StatusWith<ResolvedView> ViewCatalog::resolveView(OperationContext* txn,
const NamespaceString& nss) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
const NamespaceString* resolvedNss = &nss;
std::vector<BSONObj> resolvedPipeline;
for (int i = 0; i < ViewGraph::kMaxViewDepth; i++) {
auto view = _lookup_inlock(txn, resolvedNss->ns());
if (!view)
return StatusWith<ResolvedView>({*resolvedNss, resolvedPipeline});
resolvedNss = &(view->viewOn());
// Prepend the underlying view's pipeline to the current working pipeline.
const std::vector<BSONObj>& toPrepend = view->pipeline();
resolvedPipeline.insert(resolvedPipeline.begin(), toPrepend.begin(), toPrepend.end());
// If the first stage is a $collStats, then we return early with the viewOn namespace.
if (toPrepend.size() > 0 && !toPrepend[0]["$collStats"].eoo()) {
return StatusWith<ResolvedView>({*resolvedNss, resolvedPipeline});
}
}
return {ErrorCodes::ViewDepthLimitExceeded,
str::stream() << "View depth too deep or view cycle detected; maximum depth is "
<< ViewGraph::kMaxViewDepth};
}
StatusWith<ResolvedView> ViewCatalog::resolveView(OperationContext* opCtx,
const NamespaceString& nss) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
const NamespaceString* resolvedNss = &nss;
std::vector<BSONObj> resolvedPipeline;
BSONObj collation;
for (int i = 0; i < ViewGraph::kMaxViewDepth; i++) {
auto view = _lookup_inlock(opCtx, resolvedNss->ns());
if (!view) {
// Return error status if pipeline is too large.
int pipelineSize = 0;
for (auto obj : resolvedPipeline) {
pipelineSize += obj.objsize();
}
if (pipelineSize > ViewGraph::kMaxViewPipelineSizeBytes) {
return {ErrorCodes::ViewPipelineMaxSizeExceeded,
str::stream() << "View pipeline exceeds maximum size; maximum size is "
<< ViewGraph::kMaxViewPipelineSizeBytes};
}
return StatusWith<ResolvedView>(
{*resolvedNss, std::move(resolvedPipeline), std::move(collation)});
}
resolvedNss = &(view->viewOn());
collation = view->defaultCollator() ? view->defaultCollator()->getSpec().toBSON()
: CollationSpec::kSimpleSpec;
// Prepend the underlying view's pipeline to the current working pipeline.
const std::vector<BSONObj>& toPrepend = view->pipeline();
resolvedPipeline.insert(resolvedPipeline.begin(), toPrepend.begin(), toPrepend.end());
// If the first stage is a $collStats, then we return early with the viewOn namespace.
if (toPrepend.size() > 0 && !toPrepend[0]["$collStats"].eoo()) {
return StatusWith<ResolvedView>(
{*resolvedNss, std::move(resolvedPipeline), std::move(collation)});
}
}
return {ErrorCodes::ViewDepthLimitExceeded,
str::stream() << "View depth too deep or view cycle detected; maximum depth is "
<< ViewGraph::kMaxViewDepth};
}
StatusWith<ResolvedView> ViewCatalog::resolveView(OperationContext* opCtx,
const NamespaceString& nss) {
stdx::unique_lock<stdx::mutex> lock(_mutex);
// Keep looping until the resolution completes. If the catalog is invalidated during the
// resolution, we start over from the beginning.
while (true) {
// Points to the name of the most resolved namespace.
const NamespaceString* resolvedNss = &nss;
// Holds the combination of all the resolved views.
std::vector<BSONObj> resolvedPipeline;
// If the catalog has not been tampered with, all views seen during the resolution will have
// the same collation. As an optimization, we fill out the collation spec only once.
boost::optional<BSONObj> collation;
// The last seen view definition, which owns the NamespaceString pointed to by
// 'resolvedNss'.
std::shared_ptr<ViewDefinition> lastViewDefinition;
int depth = 0;
for (; depth < ViewGraph::kMaxViewDepth; depth++) {
// If the catalog has been invalidated, bail and restart.
if (!_valid.load()) {
uassertStatusOK(_reloadIfNeeded(lock, opCtx));
break;
}
auto view = _lookup(lock, opCtx, resolvedNss->ns());
if (!view) {
// Return error status if pipeline is too large.
int pipelineSize = 0;
for (auto obj : resolvedPipeline) {
pipelineSize += obj.objsize();
}
if (pipelineSize > ViewGraph::kMaxViewPipelineSizeBytes) {
return {ErrorCodes::ViewPipelineMaxSizeExceeded,
str::stream() << "View pipeline exceeds maximum size; maximum size is "
<< ViewGraph::kMaxViewPipelineSizeBytes};
}
return StatusWith<ResolvedView>(
{*resolvedNss, std::move(resolvedPipeline), std::move(collation.get())});
}
resolvedNss = &view->viewOn();
if (!collation) {
collation = view->defaultCollator() ? view->defaultCollator()->getSpec().toBSON()
: CollationSpec::kSimpleSpec;
}
// Prepend the underlying view's pipeline to the current working pipeline.
const std::vector<BSONObj>& toPrepend = view->pipeline();
resolvedPipeline.insert(resolvedPipeline.begin(), toPrepend.begin(), toPrepend.end());
// If the first stage is a $collStats, then we return early with the viewOn namespace.
if (toPrepend.size() > 0 && !toPrepend[0]["$collStats"].eoo()) {
return StatusWith<ResolvedView>(
{*resolvedNss, std::move(resolvedPipeline), std::move(collation.get())});
}
}
if (depth >= ViewGraph::kMaxViewDepth) {
return {ErrorCodes::ViewDepthLimitExceeded,
str::stream() << "View depth too deep or view cycle detected; maximum depth is "
<< ViewGraph::kMaxViewDepth};
}
};
MONGO_UNREACHABLE;
}
