void Strategy::getMore(OperationContext* txn, Request& request) {
Timer getMoreTimer;
const char* ns = request.getns();
const int ntoreturn = request.d().pullInt();
const long long id = request.d().pullInt64();
// TODO: Handle stale config exceptions here from coll being dropped or sharded during op
// for now has same semantics as legacy request
const NamespaceString nss(ns);
auto statusGetDb = grid.catalogCache()->getDatabase(txn, nss.db().toString());
if (statusGetDb == ErrorCodes::DatabaseNotFound) {
cursorCache.remove(id);
replyToQuery(ResultFlag_CursorNotFound, request.p(), request.m(), 0, 0, 0);
return;
}
uassertStatusOK(statusGetDb);
// Spigot which controls whether OP_QUERY style find on mongos uses the new ClusterClientCursor
// code path.
//
// TODO: Delete the spigot and always use the new code.
if (useClusterClientCursor) {
boost::optional<long long> batchSize;
if (ntoreturn) {
batchSize = ntoreturn;
}
GetMoreRequest getMoreRequest(NamespaceString(ns), id, batchSize, boost::none);
auto cursorResponse = ClusterFind::runGetMore(txn, getMoreRequest);
if (cursorResponse == ErrorCodes::CursorNotFound) {
replyToQuery(ResultFlag_CursorNotFound, request.p(), request.m(), 0, 0, 0);
return;
}
uassertStatusOK(cursorResponse.getStatus());
// Build the response document.
//
// TODO: this constant should be shared between mongos and mongod, and should not be inside
// ShardedClientCursor.
BufBuilder buffer(ShardedClientCursor::INIT_REPLY_BUFFER_SIZE);
int numResults = 0;
for (const auto& obj : cursorResponse.getValue().batch) {
buffer.appendBuf((void*)obj.objdata(), obj.objsize());
++numResults;
}
replyToQuery(0,
request.p(),
request.m(),
buffer.buf(),
buffer.len(),
numResults,
cursorResponse.getValue().numReturnedSoFar.value_or(0),
cursorResponse.getValue().cursorId);
return;
}
shared_ptr<DBConfig> config = statusGetDb.getValue();
ShardPtr primary;
ChunkManagerPtr info;
config->getChunkManagerOrPrimary(txn, ns, info, primary);
//
// TODO: Cleanup cursor cache, consolidate into single codepath
//
const string host = cursorCache.getRef(id);
ShardedClientCursorPtr cursor = cursorCache.get(id);
int cursorMaxTimeMS = cursorCache.getMaxTimeMS(id);
// Cursor ids should not overlap between sharded and unsharded cursors
massert(17012,
str::stream() << "duplicate sharded and unsharded cursor id " << id << " detected for "
<< ns << ", duplicated on host " << host,
NULL == cursorCache.get(id).get() || host.empty());
ClientBasic* client = ClientBasic::getCurrent();
NamespaceString nsString(ns);
AuthorizationSession* authSession = AuthorizationSession::get(client);
Status status = authSession->checkAuthForGetMore(nsString, id, false);
audit::logGetMoreAuthzCheck(client, nsString, id, status.code());
uassertStatusOK(status);
if (!host.empty()) {
LOG(3) << "single getmore: " << ns;
// we used ScopedDbConnection because we don't get about config versions
// not deleting data is handled elsewhere
// and we don't want to call setShardVersion
ScopedDbConnection conn(host);
Message response;
bool ok = conn->callRead(request.m(), response);
uassert(10204, "dbgrid: getmore: error calling db", ok);
bool hasMore = (response.singleData().getCursor() != 0);
if (!hasMore) {
cursorCache.removeRef(id);
}
request.reply(response, "" /*conn->getServerAddress() */);
conn.done();
return;
} else if (cursor) {
if (cursorMaxTimeMS == kMaxTimeCursorTimeLimitExpired) {
cursorCache.remove(id);
uasserted(ErrorCodes::ExceededTimeLimit, "operation exceeded time limit");
}
// TODO: Try to match logic of mongod, where on subsequent getMore() we pull lots more data?
BufBuilder buffer(ShardedClientCursor::INIT_REPLY_BUFFER_SIZE);
int docCount = 0;
const int startFrom = cursor->getTotalSent();
bool hasMore = cursor->sendNextBatch(ntoreturn, buffer, docCount);
if (hasMore) {
// still more data
cursor->accessed();
if (cursorMaxTimeMS != kMaxTimeCursorNoTimeLimit) {
// Update remaining amount of time in cursor cache.
int cursorLeftoverMillis = cursorMaxTimeMS - getMoreTimer.millis();
if (cursorLeftoverMillis <= 0) {
cursorLeftoverMillis = kMaxTimeCursorTimeLimitExpired;
}
cursorCache.updateMaxTimeMS(id, cursorLeftoverMillis);
}
} else {
// we've exhausted the cursor
cursorCache.remove(id);
}
replyToQuery(0,
request.p(),
request.m(),
buffer.buf(),
buffer.len(),
docCount,
startFrom,
hasMore ? cursor->getId() : 0);
return;
} else {
LOG(3) << "could not find cursor " << id << " in cache for " << ns;
replyToQuery(ResultFlag_CursorNotFound, request.p(), request.m(), 0, 0, 0);
return;
}
}
void Strategy::getMore( Request& r ) {
Timer getMoreTimer;
const char* ns = r.getns();
const int ntoreturn = r.d().pullInt();
const long long id = r.d().pullInt64();
// TODO: Handle stale config exceptions here from coll being dropped or sharded during op
// for now has same semantics as legacy request
const NamespaceString nss(ns);
auto statusGetDb = grid.catalogCache()->getDatabase(nss.db().toString());
if (statusGetDb == ErrorCodes::DatabaseNotFound) {
cursorCache.remove(id);
replyToQuery(ResultFlag_CursorNotFound, r.p(), r.m(), 0, 0, 0);
return;
}
uassertStatusOK(statusGetDb);
shared_ptr<DBConfig> config = statusGetDb.getValue();
ShardPtr primary;
ChunkManagerPtr info;
config->getChunkManagerOrPrimary( ns, info, primary );
//
// TODO: Cleanup cursor cache, consolidate into single codepath
//
const string host = cursorCache.getRef(id);
ShardedClientCursorPtr cursor = cursorCache.get( id );
int cursorMaxTimeMS = cursorCache.getMaxTimeMS( id );
// Cursor ids should not overlap between sharded and unsharded cursors
massert( 17012, str::stream() << "duplicate sharded and unsharded cursor id "
<< id << " detected for " << ns
<< ", duplicated on host " << host,
NULL == cursorCache.get( id ).get() || host.empty() );
ClientBasic* client = ClientBasic::getCurrent();
NamespaceString nsString(ns);
AuthorizationSession* authSession = client->getAuthorizationSession();
Status status = authSession->checkAuthForGetMore( nsString, id );
audit::logGetMoreAuthzCheck( client, nsString, id, status.code() );
uassertStatusOK(status);
if( !host.empty() ){
LOG(3) << "single getmore: " << ns << endl;
// we used ScopedDbConnection because we don't get about config versions
// not deleting data is handled elsewhere
// and we don't want to call setShardVersion
ScopedDbConnection conn(host);
Message response;
bool ok = conn->callRead( r.m() , response);
uassert( 10204 , "dbgrid: getmore: error calling db", ok);
bool hasMore = (response.singleData().getCursor() != 0);
if ( !hasMore ) {
cursorCache.removeRef( id );
}
r.reply( response , "" /*conn->getServerAddress() */ );
conn.done();
return;
}
else if ( cursor ) {
if ( cursorMaxTimeMS == kMaxTimeCursorTimeLimitExpired ) {
cursorCache.remove( id );
uasserted( ErrorCodes::ExceededTimeLimit, "operation exceeded time limit" );
}
// TODO: Try to match logic of mongod, where on subsequent getMore() we pull lots more data?
BufBuilder buffer( ShardedClientCursor::INIT_REPLY_BUFFER_SIZE );
int docCount = 0;
const int startFrom = cursor->getTotalSent();
bool hasMore = cursor->sendNextBatch(ntoreturn, buffer, docCount);
if ( hasMore ) {
// still more data
cursor->accessed();
if ( cursorMaxTimeMS != kMaxTimeCursorNoTimeLimit ) {
// Update remaining amount of time in cursor cache.
int cursorLeftoverMillis = cursorMaxTimeMS - getMoreTimer.millis();
if ( cursorLeftoverMillis <= 0 ) {
cursorLeftoverMillis = kMaxTimeCursorTimeLimitExpired;
}
cursorCache.updateMaxTimeMS( id, cursorLeftoverMillis );
}
}
else {
// we've exhausted the cursor
cursorCache.remove( id );
}
replyToQuery( 0, r.p(), r.m(), buffer.buf(), buffer.len(), docCount,
startFrom, hasMore ? cursor->getId() : 0 );
return;
}
else {
LOG( 3 ) << "could not find cursor " << id << " in cache for " << ns << endl;
replyToQuery( ResultFlag_CursorNotFound , r.p() , r.m() , 0 , 0 , 0 );
return;
}
}
