framework/db/SqlToken.php
<?php
/**
* @link https://www.yiiframework.com/
* @copyright Copyright (c) 2008 Yii Software LLC
* @license https://www.yiiframework.com/license/
*/
namespace yii\db;
use yii\base\BaseObject;
/**
* SqlToken represents SQL tokens produced by [[SqlTokenizer]] or its child classes.
*
* @property SqlToken[] $children Child tokens.
* @property-read bool $hasChildren Whether the token has children.
* @property-read bool $isCollection Whether the token represents a collection of tokens.
* @property-read string $sql SQL code.
*
* @author Sergey Makinen <sergey@makinen.ru>
* @since 2.0.13
*/
class SqlToken extends BaseObject implements \ArrayAccess
{
const TYPE_CODE = 0;
const TYPE_STATEMENT = 1;
const TYPE_TOKEN = 2;
const TYPE_PARENTHESIS = 3;
const TYPE_KEYWORD = 4;
const TYPE_OPERATOR = 5;
const TYPE_IDENTIFIER = 6;
const TYPE_STRING_LITERAL = 7;
/**
* @var int token type. It has to be one of the following constants:
*
* - [[TYPE_CODE]]
* - [[TYPE_STATEMENT]]
* - [[TYPE_TOKEN]]
* - [[TYPE_PARENTHESIS]]
* - [[TYPE_KEYWORD]]
* - [[TYPE_OPERATOR]]
* - [[TYPE_IDENTIFIER]]
* - [[TYPE_STRING_LITERAL]]
*/
public $type = self::TYPE_TOKEN;
/**
* @var string|null token content.
*/
public $content;
/**
* @var int original SQL token start position.
*/
public $startOffset;
/**
* @var int original SQL token end position.
*/
public $endOffset;
/**
* @var SqlToken parent token.
*/
public $parent;
/**
* @var SqlToken[] token children.
*/
private $_children = [];
/**
* Returns the SQL code representing the token.
* @return string SQL code.
*/
public function __toString()
{
return $this->getSql();
}
/**
* Returns whether there is a child token at the specified offset.
* This method is required by the SPL [[\ArrayAccess]] interface.
* It is implicitly called when you use something like `isset($token[$offset])`.
* @param int $offset child token offset.
* @return bool whether the token exists.
*/
#[\ReturnTypeWillChange]
public function offsetExists($offset)
{
return isset($this->_children[$this->calculateOffset($offset)]);
}
/**
* Returns a child token at the specified offset.
* This method is required by the SPL [[\ArrayAccess]] interface.
* It is implicitly called when you use something like `$child = $token[$offset];`.
* @param int $offset child token offset.
* @return SqlToken|null the child token at the specified offset, `null` if there's no token.
*/
#[\ReturnTypeWillChange]
public function offsetGet($offset)
{
$offset = $this->calculateOffset($offset);
return isset($this->_children[$offset]) ? $this->_children[$offset] : null;
}
/**
* Adds a child token to the token.
* This method is required by the SPL [[\ArrayAccess]] interface.
* It is implicitly called when you use something like `$token[$offset] = $child;`.
* @param int|null $offset child token offset.
* @param SqlToken $token token to be added.
*/
#[\ReturnTypeWillChange]
public function offsetSet($offset, $token)
{
$token->parent = $this;
if ($offset === null) {
$this->_children[] = $token;
} else {
$this->_children[$this->calculateOffset($offset)] = $token;
}
$this->updateCollectionOffsets();
}
/**
* Removes a child token at the specified offset.
* This method is required by the SPL [[\ArrayAccess]] interface.
* It is implicitly called when you use something like `unset($token[$offset])`.
* @param int $offset child token offset.
*/
#[\ReturnTypeWillChange]
public function offsetUnset($offset)
{
$offset = $this->calculateOffset($offset);
if (isset($this->_children[$offset])) {
array_splice($this->_children, $offset, 1);
}
$this->updateCollectionOffsets();
}
/**
* Returns child tokens.
* @return SqlToken[] child tokens.
*/
public function getChildren()
{
return $this->_children;
}
/**
* Sets a list of child tokens.
* @param SqlToken[] $children child tokens.
*/
public function setChildren($children)
{
$this->_children = [];
foreach ($children as $child) {
$child->parent = $this;
$this->_children[] = $child;
}
$this->updateCollectionOffsets();
}
/**
* Returns whether the token represents a collection of tokens.
* @return bool whether the token represents a collection of tokens.
*/
public function getIsCollection()
{
return in_array($this->type, [
self::TYPE_CODE,
self::TYPE_STATEMENT,
self::TYPE_PARENTHESIS,
], true);
}
/**
* Returns whether the token represents a collection of tokens and has non-zero number of children.
* @return bool whether the token has children.
*/
public function getHasChildren()
{
return $this->getIsCollection() && !empty($this->_children);
}
/**
* Returns the SQL code representing the token.
* @return string SQL code.
*/
public function getSql()
{
$code = $this;
while ($code->parent !== null) {
$code = $code->parent;
}
return mb_substr($code->content, $this->startOffset, $this->endOffset - $this->startOffset, 'UTF-8');
}
/**
* Returns whether this token (including its children) matches the specified "pattern" SQL code.
*
* Usage Example:
*
* ```php
* $patternToken = (new \yii\db\sqlite\SqlTokenizer('SELECT any FROM any'))->tokenize();
* if ($sqlToken->matches($patternToken, 0, $firstMatchIndex, $lastMatchIndex)) {
* // ...
* }
* ```
*
* @param SqlToken $patternToken tokenized SQL code to match against. In addition to normal SQL, the
* `any` keyword is supported which will match any number of keywords, identifiers, whitespaces.
* @param int $offset token children offset to start lookup with.
* @param int|null $firstMatchIndex token children offset where a successful match begins.
* @param int|null $lastMatchIndex token children offset where a successful match ends.
* @return bool whether this token matches the pattern SQL code.
*/
public function matches(SqlToken $patternToken, $offset = 0, &$firstMatchIndex = null, &$lastMatchIndex = null)
{
if (!$patternToken->getHasChildren()) {
return false;
}
$patternToken = $patternToken[0];
return $this->tokensMatch($patternToken, $this, $offset, $firstMatchIndex, $lastMatchIndex);
}
/**
* Tests the given token to match the specified pattern token.
* @param SqlToken $patternToken
* @param SqlToken $token
* @param int $offset
* @param int|null $firstMatchIndex
* @param int|null $lastMatchIndex
* @return bool
*/
private function tokensMatch(SqlToken $patternToken, SqlToken $token, $offset = 0, &$firstMatchIndex = null, &$lastMatchIndex = null)
{
if (
$patternToken->getIsCollection() !== $token->getIsCollection()
|| (!$patternToken->getIsCollection() && $patternToken->content !== $token->content)
) {
return false;
}
if ($patternToken->children === $token->children) {
$firstMatchIndex = $lastMatchIndex = $offset;
return true;
}
$firstMatchIndex = $lastMatchIndex = null;
$wildcard = false;
for ($index = 0, $count = count($patternToken->children); $index < $count; $index++) {
// Here we iterate token by token with an exception of "any" that toggles
// an iteration until we matched with a next pattern token or EOF.
if ($patternToken[$index]->content === 'any') {
$wildcard = true;
continue;
}
for ($limit = $wildcard ? count($token->children) : $offset + 1; $offset < $limit; $offset++) {
if (!$wildcard && !isset($token[$offset])) {
break;
}
if (!$this->tokensMatch($patternToken[$index], $token[$offset])) {
continue;
}
if ($firstMatchIndex === null) {
$firstMatchIndex = $offset;
}
$lastMatchIndex = $offset;
$wildcard = false;
$offset++;
continue 2;
}
return false;
}
return true;
}
/**
* Returns an absolute offset in the children array.
* @param int $offset
* @return int
*/
private function calculateOffset($offset)
{
if ($offset >= 0) {
return $offset;
}
return count($this->_children) + $offset;
}
/**
* Updates token SQL code start and end offsets based on its children.
*/
private function updateCollectionOffsets()
{
if (!empty($this->_children)) {
$this->startOffset = reset($this->_children)->startOffset;
$this->endOffset = end($this->_children)->endOffset;
}
if ($this->parent !== null) {
$this->parent->updateCollectionOffsets();
}
}
}