<?php
declare(strict_types=1);
namespace PhpMyAdmin\SqlParser\Statements;
use PhpMyAdmin\SqlParser\Components\Expression;
use PhpMyAdmin\SqlParser\Parser;
use PhpMyAdmin\SqlParser\Statement;
use PhpMyAdmin\SqlParser\Token;
use PhpMyAdmin\SqlParser\TokensList;
use function in_array;
use function trim;
/**
* `PURGE` statement.
*
* PURGE { BINARY | MASTER } LOGS
* { TO 'log_name' | BEFORE datetime_expr }
*/
class PurgeStatement extends Statement
{
/**
* The type of logs
*
* @var string|null
*/
public $log_type;
/**
* The end option of this query.
*
* @var string|null
*/
public $end_option;
/**
* The end expr of this query.
*
* @var string|null
*/
public $end_expr;
/**
* @return string
*/
public function build()
{
$ret = 'PURGE ' . $this->log_type . ' LOGS '
. ($this->end_option !== null ? ($this->end_option . ' ' . $this->end_expr) : '');
return trim($ret);
}
/**
* @param Parser $parser the instance that requests parsing
* @param TokensList $list the list of tokens to be parsed
*/
public function parse(Parser $parser, TokensList $list)
{
++$list->idx; // Skipping `PURGE`.
/**
* The state of the parser.
*
* @var int
*/
$state = 0;
$prevToken = null;
for (; $list->idx < $list->count; ++$list->idx) {
/**
* Token parsed at this moment.
*/
$token = $list->tokens[$list->idx];
// End of statement.
if ($token->type === Token::TYPE_DELIMITER) {
break;
}
// Skipping whitespaces and comments.
if (($token->type === Token::TYPE_WHITESPACE) || ($token->type === Token::TYPE_COMMENT)) {
continue;
}
switch ($state) {
case 0:
// parse `{ BINARY | MASTER }`
$this->log_type = self::parseExpectedKeyword($parser, $token, ['BINARY', 'MASTER']);
break;
case 1:
// parse `LOGS`
self::parseExpectedKeyword($parser, $token, ['LOGS']);
break;
case 2:
// parse `{ TO | BEFORE }`
$this->end_option = self::parseExpectedKeyword($parser, $token, ['TO', 'BEFORE']);
break;
case 3:
// parse `expr`
$this->end_expr = Expression::parse($parser, $list, []);
break;
default:
$parser->error('Unexpected token.', $token);
break;
}
$state++;
$prevToken = $token;
}
// Only one possible end state
if ($state === 4) {
return;
}
$parser->error('Unexpected token.', $prevToken);
}
/**
* Parse expected keyword (or throw relevant error)
*
* @param Parser $parser the instance that requests parsing
* @param Token $token token to be parsed
* @param string[] $expectedKeywords array of possibly expected keywords at this point
*
* @return mixed|null
*/
private static function parseExpectedKeyword($parser, $token, $expectedKeywords)
{
if ($token->type === Token::TYPE_KEYWORD) {
if (in_array($token->keyword, $expectedKeywords)) {
return $token->keyword;
}
$parser->error('Unexpected keyword', $token);
} else {
$parser->error('Unexpected token.', $token);
}
return null;
}
}