| Current File : /var/www/pma/libraries/classes/Advisor.php |
<?php
/* vim: set expandtab sw=4 ts=4 sts=4: */
/**
* A simple rules engine, that parses and executes the rules in advisory_rules.txt.
* Adjusted to phpMyAdmin.
*
* @package PhpMyAdmin
*/
namespace PhpMyAdmin;
use Exception;
use PhpMyAdmin\Core;
use PhpMyAdmin\DatabaseInterface;
use PhpMyAdmin\SysInfo;
use PhpMyAdmin\Url;
use PhpMyAdmin\Util;
use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
/**
* Advisor class
*
* @package PhpMyAdmin
*/
class Advisor
{
protected $dbi;
protected $variables;
protected $globals;
protected $parseResult;
protected $runResult;
protected $expression;
/**
* Constructor
*
* @param DatabaseInterface $dbi DatabaseInterface object
* @param ExpressionLanguage $expression ExpressionLanguage object
*/
public function __construct(DatabaseInterface $dbi, ExpressionLanguage $expression)
{
$this->dbi = $dbi;
$this->expression = $expression;
/*
* Register functions for ExpressionLanguage, we intentionally
* do not implement support for compile as we do not use it.
*/
$this->expression->register(
'round',
function (){},
function ($arguments, $num) {
return round($num);
}
);
$this->expression->register(
'substr',
function (){},
function ($arguments, $string, $start, $length) {
return substr($string, $start, $length);
}
);
$this->expression->register(
'preg_match',
function (){},
function ($arguments, $pattern , $subject) {
return preg_match($pattern, $subject);
}
);
$this->expression->register(
'ADVISOR_bytime',
function (){},
function ($arguments, $num, $precision) {
return self::byTime($num, $precision);
}
);
$this->expression->register(
'ADVISOR_timespanFormat',
function (){},
function ($arguments, $seconds) {
return self::timespanFormat($seconds);
}
);
$this->expression->register(
'ADVISOR_formatByteDown',
function (){},
function ($arguments, $value, $limes = 6, $comma = 0) {
return self::formatByteDown($value, $limes, $comma);
}
);
$this->expression->register(
'fired',
function (){},
function ($arguments, $value) {
if (!isset($this->runResult['fired'])) {
return 0;
}
// Did matching rule fire?
foreach ($this->runResult['fired'] as $rule) {
if ($rule['id'] == $value) {
return '1';
}
}
return '0';
}
);
/* Some global variables for advisor */
$this->globals = array(
'PMA_MYSQL_INT_VERSION' => $this->dbi->getVersion(),
);
}
/**
* Get variables
*
* @return mixed
*/
public function getVariables()
{
return $this->variables;
}
/**
* Set variables
*
* @param array $variables Variables
*
* @return Advisor
*/
public function setVariables(array $variables)
{
$this->variables = $variables;
return $this;
}
/**
* Set a variable and its value
*
* @param string|int $variable Variable to set
* @param mixed $value Value to set
*
* @return $this
*/
public function setVariable($variable, $value)
{
$this->variables[$variable] = $value;
return $this;
}
/**
* Get parseResult
*
* @return mixed
*/
public function getParseResult()
{
return $this->parseResult;
}
/**
* Set parseResult
*
* @param array $parseResult Parse result
*
* @return Advisor
*/
public function setParseResult(array $parseResult)
{
$this->parseResult = $parseResult;
return $this;
}
/**
* Get runResult
*
* @return mixed
*/
public function getRunResult()
{
return $this->runResult;
}
/**
* Set runResult
*
* @param array $runResult Run result
*
* @return Advisor
*/
public function setRunResult(array $runResult)
{
$this->runResult = $runResult;
return $this;
}
/**
* Parses and executes advisor rules
*
* @return array with run and parse results
*/
public function run()
{
// HowTo: A simple Advisory system in 3 easy steps.
// Step 1: Get some variables to evaluate on
$this->setVariables(
array_merge(
$this->dbi->fetchResult('SHOW GLOBAL STATUS', 0, 1),
$this->dbi->fetchResult('SHOW GLOBAL VARIABLES', 0, 1)
)
);
// Add total memory to variables as well
$sysinfo = SysInfo::get();
$memory = $sysinfo->memory();
$this->variables['system_memory']
= isset($memory['MemTotal']) ? $memory['MemTotal'] : 0;
// Step 2: Read and parse the list of rules
$this->setParseResult(static::parseRulesFile());
// Step 3: Feed the variables to the rules and let them fire. Sets
// $runResult
$this->runRules();
return array(
'parse' => array('errors' => $this->parseResult['errors']),
'run' => $this->runResult
);
}
/**
* Stores current error in run results.
*
* @param string $description description of an error.
* @param Exception $exception exception raised
*
* @return void
*/
public function storeError($description, $exception)
{
$this->runResult['errors'][] = $description
. ' '
. sprintf(
__('Error when evaluating: %s'),
$exception->getMessage()
);
}
/**
* Executes advisor rules
*
* @return boolean
*/
public function runRules()
{
$this->setRunResult(
array(
'fired' => array(),
'notfired' => array(),
'unchecked' => array(),
'errors' => array(),
)
);
foreach ($this->parseResult['rules'] as $rule) {
$this->variables['value'] = 0;
$precond = true;
if (isset($rule['precondition'])) {
try {
$precond = $this->ruleExprEvaluate($rule['precondition']);
} catch (Exception $e) {
$this->storeError(
sprintf(
__('Failed evaluating precondition for rule \'%s\'.'),
$rule['name']
),
$e
);
continue;
}
}
if (! $precond) {
$this->addRule('unchecked', $rule);
} else {
try {
$value = $this->ruleExprEvaluate($rule['formula']);
} catch (Exception $e) {
$this->storeError(
sprintf(
__('Failed calculating value for rule \'%s\'.'),
$rule['name']
),
$e
);
continue;
}
$this->variables['value'] = $value;
try {
if ($this->ruleExprEvaluate($rule['test'])) {
$this->addRule('fired', $rule);
} else {
$this->addRule('notfired', $rule);
}
} catch (Exception $e) {
$this->storeError(
sprintf(
__('Failed running test for rule \'%s\'.'),
$rule['name']
),
$e
);
}
}
}
return true;
}
/**
* Escapes percent string to be used in format string.
*
* @param string $str string to escape
*
* @return string
*/
public static function escapePercent($str)
{
return preg_replace('/%( |,|\.|$|\(|\)|<|>)/', '%%\1', $str);
}
/**
* Wrapper function for translating.
*
* @param string $str the string
* @param string $param the parameters
*
* @return string
*/
public function translate($str, $param = null)
{
$string = _gettext(self::escapePercent($str));
if (! is_null($param)) {
$params = $this->ruleExprEvaluate('[' . $param . ']');
} else {
$params = array();
}
return vsprintf($string, $params);
}
/**
* Splits justification to text and formula.
*
* @param array $rule the rule
*
* @return string[]
*/
public static function splitJustification(array $rule)
{
$jst = preg_split('/\s*\|\s*/', $rule['justification'], 2);
if (count($jst) > 1) {
return array($jst[0], $jst[1]);
}
return array($rule['justification']);
}
/**
* Adds a rule to the result list
*
* @param string $type type of rule
* @param array $rule rule itself
*
* @return void
*/
public function addRule($type, array $rule)
{
switch ($type) {
case 'notfired':
case 'fired':
$jst = self::splitJustification($rule);
if (count($jst) > 1) {
try {
/* Translate */
$str = $this->translate($jst[0], $jst[1]);
} catch (Exception $e) {
$this->storeError(
sprintf(
__('Failed formatting string for rule \'%s\'.'),
$rule['name']
),
$e
);
return;
}
$rule['justification'] = $str;
} else {
$rule['justification'] = $this->translate($rule['justification']);
}
$rule['id'] = $rule['name'];
$rule['name'] = $this->translate($rule['name']);
$rule['issue'] = $this->translate($rule['issue']);
// Replaces {server_variable} with 'server_variable'
// linking to server_variables.php
$rule['recommendation'] = preg_replace_callback(
'/\{([a-z_0-9]+)\}/Ui',
array($this, 'replaceVariable'),
$this->translate($rule['recommendation'])
);
// Replaces external Links with Core::linkURL() generated links
$rule['recommendation'] = preg_replace_callback(
'#href=("|\')(https?://[^\1]+)\1#i',
array($this, 'replaceLinkURL'),
$rule['recommendation']
);
break;
}
$this->runResult[$type][] = $rule;
}
/**
* Callback for wrapping links with Core::linkURL
*
* @param array $matches List of matched elements form preg_replace_callback
*
* @return string Replacement value
*/
private function replaceLinkURL(array $matches)
{
return 'href="' . Core::linkURL($matches[2]) . '" target="_blank" rel="noopener noreferrer"';
}
/**
* Callback for wrapping variable edit links
*
* @param array $matches List of matched elements form preg_replace_callback
*
* @return string Replacement value
*/
private function replaceVariable(array $matches)
{
return '<a href="server_variables.php' . Url::getCommon(array('filter' => $matches[1]))
. '">' . htmlspecialchars($matches[1]) . '</a>';
}
/**
* Runs a code expression, replacing variable names with their respective
* values
*
* @param string $expr expression to evaluate
*
* @return integer result of evaluated expression
*
* @throws Exception
*/
public function ruleExprEvaluate($expr)
{
// Actually evaluate the code
// This can throw exception
$value = $this->expression->evaluate(
$expr,
array_merge($this->variables, $this->globals)
);
return $value;
}
/**
* Reads the rule file into an array, throwing errors messages on syntax
* errors.
*
* @return array with parsed data
*/
public static function parseRulesFile()
{
$filename = 'libraries/advisory_rules.txt';
$file = file($filename, FILE_IGNORE_NEW_LINES);
$errors = array();
$rules = array();
$lines = array();
if ($file === false) {
$errors[] = sprintf(
__('Error in reading file: The file \'%s\' does not exist or is not readable!'),
$filename
);
return array('rules' => $rules, 'lines' => $lines, 'errors' => $errors);
}
$ruleSyntax = array(
'name', 'formula', 'test', 'issue', 'recommendation', 'justification'
);
$numRules = count($ruleSyntax);
$numLines = count($file);
$ruleNo = -1;
$ruleLine = -1;
for ($i = 0; $i < $numLines; $i++) {
$line = $file[$i];
if ($line == "" || $line[0] == '#') {
continue;
}
// Reading new rule
if (substr($line, 0, 4) == 'rule') {
if ($ruleLine > 0) {
$errors[] = sprintf(
__(
'Invalid rule declaration on line %1$s, expected line '
. '%2$s of previous rule.'
),
$i + 1,
$ruleSyntax[$ruleLine++]
);
continue;
}
if (preg_match("/rule\s'(.*)'( \[(.*)\])?$/", $line, $match)) {
$ruleLine = 1;
$ruleNo++;
$rules[$ruleNo] = array('name' => $match[1]);
$lines[$ruleNo] = array('name' => $i + 1);
if (isset($match[3])) {
$rules[$ruleNo]['precondition'] = $match[3];
$lines[$ruleNo]['precondition'] = $i + 1;
}
} else {
$errors[] = sprintf(
__('Invalid rule declaration on line %s.'),
$i + 1
);
}
continue;
} else {
if ($ruleLine == -1) {
$errors[] = sprintf(
__('Unexpected characters on line %s.'),
$i + 1
);
}
}
// Reading rule lines
if ($ruleLine > 0) {
if (!isset($line[0])) {
continue; // Empty lines are ok
}
// Non tabbed lines are not
if ($line[0] != "\t") {
$errors[] = sprintf(
__(
'Unexpected character on line %1$s. Expected tab, but '
. 'found "%2$s".'
),
$i + 1,
$line[0]
);
continue;
}
$rules[$ruleNo][$ruleSyntax[$ruleLine]] = chop(
mb_substr($line, 1)
);
$lines[$ruleNo][$ruleSyntax[$ruleLine]] = $i + 1;
++$ruleLine;
}
// Rule complete
if ($ruleLine == $numRules) {
$ruleLine = -1;
}
}
return array('rules' => $rules, 'lines' => $lines, 'errors' => $errors);
}
/**
* Formats interval like 10 per hour
*
* @param integer $num number to format
* @param integer $precision required precision
*
* @return string formatted string
*/
public static function byTime($num, $precision)
{
if ($num >= 1) { // per second
$per = __('per second');
} elseif ($num * 60 >= 1) { // per minute
$num = $num * 60;
$per = __('per minute');
} elseif ($num * 60 * 60 >= 1 ) { // per hour
$num = $num * 60 * 60;
$per = __('per hour');
} else {
$num = $num * 60 * 60 * 24;
$per = __('per day');
}
$num = round($num, $precision);
if ($num == 0) {
$num = '<' . pow(10, -$precision);
}
return "$num $per";
}
/**
* Wrapper for PhpMyAdmin\Util::timespanFormat
*
* This function is used when evaluating advisory_rules.txt
*
* @param int $seconds the timespan
*
* @return string the formatted value
*/
public static function timespanFormat($seconds)
{
return Util::timespanFormat($seconds);
}
/**
* Wrapper around PhpMyAdmin\Util::formatByteDown
*
* This function is used when evaluating advisory_rules.txt
*
* @param double $value the value to format
* @param int $limes the sensitiveness
* @param int $comma the number of decimals to retain
*
* @return string the formatted value with unit
*/
public static function formatByteDown($value, $limes = 6, $comma = 0)
{
return implode(' ', Util::formatByteDown($value, $limes, $comma));
}
}