void NamespaceIndex::drop() {
Lock::assertWriteLocked(_database);
init();
if (!allocated()) {
return;
}
string errmsg;
BSONObjBuilder result;
// This implementation is inefficient and slightly messy, but it was easy.
// Feel free to improve it as necessary:
// - The getCursor call will grab a table lock on .system.namespaces.
// - We'll look at the entire system.namespaces collection just for one database.
// - Code is duplicated to handle dropping system system collections in stages.
vector<string> sysIndexesEntries;
const string systemNamespacesNs = getSisterNS(_database, "system.namespaces");
NamespaceDetails *sysNsd = nsdetails(systemNamespacesNs);
for (shared_ptr<Cursor> c(BasicCursor::make(sysNsd)); c->ok(); c->advance()) {
const BSONObj nsObj = c->current();
const StringData ns = nsObj["name"].Stringdata();
if (nsToDatabaseSubstring(ns) != _database) {
// Not part of this database, skip.
continue;
}
if (nsToCollectionSubstring(ns) == "system.indexes") {
// Save .system.indexes collection for last, because dropCollection deletes from it.
sysIndexesEntries.push_back(ns.toString());
} else {
dropCollection(ns, errmsg, result, true);
}
}
if (sysNsd != NULL) {
// The .system.namespaces collection does not include itself.
dropCollection(systemNamespacesNs, errmsg, result, true);
}
// Now drop the system.indexes entries.
for (vector<string>::const_iterator it = sysIndexesEntries.begin(); it != sysIndexesEntries.end(); it++) {
// Need to close any existing handle before drop.
const string &ns = *it;
dropCollection(ns, errmsg, result, true);
}
// Everything that was open should have been closed due to drop.
verify(_namespaces.empty());
shared_ptr<storage::Dictionary> nsdb = _nsdb;
_nsdb.reset();
const int r = nsdb->close();
if (r != 0) {
storage::handle_ydb_error(r);
}
storage::db_remove(_nsdbFilename);
}
void deleteOplogFiles() {
rsOplogDetails = NULL;
rsOplogRefsDetails = NULL;
replInfoDetails = NULL;
Client::Context ctx(rsoplog, dbpath);
// TODO: code review this for possible error cases
// although, I don't think we care about error cases,
// just that after we exit, oplog files don't exist
BSONObjBuilder out;
string errmsg;
dropCollection(rsoplog, errmsg, out);
dropCollection(rsOplogRefs, errmsg, out);
dropCollection(rsReplInfo, errmsg, out);
}
void Database::clearTmpCollections(OperationContext* txn) {
txn->lockState()->assertWriteLocked( _name );
list<string> collections;
_dbEntry->getCollectionNamespaces( &collections );
for ( list<string>::iterator i = collections.begin(); i != collections.end(); ++i ) {
string ns = *i;
invariant( NamespaceString::normal( ns ) );
CollectionCatalogEntry* coll = _dbEntry->getCollectionCatalogEntry( txn, ns );
CollectionOptions options = coll->getCollectionOptions( txn );
if ( !options.temp )
continue;
WriteUnitOfWork wunit(txn);
Status status = dropCollection( txn, ns );
if ( !status.isOK() ) {
warning() << "could not drop temp collection '" << ns << "': " << status;
continue;
}
string cmdNs = _name + ".$cmd";
repl::logOp( txn,
"c",
cmdNs.c_str(),
BSON( "drop" << nsToCollectionSubstring( ns ) ) );
wunit.commit();
}
}
void Database::clearTmpCollections(OperationContext* txn) {
invariant(txn->lockState()->isDbLockedForMode(name(), MODE_X));
list<string> collections;
_dbEntry->getCollectionNamespaces(&collections);
for (list<string>::iterator i = collections.begin(); i != collections.end(); ++i) {
string ns = *i;
invariant(NamespaceString::normal(ns));
CollectionCatalogEntry* coll = _dbEntry->getCollectionCatalogEntry(ns);
CollectionOptions options = coll->getCollectionOptions(txn);
if (!options.temp)
continue;
try {
WriteUnitOfWork wunit(txn);
Status status = dropCollection(txn, ns);
if (!status.isOK()) {
warning() << "could not drop temp collection '" << ns << "': " << redact(status);
continue;
}
wunit.commit();
} catch (const WriteConflictException& exp) {
warning() << "could not drop temp collection '" << ns << "' due to "
"WriteConflictException";
txn->recoveryUnit()->abandonSnapshot();
}
}
}
bool ClientCursor::prepareToYield( YieldData &data ) {
if ( ! _c->supportYields() )
return false;
// need to store in case 'this' gets deleted
data._id = _cursorid;
data._doingDeletes = _doingDeletes;
_doingDeletes = false;
updateLocation();
{
/* a quick test that our temprelease is safe.
todo: make a YieldingCursor class
and then make the following code part of a unit test.
*/
const int test = 0;
static bool inEmpty = false;
if( test && !inEmpty ) {
inEmpty = true;
log() << "TEST: manipulate collection during cc:yield" << endl;
if( test == 1 )
Helpers::emptyCollection(_ns.c_str());
else if( test == 2 ) {
BSONObjBuilder b; string m;
dropCollection(_ns.c_str(), m, b);
}
else {
dropDatabase(_ns.c_str());
}
}
}
return true;
}
bool Client::shutdown(){
_shutdown = true;
if ( inShutdown() )
return false;
{
scoped_lock bl(clientsMutex);
clients.erase(this);
}
bool didAnything = false;
if ( _tempCollections.size() ){
didAnything = true;
for ( list<string>::iterator i = _tempCollections.begin(); i!=_tempCollections.end(); i++ ){
string ns = *i;
Top::global.collectionDropped( ns );
dblock l;
Client::Context ctx( ns );
if ( ! nsdetails( ns.c_str() ) )
continue;
try {
string err;
BSONObjBuilder b;
dropCollection( ns , err , b );
}
catch ( ... ){
log() << "error dropping temp collection: " << ns << endl;
}
}
_tempCollections.clear();
}
return didAnything;
}
virtual ~Base() {
if ( !nsd() )
return;
string s( ns() );
string errmsg;
BSONObjBuilder result;
dropCollection( s, errmsg, result );
}
void drop() {
Client::Context c(_ns);
if (nsdetails(_ns.c_str()) != NULL) {
string errmsg;
BSONObjBuilder result;
dropCollection( string(_ns), errmsg, result );
}
}
Status AuthzManagerExternalStateMock::renameCollection(const NamespaceString& oldName,
const NamespaceString& newName,
const BSONObj& writeConcern) {
if (_documents.count(oldName) == 0) {
return Status(ErrorCodes::NamespaceNotFound,
"No collection to rename named " + oldName.ns());
}
std::swap(_documents[newName], _documents[oldName]);
return dropCollection(oldName, writeConcern);
}
void drop() {
Client::WriteContext c(ns());
string errmsg;
BSONObjBuilder result;
if (nsdetails(ns()) == NULL) {
return;
}
dropCollection( string(ns()), errmsg, result );
}
bool ClientCursor::yield( int micros ) {
// need to store on the stack in case this gets deleted
CursorId id = cursorid;
bool doingDeletes = _doingDeletes;
_doingDeletes = false;
updateLocation();
{
/* a quick test that our temprelease is safe.
todo: make a YieldingCursor class
and then make the following code part of a unit test.
*/
const int test = 0;
static bool inEmpty = false;
if( test && !inEmpty ) {
inEmpty = true;
log() << "TEST: manipulate collection during cc:yield" << endl;
if( test == 1 )
Helpers::emptyCollection(ns.c_str());
else if( test == 2 ) {
BSONObjBuilder b; string m;
dropCollection(ns.c_str(), m, b);
}
else {
dropDatabase(ns.c_str());
}
}
}
{
dbtempreleasecond unlock;
if ( unlock.unlocked() ){
if ( micros == -1 )
micros = Client::recommendedYieldMicros();
if ( micros > 0 )
sleepmicros( micros );
}
else {
log( LL_WARNING ) << "ClientCursor::yield can't unlock b/c of recursive lock" << endl;
}
}
if ( ClientCursor::find( id , false ) == 0 ){
// i was deleted
return false;
}
_doingDeletes = doingDeletes;
return true;
}
TEST_F(KVCatalogTest, Coll1) {
unique_ptr<KVHarnessHelper> helper(KVHarnessHelper::create());
KVEngine* engine = helper->getEngine();
unique_ptr<RecordStore> rs;
unique_ptr<KVCatalog> catalog;
{
MyOperationContext opCtx(engine);
WriteUnitOfWork uow(&opCtx);
ASSERT_OK(engine->createRecordStore(&opCtx, "catalog", "catalog", CollectionOptions()));
rs = engine->getRecordStore(&opCtx, "catalog", "catalog", CollectionOptions());
catalog.reset(new KVCatalog(rs.get(), false, false, nullptr));
uow.commit();
}
{
MyOperationContext opCtx(engine);
WriteUnitOfWork uow(&opCtx);
ASSERT_OK(newCollection(&opCtx,
NamespaceString("a.b"),
CollectionOptions(),
KVPrefix::kNotPrefixed,
catalog.get()));
ASSERT_NOT_EQUALS("a.b", catalog->getCollectionIdent("a.b"));
uow.commit();
}
string ident = catalog->getCollectionIdent("a.b");
{
MyOperationContext opCtx(engine);
WriteUnitOfWork uow(&opCtx);
catalog.reset(new KVCatalog(rs.get(), false, false, nullptr));
catalog->init(&opCtx);
uow.commit();
}
ASSERT_EQUALS(ident, catalog->getCollectionIdent("a.b"));
{
MyOperationContext opCtx(engine);
WriteUnitOfWork uow(&opCtx);
dropCollection(&opCtx, "a.b", catalog.get()).transitional_ignore();
newCollection(&opCtx,
NamespaceString("a.b"),
CollectionOptions(),
KVPrefix::kNotPrefixed,
catalog.get())
.transitional_ignore();
uow.commit();
}
ASSERT_NOT_EQUALS(ident, catalog->getCollectionIdent("a.b"));
}
DbSet::~DbSet() {
if ( name_.empty() )
return;
try {
Client::Context c( name_.c_str() );
if ( nsdetails( name_.c_str() ) ) {
string errmsg;
BSONObjBuilder result;
dropCollection( name_, errmsg, result );
}
} catch ( ... ) {
problem() << "exception cleaning up DbSet" << endl;
}
}
Collection* RollbackTest::_createCollection(OperationContext* opCtx,
const NamespaceString& nss,
const CollectionOptions& options) {
Lock::DBLock dbLock(opCtx, nss.db(), MODE_X);
mongo::WriteUnitOfWork wuow(opCtx);
auto databaseHolder = DatabaseHolder::get(opCtx);
auto db = databaseHolder->openDb(opCtx, nss.db());
ASSERT_TRUE(db);
db->dropCollection(opCtx, nss.ns()).transitional_ignore();
auto coll = db->createCollection(opCtx, nss.ns(), options);
ASSERT_TRUE(coll);
wuow.commit();
return coll;
}
QueryStageCachedPlanBase() {
// If collection exists already, we need to drop it.
dropCollection();
// Add indices.
addIndex(BSON("a" << 1));
addIndex(BSON("b" << 1));
OldClientWriteContext ctx(&_txn, nss.ns());
Collection* collection = ctx.getCollection();
ASSERT(collection);
// Add data.
for (int i = 0; i < 10; i++) {
insertDocument(collection, BSON("_id" << i << "a" << i << "b" << 1));
}
}
void setUp() {
// If collection exists already, we need to drop it.
dropCollection();
// Add indices.
addIndex(BSON("a" << 1));
addIndex(BSON("b" << 1));
dbtests::WriteContextForTests ctx(&_opCtx, nss.ns());
Collection* collection = ctx.getCollection();
ASSERT(collection);
// Add data.
for (int i = 0; i < 10; i++) {
insertDocument(collection, BSON("_id" << i << "a" << i << "b" << 1));
}
}
void run() {
Client::WriteContext ctx(&_txn, ns());
insert(BSON("_id" << 1));
insert(BSON("_id" << 2));
BSONObj filterObj = fromjson("{_id: {$gt: 0}}");
scoped_ptr<SingleSolutionRunner> ssr(makeCollScanRunner(ctx.ctx(),filterObj));
registerRunner(ssr.get());
BSONObj objOut;
ASSERT_EQUALS(Runner::RUNNER_ADVANCED, ssr->getNext(&objOut, NULL));
ASSERT_EQUALS(1, objOut["_id"].numberInt());
// After dropping the collection, the runner
// should be dead.
dropCollection();
ASSERT_EQUALS(Runner::RUNNER_DEAD, ssr->getNext(&objOut, NULL));
deregisterRunner(ssr.get());
}
void run() {
NamespaceString nss("unittests.rollback_create_drop_collection");
const ServiceContext::UniqueOperationContext opCtxPtr = cc().makeOperationContext();
OperationContext& opCtx = *opCtxPtr;
dropDatabase(&opCtx, nss);
Lock::DBLock dbXLock(&opCtx, nss.db(), MODE_X);
OldClientContext ctx(&opCtx, nss.ns());
BSONObj doc = BSON("_id"
<< "example string");
ASSERT(!collectionExists(&ctx, nss.ns()));
{
WriteUnitOfWork uow(&opCtx);
ASSERT_OK(userCreateNS(&opCtx,
ctx.db(),
nss.ns(),
BSONObj(),
CollectionOptions::parseForCommand,
defaultIndexes));
ASSERT(collectionExists(&ctx, nss.ns()));
insertRecord(&opCtx, nss, doc);
assertOnlyRecord(&opCtx, nss, doc);
BSONObjBuilder result;
ASSERT_OK(
dropCollection(&opCtx,
nss,
result,
{},
DropCollectionSystemCollectionMode::kDisallowSystemCollectionDrops));
ASSERT(!collectionExists(&ctx, nss.ns()));
if (!rollback) {
uow.commit();
}
}
ASSERT(!collectionExists(&ctx, nss.ns()));
}
void Database::clearTmpCollections() {
Lock::assertWriteLocked( _name );
Client::Context ctx( _name );
string systemNamespaces = _name + ".system.namespaces";
// Note: we build up a toDelete vector rather than dropping the collection inside the loop
// to avoid modifying the system.namespaces collection while iterating over it since that
// would corrupt the cursor.
vector<string> toDelete;
auto_ptr<Runner> runner(InternalPlanner::collectionScan(systemNamespaces));
BSONObj nsObj;
Runner::RunnerState state;
while (Runner::RUNNER_ADVANCED == (state = runner->getNext(&nsObj, NULL))) {
BSONElement e = nsObj.getFieldDotted( "options.temp" );
if ( !e.trueValue() )
continue;
string ns = nsObj["name"].String();
// Do not attempt to drop indexes
if ( !NamespaceString::normal(ns.c_str()) )
continue;
toDelete.push_back(ns);
}
if (Runner::RUNNER_EOF != state) {
warning() << "Internal error while reading collection " << systemNamespaces << endl;
}
for (size_t i=0; i < toDelete.size(); i++) {
Status s = dropCollection( toDelete[i] );
if ( !s.isOK() )
warning() << "could not drop temp collection: " << toDelete[i]
<< " because of " << s << endl;
}
}
void run() {
Client::WriteContext ctx(&_txn, ns());
insert(BSON("_id" << 1 << "a" << 6));
insert(BSON("_id" << 2 << "a" << 7));
insert(BSON("_id" << 3 << "a" << 8));
BSONObj indexSpec = BSON("a" << 1);
addIndex(indexSpec);
scoped_ptr<SingleSolutionRunner> ssr(makeIndexScanRunner(ctx.ctx(), indexSpec, 7, 10));
registerRunner(ssr.get());
BSONObj objOut;
ASSERT_EQUALS(Runner::RUNNER_ADVANCED, ssr->getNext(&objOut, NULL));
ASSERT_EQUALS(7, objOut["a"].numberInt());
// After dropping the collection, the runner
// should be dead.
dropCollection();
ASSERT_EQUALS(Runner::RUNNER_DEAD, ssr->getNext(&objOut, NULL));
deregisterRunner(ssr.get());
}
void Client::dropTempCollectionsInDB( const string db ) {
list<string>::iterator i = _tempCollections.begin();
while ( i!=_tempCollections.end() ) {
string ns = *i;
dblock l;
Client::Context ctx( ns );
if ( nsdetails( ns.c_str() ) &&
ns.compare( 0, db.length(), db ) == 0 ) {
try {
string err;
BSONObjBuilder b;
dropCollection( ns, err, b );
i = _tempCollections.erase(i);
++i;
}
catch ( ... ){
log() << "error dropping temp collection: " << ns << endl;
}
} else {
++i;
}
}
}
void Database::clearTmpCollections(OperationContext* txn) {
invariant(txn->lockState()->isDbLockedForMode(name(), MODE_X));
list<string> collections;
_dbEntry->getCollectionNamespaces( &collections );
for ( list<string>::iterator i = collections.begin(); i != collections.end(); ++i ) {
string ns = *i;
invariant( NamespaceString::normal( ns ) );
CollectionCatalogEntry* coll = _dbEntry->getCollectionCatalogEntry( ns );
CollectionOptions options = coll->getCollectionOptions( txn );
if ( !options.temp )
continue;
try {
WriteUnitOfWork wunit(txn);
Status status = dropCollection( txn, ns );
if ( !status.isOK() ) {
warning() << "could not drop temp collection '" << ns << "': " << status;
continue;
}
string cmdNs = _name + ".$cmd";
repl::logOp( txn,
"c",
cmdNs.c_str(),
BSON( "drop" << nsToCollectionSubstring( ns ) ) );
wunit.commit();
}
catch (const WriteConflictException& exp) {
warning() << "could not drop temp collection '" << ns << "' due to "
"WriteConflictException";
txn->recoveryUnit()->commitAndRestart();
}
}
}
virtual bool run(const char *ns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
string source = cmdObj.getStringField( name.c_str() );
string target = cmdObj.getStringField( "to" );
if ( source.empty() || target.empty() ) {
errmsg = "invalid command syntax";
return false;
}
setClient( source.c_str() );
NamespaceDetails *nsd = nsdetails( source.c_str() );
uassert( "source namespace does not exist", nsd );
bool capped = nsd->capped;
long long size = 0;
if ( capped )
for( DiskLoc i = nsd->firstExtent; !i.isNull(); i = i.ext()->xnext )
size += i.ext()->length;
setClient( target.c_str() );
uassert( "target namespace exists", !nsdetails( target.c_str() ) );
{
char from[256];
nsToClient( source.c_str(), from );
char to[256];
nsToClient( target.c_str(), to );
if ( strcmp( from, to ) == 0 ) {
renameNamespace( source.c_str(), target.c_str() );
return true;
}
}
BSONObjBuilder spec;
if ( capped ) {
spec.appendBool( "capped", true );
spec.append( "size", double( size ) );
}
if ( !userCreateNS( target.c_str(), spec.done(), errmsg, false ) )
return false;
auto_ptr< DBClientCursor > c;
DBDirectClient bridge;
{
c = bridge.query( source, BSONObj() );
}
while( 1 ) {
{
if ( !c->more() )
break;
}
BSONObj o = c->next();
theDataFileMgr.insert( target.c_str(), o );
}
char cl[256];
nsToClient( source.c_str(), cl );
string sourceIndexes = string( cl ) + ".system.indexes";
nsToClient( target.c_str(), cl );
string targetIndexes = string( cl ) + ".system.indexes";
{
c = bridge.query( sourceIndexes, QUERY( "ns" << source ) );
}
while( 1 ) {
{
if ( !c->more() )
break;
}
BSONObj o = c->next();
BSONObjBuilder b;
BSONObjIterator i( o );
while( i.moreWithEOO() ) {
BSONElement e = i.next();
if ( e.eoo() )
break;
if ( strcmp( e.fieldName(), "ns" ) == 0 ) {
b.append( "ns", target );
} else {
b.append( e );
}
}
BSONObj n = b.done();
theDataFileMgr.insert( targetIndexes.c_str(), n );
}
setClient( source.c_str() );
dropCollection( source, errmsg, result );
return true;
}
Status renameCollectionForApplyOps(OperationContext* opCtx,
const std::string& dbName,
const BSONElement& ui,
const BSONObj& cmd) {
const auto sourceNsElt = cmd.firstElement();
const auto targetNsElt = cmd["to"];
const auto dropSourceElt = cmd["dropSource"];
uassert(ErrorCodes::TypeMismatch,
"'renameCollection' must be of type String",
sourceNsElt.type() == BSONType::String);
uassert(ErrorCodes::TypeMismatch,
"'to' must be of type String",
targetNsElt.type() == BSONType::String);
NamespaceString sourceNss(sourceNsElt.valueStringData());
NamespaceString targetNss(targetNsElt.valueStringData());
NamespaceString uiNss(getNamespaceFromUUID(opCtx, ui));
NamespaceString dropSourceNss(getNamespaceFromUUID(opCtx, dropSourceElt));
// If the UUID we're targeting already exists, rename from there no matter what.
// When dropSource is specified, the rename is accross databases. In that case, ui indicates
// the UUID of the new target collection and the dropSourceNss specifies the sourceNss.
if (!uiNss.isEmpty()) {
sourceNss = uiNss;
// The cross-database rename was already done and just needs a local rename, but we may
// still need to actually remove the source collection.
auto dropSourceNss = getNamespaceFromUUID(opCtx, dropSourceElt);
if (!dropSourceNss.isEmpty()) {
BSONObjBuilder unusedBuilder;
dropCollection(opCtx,
dropSourceNss,
unusedBuilder,
repl::OpTime(),
DropCollectionSystemCollectionMode::kAllowSystemCollectionDrops)
.ignore();
}
} else if (!dropSourceNss.isEmpty()) {
sourceNss = dropSourceNss;
} else {
// When replaying cross-database renames, both source and target collections may no longer
// exist. Attempting a rename anyway could result in removing a newer collection of the
// same name.
uassert(ErrorCodes::NamespaceNotFound,
str::stream() << "source collection (UUID "
<< uassertStatusOK(UUID::parse(dropSourceElt))
<< ") for rename to "
<< targetNss.ns()
<< " no longer exists",
!dropSourceElt);
}
OptionalCollectionUUID targetUUID;
if (!ui.eoo())
targetUUID = uassertStatusOK(UUID::parse(ui));
return renameCollectionCommon(opCtx,
sourceNss,
targetNss,
targetUUID,
cmd["dropTarget"].trueValue(),
cmd["stayTemp"].trueValue());
}
void run() {
NamespaceString source("unittests.rollback_rename_droptarget_collection_src");
NamespaceString target("unittests.rollback_rename_droptarget_collection_dest");
const ServiceContext::UniqueOperationContext opCtxPtr = cc().makeOperationContext();
OperationContext& opCtx = *opCtxPtr;
dropDatabase(&opCtx, source);
dropDatabase(&opCtx, target);
Lock::GlobalWrite globalWriteLock(&opCtx);
OldClientContext ctx(&opCtx, source.ns());
BSONObj sourceDoc = BSON("_id"
<< "source");
BSONObj targetDoc = BSON("_id"
<< "target");
{
WriteUnitOfWork uow(&opCtx);
ASSERT(!collectionExists(&ctx, source.ns()));
ASSERT(!collectionExists(&ctx, target.ns()));
auto options = capped ? BSON("capped" << true << "size" << 1000) : BSONObj();
ASSERT_OK(userCreateNS(&opCtx,
ctx.db(),
source.ns(),
options,
CollectionOptions::parseForCommand,
defaultIndexes));
ASSERT_OK(userCreateNS(&opCtx,
ctx.db(),
target.ns(),
options,
CollectionOptions::parseForCommand,
defaultIndexes));
insertRecord(&opCtx, source, sourceDoc);
insertRecord(&opCtx, target, targetDoc);
uow.commit();
}
ASSERT(collectionExists(&ctx, source.ns()));
ASSERT(collectionExists(&ctx, target.ns()));
assertOnlyRecord(&opCtx, source, sourceDoc);
assertOnlyRecord(&opCtx, target, targetDoc);
// END OF SETUP / START OF TEST
{
WriteUnitOfWork uow(&opCtx);
BSONObjBuilder result;
ASSERT_OK(
dropCollection(&opCtx,
target,
result,
{},
DropCollectionSystemCollectionMode::kDisallowSystemCollectionDrops));
ASSERT_OK(renameCollection(&opCtx, source, target));
ASSERT(!collectionExists(&ctx, source.ns()));
ASSERT(collectionExists(&ctx, target.ns()));
assertOnlyRecord(&opCtx, target, sourceDoc);
if (!rollback) {
uow.commit();
}
}
if (rollback) {
ASSERT(collectionExists(&ctx, source.ns()));
ASSERT(collectionExists(&ctx, target.ns()));
assertOnlyRecord(&opCtx, source, sourceDoc);
assertOnlyRecord(&opCtx, target, targetDoc);
} else {
ASSERT(!collectionExists(&ctx, source.ns()));
ASSERT(collectionExists(&ctx, target.ns()));
assertOnlyRecord(&opCtx, target, sourceDoc);
}
}
void drop() {
string s( _ns );
string errmsg;
BSONObjBuilder result;
dropCollection( s, errmsg, result );
}