Michael RICOIS f46be40623 Init
2017-06-07 16:31:24 +02:00

222 lines
9.5 KiB
PHP

<?php
/**
* position-calculator.php
*
* This file implements the calculator for the position elements of
* the output of the PHPSQLParser.
*
* Copyright (c) 2010-2012, Justin Swanhart
* with contributions by André Rothe <arothe@phosco.info, phosco@gmx.de>
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
* SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*/
require_once dirname(__FILE__) . '/../utils/PHPSQLParserConstants.php';
require_once dirname(__FILE__) . '/../exceptions/UnableToCalculatePositionException.php';
/**
* This class calculates the positions
* of base_expr within the original SQL statement.
*
* @author arothe <andre.rothe@phosco.info>
*
*/
class PositionCalculator {
private static $_allowedOnOperator = array("\t", "\n", "\r", " ", ",", "(", ")", "_", "'", "\"");
private static $_allowedOnOther = array("\t", "\n", "\r", " ", ",", "(", ")", "<", ">", "*", "+", "-", "/", "|",
"&", "=", "!", ";");
private function _printPos($text, $sql, $charPos, $key, $parsed, $backtracking) {
if (!isset($_ENV['DEBUG'])) {
return;
}
$spaces = "";
$caller = debug_backtrace();
$i = 1;
while ($caller[$i]['function'] === 'lookForBaseExpression') {
$spaces .= " ";
$i++;
}
$holdem = substr($sql, 0, $charPos) . "^" . substr($sql, $charPos);
echo $spaces . $text . " key:" . $key . " parsed:" . $parsed . " back:" . serialize($backtracking) . " "
. $holdem . "\n";
}
public function setPositionsWithinSQL($sql, $parsed) {
$charPos = 0;
$backtracking = array();
$this->lookForBaseExpression($sql, $charPos, $parsed, 0, $backtracking);
return $parsed;
}
private function findPositionWithinString($sql, $value, $expr_type) {
$offset = 0;
$ok = false;
while (true) {
$pos = strpos($sql, $value, $offset);
if ($pos === false) {
break;
}
$before = "";
if ($pos > 0) {
$before = $sql[$pos - 1];
}
$after = "";
if (isset($sql[$pos + strlen($value)])) {
$after = $sql[$pos + strlen($value)];
}
// if we have an operator, it should be surrounded by
// whitespace, comma, parenthesis, digit or letter, end_of_string
// an operator should not be surrounded by another operator
if ($expr_type === 'operator') {
$ok = ($before === "" || in_array($before, self::$_allowedOnOperator, true))
|| (strtolower($before) >= 'a' && strtolower($before) <= 'z') || ($before >= '0' && $before <= '9');
$ok = $ok
&& ($after === "" || in_array($after, self::$_allowedOnOperator, true)
|| (strtolower($after) >= 'a' && strtolower($after) <= 'z') || ($after >= '0' && $after <= '9')
|| ($after === '?') || ($after === '@'));
if (!$ok) {
$offset = $pos + 1;
continue;
}
break;
}
// in all other cases we accept
// whitespace, comma, operators, parenthesis and end_of_string
$ok = ($before === "" || in_array($before, self::$_allowedOnOther, true));
$ok = $ok && ($after === "" || in_array($after, self::$_allowedOnOther, true));
if ($ok) {
break;
}
$offset = $pos + 1;
}
return $pos;
}
private function lookForBaseExpression($sql, &$charPos, &$parsed, $key, &$backtracking) {
if (!is_numeric($key)) {
if (($key === 'UNION' || $key === 'UNION ALL')
|| ($key === 'expr_type' && $parsed === ExpressionType::EXPRESSION)
|| ($key === 'expr_type' && $parsed === ExpressionType::SUBQUERY)
|| ($key === 'expr_type' && $parsed === ExpressionType::BRACKET_EXPRESSION)
|| ($key === 'expr_type' && $parsed === ExpressionType::TABLE_EXPRESSION)
|| ($key === 'expr_type' && $parsed === ExpressionType::RECORD)
|| ($key === 'expr_type' && $parsed === ExpressionType::IN_LIST)
|| ($key === 'expr_type' && $parsed === ExpressionType::MATCH_ARGUMENTS)
|| ($key === 'expr_type' && $parsed === ExpressionType::TABLE)
|| ($key === 'expr_type' && $parsed === ExpressionType::TEMPORARY_TABLE)
|| ($key === 'expr_type' && $parsed === ExpressionType::COLUMN_TYPE)
|| ($key === 'expr_type' && $parsed === ExpressionType::COLDEF)
|| ($key === 'expr_type' && $parsed === ExpressionType::PRIMARY_KEY)
|| ($key === 'expr_type' && $parsed === ExpressionType::CONSTRAINT)
|| ($key === 'expr_type' && $parsed === ExpressionType::COLUMN_LIST)
|| ($key === 'expr_type' && $parsed === ExpressionType::CHECK)
|| ($key === 'expr_type' && $parsed === ExpressionType::COLLATE)
|| ($key === 'expr_type' && $parsed === ExpressionType::LIKE)
|| ($key === 'expr_type' && $parsed === ExpressionType::INDEX)
|| ($key === 'select-option' && $parsed !== false) || ($key === 'alias' && $parsed !== false)) {
// we hold the current position and come back after the next base_expr
// we do this, because the next base_expr contains the complete expression/subquery/record
// and we have to look into it too
$backtracking[] = $charPos;
} elseif (($key === 'ref_clause' || $key === 'columns') && $parsed !== false) {
// we hold the current position and come back after n base_expr(s)
// there is an array of sub-elements before (!) the base_expr clause of the current element
// so we go through the sub-elements and must come at the end
$backtracking[] = $charPos;
for ($i = 1; $i < count($parsed); $i++) {
$backtracking[] = false; // backtracking only after n base_expr!
}
} elseif (($key === 'sub_tree' && $parsed !== false) || ($key === 'options' && $parsed !== false)) {
// we prevent wrong backtracking on subtrees (too much array_pop())
// there is an array of sub-elements after(!) the base_expr clause of the current element
// so we go through the sub-elements and must not come back at the end
for ($i = 1; $i < count($parsed); $i++) {
$backtracking[] = false;
}
} elseif (($key === 'TABLE') || ($key === 'create-def' && $parsed !== false)) {
// do nothing
} else {
// move the current pos after the keyword
// SELECT, WHERE, INSERT etc.
if (PHPSQLParserConstants::isReserved($key)) {
$charPos = stripos($sql, $key, $charPos);
$charPos += strlen($key);
}
}
}
if (!is_array($parsed)) {
return;
}
foreach ($parsed as $key => $value) {
if ($key === 'base_expr') {
//$this->_printPos("0", $sql, $charPos, $key, $value, $backtracking);
$subject = substr($sql, $charPos);
$pos = $this->findPositionWithinString($subject, $value,
isset($parsed['expr_type']) ? $parsed['expr_type'] : 'alias');
if ($pos === false) {
throw new UnableToCalculatePositionException($value, $subject);
}
$parsed['position'] = $charPos + $pos;
$charPos += $pos + strlen($value);
//$this->_printPos("1", $sql, $charPos, $key, $value, $backtracking);
$oldPos = array_pop($backtracking);
if (isset($oldPos) && $oldPos !== false) {
$charPos = $oldPos;
}
//$this->_printPos("2", $sql, $charPos, $key, $value, $backtracking);
} else {
$this->lookForBaseExpression($sql, $charPos, $parsed[$key], $key, $backtracking);
}
}
}
}
?>