StatusWith<CursorResponse> ClusterFind::runGetMore(OperationContext* txn,
const GetMoreRequest& request) {
auto cursorManager = grid.getCursorManager();
auto pinnedCursor = cursorManager->checkOutCursor(request.nss, request.cursorid);
if (!pinnedCursor.isOK()) {
return pinnedCursor.getStatus();
}
invariant(request.cursorid == pinnedCursor.getValue().getCursorId());
// If the fail point is enabled, busy wait until it is disabled.
while (MONGO_FAIL_POINT(keepCursorPinnedDuringGetMore)) {
}
if (request.awaitDataTimeout) {
auto status = pinnedCursor.getValue().setAwaitDataTimeout(*request.awaitDataTimeout);
if (!status.isOK()) {
return status;
}
}
std::vector<BSONObj> batch;
int bytesBuffered = 0;
long long batchSize = request.batchSize.value_or(0);
long long startingFrom = pinnedCursor.getValue().getNumReturnedSoFar();
auto cursorState = ClusterCursorManager::CursorState::NotExhausted;
while (!FindCommon::enoughForGetMore(batchSize, batch.size())) {
auto next = pinnedCursor.getValue().next();
if (!next.isOK()) {
return next.getStatus();
}
if (!next.getValue()) {
// We reached end-of-stream.
if (!pinnedCursor.getValue().isTailable()) {
cursorState = ClusterCursorManager::CursorState::Exhausted;
}
break;
}
if (!FindCommon::haveSpaceForNext(*next.getValue(), batch.size(), bytesBuffered)) {
pinnedCursor.getValue().queueResult(*next.getValue());
break;
}
// Add doc to the batch. Account for the space overhead associated with returning this doc
// inside a BSON array.
bytesBuffered += (next.getValue()->objsize() + kPerDocumentOverheadBytesUpperBound);
batch.push_back(std::move(*next.getValue()));
}
// Transfer ownership of the cursor back to the cursor manager.
pinnedCursor.getValue().returnCursor(cursorState);
CursorId idToReturn = (cursorState == ClusterCursorManager::CursorState::Exhausted)
? CursorId(0)
: request.cursorid;
return CursorResponse(request.nss, idToReturn, std::move(batch), startingFrom);
}
StatusWith<CursorResponse> ClusterFind::runGetMore(OperationContext* txn,
const GetMoreRequest& request) {
auto cursorManager = grid.getCursorManager();
auto pinnedCursor = cursorManager->checkOutCursor(request.nss, request.cursorid);
if (!pinnedCursor.isOK()) {
return pinnedCursor.getStatus();
}
invariant(request.cursorid == pinnedCursor.getValue().getCursorId());
std::vector<BSONObj> batch;
int bytesBuffered = 0;
long long batchSize = request.batchSize.value_or(0);
long long startingFrom = pinnedCursor.getValue().getNumReturnedSoFar();
auto cursorState = ClusterCursorManager::CursorState::NotExhausted;
while (!FindCommon::enoughForGetMore(batchSize, batch.size(), bytesBuffered)) {
auto next = pinnedCursor.getValue().next();
if (!next.isOK()) {
return next.getStatus();
}
if (!next.getValue()) {
// We reached end-of-stream.
if (!pinnedCursor.getValue().isTailable()) {
cursorState = ClusterCursorManager::CursorState::Exhausted;
}
break;
}
// If adding this object will cause us to exceed the BSON size limit, then we stash it for
// later. By using BSONObjMaxUserSize, we ensure that there is enough room for the
// "envelope" (e.g. the "ns" and "id" fields included in the response) before exceeding
// BSONObjMaxInternalSize.
int sizeEstimate = bytesBuffered + next.getValue()->objsize() +
((batch.size() + 1U) * kPerDocumentOverheadBytesUpperBound);
if (sizeEstimate > BSONObjMaxUserSize && !batch.empty()) {
pinnedCursor.getValue().queueResult(*next.getValue());
break;
}
// Add doc to the batch.
bytesBuffered += next.getValue()->objsize();
batch.push_back(std::move(*next.getValue()));
}
// Transfer ownership of the cursor back to the cursor manager.
pinnedCursor.getValue().returnCursor(cursorState);
CursorId idToReturn = (cursorState == ClusterCursorManager::CursorState::Exhausted)
? CursorId(0)
: request.cursorid;
return CursorResponse(request.nss, idToReturn, std::move(batch), startingFrom);
}
StatusWith<CursorResponse> ClusterFind::runGetMore(OperationContext* txn,
const GetMoreRequest& request) {
auto cursorManager = grid.getCursorManager();
auto pinnedCursor = cursorManager->checkOutCursor(request.nss, request.cursorid);
if (!pinnedCursor.isOK()) {
return pinnedCursor.getStatus();
}
invariant(request.cursorid == pinnedCursor.getValue().getCursorId());
std::vector<BSONObj> batch;
int bytesBuffered = 0;
long long batchSize = request.batchSize.value_or(0);
long long startingFrom = pinnedCursor.getValue().getNumReturnedSoFar();
auto cursorState = ClusterCursorManager::CursorState::NotExhausted;
while (!FindCommon::enoughForGetMore(batchSize, batch.size(), bytesBuffered)) {
auto next = pinnedCursor.getValue().next();
if (!next.isOK()) {
return next.getStatus();
}
if (!next.getValue()) {
// We reached end-of-stream.
if (!pinnedCursor.getValue().isTailable()) {
cursorState = ClusterCursorManager::CursorState::Exhausted;
}
break;
}
// Add doc to the batch.
bytesBuffered += next.getValue()->objsize();
batch.push_back(std::move(*next.getValue()));
}
// Transfer ownership of the cursor back to the cursor manager.
pinnedCursor.getValue().returnCursor(cursorState);
CursorId idToReturn = (cursorState == ClusterCursorManager::CursorState::Exhausted)
? CursorId(0)
: request.cursorid;
return CursorResponse(request.nss, idToReturn, std::move(batch), startingFrom);
}