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     {
  18         // HowTo: A simple Advisory system in 3 easy steps.
  19
  20         // Step 1: Get some variables to evaluate on
  21         $this->variables = array_merge(
  22             PMA_DBI_fetch_result('SHOW GLOBAL STATUS', 0, 1),
  23             PMA_DBI_fetch_result('SHOW GLOBAL VARIABLES', 0, 1)
  24         );
  25         if (PMA_DRIZZLE) {
  26             $this->variables = array_merge(
  27                 $this->variables,
  28                 PMA_DBI_fetch_result(
  29                     "SELECT concat('Com_', variable_name), variable_value
  30                     FROM data_dictionary.GLOBAL_STATEMENTS", 0, 1
  31                 )
  32             );
  33         }
  34         // Add total memory to variables as well
  35         include_once 'libraries/sysinfo.lib.php';
  36         $sysinfo = getSysInfo();
  37         $memory  = $sysinfo->memory();
  38         $this->variables['system_memory'] = $memory['MemTotal'];
  39
  40         // Step 2: Read and parse the list of rules
  41         $this->parseResult = $this->parseRulesFile();
  42         // Step 3: Feed the variables to the rules and let them fire. Sets $runResult
  43         $this->runRules();
  44
  45         return array(
  46             'parse' => array('errors' => $this->parseResult['errors']),
  47             'run'   => $this->runResult
  48         );
  49     }
  50
  51     function runRules()
  52     {
  53         $this->runResult = array(
  54             'fired' => array(),
  55             'notfired' => array(),
  56             'unchecked'=> array(),
  57             'errors' => array()
  58         );
  59
  60         foreach ($this->parseResult['rules'] as $rule) {
  61             $this->variables['value'] = 0;
  62             $precond = true;
  63
  64             if (isset($rule['precondition'])) {
  65                 try {
  66                      $precond = $this->ruleExprEvaluate($rule['precondition']);
  67                 } catch (Exception $e) {
  68                     $this->runResult['errors'][] = 'Failed evaluating precondition for rule \''
  69                         . $rule['name'] . '\'. PHP threw following error: '
  70                         . $e->getMessage();
  71                     continue;
  72                 }
  73             }
  74
  75             if (! $precond) {
  76                 $this->addRule('unchecked', $rule);
  77             } else {
  78                 try {
  79                     $value = $this->ruleExprEvaluate($rule['formula']);
  80                 } catch(Exception $e) {
  81                     $this->runResult['errors'][] = 'Failed calculating value for rule \''
  82                         . $rule['name'] . '\'. PHP threw following error: '
  83                         . $e->getMessage();
  84                     continue;
  85                 }
  86
  87                 $this->variables['value'] = $value;
  88
  89                 try {
  90                     if ($this->ruleExprEvaluate($rule['test'])) {
  91                         $this->addRule('fired', $rule);
  92                     } else {
  93                         $this->addRule('notfired', $rule);
  94                     }
  95                 }  catch(Exception $e) {
  96                     $this->runResult['errors'][] = 'Failed running test for rule \''
  97                         . $rule['name'] . '\'. PHP threw following error: '
  98                         . $e->getMessage();
  99                 }
 100             }
 101         }
 102
 103         return true;
 104     }
 105
 106     /**
 107      * Escapes percent string to be used in format string.
 108      *
 109      * @param string $str string to escape
 110      *
 111      * @return string
 112      */
 113     function escapePercent($str)
 114     {
 115         return preg_replace('/%( |,|\.|$)/', '%%\1', $str);
 116     }
 117
 118     /**
 119      * Wrapper function for translating.
 120      *
 121      * @param string $str
 122      * @param mixed  $param
 123      *
 124      * @return string
 125      */
 126     function translate($str, $param = null)
 127     {
 128         if (is_null($param)) {
 129             return sprintf(_gettext(Advisor::escapePercent($str)));
 130         } else {
 131             $printf = 'sprintf("' . _gettext(Advisor::escapePercent($str)) . '",';
 132             return $this->ruleExprEvaluate(
 133                 $printf . $param . ')',
 134                 strlen($printf)
 135             );
 136         }
 137     }
 138
 139     /**
 140      * Splits justification to text and formula.
 141      *
 142      * @param string $rule
 143      *
 144      * @return array
 145      */
 146     function splitJustification($rule)
 147     {
 148         $jst = preg_split('/\s*\|\s*/', $rule['justification'], 2);
 149         if (count($jst) > 1) {
 150             return array($jst[0], $jst[1]);
 151         }
 152         return array($rule['justification']);
 153     }
 154
 155     // Adds a rule to the result list
 156     function addRule($type, $rule)
 157     {
 158         switch($type) {
 159         case 'notfired':
 160         case 'fired':
 161             $jst = Advisor::splitJustification($rule);
 162             if (count($jst) > 1) {
 163                 try {
 164                     /* Translate */
 165                     $str = $this->translate($jst[0], $jst[1]);
 166                 } catch (Exception $e) {
 167                     $this->runResult['errors'][] = sprintf(
 168                         __('Failed formatting string for rule \'%s\'. PHP threw following error: %s'),
 169                         $rule['name'],
 170                         $e->getMessage()
 171                     );
 172                     return;
 173                 }
 174
 175                 $rule['justification'] = $str;
 176             } else {
 177                 $rule['justification'] = $this->translate($rule['justification']);
 178             }
 179             $rule['name'] = $this->translate($rule['name']);
 180             $rule['issue'] = $this->translate($rule['issue']);
 181
 182             // Replaces {server_variable} with 'server_variable'
 183             // linking to server_variables.php
 184             $rule['recommendation'] = preg_replace(
 185                 '/\{([a-z_0-9]+)\}/Ui',
 186                 '<a href="server_variables.php?' . PMA_generate_common_url() . '#filter=\1">\1</a>',
 187                 $this->translate($rule['recommendation'])
 188             );
 189
 190             // Replaces external Links with PMA_linkURL() generated links
 191             $rule['recommendation'] = preg_replace(
 192                 '#href=("|\')(https?://[^\1]+)\1#ie',
 193                 '\'href="\' . PMA_linkURL("\2") . \'"\'',
 194                 $rule['recommendation']
 195             );
 196             break;
 197         }
 198
 199         $this->runResult[$type][] = $rule;
 200     }
 201
 202     private function ruleExprEvaluate_var1($matches)
 203     {
 204         // '/fired\s*\(\s*(\'|")(.*)\1\s*\)/Uie'
 205         return '1'; //isset($this->runResult[\'fired\']
 206     }
 207
 208     private function ruleExprEvaluate_var2($matches)
 209     {
 210         // '/\b(\w+)\b/e'
 211         return isset($this->variables[$matches[1]])
 212             ? (is_numeric($this->variables[$matches[1]])
 213                 ? $this->variables[$matches[1]]
 214                 : '"'.$this->variables[$matches[1]].'"')
 215             : $matches[1];
 216     }
 217
 218     // Runs a code expression, replacing variable names with their respective values
 219     // ignoreUntil: if > 0, it doesn't replace any variables until that string
 220     // position, but still evaluates the whole expr
 221     function ruleExprEvaluate($expr, $ignoreUntil = 0)
 222     {
 223         if ($ignoreUntil > 0) {
 224             $exprIgnore = substr($expr, 0, $ignoreUntil);
 225             $expr = substr($expr, $ignoreUntil);
 226         }
 227         $expr = preg_replace_callback(
 228             '/fired\s*\(\s*(\'|")(.*)\1\s*\)/Ui',
 229             array($this, 'ruleExprEvaluate_var1'),
 230             $expr
 231         );
 232         $expr = preg_replace_callback(
 233             '/\b(\w+)\b/',
 234             array($this, 'ruleExprEvaluate_var2'),
 235             $expr
 236         );
 237         if ($ignoreUntil > 0) {
 238             $expr = $exprIgnore . $expr;
 239         }
 240         $value = 0;
 241         $err = 0;
 242
 243         ob_start();
 244         eval('$value = '.$expr.';');
 245         $err = ob_get_contents();
 246         ob_end_clean();
 247         if ($err) {
 248             throw new Exception(
 249                 strip_tags($err) . '<br />Executed code: $value = ' . $expr . ';'
 250             );
 251         }
 252         return $value;
 253     }
 254
 255     // Reads the rule file into an array, throwing errors messages on syntax errors
 256     function parseRulesFile()
 257     {
 258         $file = file('libraries/advisory_rules.txt');
 259         $errors = array();
 260         $rules = array();
 261         $ruleSyntax = array('name', 'formula', 'test', 'issue', 'recommendation', 'justification');
 262         $numRules = count($ruleSyntax);
 263         $numLines = count($file);
 264         $j = -1;
 265         $ruleLine = -1;
 266
 267         for ($i = 0; $i<$numLines; $i++) {
 268             $line = $file[$i];
 269             if ($line[0] == '#' || $line[0] == "\n") {
 270                 continue;
 271             }
 272
 273             // Reading new rule
 274             if (substr($line, 0, 4) == 'rule') {
 275                 if ($ruleLine > 0) {
 276                     $errors[] = 'Invalid rule declaration on line ' . ($i+1)
 277                         . ', expected line ' . $ruleSyntax[$ruleLine++]
 278                         . ' of previous rule' ;
 279                     continue;
 280                 }
 281                 if (preg_match("/rule\s'(.*)'( \[(.*)\])?$/", $line, $match)) {
 282                     $ruleLine = 1;
 283                     $j++;
 284                     $rules[$j] = array( 'name' => $match[1]);
 285                     if (isset($match[3])) {
 286                         $rules[$j]['precondition'] = $match[3];
 287                     }
 288                 } else {
 289                     $errors[] = 'Invalid rule declaration on line '.($i+1);
 290                 }
 291                 continue;
 292             } else {
 293                 if ($ruleLine == -1) {
 294                     $errors[] = 'Unexpected characters on line '.($i+1);
 295                 }
 296             }
 297
 298             // Reading rule lines
 299             if ($ruleLine > 0) {
 300                 if (!isset($line[0])) {
 301                     continue; // Empty lines are ok
 302                 }
 303                 // Non tabbed lines are not
 304                 if ($line[0] != "\t") {
 305                     $errors[] = 'Unexpected character on line '.($i+1).'
 306                         . Expected tab, but found \''.$line[0].'\'';
 307                     continue;
 308                 }
 309                 $rules[$j][$ruleSyntax[$ruleLine++]] = chop(substr($line, 1));
 310             }
 311
 312             // Rule complete
 313             if ($ruleLine == $numRules) {
 314                 $ruleLine = -1;
 315             }
 316         }
 317
 318         return array('rules' => $rules, 'errors' => $errors);
 319     }
 320 }
 321
 322 function PMA_bytime($num, $precision)
 323 {
 324     $per = '';
 325     if ($num >= 1) { // per second
 326         $per = "per second";
 327     } elseif ($num*60 >= 1) { // per minute
 328         $num = $num*60;
 329         $per = "per minute";
 330     } elseif ($num*60*60 >=1 ) { // per hour
 331         $num = $num*60*60;
 332         $per = "per hour";
 333     } else {
 334         $num = $num*60*60*24;
 335         $per = "per day";
 336     }
 337
 338     $num = round($num, $precision);
 339
 340     if ($num == 0) {
 341         $num = '<' . pow(10, -$precision);
 342     }
 343
 344     return "$num $per";
 345 }
 346
 347 ?>