/**
* Parses the json string 'findCmd', specifying a find command, to a CanonicalQuery.
*/
std::unique_ptr<CanonicalQuery> cqFromFindCommand(const std::string& findCmd) {
BSONObj cmdObj = fromjson(findCmd);
bool isExplain = false;
auto qr = unittest::assertGet(QueryRequest::makeFromFindCommand(nss, cmdObj, isExplain));
auto cq = unittest::assertGet(
CanonicalQuery::canonicalize(txn(), std::move(qr), ExtensionsCallbackNoop()));
return cq;
}
TEST(MatchExpressionParserTest, TextParsesSuccessfullyWhenAllowed) {
auto query = fromjson("{$text: {$search: 'str'}}");
const CollatorInterface* collator = nullptr;
const boost::intrusive_ptr<ExpressionContextForTest> expCtx(new ExpressionContextForTest());
ASSERT_OK(MatchExpressionParser::parse(query,
collator,
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::AllowedFeatures::kText)
.getStatus());
}
void SortKeyGenerator::getBoundsForSort(OperationContext* txn,
const BSONObj& queryObj,
const BSONObj& sortObj) {
QueryPlannerParams params;
params.options = QueryPlannerParams::NO_TABLE_SCAN;
// We're creating a "virtual index" with key pattern equal to the sort order.
IndexEntry sortOrder(sortObj,
IndexNames::BTREE,
true,
MultikeyPaths{},
false,
false,
"doesnt_matter",
NULL,
BSONObj());
params.indices.push_back(sortOrder);
auto statusWithQueryForSort = CanonicalQuery::canonicalize(
txn, NamespaceString("fake.ns"), queryObj, ExtensionsCallbackNoop());
verify(statusWithQueryForSort.isOK());
std::unique_ptr<CanonicalQuery> queryForSort = std::move(statusWithQueryForSort.getValue());
std::vector<QuerySolution*> solns;
LOG(5) << "Sort key generation: Planning to obtain bounds for sort.";
QueryPlanner::plan(*queryForSort, params, &solns);
// TODO: are there ever > 1 solns? If so, do we look for a specific soln?
if (1 == solns.size()) {
IndexScanNode* ixScan = NULL;
QuerySolutionNode* rootNode = solns[0]->root.get();
if (rootNode->getType() == STAGE_FETCH) {
FetchNode* fetchNode = static_cast<FetchNode*>(rootNode);
if (fetchNode->children[0]->getType() != STAGE_IXSCAN) {
delete solns[0];
// No bounds.
return;
}
ixScan = static_cast<IndexScanNode*>(fetchNode->children[0]);
} else if (rootNode->getType() == STAGE_IXSCAN) {
ixScan = static_cast<IndexScanNode*>(rootNode);
}
if (ixScan) {
_bounds.fields.swap(ixScan->bounds.fields);
_hasBounds = true;
}
}
for (size_t i = 0; i < solns.size(); ++i) {
delete solns[i];
}
}
TEST(MatchExpressionParserTest, ExprFailsToParseWithinTopLevelOr) {
auto query = fromjson("{$or: [{x: 1}, {$expr: {$eq: ['$a', 5]}}]}");
const CollatorInterface* collator = nullptr;
const boost::intrusive_ptr<ExpressionContextForTest> expCtx(new ExpressionContextForTest());
ASSERT_NOT_OK(MatchExpressionParser::parse(query,
collator,
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::AllowedFeatures::kExpr)
.getStatus());
}
TEST(MatchExpressionParserTest, ExprParsesSuccessfullyWithAdditionalTopLevelPredicates) {
auto query = fromjson("{x: 1, $expr: {$eq: ['$a', 5]}, y: 1}");
const CollatorInterface* collator = nullptr;
const boost::intrusive_ptr<ExpressionContextForTest> expCtx(new ExpressionContextForTest());
ASSERT_OK(MatchExpressionParser::parse(query,
collator,
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::AllowedFeatures::kExpr)
.getStatus());
}
TEST(MatchExpressionParserTest, NearParsesSuccessfullyWhenAllowed) {
auto query = fromjson("{a: {$near: {$geometry: {type: 'Point', coordinates: [0, 0]}}}}");
const CollatorInterface* collator = nullptr;
const boost::intrusive_ptr<ExpressionContextForTest> expCtx(new ExpressionContextForTest());
ASSERT_OK(MatchExpressionParser::parse(query,
collator,
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::AllowedFeatures::kGeoNear)
.getStatus());
}
TEST(MatchExpressionParserTest, WhereParsesSuccessfullyWhenAllowed) {
auto query = fromjson("{$where: 'this.a == this.b'}");
const CollatorInterface* collator = nullptr;
const boost::intrusive_ptr<ExpressionContextForTest> expCtx(new ExpressionContextForTest());
ASSERT_OK(MatchExpressionParser::parse(query,
collator,
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::AllowedFeatures::kJavascript)
.getStatus());
}
/**
* Parses the json string 'findCmd', specifying a find command, to a CanonicalQuery.
*/
std::unique_ptr<CanonicalQuery> cqFromFindCommand(const std::string& findCmd) {
BSONObj cmdObj = fromjson(findCmd);
bool isExplain = false;
auto lpq =
unittest::assertGet(LiteParsedQuery::makeFromFindCommand(nss, cmdObj, isExplain));
auto cq = unittest::assertGet(
CanonicalQuery::canonicalize(lpq.release(), ExtensionsCallbackNoop()));
return cq;
}
void ChunkManager::getShardIdsForQuery(OperationContext* txn,
const BSONObj& query,
set<ShardId>* shardIds) const {
auto statusWithCQ =
CanonicalQuery::canonicalize(NamespaceString(_ns), query, ExtensionsCallbackNoop());
uassertStatusOK(statusWithCQ.getStatus());
unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
// Query validation
if (QueryPlannerCommon::hasNode(cq->root(), MatchExpression::GEO_NEAR)) {
uassert(13501, "use geoNear command rather than $near query", false);
}
// Fast path for targeting equalities on the shard key.
auto shardKeyToFind = _keyPattern.extractShardKeyFromQuery(*cq);
if (shardKeyToFind.isOK() && !shardKeyToFind.getValue().isEmpty()) {
auto chunk = findIntersectingChunk(txn, shardKeyToFind.getValue());
shardIds->insert(chunk->getShardId());
return;
}
// Transforms query into bounds for each field in the shard key
// for example :
// Key { a: 1, b: 1 },
// Query { a : { $gte : 1, $lt : 2 },
// b : { $gte : 3, $lt : 4 } }
// => Bounds { a : [1, 2), b : [3, 4) }
IndexBounds bounds = getIndexBoundsForQuery(_keyPattern.toBSON(), *cq);
// Transforms bounds for each shard key field into full shard key ranges
// for example :
// Key { a : 1, b : 1 }
// Bounds { a : [1, 2), b : [3, 4) }
// => Ranges { a : 1, b : 3 } => { a : 2, b : 4 }
BoundList ranges = _keyPattern.flattenBounds(bounds);
for (BoundList::const_iterator it = ranges.begin(); it != ranges.end(); ++it) {
getShardIdsForRange(*shardIds, it->first /*min*/, it->second /*max*/);
// once we know we need to visit all shards no need to keep looping
if (shardIds->size() == _shardIds.size())
break;
}
// SERVER-4914 Some clients of getShardIdsForQuery() assume at least one shard will be
// returned. For now, we satisfy that assumption by adding a shard with no matches rather
// than return an empty set of shards.
if (shardIds->empty()) {
massert(16068, "no chunk ranges available", !_chunkRanges.ranges().empty());
shardIds->insert(_chunkRanges.ranges().begin()->second->getShardId());
}
}
// $near must be the only field in the expression object.
TEST(MatchExpressionParserGeoNear, ParseNearExtraField) {
BSONObj query = fromjson(
"{loc:{$near:{$maxDistance:100, "
"$geometry:{type:\"Point\", coordinates:[0,0]}}, foo: 1}}");
const CollatorInterface* collator = nullptr;
const boost::intrusive_ptr<ExpressionContextForTest> expCtx(new ExpressionContextForTest());
ASSERT_THROWS(MatchExpressionParser::parse(query,
collator,
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::kAllowAllSpecialFeatures)
.status_with_transitional_ignore(),
AssertionException);
}
StatusWith<LogicalSessionIdSet> SessionsCollectionSharded::findRemovedSessions(
OperationContext* opCtx, const LogicalSessionIdSet& sessions) {
auto send = [&](BSONObj toSend) -> StatusWith<BSONObj> {
auto qr = QueryRequest::makeFromFindCommand(
NamespaceString::kLogicalSessionsNamespace, toSend, false);
if (!qr.isOK()) {
return qr.getStatus();
}
const boost::intrusive_ptr<ExpressionContext> expCtx;
auto cq = CanonicalQuery::canonicalize(opCtx,
std::move(qr.getValue()),
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::kBanAllSpecialFeatures);
if (!cq.isOK()) {
return cq.getStatus();
}
// Do the work to generate the first batch of results. This blocks waiting to get responses
// from the shard(s).
std::vector<BSONObj> batch;
CursorId cursorId;
try {
cursorId = ClusterFind::runQuery(
opCtx, *cq.getValue(), ReadPreferenceSetting::get(opCtx), &batch);
} catch (const DBException& ex) {
return ex.toStatus();
}
rpc::OpMsgReplyBuilder replyBuilder;
CursorResponseBuilder::Options options;
options.isInitialResponse = true;
CursorResponseBuilder firstBatch(&replyBuilder, options);
for (const auto& obj : batch) {
firstBatch.append(obj);
}
firstBatch.done(cursorId, NamespaceString::kLogicalSessionsNamespace.ns());
return replyBuilder.releaseBody();
};
return doFetch(NamespaceString::kLogicalSessionsNamespace, sessions, send);
}
StatusWith<LogicalSessionIdSet> SessionsCollectionSharded::findRemovedSessions(
OperationContext* opCtx, const LogicalSessionIdSet& sessions) {
auto send = [&](BSONObj toSend) -> StatusWith<BSONObj> {
const NamespaceString nss(SessionsCollection::kSessionsFullNS);
auto qr = QueryRequest::makeFromFindCommand(nss, toSend, false);
if (!qr.isOK()) {
return qr.getStatus();
}
const boost::intrusive_ptr<ExpressionContext> expCtx;
auto cq = CanonicalQuery::canonicalize(opCtx,
std::move(qr.getValue()),
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::kAllowAllSpecialFeatures &
~MatchExpressionParser::AllowedFeatures::kExpr);
if (!cq.isOK()) {
return cq.getStatus();
}
// Do the work to generate the first batch of results. This blocks waiting to get responses
// from the shard(s).
std::vector<BSONObj> batch;
BSONObj viewDefinition;
auto cursorId = ClusterFind::runQuery(
opCtx, *cq.getValue(), ReadPreferenceSetting::get(opCtx), &batch, &viewDefinition);
if (!cursorId.isOK()) {
return cursorId.getStatus();
}
BSONObjBuilder result;
CursorResponseBuilder firstBatch(/*firstBatch*/ true, &result);
for (const auto& obj : batch) {
firstBatch.append(obj);
}
firstBatch.done(cursorId.getValue(), nss.ns());
return result.obj();
};
return doFetch(sessions, send);
}
TEST(MatchExpressionParserGeo, WithinBox) {
BSONObj query = fromjson("{a:{$within:{$box:[{x: 4, y:4},[6,6]]}}}");
const CollatorInterface* collator = nullptr;
const boost::intrusive_ptr<ExpressionContextForTest> expCtx(new ExpressionContextForTest());
StatusWithMatchExpression result =
MatchExpressionParser::parse(query,
collator,
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::kAllowAllSpecialFeatures);
ASSERT_TRUE(result.isOK());
ASSERT(!result.getValue()->matchesBSON(fromjson("{a: [3,4]}")));
ASSERT(result.getValue()->matchesBSON(fromjson("{a: [4,4]}")));
ASSERT(result.getValue()->matchesBSON(fromjson("{a: [5,5]}")));
ASSERT(result.getValue()->matchesBSON(fromjson("{a: [5,5.1]}")));
ASSERT(result.getValue()->matchesBSON(fromjson("{a: {x: 5, y:5.1}}")));
}
TEST(MatchExpressionParserGeoNear, ParseValidNearSphere) {
BSONObj query = fromjson("{loc: {$nearSphere: [0,0], $maxDistance: 100, $minDistance: 50}}");
const CollatorInterface* collator = nullptr;
const boost::intrusive_ptr<ExpressionContextForTest> expCtx(new ExpressionContextForTest());
StatusWithMatchExpression result =
MatchExpressionParser::parse(query,
collator,
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::kAllowAllSpecialFeatures);
ASSERT_TRUE(result.isOK());
MatchExpression* exp = result.getValue().get();
ASSERT_EQ(MatchExpression::GEO_NEAR, exp->matchType());
GeoNearMatchExpression* gnexp = static_cast<GeoNearMatchExpression*>(exp);
ASSERT_EQ(gnexp->getData().maxDistance, 100);
ASSERT_EQ(gnexp->getData().minDistance, 50);
}
StatusWith<std::map<StringData, std::unique_ptr<ExpressionWithPlaceholder>>>
ParsedUpdate::parseArrayFilters(const std::vector<BSONObj>& rawArrayFiltersIn,
OperationContext* opCtx,
CollatorInterface* collator) {
std::map<StringData, std::unique_ptr<ExpressionWithPlaceholder>> arrayFiltersOut;
for (auto rawArrayFilter : rawArrayFiltersIn) {
boost::intrusive_ptr<ExpressionContext> expCtx(new ExpressionContext(opCtx, collator));
auto parsedArrayFilter =
MatchExpressionParser::parse(rawArrayFilter,
std::move(expCtx),
ExtensionsCallbackNoop(),
MatchExpressionParser::kBanAllSpecialFeatures);
if (!parsedArrayFilter.isOK()) {
return parsedArrayFilter.getStatus().withContext("Error parsing array filter");
}
auto parsedArrayFilterWithPlaceholder =
ExpressionWithPlaceholder::make(std::move(parsedArrayFilter.getValue()));
if (!parsedArrayFilterWithPlaceholder.isOK()) {
return parsedArrayFilterWithPlaceholder.getStatus().withContext(
"Error parsing array filter");
}
auto finalArrayFilter = std::move(parsedArrayFilterWithPlaceholder.getValue());
auto fieldName = finalArrayFilter->getPlaceholder();
if (!fieldName) {
return Status(
ErrorCodes::FailedToParse,
"Cannot use an expression without a top-level field name in arrayFilters");
}
if (arrayFiltersOut.find(*fieldName) != arrayFiltersOut.end()) {
return Status(ErrorCodes::FailedToParse,
str::stream()
<< "Found multiple array filters with the same top-level field name "
<< *fieldName);
}
arrayFiltersOut[*fieldName] = std::move(finalArrayFilter);
}
return std::move(arrayFiltersOut);
}
Status ParsedUpdate::parseArrayFilters() {
for (auto rawArrayFilter : _request->getArrayFilters()) {
boost::intrusive_ptr<ExpressionContext> expCtx(
new ExpressionContext(_opCtx, _collator.get()));
auto parsedArrayFilter =
MatchExpressionParser::parse(rawArrayFilter,
std::move(expCtx),
ExtensionsCallbackNoop(),
MatchExpressionParser::kBanAllSpecialFeatures);
if (!parsedArrayFilter.isOK()) {
return parsedArrayFilter.getStatus().withContext("Error parsing array filter");
}
auto parsedArrayFilterWithPlaceholder =
ExpressionWithPlaceholder::make(std::move(parsedArrayFilter.getValue()));
if (!parsedArrayFilterWithPlaceholder.isOK()) {
return parsedArrayFilterWithPlaceholder.getStatus().withContext(
"Error parsing array filter");
}
auto finalArrayFilter = std::move(parsedArrayFilterWithPlaceholder.getValue());
auto fieldName = finalArrayFilter->getPlaceholder();
if (!fieldName) {
return Status(
ErrorCodes::FailedToParse,
"Cannot use an expression without a top-level field name in arrayFilters");
}
if (_arrayFilters.find(*fieldName) != _arrayFilters.end()) {
return Status(ErrorCodes::FailedToParse,
str::stream()
<< "Found multiple array filters with the same top-level field name "
<< *fieldName);
}
_arrayFilters[*fieldName] = std::move(finalArrayFilter);
}
return Status::OK();
}
TEST(MatchExpressionParserGeoNear, ParseInvalidNearSphere) {
{
BSONObj query = fromjson("{loc: {$maxDistance: 100, $nearSphere: [0,0]}}");
const CollatorInterface* collator = nullptr;
const boost::intrusive_ptr<ExpressionContextForTest> expCtx(new ExpressionContextForTest());
StatusWithMatchExpression result =
MatchExpressionParser::parse(query,
collator,
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::kAllowAllSpecialFeatures);
ASSERT_FALSE(result.isOK());
}
{
BSONObj query = fromjson("{loc: {$minDistance: 100, $nearSphere: [0,0]}}");
const CollatorInterface* collator = nullptr;
const boost::intrusive_ptr<ExpressionContextForTest> expCtx(new ExpressionContextForTest());
StatusWithMatchExpression result =
MatchExpressionParser::parse(query,
collator,
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::kAllowAllSpecialFeatures);
ASSERT_FALSE(result.isOK());
}
{
BSONObj query = fromjson("{loc: {$nearSphere: [0,0], $maxDistance: {}}}");
const CollatorInterface* collator = nullptr;
const boost::intrusive_ptr<ExpressionContextForTest> expCtx(new ExpressionContextForTest());
ASSERT_THROWS(MatchExpressionParser::parse(query,
collator,
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::kAllowAllSpecialFeatures)
.status_with_transitional_ignore(),
AssertionException);
}
{
BSONObj query = fromjson("{loc: {$nearSphere: [0,0], $minDistance: {}}}");
const CollatorInterface* collator = nullptr;
const boost::intrusive_ptr<ExpressionContextForTest> expCtx(new ExpressionContextForTest());
ASSERT_THROWS(MatchExpressionParser::parse(query,
collator,
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::kAllowAllSpecialFeatures)
.status_with_transitional_ignore(),
AssertionException);
}
{
BSONObj query = fromjson("{loc: {$nearSphere: [0,0], $eq: 1}}");
const CollatorInterface* collator = nullptr;
const boost::intrusive_ptr<ExpressionContextForTest> expCtx(new ExpressionContextForTest());
ASSERT_THROWS(MatchExpressionParser::parse(query,
collator,
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::kAllowAllSpecialFeatures)
.status_with_transitional_ignore(),
AssertionException);
}
}
ASSERT_TRUE(next.isAdvanced());
ASSERT_DOCUMENT_EQ(next.releaseDocument(), (Document{{"a", 1}, {"b", 1}}));
// The rest should not match.
ASSERT_TRUE(match->getNext().isEOF());
ASSERT_TRUE(match->getNext().isEOF());
ASSERT_TRUE(match->getNext().isEOF());
}
DEATH_TEST_F(DocumentSourceMatchTest,
ShouldFailToDescendExpressionOnPathThatIsNotACommonPrefix,
"Invariant failure expression::isPathPrefixOf") {
const auto expCtx = getExpCtx();
const auto matchSpec = BSON("a.b" << 1 << "b.c" << 1);
const auto matchExpression = unittest::assertGet(
MatchExpressionParser::parse(matchSpec, ExtensionsCallbackNoop(), expCtx->getCollator()));
DocumentSourceMatch::descendMatchOnPath(matchExpression.get(), "a", expCtx);
}
DEATH_TEST_F(DocumentSourceMatchTest,
ShouldFailToDescendExpressionOnPathThatContainsElemMatchWithObject,
"Invariant failure node->matchType()") {
const auto expCtx = getExpCtx();
const auto matchSpec = BSON("a" << BSON("$elemMatch" << BSON("a.b" << 1)));
const auto matchExpression = unittest::assertGet(
MatchExpressionParser::parse(matchSpec, ExtensionsCallbackNoop(), expCtx->getCollator()));
BSONObjBuilder out;
matchExpression->serialize(&out);
DocumentSourceMatch::descendMatchOnPath(matchExpression.get(), "a", expCtx);
}
StatusWith<std::vector<ShardEndpoint>> ChunkManagerTargeter::targetDelete(
OperationContext* opCtx, const write_ops::DeleteOpEntry& deleteDoc) const {
BSONObj shardKey;
if (_routingInfo->cm()) {
//
// Sharded collections have the following further requirements for targeting:
//
// Limit-1 deletes must be targeted exactly by shard key *or* exact _id
//
// Get the shard key
StatusWith<BSONObj> status =
_routingInfo->cm()->getShardKeyPattern().extractShardKeyFromQuery(opCtx,
deleteDoc.getQ());
// Bad query
if (!status.isOK())
return status.getStatus();
shardKey = status.getValue();
}
const auto collation = write_ops::collationOf(deleteDoc);
// Target the shard key or delete query
if (!shardKey.isEmpty()) {
try {
return std::vector<ShardEndpoint>{_targetShardKey(shardKey, collation, 0)};
} catch (const DBException&) {
// This delete is potentially not constrained to a single shard
}
}
// We failed to target a single shard.
// Parse delete query.
auto qr = stdx::make_unique<QueryRequest>(getNS());
qr->setFilter(deleteDoc.getQ());
if (!collation.isEmpty()) {
qr->setCollation(collation);
}
const boost::intrusive_ptr<ExpressionContext> expCtx;
auto cq = CanonicalQuery::canonicalize(opCtx,
std::move(qr),
expCtx,
ExtensionsCallbackNoop(),
MatchExpressionParser::kAllowAllSpecialFeatures);
if (!cq.isOK()) {
return cq.getStatus().withContext(str::stream() << "Could not parse delete query "
<< deleteDoc.getQ());
}
// Single deletes must target a single shard or be exact-ID.
if (_routingInfo->cm() && !deleteDoc.getMulti() &&
!isExactIdQuery(opCtx, *cq.getValue(), _routingInfo->cm().get())) {
return Status(ErrorCodes::ShardKeyNotFound,
str::stream()
<< "A single delete on a sharded collection must contain an exact "
"match on _id (and have the collection default collation) or "
"contain the shard key (and have the simple collation). Delete "
"request: "
<< deleteDoc.toBSON()
<< ", shard key pattern: "
<< _routingInfo->cm()->getShardKeyPattern().toString());
}
return _targetQuery(opCtx, deleteDoc.getQ(), collation);
}
void Strategy::queryOp(OperationContext* txn, Request& request) {
verify(!NamespaceString(request.getns()).isCommand());
Timer queryTimer;
globalOpCounters.gotQuery();
QueryMessage q(request.d());
NamespaceString ns(q.ns);
ClientBasic* client = txn->getClient();
AuthorizationSession* authSession = AuthorizationSession::get(client);
Status status = authSession->checkAuthForFind(ns, false);
audit::logQueryAuthzCheck(client, ns, q.query, status.code());
uassertStatusOK(status);
LOG(3) << "query: " << q.ns << " " << q.query << " ntoreturn: " << q.ntoreturn
<< " options: " << q.queryOptions;
if (q.ntoreturn == 1 && strstr(q.ns, ".$cmd"))
throw UserException(8010, "something is wrong, shouldn't see a command here");
if (q.queryOptions & QueryOption_Exhaust) {
uasserted(18526,
string("the 'exhaust' query option is invalid for mongos queries: ") + q.ns +
" " + q.query.toString());
}
// 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) {
// Determine the default read preference mode based on the value of the slaveOk flag.
ReadPreference readPreferenceOption = (q.queryOptions & QueryOption_SlaveOk)
? ReadPreference::SecondaryPreferred
: ReadPreference::PrimaryOnly;
ReadPreferenceSetting readPreference(readPreferenceOption, TagSet());
BSONElement rpElem;
auto readPrefExtractStatus = bsonExtractTypedField(
q.query, LiteParsedQuery::kWrappedReadPrefField, mongo::Object, &rpElem);
if (readPrefExtractStatus.isOK()) {
auto parsedRps = ReadPreferenceSetting::fromBSON(rpElem.Obj());
uassertStatusOK(parsedRps.getStatus());
readPreference = parsedRps.getValue();
} else if (readPrefExtractStatus != ErrorCodes::NoSuchKey) {
uassertStatusOK(readPrefExtractStatus);
}
auto canonicalQuery = CanonicalQuery::canonicalize(q, ExtensionsCallbackNoop());
uassertStatusOK(canonicalQuery.getStatus());
// If the $explain flag was set, we must run the operation on the shards as an explain
// command rather than a find command.
if (canonicalQuery.getValue()->getParsed().isExplain()) {
const LiteParsedQuery& lpq = canonicalQuery.getValue()->getParsed();
BSONObj findCommand = lpq.asFindCommand();
// We default to allPlansExecution verbosity.
auto verbosity = ExplainCommon::EXEC_ALL_PLANS;
const bool secondaryOk = (readPreference.pref != ReadPreference::PrimaryOnly);
rpc::ServerSelectionMetadata metadata(secondaryOk, readPreference);
BSONObjBuilder explainBuilder;
uassertStatusOK(
Strategy::explainFind(txn, findCommand, lpq, verbosity, metadata, &explainBuilder));
BSONObj explainObj = explainBuilder.done();
replyToQuery(0, // query result flags
request.p(),
request.m(),
static_cast<const void*>(explainObj.objdata()),
explainObj.objsize(),
1, // numResults
0, // startingFrom
CursorId(0));
return;
}
// Do the work to generate the first batch of results. This blocks waiting to get responses
// from the shard(s).
std::vector<BSONObj> batch;
// 0 means the cursor is exhausted and
// otherwise we assume that a cursor with the returned id can be retrieved via the
// ClusterCursorManager
auto cursorId =
ClusterFind::runQuery(txn, *canonicalQuery.getValue(), readPreference, &batch);
uassertStatusOK(cursorId.getStatus());
// TODO: this constant should be shared between mongos and mongod, and should
// not be inside ShardedClientCursor.
BufBuilder buffer(ShardedClientCursor::INIT_REPLY_BUFFER_SIZE);
// Fill out the response buffer.
int numResults = 0;
for (const auto& obj : batch) {
buffer.appendBuf((void*)obj.objdata(), obj.objsize());
numResults++;
}
replyToQuery(0, // query result flags
request.p(),
request.m(),
buffer.buf(),
buffer.len(),
numResults,
0, // startingFrom
cursorId.getValue());
return;
}
QuerySpec qSpec((string)q.ns, q.query, q.fields, q.ntoskip, q.ntoreturn, q.queryOptions);
// Parse "$maxTimeMS".
StatusWith<int> maxTimeMS =
LiteParsedQuery::parseMaxTimeMS(q.query[LiteParsedQuery::queryOptionMaxTimeMS]);
uassert(17233, maxTimeMS.getStatus().reason(), maxTimeMS.isOK());
if (_isSystemIndexes(q.ns) && doShardedIndexQuery(txn, request, qSpec)) {
return;
}
ParallelSortClusteredCursor* cursor = new ParallelSortClusteredCursor(qSpec, CommandInfo());
verify(cursor);
// TODO: Move out to Request itself, not strategy based
try {
cursor->init(txn);
if (qSpec.isExplain()) {
BSONObjBuilder explain_builder;
cursor->explain(explain_builder);
explain_builder.appendNumber("executionTimeMillis",
static_cast<long long>(queryTimer.millis()));
BSONObj b = explain_builder.obj();
replyToQuery(0, request.p(), request.m(), b);
delete (cursor);
return;
}
} catch (...) {
delete cursor;
throw;
}
// TODO: Revisit all of this when we revisit the sharded cursor cache
if (cursor->getNumQueryShards() != 1) {
// More than one shard (or zero), manage with a ShardedClientCursor
// NOTE: We may also have *zero* shards here when the returnPartial flag is set.
// Currently the code in ShardedClientCursor handles this.
ShardedClientCursorPtr cc(new ShardedClientCursor(q, cursor));
BufBuilder buffer(ShardedClientCursor::INIT_REPLY_BUFFER_SIZE);
int docCount = 0;
const int startFrom = cc->getTotalSent();
bool hasMore = cc->sendNextBatch(q.ntoreturn, buffer, docCount);
if (hasMore) {
LOG(5) << "storing cursor : " << cc->getId();
int cursorLeftoverMillis = maxTimeMS.getValue() - queryTimer.millis();
if (maxTimeMS.getValue() == 0) { // 0 represents "no limit".
cursorLeftoverMillis = kMaxTimeCursorNoTimeLimit;
} else if (cursorLeftoverMillis <= 0) {
cursorLeftoverMillis = kMaxTimeCursorTimeLimitExpired;
}
cursorCache.store(cc, cursorLeftoverMillis);
}
replyToQuery(0,
request.p(),
request.m(),
buffer.buf(),
buffer.len(),
docCount,
startFrom,
hasMore ? cc->getId() : 0);
} else {
// Only one shard is used
// Remote cursors are stored remotely, we shouldn't need this around.
unique_ptr<ParallelSortClusteredCursor> cursorDeleter(cursor);
ShardPtr shard = grid.shardRegistry()->getShard(txn, cursor->getQueryShardId());
verify(shard.get());
DBClientCursorPtr shardCursor = cursor->getShardCursor(shard->getId());
// Implicitly stores the cursor in the cache
request.reply(*(shardCursor->getMessage()), shardCursor->originalHost());
// We don't want to kill the cursor remotely if there's still data left
shardCursor->decouple();
}
}
