<?php
/**
*
* This file is part of the phpBB Forum Software package.
*
* @copyright (c) phpBB Limited <https://www.phpbb.com>
* @license GNU General Public License, version 2 (GPL-2.0)
*
* For full copyright and license information, please see
* the docs/CREDITS.txt file.
*
*/
namespace phpbb\db;
/**
* Collects rows for insert into a database until the buffer size is reached.
* Then flushes the buffer to the database and starts over again.
*
* Benefits over collecting a (possibly huge) insert array and then using
* $db->sql_multi_insert() include:
*
* - Going over max packet size of the database connection is usually prevented
* because the data is submitted in batches.
*
* - Reaching database connection timeout is usually prevented because
* submission of batches talks to the database every now and then.
*
* - Usage of less PHP memory because data no longer needed is discarded on
* buffer flush.
*
* Attention:
* Please note that users of this class have to call flush() to flush the
* remaining rows to the database after their batch insert operation is
* finished.
*
* Usage:
* <code>
* $buffer = new \phpbb\db\sql_insert_buffer($db, 'test_table', 1234);
*
* while (do_stuff())
* {
* $buffer->insert(array(
* 'column1' => 'value1',
* 'column2' => 'value2',
* ));
* }
*
* $buffer->flush();
* </code>
*/
class sql_insert_buffer
{
/** @var \phpbb\db\driver\driver_interface */
protected $db;
/** @var string */
protected $table_name;
/** @var int */
protected $max_buffered_rows;
/** @var array */
protected $buffer = array();
/**
* @param \phpbb\db\driver\driver_interface $db
* @param string $table_name
* @param int $max_buffered_rows
*/
public function __construct(\phpbb\db\driver\driver_interface $db, $table_name, $max_buffered_rows = 500)
{
$this->db = $db;
$this->table_name = $table_name;
$this->max_buffered_rows = $max_buffered_rows;
}
/**
* Inserts a single row into the buffer if multi insert is supported by the
* database (otherwise an insert query is sent immediately). Then flushes
* the buffer if the number of rows in the buffer is now greater than or
* equal to $max_buffered_rows.
*
* @param array $row
*
* @return bool True when some data was flushed to the database.
* False otherwise.
*/
public function insert(array $row)
{
$this->buffer[] = $row;
// Flush buffer if it is full or when DB does not support multi inserts.
// In the later case, the buffer will always only contain one row.
if (!$this->db->get_multi_insert() || count($this->buffer) >= $this->max_buffered_rows)
{
return $this->flush();
}
return false;
}
/**
* Inserts a row set, i.e. an array of rows, by calling insert().
*
* Please note that it is in most cases better to use insert() instead of
* first building a huge rowset. Or at least count($rows) should be kept
* small.
*
* @param array $rows
*
* @return bool True when some data was flushed to the database.
* False otherwise.
*/
public function insert_all(array $rows)
{
// Using bitwise |= because PHP does not have logical ||=
$result = 0;
foreach ($rows as $row)
{
$result |= (int) $this->insert($row);
}
return (bool) $result;
}
/**
* Flushes the buffer content to the DB and clears the buffer.
*
* @return bool True when some data was flushed to the database.
* False otherwise.
*/
public function flush()
{
if (!empty($this->buffer))
{
$this->db->sql_multi_insert($this->table_name, $this->buffer);
$this->buffer = array();
return true;
}
return false;
}
}