NamespaceDetails::Extra* NamespaceDetails::allocExtra(OperationContext* txn,
StringData ns,
NamespaceIndex& ni,
int nindexessofar) {
// Namespace details must always be changed under an exclusive DB lock
const NamespaceString nss(ns);
invariant(txn->lockState()->isDbLockedForMode(nss.db(), MODE_X));
int i = (nindexessofar - NIndexesBase) / NIndexesExtra;
verify(i >= 0 && i <= 1);
Namespace fullns(ns);
Namespace extrans(fullns.extraName(i)); // throws UserException if ns name too long
massert(10350, "allocExtra: base ns missing?", this);
massert(10351, "allocExtra: extra already exists", ni.details(extrans) == 0);
Extra temp;
temp.init();
ni.add_ns(txn, extrans, reinterpret_cast<NamespaceDetails*>(&temp));
Extra* e = reinterpret_cast<NamespaceDetails::Extra*>(ni.details(extrans));
long ofs = e->ofsFrom(this);
if (i == 0) {
verify(_extraOffset == 0);
*txn->recoveryUnit()->writing(&_extraOffset) = ofs;
verify(extra() == e);
} else {
Extra* hd = extra();
verify(hd->next(this) == 0);
hd->setNext(txn, ofs);
}
return e;
}
// must be called when renaming a NS to fix up extra
void NamespaceDetails::copyingFrom( OperationContext* txn,
const StringData& thisns,
NamespaceIndex& ni,
NamespaceDetails* src) {
_extraOffset = 0; // we are a copy -- the old value is wrong. fixing it up below.
Extra *se = src->extra();
int n = NIndexesBase;
if( se ) {
Extra *e = allocExtra(txn, thisns, ni, n);
while( 1 ) {
n += NIndexesExtra;
e->copy(this, *se);
se = se->next(src);
if( se == 0 ) break;
Extra *nxt = allocExtra(txn, thisns, ni, n);
e->setNext( txn, nxt->ofsFrom(this) );
e = nxt;
}
verify( _extraOffset );
}
}