SimplePie_Cache_MySQL::save

	 * Save data to the cache
	 *
	 * @param array|SimplePie $data Data to store in the cache. If passed a SimplePie object, only cache the $data property
	 * @return bool Successfulness
	 */
	public function save($data)
	{
		if ($this->mysql === null)
		{
			return false;
		}

		$query = $this->mysql->prepare('DELETE i, cd FROM `' . $this->options['extras']['prefix'] . 'cache_data` cd, ' .
			'`' . $this->options['extras']['prefix'] . 'items` i ' .
			'WHERE cd.id = i.feed_id ' .
			'AND cd.mtime < (unix_timestamp() - :purge_time)');
		$query->bindValue(':purge_time', $this->options['extras']['cache_purge_time']);

		if (!$query->execute())
		{
			return false;
		}

		if ($data instanceof SimplePie)
		{
			$data = clone $data;

			$prepared = self::prepare_simplepie_object_for_cache($data);

			$query = $this->mysql->prepare('SELECT COUNT(*) FROM `' . $this->options['extras']['prefix'] . 'cache_data` WHERE `id` = :feed');
			$query->bindValue(':feed', $this->id);
			if ($query->execute())
			{
				if ($query->fetchColumn() > 0)
				{
					$items = count($prepared[1]);
					if ($items)
					{
						$sql = 'UPDATE `' . $this->options['extras']['prefix'] . 'cache_data` SET `items` = :items, `data` = :data, `mtime` = :time WHERE `id` = :feed';
						$query = $this->mysql->prepare($sql);
						$query->bindValue(':items', $items);
					}
					else
					{
						$sql = 'UPDATE `' . $this->options['extras']['prefix'] . 'cache_data` SET `data` = :data, `mtime` = :time WHERE `id` = :feed';
						$query = $this->mysql->prepare($sql);
					}

					$query->bindValue(':data', $prepared[0]);
					$query->bindValue(':time', time());
					$query->bindValue(':feed', $this->id);
					if (!$query->execute())
					{
						return false;
					}
				}
				else
				{
					$query = $this->mysql->prepare('INSERT INTO `' . $this->options['extras']['prefix'] . 'cache_data` (`id`, `items`, `data`, `mtime`) VALUES(:feed, :count, :data, :time)');
					$query->bindValue(':feed', $this->id);
					$query->bindValue(':count', count($prepared[1]));
					$query->bindValue(':data', $prepared[0]);
					$query->bindValue(':time', time());
					if (!$query->execute())
					{
						return false;
					}
				}

				$ids = array_keys($prepared[1]);
				if (!empty($ids))
				{
					foreach ($ids as $id)
					{
						$database_ids[] = $this->mysql->quote($id);
					}

					$query = $this->mysql->prepare('SELECT `id` FROM `' . $this->options['extras']['prefix'] . 'items` WHERE `id` = ' . implode(' OR `id` = ', $database_ids) . ' AND `feed_id` = :feed');
					$query->bindValue(':feed', $this->id);

					if ($query->execute())
					{
						$existing_ids = array();
						while ($row = $query->fetchColumn())
						{
							$existing_ids[] = $row;
						}

						$new_ids = array_diff($ids, $existing_ids);

						foreach ($new_ids as $new_id)
						{
							if (!($date = $prepared[1][$new_id]->get_date('U')))
							{
								$date = time();
							}

							$query = $this->mysql->prepare('INSERT INTO `' . $this->options['extras']['prefix'] . 'items` (`feed_id`, `id`, `data`, `posted`) VALUES(:feed, :id, :data, :date)');
							$query->bindValue(':feed', $this->id);
							$query->bindValue(':id', $new_id);
							$query->bindValue(':data', serialize($prepared[1][$new_id]->data));
							$query->bindValue(':date', $date);
							if (!$query->execute())
							{
								return false;
							}
						}
						return true;
					}
				}
				else
				{
					return true;
				}
			}
		}
		else
		{
			$query = $this->mysql->prepare('SELECT `id` FROM `' . $this->options['extras']['prefix'] . 'cache_data` WHERE `id` = :feed');
			$query->bindValue(':feed', $this->id);
			if ($query->execute())
			{
				if ($query->rowCount() > 0)
				{
					$query = $this->mysql->prepare('UPDATE `' . $this->options['extras']['prefix'] . 'cache_data` SET `items` = 0, `data` = :data, `mtime` = :time WHERE `id` = :feed');
					$query->bindValue(':data', serialize($data));
					$query->bindValue(':time', time());
					$query->bindValue(':feed', $this->id);
					if ($this->execute())
					{
						return true;
					}