Status ViewCatalog::createView(OperationContext* txn,
const NamespaceString& viewName,
const NamespaceString& viewOn,
const BSONArray& pipeline) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
if (!enableViews)
return Status(ErrorCodes::CommandNotSupported, "View support not enabled");
if (viewName.db() != viewOn.db())
return Status(ErrorCodes::BadValue,
"View must be created on a view or collection in the same database");
if (_lookup_inlock(txn, StringData(viewName.ns())))
return Status(ErrorCodes::NamespaceExists, "Namespace already exists");
if (!NamespaceString::validCollectionName(viewOn.coll()))
return Status(ErrorCodes::InvalidNamespace,
str::stream() << "invalid name for 'viewOn': " << viewOn.coll());
// TODO(SERVER-24768): Need to ensure view is correct and doesn't introduce a cycle.
_createOrUpdateView_inlock(txn, viewName, viewOn, pipeline);
return Status::OK();
}
Status ViewCatalog::dropView(OperationContext* opCtx, const NamespaceString& viewName) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
_requireValidCatalog_inlock(opCtx);
// Save a copy of the view definition in case we need to roll back.
auto viewPtr = _lookup_inlock(opCtx, viewName.ns());
if (!viewPtr) {
return {ErrorCodes::NamespaceNotFound,
str::stream() << "cannot drop missing view: " << viewName.ns()};
}
ViewDefinition savedDefinition = *viewPtr;
invariant(_valid.load());
_durable->remove(opCtx, viewName);
_viewGraph.remove(savedDefinition.name());
_viewMap.erase(viewName.ns());
opCtx->recoveryUnit()->onRollback([this, viewName, savedDefinition]() {
this->_viewGraphNeedsRefresh = true;
this->_viewMap[viewName.ns()] = std::make_shared<ViewDefinition>(savedDefinition);
});
// We may get invalidated, but we're exclusively locked, so the change must be ours.
opCtx->recoveryUnit()->onCommit([this]() { this->_valid.store(true); });
return Status::OK();
}
Status ViewCatalog::createView(OperationContext* opCtx,
const NamespaceString& viewName,
const NamespaceString& viewOn,
const BSONArray& pipeline,
const BSONObj& collation) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
if (viewName.db() != viewOn.db())
return Status(ErrorCodes::BadValue,
"View must be created on a view or collection in the same database");
if (_lookup_inlock(opCtx, StringData(viewName.ns())))
return Status(ErrorCodes::NamespaceExists, "Namespace already exists");
if (!NamespaceString::validCollectionName(viewOn.coll()))
return Status(ErrorCodes::InvalidNamespace,
str::stream() << "invalid name for 'viewOn': " << viewOn.coll());
if (viewName.isSystem())
return Status(
ErrorCodes::InvalidNamespace,
"View name cannot start with 'system.', which is reserved for system namespaces");
auto collator = parseCollator(opCtx, collation);
if (!collator.isOK())
return collator.getStatus();
return _createOrUpdateView_inlock(
opCtx, viewName, viewOn, pipeline, std::move(collator.getValue()));
}
Status ViewCatalog::modifyView(OperationContext* opCtx,
const NamespaceString& viewName,
const NamespaceString& viewOn,
const BSONArray& pipeline) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
if (viewName.db() != viewOn.db())
return Status(ErrorCodes::BadValue,
"View must be created on a view or collection in the same database");
auto viewPtr = _lookup_inlock(opCtx, viewName.ns());
if (!viewPtr)
return Status(ErrorCodes::NamespaceNotFound,
str::stream() << "cannot modify missing view " << viewName.ns());
if (!NamespaceString::validCollectionName(viewOn.coll()))
return Status(ErrorCodes::InvalidNamespace,
str::stream() << "invalid name for 'viewOn': " << viewOn.coll());
ViewDefinition savedDefinition = *viewPtr;
opCtx->recoveryUnit()->onRollback([this, viewName, savedDefinition]() {
this->_viewMap[viewName.ns()] = std::make_shared<ViewDefinition>(savedDefinition);
});
return _createOrUpdateView_inlock(
opCtx,
viewName,
viewOn,
pipeline,
CollatorInterface::cloneCollator(savedDefinition.defaultCollator()));
}
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};
}
Status ViewCatalog::modifyView(OperationContext* txn,
const NamespaceString& viewName,
const NamespaceString& viewOn,
const BSONArray& pipeline) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
if (serverGlobalParams.featureCompatibilityVersion.load() ==
ServerGlobalParams::FeatureCompatibilityVersion_32) {
return Status(ErrorCodes::CommandNotSupported,
"Cannot modify view when the featureCompatibilityVersion is 3.2. See "
"http://dochub.mongodb.org/core/3.4-feature-compatibility.");
}
if (viewName.db() != viewOn.db())
return Status(ErrorCodes::BadValue,
"View must be created on a view or collection in the same database");
auto viewPtr = _lookup_inlock(txn, viewName.ns());
if (!viewPtr)
return Status(ErrorCodes::NamespaceNotFound,
str::stream() << "cannot modify missing view " << viewName.ns());
if (!NamespaceString::validCollectionName(viewOn.coll()))
return Status(ErrorCodes::InvalidNamespace,
str::stream() << "invalid name for 'viewOn': " << viewOn.coll());
ViewDefinition savedDefinition = *viewPtr;
txn->recoveryUnit()->onRollback([this, txn, viewName, savedDefinition]() {
this->_viewMap[viewName.ns()] = std::make_shared<ViewDefinition>(savedDefinition);
});
return _createOrUpdateView_inlock(txn, viewName, viewOn, pipeline);
}
Status ViewCatalog::createView(OperationContext* txn,
const NamespaceString& viewName,
const NamespaceString& viewOn,
const BSONArray& pipeline) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
if (serverGlobalParams.featureCompatibilityVersion.load() ==
ServerGlobalParams::FeatureCompatibilityVersion_32) {
return Status(ErrorCodes::CommandNotSupported,
"Cannot create view when the featureCompatibilityVersion is 3.2. See "
"http://dochub.mongodb.org/core/3.4-feature-compatibility.");
}
if (viewName.db() != viewOn.db())
return Status(ErrorCodes::BadValue,
"View must be created on a view or collection in the same database");
if (_lookup_inlock(txn, StringData(viewName.ns())))
return Status(ErrorCodes::NamespaceExists, "Namespace already exists");
if (!NamespaceString::validCollectionName(viewOn.coll()))
return Status(ErrorCodes::InvalidNamespace,
str::stream() << "invalid name for 'viewOn': " << viewOn.coll());
return _createOrUpdateView_inlock(txn, viewName, viewOn, pipeline);
}
Status ViewCatalog::_validateCollation_inlock(OperationContext* opCtx,
const ViewDefinition& view,
const std::vector<NamespaceString>& refs) {
for (auto&& potentialViewNss : refs) {
auto otherView = _lookup_inlock(opCtx, potentialViewNss.ns());
if (otherView &&
!CollatorInterface::collatorsMatch(view.defaultCollator(),
otherView->defaultCollator())) {
return {ErrorCodes::OptionNotSupportedOnView,
str::stream() << "View " << view.name().toString()
<< " has conflicting collation with view "
<< otherView->name().toString()};
}
}
return Status::OK();
}
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};
}
Status ViewCatalog::modifyView(OperationContext* txn,
const NamespaceString& viewName,
const NamespaceString& viewOn,
const BSONArray& pipeline) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
if (viewName.db() != viewOn.db())
return Status(ErrorCodes::BadValue,
"View must be created on a view or collection in the same database");
if (!_lookup_inlock(txn, StringData(viewName.ns())))
return Status(ErrorCodes::NamespaceNotFound,
str::stream() << "cannot modify missing view " << viewName.ns());
if (!NamespaceString::validCollectionName(viewOn.coll()))
return Status(ErrorCodes::InvalidNamespace,
str::stream() << "invalid name for 'viewOn': " << viewOn.coll());
_createOrUpdateView_inlock(txn, viewName, viewOn, pipeline);
return Status::OK();
}
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 (std::uint32_t i = 0; i < ViewCatalog::kMaxViewDepth; i++) {
ViewDefinition* 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());
}
return {ErrorCodes::ViewDepthLimitExceeded,
str::stream() << "View depth too deep or view cycle detected; maximum depth is "
<< kMaxViewDepth};
}
ViewDefinition* ViewCatalog::lookup(OperationContext* txn, StringData ns) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
return _lookup_inlock(txn, ns);
}
std::shared_ptr<ViewDefinition> ViewCatalog::lookup(OperationContext* opCtx, StringData ns) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
return _lookup_inlock(opCtx, ns);
}
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++) {
while (MONGO_FAIL_POINT(hangDuringViewResolution)) {
log() << "Yielding mutex and hanging due to 'hangDuringViewResolution' failpoint";
lock.unlock();
sleepmillis(1000);
lock.lock();
}
// If the catalog has been invalidated, bail and restart.
if (!_valid.load()) {
uassertStatusOK(_reloadIfNeeded_inlock(opCtx));
break;
}
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.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;
}