コード例 #1
0
ファイル: Index.php プロジェクト: malkusch/php-index
 /**
  * Searches a range
  * 
  * @param Range $range 
  * 
  * @return RangeIterator
  */
 public function searchRange(Range $range)
 {
     $iterator = $this->getIterator();
     // find start
     $start = null;
     $binarySearch = new BinarySearch($this);
     $startHint = $binarySearch->search($range->getMin());
     if ($startHint == null) {
         return new RangeIterator($iterator, Range::getEmptyRange());
     }
     $iterator->setOffset($startHint->getOffset(), Parser::HINT_RESULT_BOUNDARY);
     if (!$range->contains($startHint->getKey()) && $startHint->getKey() <= $range->getMin()) {
         // shift $startHint higher
         foreach ($iterator as $result) {
             if ($range->contains($result->getKey())) {
                 $start = $result;
                 break;
             }
         }
     } else {
         // shift $startHint lower
         if ($range->contains($startHint->getKey())) {
             $start = $startHint;
         }
         $iterator->setDirection(KeyReader::DIRECTION_BACKWARD);
         foreach ($iterator as $result) {
             // Skip everything which is too big
             if (!$range->contains($result->getKey() && $result->getKey() >= $range->getMax())) {
                 continue;
             }
             // shift the start left until no more key is included
             if ($range->contains($result->getKey())) {
                 $start = $result;
             } else {
                 break;
             }
         }
     }
     if (is_null($start)) {
         return new RangeIterator($iterator, Range::getEmptyRange());
     }
     $iterator = $this->getIterator();
     $iterator->setOffset($start->getOffset(), Parser::HINT_RESULT_BOUNDARY);
     return new RangeIterator($iterator, $range);
 }