/**
* Scans terms dictionary and returns next term
*
* @return \Zend\Search\Lucene\Index\Term|null
*/
public function nextTerm()
{
if ($this->_tisFile === null || $this->_termCount == 0) {
$this->_lastTerm = null;
$this->_lastTermInfo = null;
$this->_lastTermPositions = null;
$this->_docMap = null;
// may be necessary for "empty" segment
$this->_tisFile = null;
$this->_frqFile = null;
$this->_prxFile = null;
return null;
}
$termPrefixLength = $this->_tisFile->readVInt();
$termSuffix = $this->_tisFile->readString();
$termFieldNum = $this->_tisFile->readVInt();
$termValue = Term::getPrefix($this->_lastTerm->text, $termPrefixLength) . $termSuffix;
$this->_lastTerm = new Term($termValue, $this->_fields[$termFieldNum]->name);
$docFreq = $this->_tisFile->readVInt();
$freqPointer = $this->_lastTermInfo->freqPointer + $this->_tisFile->readVInt();
$proxPointer = $this->_lastTermInfo->proxPointer + $this->_tisFile->readVInt();
if ($docFreq >= $this->_skipInterval) {
$skipOffset = $this->_tisFile->readVInt();
} else {
$skipOffset = 0;
}
$this->_lastTermInfo = new TermInfo($docFreq, $freqPointer, $proxPointer, $skipOffset);
if ($this->_termsScanMode == self::SM_FULL_INFO || $this->_termsScanMode == self::SM_MERGE_INFO) {
$this->_lastTermPositions = array();
$this->_frqFile->seek($this->_lastTermInfo->freqPointer + $this->_frqFileOffset, SEEK_SET);
$freqs = array();
$docId = 0;
for ($count = 0; $count < $this->_lastTermInfo->docFreq; $count++) {
$docDelta = $this->_frqFile->readVInt();
if ($docDelta % 2 == 1) {
$docId += ($docDelta - 1) / 2;
$freqs[$docId] = 1;
} else {
$docId += $docDelta / 2;
$freqs[$docId] = $this->_frqFile->readVInt();
}
}
$this->_prxFile->seek($this->_lastTermInfo->proxPointer + $this->_prxFileOffset, SEEK_SET);
foreach ($freqs as $docId => $freq) {
$termPosition = 0;
$positions = array();
for ($count = 0; $count < $freq; $count++) {
$termPosition += $this->_prxFile->readVInt();
$positions[] = $termPosition;
}
if (isset($this->_docMap[$docId])) {
$this->_lastTermPositions[$this->_docMap[$docId]] = $positions;
}
}
}
$this->_termCount--;
if ($this->_termCount == 0) {
$this->_tisFile = null;
$this->_frqFile = null;
$this->_prxFile = null;
}
return $this->_lastTerm;
}
