public function has($value)
{
$hashes = $this->_hashes($value);
if (function_exists('gmp_testbit')) {
foreach ($hashes as $hash) {
if (!gmp_testbit($this->_gmp, $hash)) {
return false;
}
}
} else {
foreach ($hashes as $hash) {
if (gmp_scan1($this->_gmp, $hash) !== $hash) {
return false;
}
}
}
return true;
}
/**
* Scan the blobs table for rows not registered in blob_tracking (and thus not
* registered in the text table).
*
* Orphan blobs are indicative of DB corruption. They are inaccessible and
* should probably be deleted.
*/
function findOrphanBlobs()
{
if (!extension_loaded('gmp')) {
echo "Can't find orphan blobs, need bitfield support provided by GMP.\n";
return;
}
$dbw = wfGetDB(DB_MASTER);
foreach ($this->clusters as $cluster) {
echo "Searching for orphan blobs in {$cluster}...\n";
$lb = wfGetLBFactory()->getExternalLB($cluster);
try {
$extDB = $lb->getConnection(DB_SLAVE);
} catch (DBConnectionError $e) {
if (strpos($e->error, 'Unknown database') !== false) {
echo "No database on {$cluster}\n";
} else {
echo "Error on {$cluster}: " . $e->getMessage() . "\n";
}
continue;
}
$table = $extDB->getLBInfo('blobs table');
if (is_null($table)) {
$table = 'blobs';
}
if (!$extDB->tableExists($table)) {
echo "No blobs table on cluster {$cluster}\n";
continue;
}
$startId = 0;
$batchesDone = 0;
$actualBlobs = gmp_init(0);
$endId = $extDB->selectField($table, 'MAX(blob_id)', false, __METHOD__);
// Build a bitmap of actual blob rows
while (true) {
$res = $extDB->select($table, array('blob_id'), array('blob_id > ' . $extDB->addQuotes($startId)), __METHOD__, array('LIMIT' => $this->batchSize, 'ORDER BY' => 'blob_id'));
if (!$res->numRows()) {
break;
}
foreach ($res as $row) {
gmp_setbit($actualBlobs, $row->blob_id);
}
$startId = $row->blob_id;
++$batchesDone;
if ($batchesDone >= $this->reportingInterval) {
$batchesDone = 0;
echo "{$startId} / {$endId}\n";
}
}
// Find actual blobs that weren't tracked by the previous passes
// This is a set-theoretic difference A \ B, or in bitwise terms, A & ~B
$orphans = gmp_and($actualBlobs, gmp_com($this->trackedBlobs[$cluster]));
// Traverse the orphan list
$insertBatch = array();
$id = 0;
$numOrphans = 0;
while (true) {
$id = gmp_scan1($orphans, $id);
if ($id == -1) {
break;
}
$insertBatch[] = array('bo_cluster' => $cluster, 'bo_blob_id' => $id);
if (count($insertBatch) > $this->batchSize) {
$dbw->insert('blob_orphans', $insertBatch, __METHOD__);
$insertBatch = array();
}
++$id;
++$numOrphans;
}
if ($insertBatch) {
$dbw->insert('blob_orphans', $insertBatch, __METHOD__);
}
echo "Found {$numOrphans} orphan(s) in {$cluster}\n";
}
}
// definitely a prime
// gmp_random -- not implemented
// gmp_scan0
// "0" bit is found at position 3. index starts at 0
$s1 = gmp_init("10111", 2);
echo gmp_scan0($s1, 0) . "\n";
// "0" bit is found at position 7. index starts at 5
$s2 = gmp_init("101110000", 2);
echo gmp_scan0($s2, 5) . "\n";
// gmp_scan1
// "0" bit is found at position 3. index starts at 0
$s1 = gmp_init("01000", 2);
echo gmp_scan1($s1, 0) . "\n";
// "0" bit is found at position 7. index starts at 5
$s2 = gmp_init("01000001111", 2);
echo gmp_scan1($s2, 5) . "\n";
// gmp_setbit
$a = gmp_init("2");
//
echo gmp_strval($a), ' -> 0b', gmp_strval($a, 2), "\n";
gmp_setbit($a, 0);
// 0b10 now becomes 0b11
echo gmp_strval($a), ' -> 0b', gmp_strval($a, 2), "\n";
$a = gmp_init("0xfd");
echo gmp_strval($a), ' -> 0b', gmp_strval($a, 2), "\n";
gmp_setbit($a, 1);
// index starts at 0
echo gmp_strval($a), ' -> 0b', gmp_strval($a, 2), "\n";
$a = gmp_init("0xff");
echo gmp_strval($a), ' -> 0b', gmp_strval($a, 2), "\n";
gmp_setbit($a, 0, false);
<?php
var_dump(gmp_scan1("434234", -10));
var_dump(gmp_scan1("434234", 1));
var_dump(gmp_scan1(4096, 0));
var_dump(gmp_scan1("1000000000", 5));
var_dump(gmp_scan1("1000000000", 200));
$n = gmp_init("24234527465274");
var_dump(gmp_scan1($n, 10));
var_dump(gmp_scan1(array(), 200));
var_dump(gmp_scan1(array()));
var_dump(gmp_scan1());
echo "Done\n";
