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<?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
*/
class Advisor
{
var $variables;
var $parseResult;
var $runResult;
function run()
{
// HowTo: A simple Advisory system in 3 easy steps.
// Step 1: Get some variables to evaluate on
$this->variables = array_merge(
PMA_DBI_fetch_result('SHOW GLOBAL STATUS', 0, 1),
PMA_DBI_fetch_result('SHOW GLOBAL VARIABLES', 0, 1)
);
if (PMA_DRIZZLE) {
$this->variables = array_merge(
$this->variables,
PMA_DBI_fetch_result(
"SELECT concat('Com_', variable_name), variable_value
FROM data_dictionary.GLOBAL_STATEMENTS", 0, 1
)
);
}
// Add total memory to variables as well
include_once 'libraries/sysinfo.lib.php';
$sysinfo = PMA_getSysInfo();
$memory = $sysinfo->memory();
$this->variables['system_memory'] = $memory['MemTotal'];
// Step 2: Read and parse the list of rules
$this->parseResult = $this->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
);
}
function runRules()
{
$this->runResult = array(
'fired' => array(),
'notfired' => array(),
'unchecked'=> array(),
'errors' => array()
);
foreach ($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->runResult['errors'][] = 'Failed evaluating precondition for rule \''
. $rule['name'] . '\'. PHP threw following error: '
. $e->getMessage();
continue;
}
}
if (! $precond) {
$this->addRule('unchecked', $rule);
} else {
try {
$value = $this->ruleExprEvaluate($rule['formula']);
} catch(Exception $e) {
$this->runResult['errors'][] = 'Failed calculating value for rule \''
. $rule['name'] . '\'. PHP threw following error: '
. $e->getMessage();
continue;
}
$this->variables['value'] = $value;
try {
if ($this->ruleExprEvaluate($rule['test'])) {
$this->addRule('fired', $rule);
} else {
$this->addRule('notfired', $rule);
}
} catch(Exception $e) {
$this->runResult['errors'][] = 'Failed running test for rule \''
. $rule['name'] . '\'. PHP threw following error: '
. $e->getMessage();
}
}
}
return true;
}
/**
* Escapes percent string to be used in format string.
*
* @param string $str string to escape
*
* @return string
*/
static function escapePercent($str)
{
return preg_replace('/%( |,|\.|$|\(|\)|<|>)/', '%%\1', $str);
}
/**
* Wrapper function for translating.
*
* @param string $str
* @param mixed $param
*
* @return string
*/
function translate($str, $param = null)
{
if (is_null($param)) {
return sprintf(_gettext(Advisor::escapePercent($str)));
} else {
$printf = 'sprintf("' . _gettext(Advisor::escapePercent($str)) . '",';
return $this->ruleExprEvaluate(
$printf . $param . ')',
strlen($printf)
);
}
}
/**
* Splits justification to text and formula.
*
* @param string $rule
*
* @return array
*/
function splitJustification($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
function addRule($type, $rule)
{
switch($type) {
case 'notfired':
case 'fired':
$jst = Advisor::splitJustification($rule);
if (count($jst) > 1) {
try {
/* Translate */
$str = $this->translate($jst[0], $jst[1]);
} catch (Exception $e) {
$this->runResult['errors'][] = sprintf(
__('Failed formatting string for rule \'%s\'. PHP threw following error: %s'),
$rule['name'],
$e->getMessage()
);
return;
}
$rule['justification'] = $str;
} else {
$rule['justification'] = $this->translate($rule['justification']);
}
$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(
'/\{([a-z_0-9]+)\}/Ui',
'<a href="server_variables.php?' . PMA_generate_common_url() . '#filter=\1">\1</a>',
$this->translate($rule['recommendation'])
);
// Replaces external Links with PMA_linkURL() generated links
$rule['recommendation'] = preg_replace(
'#href=("|\')(https?://[^\1]+)\1#ie',
'\'href="\' . PMA_linkURL("\2") . \'"\'',
$rule['recommendation']
);
break;
}
$this->runResult[$type][] = $rule;
}
private function ruleExprEvaluate_var1($matches)
{
// '/fired\s*\(\s*(\'|")(.*)\1\s*\)/Uie'
return '1'; //isset($this->runResult[\'fired\']
}
private function ruleExprEvaluate_var2($matches)
{
// '/\b(\w+)\b/e'
return isset($this->variables[$matches[1]])
? (is_numeric($this->variables[$matches[1]])
? $this->variables[$matches[1]]
: '"'.$this->variables[$matches[1]].'"')
: $matches[1];
}
// Runs a code expression, replacing variable names with their respective values
// ignoreUntil: if > 0, it doesn't replace any variables until that string
// position, but still evaluates the whole expr
function ruleExprEvaluate($expr, $ignoreUntil = 0)
{
if ($ignoreUntil > 0) {
$exprIgnore = substr($expr, 0, $ignoreUntil);
$expr = substr($expr, $ignoreUntil);
}
$expr = preg_replace_callback(
'/fired\s*\(\s*(\'|")(.*)\1\s*\)/Ui',
array($this, 'ruleExprEvaluate_var1'),
$expr
);
$expr = preg_replace_callback(
'/\b(\w+)\b/',
array($this, 'ruleExprEvaluate_var2'),
$expr
);
if ($ignoreUntil > 0) {
$expr = $exprIgnore . $expr;
}
$value = 0;
$err = 0;
ob_start();
eval('$value = '.$expr.';');
$err = ob_get_contents();
ob_end_clean();
if ($err) {
throw new Exception(
strip_tags($err) . '<br />Executed code: $value = ' . $expr . ';'
);
}
return $value;
}
// Reads the rule file into an array, throwing errors messages on syntax errors
function parseRulesFile()
{
$file = file('libraries/advisory_rules.txt');
$errors = array();
$rules = array();
$ruleSyntax = array('name', 'formula', 'test', 'issue', 'recommendation', 'justification');
$numRules = count($ruleSyntax);
$numLines = count($file);
$j = -1;
$ruleLine = -1;
for ($i = 0; $i<$numLines; $i++) {
$line = $file[$i];
if ($line[0] == '#' || $line[0] == "\n") {
continue;
}
// Reading new rule
if (substr($line, 0, 4) == 'rule') {
if ($ruleLine > 0) {
$errors[] = 'Invalid rule declaration on line ' . ($i+1)
. ', expected line ' . $ruleSyntax[$ruleLine++]
. ' of previous rule' ;
continue;
}
if (preg_match("/rule\s'(.*)'( \[(.*)\])?$/", $line, $match)) {
$ruleLine = 1;
$j++;
$rules[$j] = array( 'name' => $match[1]);
if (isset($match[3])) {
$rules[$j]['precondition'] = $match[3];
}
} else {
$errors[] = 'Invalid rule declaration on line '.($i+1);
}
continue;
} else {
if ($ruleLine == -1) {
$errors[] = 'Unexpected characters on line '.($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") {
$errors[] = 'Unexpected character on line '.($i+1).'
. Expected tab, but found \''.$line[0].'\'';
continue;
}
$rules[$j][$ruleSyntax[$ruleLine++]] = chop(substr($line, 1));
}
// Rule complete
if ($ruleLine == $numRules) {
$ruleLine = -1;
}
}
return array('rules' => $rules, 'errors' => $errors);
}
}
function PMA_bytime($num, $precision)
{
$per = '';
if ($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";
}
?>
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