Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * Native postgresql recordset.

 *

 * @package    core_dml

 * @copyright  2008 Petr Skoda (http://skodak.org)

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

defined('MOODLE_INTERNAL') || die();

require_once(__DIR__.'/moodle_recordset.php');

/**

 * pgsql specific moodle recordset class

 *

 * @package    core_dml

 * @copyright  2008 Petr Skoda (http://skodak.org)

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class pgsql_native_moodle_recordset extends moodle_recordset {

    /** @var PgSql\Result|resource|null */

    protected $result;

    /** @var current row as array.*/

    protected $current;

    protected $blobs = array();

    /** @var string Name of cursor or '' if none */

    protected $cursorname;

    /** @var pgsql_native_moodle_database Postgres database resource */

    protected $db;

    /** @var bool True if there are no more rows to fetch from the cursor */

    protected $lastbatch;

    /**

     * Build a new recordset to iterate over.

     *

     * When using cursors, $result will be null initially.

     *

     * @param resource|PgSql\Result|null $result A pg_query() result object to create a recordset from.

     * @param pgsql_native_moodle_database $db Database object (only required when using cursors)

     * @param string $cursorname Name of cursor or '' if none

     */

    public function __construct($result, pgsql_native_moodle_database $db = null, $cursorname = '') {

        if ($cursorname && !$db) {

            throw new coding_exception('When specifying a cursor, $db is required');

        }

        $this->result = $result;

        $this->db = $db;

        $this->cursorname = $cursorname;

        // When there is a cursor, do the initial fetch.

        if ($cursorname) {

            $this->fetch_cursor_block();

        }

        // Find out if there are any blobs.

        $numfields = pg_num_fields($this->result);

        for ($i = 0; $i < $numfields; $i++) {

            $type = $this->db->pg_field_type($this->result, $i);

            if ($type == 'bytea') {

                $this->blobs[] = pg_field_name($this->result, $i);

            }

        }

        $this->current = $this->fetch_next();

    }

    /**

     * Fetches the next block of data when using cursors.

     *

     * @throws coding_exception If you call this when the fetch buffer wasn't freed yet

     */

    protected function fetch_cursor_block() {

        if ($this->result) {

            throw new coding_exception('Unexpected non-empty result when fetching from cursor');

        }

        list($this->result, $this->lastbatch) = $this->db->fetch_from_cursor($this->cursorname);

        if (!$this->result) {

            throw new coding_exception('Unexpected failure when fetching from cursor');

        }

    }

    public function __destruct() {

        $this->close();

    }

    private function fetch_next() {

        if (!$this->result) {

            return false;

        }

        if (!$row = pg_fetch_assoc($this->result)) {

            // There are no more rows in this result.

            pg_free_result($this->result);

            $this->result = null;

            // If using a cursor, can we fetch the next block?

            if ($this->cursorname && !$this->lastbatch) {

                $this->fetch_cursor_block();

                if (!$row = pg_fetch_assoc($this->result)) {

                    pg_free_result($this->result);

                    $this->result = null;

                    return false;

                }

            } else {

                return false;

            }

        }

        if ($this->blobs) {

            foreach ($this->blobs as $blob) {

                $row[$blob] = $row[$blob] !== null ? pg_unescape_bytea($row[$blob]) : null;

            }

        }

        return $row;

    }

    public function current(): stdClass {

        return (object)$this->current;

    }

    #[\ReturnTypeWillChange]

    public function key() {

        // return first column value as key

        if (!$this->current) {

            return false;

        }

        $key = reset($this->current);

        return $key;

    }

    public function next(): void {

        $this->current = $this->fetch_next();

    }

    public function valid(): bool {

        return !empty($this->current);

    }

    public function close() {

        if ($this->result) {

            pg_free_result($this->result);

            $this->result  = null;

        }

        $this->current = null;

        $this->blobs   = null;

        // If using cursors, close the cursor.

        if ($this->cursorname) {

            $this->db->close_cursor($this->cursorname);

            $this->cursorname = null;

        }

    }

}