virtual bool run(OperationContext* txn, const string& dbname, BSONObj& cmdObj, int options,
string& errmsg, BSONObjBuilder& result,
bool fromRepl = false ) {
NamespaceString ns( dbname, cmdObj[name].String() );
AutoGetCollectionForRead ctx(txn, ns.ns());
Collection* collection = ctx.getCollection();
if ( !collection )
return appendCommandStatus( result,
Status( ErrorCodes::NamespaceNotFound,
str::stream() <<
"ns does not exist: " << ns.ns() ) );
size_t numCursors = static_cast<size_t>( cmdObj["numCursors"].numberInt() );
if ( numCursors == 0 || numCursors > 10000 )
return appendCommandStatus( result,
Status( ErrorCodes::BadValue,
str::stream() <<
"numCursors has to be between 1 and 10000" <<
" was: " << numCursors ) );
OwnedPointerVector<RecordIterator> iterators(collection->getManyIterators(txn));
if (iterators.size() < numCursors) {
numCursors = iterators.size();
}
OwnedPointerVector<PlanExecutor> execs;
for ( size_t i = 0; i < numCursors; i++ ) {
WorkingSet* ws = new WorkingSet();
MultiIteratorStage* mis = new MultiIteratorStage(txn, ws, collection);
// Takes ownership of 'ws' and 'mis'.
auto_ptr<PlanExecutor> curExec(new PlanExecutor(txn, ws, mis, collection));
// Each of the plan executors should yield automatically. We pass "false" to
// indicate that 'curExec' should not register itself, as it will get registered
// by ClientCursor instead.
curExec->setYieldPolicy(PlanExecutor::YIELD_AUTO, false);
// Need to save state while yielding locks between now and newGetMore.
curExec->saveState();
execs.push_back(curExec.release());
}
// transfer iterators to executors using a round-robin distribution.
// TODO consider using a common work queue once invalidation issues go away.
for (size_t i = 0; i < iterators.size(); i++) {
PlanExecutor* theExec = execs[i % execs.size()];
MultiIteratorStage* mis = static_cast<MultiIteratorStage*>(theExec->getRootStage());
mis->addIterator(iterators.releaseAt(i));
}
{
BSONArrayBuilder bucketsBuilder;
for (size_t i = 0; i < execs.size(); i++) {
// transfer ownership of an executor to the ClientCursor (which manages its own
// lifetime).
ClientCursor* cc = new ClientCursor( collection, execs.releaseAt(i) );
// we are mimicking the aggregation cursor output here
// that is why there are ns, ok and empty firstBatch
BSONObjBuilder threadResult;
{
BSONObjBuilder cursor;
cursor.appendArray( "firstBatch", BSONObj() );
cursor.append( "ns", ns );
cursor.append( "id", cc->cursorid() );
threadResult.append( "cursor", cursor.obj() );
}
threadResult.appendBool( "ok", 1 );
bucketsBuilder.append( threadResult.obj() );
}
result.appendArray( "cursors", bucketsBuilder.obj() );
}
return true;
}
virtual bool run(OperationContext* txn, const string& dbname, BSONObj& cmdObj, int options,
string& errmsg, BSONObjBuilder& result,
bool fromRepl = false ) {
NamespaceString ns( dbname, cmdObj[name].String() );
AutoGetCollectionForRead ctx(txn, ns.ns());
Collection* collection = ctx.getCollection();
if ( !collection )
return appendCommandStatus( result,
Status( ErrorCodes::NamespaceNotFound,
str::stream() <<
"ns does not exist: " << ns.ns() ) );
size_t numCursors = static_cast<size_t>( cmdObj["numCursors"].numberInt() );
if ( numCursors == 0 || numCursors > 10000 )
return appendCommandStatus( result,
Status( ErrorCodes::BadValue,
str::stream() <<
"numCursors has to be between 1 and 10000" <<
" was: " << numCursors ) );
OwnedPointerVector<RecordIterator> iterators(collection->getManyIterators(txn));
if (iterators.size() < numCursors) {
numCursors = iterators.size();
}
OwnedPointerVector<PlanExecutor> execs;
for ( size_t i = 0; i < numCursors; i++ ) {
WorkingSet* ws = new WorkingSet();
MultiIteratorStage* mis = new MultiIteratorStage(txn, ws, collection);
PlanExecutor* rawExec;
// Takes ownership of 'ws' and 'mis'.
Status execStatus = PlanExecutor::make(txn, ws, mis, collection,
PlanExecutor::YIELD_AUTO, &rawExec);
invariant(execStatus.isOK());
auto_ptr<PlanExecutor> curExec(rawExec);
// The PlanExecutor was registered on construction due to the YIELD_AUTO policy.
// We have to deregister it, as it will be registered with ClientCursor.
curExec->deregisterExec();
// Need to save state while yielding locks between now and getMore().
curExec->saveState();
execs.push_back(curExec.release());
}
// transfer iterators to executors using a round-robin distribution.
// TODO consider using a common work queue once invalidation issues go away.
for (size_t i = 0; i < iterators.size(); i++) {
PlanExecutor* theExec = execs[i % execs.size()];
MultiIteratorStage* mis = static_cast<MultiIteratorStage*>(theExec->getRootStage());
// This wasn't called above as they weren't assigned yet
iterators[i]->saveState();
mis->addIterator(iterators.releaseAt(i));
}
{
BSONArrayBuilder bucketsBuilder;
for (size_t i = 0; i < execs.size(); i++) {
// transfer ownership of an executor to the ClientCursor (which manages its own
// lifetime).
ClientCursor* cc = new ClientCursor( collection->getCursorManager(),
execs.releaseAt(i),
ns.ns() );
BSONObjBuilder threadResult;
appendCursorResponseObject( cc->cursorid(),
ns.ns(),
BSONArray(),
&threadResult );
threadResult.appendBool( "ok", 1 );
bucketsBuilder.append( threadResult.obj() );
}
result.appendArray( "cursors", bucketsBuilder.obj() );
}
return true;
}
virtual bool run(OperationContext* txn,
const string& dbname,
BSONObj& cmdObj,
int options,
string& errmsg,
BSONObjBuilder& result) {
NamespaceString ns(dbname, cmdObj[name].String());
AutoGetCollectionForRead ctx(txn, ns.ns());
Collection* collection = ctx.getCollection();
if (!collection)
return appendCommandStatus(result,
Status(ErrorCodes::NamespaceNotFound,
str::stream() << "ns does not exist: " << ns.ns()));
size_t numCursors = static_cast<size_t>(cmdObj["numCursors"].numberInt());
if (numCursors == 0 || numCursors > 10000)
return appendCommandStatus(result,
Status(ErrorCodes::BadValue,
str::stream()
<< "numCursors has to be between 1 and 10000"
<< " was: " << numCursors));
auto iterators = collection->getManyCursors(txn);
if (iterators.size() < numCursors) {
numCursors = iterators.size();
}
std::vector<std::unique_ptr<PlanExecutor>> execs;
for (size_t i = 0; i < numCursors; i++) {
unique_ptr<WorkingSet> ws = make_unique<WorkingSet>();
unique_ptr<MultiIteratorStage> mis =
make_unique<MultiIteratorStage>(txn, ws.get(), collection);
// Takes ownership of 'ws' and 'mis'.
auto statusWithPlanExecutor = PlanExecutor::make(
txn, std::move(ws), std::move(mis), collection, PlanExecutor::YIELD_AUTO);
invariant(statusWithPlanExecutor.isOK());
execs.push_back(std::move(statusWithPlanExecutor.getValue()));
}
// transfer iterators to executors using a round-robin distribution.
// TODO consider using a common work queue once invalidation issues go away.
for (size_t i = 0; i < iterators.size(); i++) {
auto& planExec = execs[i % execs.size()];
MultiIteratorStage* mis = checked_cast<MultiIteratorStage*>(planExec->getRootStage());
mis->addIterator(std::move(iterators[i]));
}
{
BSONArrayBuilder bucketsBuilder;
for (auto&& exec : execs) {
// The PlanExecutor was registered on construction due to the YIELD_AUTO policy.
// We have to deregister it, as it will be registered with ClientCursor.
exec->deregisterExec();
// Need to save state while yielding locks between now and getMore().
exec->saveState();
exec->detachFromOperationContext();
// transfer ownership of an executor to the ClientCursor (which manages its own
// lifetime).
ClientCursor* cc =
new ClientCursor(collection->getCursorManager(),
exec.release(),
ns.ns(),
txn->recoveryUnit()->isReadingFromMajorityCommittedSnapshot());
BSONObjBuilder threadResult;
appendCursorResponseObject(cc->cursorid(), ns.ns(), BSONArray(), &threadResult);
threadResult.appendBool("ok", 1);
bucketsBuilder.append(threadResult.obj());
}
result.appendArray("cursors", bucketsBuilder.obj());
}
return true;
}
