AutoGetCollectionForRead::AutoGetCollectionForRead(OperationContext* txn,
const NamespaceString& nss)
: _txn(txn), _transaction(txn, MODE_IS) {
{
_autoColl.emplace(txn, nss, MODE_IS);
auto curOp = CurOp::get(_txn);
stdx::lock_guard<Client> lk(*_txn->getClient());
// TODO: OldClientContext legacy, needs to be removed
curOp->ensureStarted();
curOp->setNS_inlock(nss.ns());
// At this point, we are locked in shared mode for the database by the DB lock in the
// constructor, so it is safe to load the DB pointer.
if (_autoColl->getDb()) {
// TODO: OldClientContext legacy, needs to be removed
curOp->enter_inlock(nss.ns().c_str(), _autoColl->getDb()->getProfilingLevel());
}
}
// Note: this can yield.
_ensureMajorityCommittedSnapshotIsValid(nss);
// We have both the DB and collection locked, which is the prerequisite to do a stable shard
// version check, but we'd like to do the check after we have a satisfactory snapshot.
auto css = CollectionShardingState::get(txn, nss);
css->checkShardVersionOrThrow(txn);
}
void AutoGetCollectionForRead::_init(const std::string& ns, StringData coll) {
massert(28535, "need a non-empty collection name", !coll.empty());
// We have both the DB and collection locked, which the prerequisite to do a stable shard
// version check.
ensureShardVersionOKOrThrow(_txn, ns);
auto curOp = CurOp::get(_txn);
stdx::lock_guard<Client> lk(*_txn->getClient());
// TODO: OldClientContext legacy, needs to be removed
curOp->ensureStarted();
curOp->setNS_inlock(ns);
// At this point, we are locked in shared mode for the database by the DB lock in the
// constructor, so it is safe to load the DB pointer.
if (_db.getDb()) {
// TODO: OldClientContext legacy, needs to be removed
curOp->enter_inlock(ns.c_str(), _db.getDb()->getProfilingLevel());
_coll = _db.getDb()->getCollection(ns);
}
if (_coll) {
if (auto minSnapshot = _coll->getMinimumVisibleSnapshot()) {
if (auto mySnapshot = _txn->recoveryUnit()->getMajorityCommittedSnapshot()) {
while (mySnapshot < minSnapshot) {
// Wait until a snapshot is available.
repl::ReplicationCoordinator::get(_txn)->waitForNewSnapshot(_txn);
Status status = _txn->recoveryUnit()->setReadFromMajorityCommittedSnapshot();
uassert(28786,
"failed to set read from majority-committed snapshot",
status.isOK());
mySnapshot = _txn->recoveryUnit()->getMajorityCommittedSnapshot();
}
}
}
}
}
void AutoGetCollectionForRead::_init(const std::string& ns, StringData coll) {
massert(28535, "need a non-empty collection name", !coll.empty());
// We have both the DB and collection locked, which the prerequisite to do a stable shard
// version check.
ensureShardVersionOKOrThrow(_txn->getClient(), ns);
auto curOp = CurOp::get(_txn);
stdx::lock_guard<Client> lk(*_txn->getClient());
// TODO: OldClientContext legacy, needs to be removed
curOp->ensureStarted();
curOp->setNS_inlock(ns);
// At this point, we are locked in shared mode for the database by the DB lock in the
// constructor, so it is safe to load the DB pointer.
if (_db.getDb()) {
// TODO: OldClientContext legacy, needs to be removed
curOp->enter_inlock(ns.c_str(), _db.getDb()->getProfilingLevel());
_coll = _db.getDb()->getCollection(ns);
}
}