[$row_index++] = $data;
+			}
+			// Un-comment the following line, in case it becomes needed
+			// $this->_data_seek();
+		}
+
+		/* As described for the num_rows() method - there's no easy
+		 * way to get the number of rows selected. Our work-around
+		 * solution (as in here as well) first checks if result_array
+		 * or result_object exist and returns their count. It doesn't
+		 * however check for a custom_object_result, so - do it here.
+		 */
+		if ( ! is_int($this->num_rows))
+		{
+			$this->num_rows = count($result_object);
+		}
+
+		// Cache and return the array
+		return $this->custom_result_object[$class_name] = $result_object;
+        }
+
+	// --------------------------------------------------------------------
+
+	/* Single row result.
+	 *
+	 * Acts as a wrapper for row_object(), row_array()
+	 * and custom_row_object(). Also used by first_row(), next_row()
+	 * and previous_row().
+	 *
+	 * @param	int	row index
+	 * @param	string	('object', 'array' or a custom class name)
+	 * @return	mixed	whatever was passed to the second parameter
+	 */
+
+	public function row($n = 0, $type = 'object')
+	{
+		if ($type === 'object') return $this->row_object($n);
+		elseif ($type === 'array') return $this->row_array($n);
+		else return $this->custom_row_object($n, $type);
+	}
+
+	// --------------------------------------------------------------------
+
+	/* Single row result. Array version.
+	 *
+	 * @param	int	row index
+	 * @return	array
+	 */
+
+	public function row_array($n = 0)
+	{
+		// Make sure $n is not a string
+		if ( ! is_int($n))
+		{
+			$n = (int) $n;
+		}
+
+		/* If row_data is initialized, it means that we've already tried
+		 * (at least) to fetch some data, so ... check if we already have
+		 * this row.
+		*/
+		if (is_array($this->row_data))
+		{
+			/* If we already have row_data[$n] - return it.
+			 *
+			 * If we enter the elseif, there's a number of reasons to
+			 * return an empty array:
+			 *
+			 *	- count($this->row_data) === 0 means there are no results
+			 *	- num_rows being set, result_array and/or result_object
+			 *	  having count() > 0 means that we've already fetched all
+			 *	  data and $n is greater than our highest row index available
+			 *	- $n < $this->current_row means that if such row existed,
+			 *	  we would've already returned it, therefore $n is an
+			 *	  invalid index
+			 */
+			if (isset($this->row_data[$n])) // We already have this row
+			{
+				$this->current_row = $n;
+				return $this->row_data[$n];
+			}
+			elseif (count($this->row_data) === 0 OR is_int($this->num_rows)
+				OR count($this->result_array) > 0 OR count($this->result_object) > 0
+				OR $n < $this->current_row)
+			{
+				// No such row exists
+				return array();
+			}
+
+			// Get the next row index that would actually need to be fetched
+			$current_row = ($this->current_row < count($this->row_data)) ? count($this->row_data) : $this->current_row + 1;
+		}
+		else
+		{
+			$current_row = $this->current_row = 0;
+			$this->row_data = array();
+		}
+
+		/* Fetch more data, if available
+		 *
+		 * NOTE: Operator precedence is important here, if you change
+		 *	 'AND' with '&&' - it WILL BREAK the results, as
+		 *	 $row will be assigned the scalar value of both
+		 *	 expressions!
+		 */
+		while ($row = $this->_fetch_assoc() AND $current_row <= $n)
+		{
+			$this->row_data[$current_row++] = $row;
+		}
+
+		// This would mean that there's no (more) data to fetch
+		if ( ! is_array($this->row_data) OR ! isset($this->row_data[$n]))
+		{
+			// Cache what we already have
+			if (is_array($this->row_data))
+			{
+				$this->num_rows = count($this->row_data);
+				/* Usually, row_data could have less elements than result_array,
+				 * but at this point - they should be exactly the same.
+				 */
+				$this->result_array = $this->row_data;
+			}
+			else
+			{
+				$this->num_rows = 0;
+			}
+
+			return array();
+		}
+
+		$this->current_row = $n;
+		return $this->row_data[$n];
+	}
+
+	// --------------------------------------------------------------------
+
+	/* Single row result. Object version.
+	 *
+	 * @param	int	row index
+	 * @return	mixed	object if row found; empty array if not
+	 */
+	public function row_object($n = 0)
+	{
+		// Make sure $n is not a string
+		if ( ! is_int($n))
+		{
+			$n = (int) $n;
+		}
+		/* Logic here is exactly the same as in row_array,
+		 * except we have to cast row_data[$n] to an object.
+		 *
+		 * If we already have result_object though - we can
+		 * directly return from it.
+		 */
+		if (isset($this->result_object[$n]))
+		{
+			$this->current_row = $n;
+			// Set this, if not already done.
+			if ( ! is_int($this->num_rows))
+			{
+				$this->num_rows = count($this->result_object);
+			}
+
+			return $this->result_object[$n];
+		}
+
+		$row = $this->row_array($n);
+		// Cast only if the row exists
+		if (count($row) > 0)
+		{
+			$this->current_row = $n;
+			return (object) $row;
+		}
+
+		return array();
+	}
+
+	// --------------------------------------------------------------------
+
+	/* Single row result. Custom object version.
+	 *
+	 * @param	int	row index
+	 * @param	string	custom class name
+	 * @return	mixed	custom object if row found; empty array otherwise
+	 */
+
+	public function custom_row_object($n = 0, $class_name)
+	{
+		// Make sure $n is not a string
+		if ( ! is_int($n))
+		{
+			$n = (int) $n;
+		}
+
+		if (array_key_exists($class_name, $this->custom_result_object))
+		{
+			/* We already have a the whole result set with this class_name,
+			 * return the specified row if it exists, and an empty array if
+			 * it doesn't.
+			 */
+			if (isset($this->custom_result_object[$class_name][$n]))
+			{
+				$this->current_row = $n;
+				return $this->custom_result_object[$class_name][$n];
+			}
+			else
+			{
+				return array();
+			}
+		}
+		elseif ( ! class_exists($class_name)) // No such class exists
+		{
+			return array();
+		}
+
+		$row = $this->row_array($n);
+		// An array would mean that the row doesn't exist
+		if (is_array($row))
+		{
+			return $row;
+		}
+
+		// Convert to the desired class and return
+		$row_object = new $class_name();
+		foreach ($row as $key => $value)
+		{
+			$row_object->$key = $value;
+		}
+
+		$this->current_row = $n;
+		return $row_object;
+	}
+
+	// --------------------------------------------------------------------
+
+	/* First row result.
+	 *
+	 * @param	string	('object', 'array' or a custom class name)
+	 * @return	mixed	whatever was passed to the second parameter
+	 */
+
+	public function first_row($type = 'object')
+	{
+		return $this->row(0, $type);
+	}
+
+	// --------------------------------------------------------------------
+
+	/* Last row result.
+	 *
+	 * @param	string	('object', 'array' or a custom class name)
+	 * @return	mixed	whatever was passed to the second parameter
+	 */
+	public function last_row($type = 'object')
+	{
+		$result = &$this->result($type);
+		if ( ! isset($this->num_rows))
+		{
+			$this->num_rows = count($result);
+		}
+		$this->current_row = $this->num_rows - 1;
+		return $result[$this->current_row];
+	}
+
+	// --------------------------------------------------------------------
+
+	/* Next row result.
+	 *
+	 * @param	string	('object', 'array' or a custom class name)
+	 * @return	mixed	whatever was passed to the second parameter
+	 */
+	public function next_row($type = 'object')
+	{
+		if (is_array($this->row_data))
+		{
+			$count = count($this->row_data);
+			if ($this->current_row > $count OR ($this->current_row === 0 && $count === 0))
+			{
+				$n = $count;
+			}
+			else
+			{
+				$n = $this->current_row + 1;
+			}
+		}
+		else
+		{
+			$n = 0;
+		}
+
+		return $this->row($n, $type);
+	}
+
+	// --------------------------------------------------------------------
+
+	/* Previous row result.
+	 *
+	 * @param	string	('object', 'array' or a custom class name)
+	 * @return	mixed	whatever was passed to the second parameter
+	 */
+	public function previous_row($type = 'object')
+	{
+		$n = ($this->current_row !== 0) ? $this->current_row - 1 : 0;
+		return $this->row($n, $type);
 	}
 
 	// --------------------------------------------------------------------
@@ -212,20 +727,59 @@
 	/**
 	 * Data Seek
 	 *
-	 * Moves the internal pointer to the desired offset.  We call
+	 * Moves the internal pointer to the desired offset. We call
 	 * this internally before fetching results to make sure the
-	 * result set starts at zero
+	 * result set starts at zero.
 	 *
-	 * @access	protected
-	 * @return	array
+	 * Oracle's PHP extension doesn't have an easy way of doing this
+	 * and the only workaround is to (re)execute the statement or cursor
+	 * in order to go to the first (zero) index of the result set.
+	 * Then, we would need to "dummy" fetch ($n - 1) rows to get to the
+	 * right one.
+	 *
+	 * This is as ridiculous as it sounds and it's the reason why every
+	 * other method that is fetching data tries to use an already "cached"
+	 * result set. Keeping this just in case it becomes needed at
+	 * some point in the future, but it will only work for resetting the
+	 * pointer to zero.
+	 *
+	 * @return	bool
 	 */
-	protected function _data_seek($n = 0)
+	protected function _data_seek()
 	{
-		return FALSE; // Not needed
+		/* The PHP manual says that if OCI_NO_AUTO_COMMIT mode
+		 * is used, and oci_rollback() and/or oci_commit() are
+		 * not subsequently called - this will cause an unnecessary
+		 * rollback to be triggered at the end of the script execution.
+		 *
+		 * Therefore we'll try to avoid using that mode flag
+		 * if we're not currently in the middle of a transaction.
+		 */
+		if ($this->commit_mode !== OCI_COMMIT_ON_SUCCESS)
+		{
+			$result = @oci_execute($this->stmt_id, $this->commit_mode);
+		}
+		else
+		{
+			$result = @oci_execute($this->stmt_id);
+		}
+
+		if ($result && $this->curs_id)
+		{
+			if ($this->commit_mode !== OCI_COMMIT_ON_SUCCESS)
+			{
+				return @oci_execute($this->curs_id, $this->commit_mode);
+			}
+			else
+			{
+				return @oci_execute($this->curs_id);
+			}
+		}
+
+		return $result;
 	}
 
 }
 
-
 /* End of file oci8_result.php */
 /* Location: ./system/database/drivers/oci8/oci8_result.php */