libraries/Advisor.class.php

   1 <?php
   2 /* vim: set expandtab sw=4 ts=4 sts=4: */
   3 /**
   4  * A simple rules engine, that parses and executes the rules in advisory_rules.txt. Adjusted to phpMyAdmin
   5  *
   6  *
   7  * @package phpMyAdmin
   8  */
   9
  10 class Advisor
  11 {
  12     var $variables;
  13     var $parseResult;
  14     var $runResult;
  15
  16     function run() {
  17         // HowTo: A simple Advisory system in 3 easy steps.
  18
  19         // Step 1: Get some variables to evaluate on
  20         $this->variables = array_merge(
  21             PMA_DBI_fetch_result('SHOW GLOBAL STATUS', 0, 1),
  22             PMA_DBI_fetch_result('SHOW GLOBAL VARIABLES', 0, 1)
  23         );
  24         // Add total memory to variables as well
  25         require_once('libraries/sysinfo.lib.php');
  26         $sysinfo = getSysInfo();
  27         $memory  = $sysinfo->memory();
  28         $this->variables['system_memory'] = $memory['MemTotal'];
  29
  30         // Step 2: Read and parse the list of rules
  31         $this->parseResult = $this->parseRulesFile();
  32         // Step 3: Feed the variables to the rules and let them fire. Sets $runResult
  33         $this->runRules();
  34
  35         return array('parse' => array('errors' => $this->parseResult['errors']), 'run' => $this->runResult);
  36     }
  37
  38     function runRules() {
  39         $this->runResult = array(
  40             'fired' => array(),
  41             'notfired' => array(),
  42             'unchecked'=> array(),
  43             'errors' => array()
  44         );
  45
  46         foreach ($this->parseResult['rules'] as $rule) {
  47             $this->variables['value'] = 0;
  48             $precond = true;
  49
  50             if (isset($rule['precondition'])) {
  51                 try {
  52                      $precond = $this->ruleExprEvaluate($rule['precondition']);
  53                 } catch (Exception $e) {
  54                     $this->runResult['errors'][] = 'Failed evaluating precondition for rule \''.$rule['name'].'\'. PHP threw following error: '.$e->getMessage();
  55                     continue;
  56                 }
  57             }
  58
  59             if (! $precond) {
  60                 $this->addRule('unchecked', $rule);
  61             } else {
  62                 try {
  63                     $value = $this->ruleExprEvaluate($rule['formula']);
  64                 } catch(Exception $e) {
  65                     $this->runResult['errors'][] = 'Failed calculating value for rule \''.$rule['name'].'\'. PHP threw following error: '.$e->getMessage();
  66                     continue;
  67                 }
  68
  69                 $this->variables['value'] = $value;
  70
  71                 try {
  72                     if ($this->ruleExprEvaluate($rule['test'])) {
  73                         $this->addRule('fired', $rule);
  74                     } else {
  75                         $this->addRule('notfired', $rule);
  76                     }
  77                 }  catch(Exception $e) {
  78                     $this->runResult['errors'][] = 'Failed running test for rule \''.$rule['name'].'\'. PHP threw following error: '.$e->getMessage();
  79                 }
  80             }
  81         }
  82
  83         return true;
  84     }
  85
  86     /**
  87      * Escapes percent string to be used in format string.
  88      *
  89      * @param string $str
  90      * @return string
  91      */
  92     function escapePercent($str)
  93     {
  94         return preg_replace('/%( |,|\.|$)/','%%\1', $str);
  95     }
  96
  97     /**
  98      * Wrapper function for translating.
  99      *
 100      * @param string $str
 101      * @param mixed  $param
 102      * @return string
 103      */
 104     function translate($str, $param = null)
 105     {
 106         if (is_null($param)) {
 107             return sprintf(_gettext(Advisor::escapePercent($str)));
 108         } else {
 109             $printf = 'sprintf("' . _gettext(Advisor::escapePercent($str)) . '",';
 110             return $this->ruleExprEvaluate(
 111                 $printf . $param . ')',
 112                 strlen($printf)
 113             );
 114         }
 115     }
 116
 117     /**
 118      * Splits justification to text and formula.
 119      *
 120      * @param string $rule
 121      * @return array
 122      */
 123     function splitJustification($rule)
 124     {
 125         $jst = preg_split('/\s*\|\s*/', $rule['justification'], 2);
 126         if (count($jst) > 1) {
 127             return array($jst[0], $jst[1]);
 128        }
 129         return array($rule['justification']);
 130     }
 131
 132     // Adds a rule to the result list
 133     function addRule($type, $rule)
 134     {
 135         switch($type) {
 136             case 'notfired':
 137             case 'fired':
 138                 $jst = Advisor::splitJustification($rule);
 139                 if (count($jst) > 1) {
 140                     try {
 141                         /* Translate */
 142                         $str = $this->translate($jst[0], $jst[1]);
 143                     } catch (Exception $e) {
 144                         $this->runResult['errors'][] = sprintf(
 145                             __('Failed formatting string for rule \'%s\'. PHP threw following error: %s'),
 146                             $rule['name'],
 147                             $e->getMessage()
 148                         );
 149                         return;
 150                     }
 151
 152                     $rule['justification'] = $str;
 153                 } else {
 154                     $rule['justification'] = $this->translate($rule['justification']);
 155                 }
 156                 $rule['name'] = $this->translate($rule['name']);
 157                 $rule['issue'] = $this->translate($rule['issue']);
 158
 159                 // Replaces {server_variable} with 'server_variable' linking to server_variables.php
 160                 $rule['recommendation'] = preg_replace(
 161                     '/\{([a-z_0-9]+)\}/Ui',
 162                     '<a href="server_variables.php?' . PMA_generate_common_url() . '#filter=\1">\1</a>',
 163                     $this->translate($rule['recommendation']));
 164
 165                 // Replaces external Links with PMA_linkURL() generated links
 166                 $rule['recommendation'] = preg_replace(
 167                     '#href=("|\')(https?://[^\1]+)\1#ie',
 168                     '\'href="\' . PMA_linkURL("\2") . \'"\'',
 169                     $rule['recommendation']
 170                 );
 171                 break;
 172         }
 173
 174         $this->runResult[$type][] = $rule;
 175     }
 176
 177     private function ruleExprEvaluate_var1($matches)
 178     {
 179         // '/fired\s*\(\s*(\'|")(.*)\1\s*\)/Uie'
 180         return '1'; //isset($this->runResult[\'fired\']
 181     }
 182
 183     private function ruleExprEvaluate_var2($matches)
 184     {
 185         // '/\b(\w+)\b/e'
 186         return isset($this->variables[$matches[1]])
 187             ? (is_numeric($this->variables[$matches[1]])
 188                 ? $this->variables[$matches[1]]
 189                 : '"'.$this->variables[$matches[1]].'"')
 190             : $matches[1];
 191     }
 192
 193     // Runs a code expression, replacing variable names with their respective values
 194     // ignoreUntil: if > 0, it doesn't replace any variables until that string position, but still evaluates the whole expr
 195     function ruleExprEvaluate($expr, $ignoreUntil = 0)
 196     {
 197         if ($ignoreUntil > 0) {
 198             $exprIgnore = substr($expr,0,$ignoreUntil);
 199             $expr = substr($expr,$ignoreUntil);
 200         }
 201         $expr = preg_replace_callback('/fired\s*\(\s*(\'|")(.*)\1\s*\)/Ui', array($this, 'ruleExprEvaluate_var1'), $expr);
 202         $expr = preg_replace_callback('/\b(\w+)\b/', array($this, 'ruleExprEvaluate_var2'), $expr);
 203         if ($ignoreUntil > 0) {
 204             $expr = $exprIgnore . $expr;
 205         }
 206         $value = 0;
 207         $err = 0;
 208
 209         ob_start();
 210         eval('$value = '.$expr.';');
 211         $err = ob_get_contents();
 212         ob_end_clean();
 213         if ($err) {
 214             throw new Exception(strip_tags($err) . '<br />Executed code: $value = '.$expr.';');
 215         }
 216         return $value;
 217     }
 218
 219     // Reads the rule file into an array, throwing errors messages on syntax errors
 220     function parseRulesFile()
 221     {
 222         $file = file('libraries/advisory_rules.txt');
 223         $errors = array();
 224         $rules = array();
 225         $ruleSyntax = array('name','formula','test','issue','recommendation','justification');
 226         $numRules = count($ruleSyntax);
 227         $numLines = count($file);
 228         $j = -1;
 229         $ruleLine = -1;
 230
 231         for ($i = 0; $i<$numLines; $i++) {
 232             $line = $file[$i];
 233             if ($line[0] == '#' || $line[0] == "\n") {
 234                 continue;
 235             }
 236
 237             // Reading new rule
 238             if (substr($line, 0, 4) == 'rule') {
 239                 if ($ruleLine > 0) {
 240                     $errors[] = 'Invalid rule declaration on line '.($i+1). ', expected line '.$ruleSyntax[$ruleLine++].' of previous rule' ;
 241                     continue;
 242                 }
 243                 if (preg_match("/rule\s'(.*)'( \[(.*)\])?$/",$line,$match)) {
 244                     $ruleLine = 1;
 245                     $j++;
 246                     $rules[$j] = array( 'name' => $match[1]);
 247                     if(isset($match[3])) $rules[$j]['precondition'] = $match[3];
 248                 } else {
 249                     $errors[] = 'Invalid rule declaration on line '.($i+1);
 250                 }
 251                 continue;
 252             } else {
 253                 if ($ruleLine == -1) {
 254                     $errors[] = 'Unexpected characters on line '.($i+1);
 255                 }
 256             }
 257
 258             // Reading rule lines
 259             if ($ruleLine > 0) {
 260                 if (!isset($line[0])) {
 261                     continue; // Empty lines are ok
 262                 }
 263                 // Non tabbed lines are not
 264                 if ($line[0] != "\t") {
 265                     $errors[] = 'Unexpected character on line '.($i+1).'
 266                         . Expected tab, but found \''.$line[0].'\'';
 267                     continue;
 268                 }
 269                 $rules[$j][$ruleSyntax[$ruleLine++]] = chop(substr($line,1));
 270             }
 271
 272             // Rule complete
 273             if ($ruleLine == $numRules) {
 274                 $ruleLine = -1;
 275             }
 276         }
 277
 278         return array('rules' => $rules, 'errors' => $errors);
 279     }
 280 }
 281
 282 function PMA_bytime($num, $precision)
 283 {
 284     $per = '';
 285     if ($num >= 1) { # per second
 286         $per = "per second";
 287     } elseif ($num*60 >= 1) { # per minute
 288         $num = $num*60;
 289         $per = "per minute";
 290     } elseif ($num*60*60 >=1 ) { # per hour
 291         $num = $num*60*60;
 292         $per = "per hour";
 293     } else {
 294         $num = $num*60*60*24;
 295         $per = "per day";
 296     }
 297
 298     $num = round($num, $precision);
 299
 300     if ($num == 0) {
 301         $num = '<'.pow(10,-$precision);
 302     }
 303
 304     return "$num $per";
 305 }
 306
 307 ?>