/**
* @throws Exception
*/
protected function finish()
{
// Hack for DBA cross-check
$this->hplist = array_reverse($this->hplist);
// Calculate the number of items that will be in each hashtable
$counts = array_fill(0, 256, 0);
foreach ($this->hplist as $item) {
++$counts[255 & $item['h']];
}
// Fill in $starts with the *end* indexes
$starts = array();
$pos = 0;
for ($i = 0; $i < 256; ++$i) {
$pos += $counts[$i];
$starts[$i] = $pos;
}
// Excessively clever and indulgent code to simultaneously fill $packedTables
// with the packed hashtables, and adjust the elements of $starts
// to actually point to the starts instead of the ends.
$packedTables = array_fill(0, $this->numentries, false);
foreach ($this->hplist as $item) {
$packedTables[--$starts[255 & $item['h']]] = $item;
}
$final = '';
for ($i = 0; $i < 256; ++$i) {
$count = $counts[$i];
// The size of the hashtable will be double the item count.
// The rest of the slots will be empty.
$len = $count + $count;
$final .= pack('VV', $this->pos, $len);
$hashtable = array();
for ($u = 0; $u < $len; ++$u) {
$hashtable[$u] = array('h' => 0, 'p' => 0);
}
// Fill the hashtable, using the next empty slot if the hashed slot
// is taken.
for ($u = 0; $u < $count; ++$u) {
$hp = $packedTables[$starts[$i] + $u];
$where = Util::unsignedMod(Util::unsignedShiftRight($hp['h'], 8), $len);
while ($hashtable[$where]['p']) {
if (++$where == $len) {
$where = 0;
}
}
$hashtable[$where] = $hp;
}
// Write the hashtable
for ($u = 0; $u < $len; ++$u) {
$buf = pack('vvV', $hashtable[$u]['h'] & 0xffff, Util::unsignedShiftRight($hashtable[$u]['h'], 16), $hashtable[$u]['p']);
$this->write($buf);
$this->posplus(8);
}
}
// Write the pointer array at the start of the file
rewind($this->handle);
if (ftell($this->handle) != 0) {
$this->throwException('Error rewinding to start of file "' . $this->tmpFileName . '".');
}
$this->write($final);
}
/**
* @param string $key
* @return bool
*/
protected function findNext($key)
{
if (!$this->loop) {
$u = Util::hash($key);
$buf = $this->read(8, $u << 3 & 2047);
$this->hslots = $this->unpack31(substr($buf, 4));
if (!$this->hslots) {
return false;
}
$this->hpos = $this->unpack31(substr($buf, 0, 4));
$this->khash = $u;
$u = Util::unsignedShiftRight($u, 8);
$u = Util::unsignedMod($u, $this->hslots);
$u <<= 3;
$this->kpos = $this->hpos + $u;
}
while ($this->loop < $this->hslots) {
$buf = $this->read(8, $this->kpos);
$pos = $this->unpack31(substr($buf, 4));
if (!$pos) {
return false;
}
$this->loop += 1;
$this->kpos += 8;
if ($this->kpos == $this->hpos + ($this->hslots << 3)) {
$this->kpos = $this->hpos;
}
$u = $this->unpackSigned(substr($buf, 0, 4));
if ($u === $this->khash) {
$buf = $this->read(8, $pos);
$keyLen = $this->unpack31(substr($buf, 0, 4));
if ($keyLen == strlen($key) && $this->match($key, $pos + 8)) {
// Found
$this->dlen = $this->unpack31(substr($buf, 4));
$this->dpos = $pos + 8 + $keyLen;
return true;
}
}
}
return false;
}
/**
* Search the CDB file for a key.
*
* Sets `dataLen` and `dataPos` properties if successful.
*
* @param string $key
* @return bool Whether the key was found.
*/
protected function find($key)
{
$keyLen = strlen($key);
$u = Util::hash($key);
$upos = $u << 3 & 2047;
$hashSlots = $this->readInt31($upos + 4);
if (!$hashSlots) {
return false;
}
$hashPos = $this->readInt31($upos);
$keyHash = $u;
$u = Util::unsignedShiftRight($u, 8);
$u = Util::unsignedMod($u, $hashSlots);
$u <<= 3;
$keyPos = $hashPos + $u;
for ($i = 0; $i < $hashSlots; $i++) {
$hash = $this->readInt32($keyPos);
$pos = $this->readInt31($keyPos + 4);
if (!$pos) {
return false;
}
$keyPos += 8;
if ($keyPos == $hashPos + ($hashSlots << 3)) {
$keyPos = $hashPos;
}
if ($hash === $keyHash) {
if ($keyLen === $this->readInt31($pos)) {
$dataLen = $this->readInt31($pos + 4);
$dataPos = $pos + 8 + $keyLen;
$foundKey = $this->read($pos + 8, $keyLen);
if ($foundKey === $key) {
// Found
$this->dataLen = $dataLen;
$this->dataPos = $dataPos;
return true;
}
}
}
}
return false;
}