/**
* Attempts to construct a map based on given DBC, predicting what each field could possibly hold by way of sampling
*/
public static function fromDBC(DBC $dbc, $attach = true)
{
$fields = $dbc->getFieldCount();
$samples = $dbc->getRecordCount() > self::SAMPLES ? self::SAMPLES : $dbc->getRecordCount();
$block = $dbc->getStringBlock();
preg_match_all('#\\0#', $block, $matches, PREG_OFFSET_CAPTURE);
$strings = array();
foreach ($matches[0] as $offset) {
$offset = (int) $offset[1] + 1;
if ($offset < strlen($block) - 1) {
$strings[$offset] = true;
}
}
$matrix = array_fill(1, $fields, 0);
for ($i = 0; $i < $samples; $i++) {
$record = $dbc->getRecord($i);
$values = $record->asArray();
foreach ($values as $offset => $value) {
if ($value < 0) {
$matrix[$offset] += 1 << 0;
}
if (self::isProbableFloat($value)) {
$matrix[$offset] += 1 << 8;
}
if (isset($strings[$value]) || $value === 0) {
$matrix[$offset] += 1 << 16;
if ($value !== 0) {
$matrix[$offset] |= 1 << 24;
}
}
}
}
$map = new self();
for ($i = 1; $i <= $fields; $i++) {
$probs = $matrix[$i];
$int = ($probs & 0xff) / $samples;
$flt = (($probs & 0xff00) >> 8) / $samples;
$str = (($probs & 0xff0000) >> 16) / $samples;
$strbit = ($probs & 0xff000000) >> 24;
$field = 'field' . $i;
if ($flt > 0.6) {
$type = DBC::FLOAT;
} else {
if ($strbit > 0 && $str > 0.99) {
$type = DBC::STRING;
if ($i + DBC::LOCALIZATION <= $fields) {
$type = DBC::STRING_LOC;
for ($j = $i + 1; $j <= $i + DBC::LOCALIZATION; $j++) {
$probs = $matrix[$j];
$str = (($probs & 0xff0000) >> 16) / $samples;
$strbit = ($probs & 0xff000000) >> 24;
if ($str !== 1 || $strbit !== 0) {
$type = DBC::STRING;
}
}
if ($type === DBC::STRING_LOC) {
$i += DBC::LOCALIZATION;
}
}
} else {
if ($int > 0.01) {
$type = DBC::INT;
} else {
$type = DBC::UINT;
}
}
}
$map->add($field, $type);
}
if ($attach && $dbc->getMap() === null) {
$dbc->attach($map);
}
return $map;
}