Status ensureIdAndFirst(mb::Document& doc) {
mb::Element idElem = mb::findFirstChildNamed(doc.root(), idFieldName);
// Move _id as first element if it exists
if (idElem.ok()) {
if (idElem.leftSibling().ok()) {
Status s = idElem.remove();
if (!s.isOK())
return s;
s = doc.root().pushFront(idElem);
if (!s.isOK())
return s;
}
} else {
// Create _id if the document does not currently have one.
idElem = doc.makeElementNewOID(idFieldName);
if (!idElem.ok())
return Status(
ErrorCodes::BadValue, "Could not create new _id ObjectId element.", 17268);
Status s = doc.root().pushFront(idElem);
if (!s.isOK())
return s;
}
return Status::OK();
}
/**
* This will verify that all updated fields are
* 1.) Valid for storage (checking parent to make sure things like DBRefs are valid)
* 2.) Compare updated immutable fields do not change values
*
* If updateFields is empty then it was replacement and/or we need to check all fields
*/
inline Status validate(const BSONObj& original,
const FieldRefSet& updatedFields,
const mb::Document& updated,
const std::vector<FieldRef*>* immutableAndSingleValueFields,
const ModifierInterface::Options& opts) {
LOG(3) << "update validate options -- "
<< " updatedFields: " << updatedFields << " immutableAndSingleValueFields.size:"
<< (immutableAndSingleValueFields ? immutableAndSingleValueFields->size() : 0)
<< " validate:" << opts.enforceOkForStorage;
// 1.) Loop through each updated field and validate for storage
// and detect immutable field updates
// The set of possibly changed immutable fields -- we will need to check their vals
FieldRefSet changedImmutableFields;
// Check to see if there were no fields specified or if we are not validating
// The case if a range query, or query that didn't result in saved fields
if (updatedFields.empty() || !opts.enforceOkForStorage) {
if (opts.enforceOkForStorage) {
// No specific fields were updated so the whole doc must be checked
Status s = storageValid(updated, true);
if (!s.isOK())
return s;
}
// Check all immutable fields
if (immutableAndSingleValueFields)
changedImmutableFields.fillFrom(*immutableAndSingleValueFields);
} else {
// TODO: Change impl so we don't need to create a new FieldRefSet
// -- move all conflict logic into static function on FieldRefSet?
FieldRefSet immutableFieldRef;
if (immutableAndSingleValueFields)
immutableFieldRef.fillFrom(*immutableAndSingleValueFields);
FieldRefSet::const_iterator where = updatedFields.begin();
const FieldRefSet::const_iterator end = updatedFields.end();
for (; where != end; ++where) {
const FieldRef& current = **where;
// Find the updated field in the updated document.
mutablebson::ConstElement newElem = updated.root();
size_t currentPart = 0;
while (newElem.ok() && currentPart < current.numParts())
newElem = newElem[current.getPart(currentPart++)];
// newElem might be missing if $unset/$renamed-away
if (newElem.ok()) {
// Check element, and its children
Status s = storageValid(newElem, true);
if (!s.isOK())
return s;
// Check parents to make sure they are valid as well.
s = storageValidParents(newElem);
if (!s.isOK())
return s;
}
// Check if the updated field conflicts with immutable fields
immutableFieldRef.findConflicts(¤t, &changedImmutableFields);
}
}
const bool checkIdField = (updatedFields.empty() && !original.isEmpty()) ||
updatedFields.findConflicts(&idFieldRef, NULL);
// Add _id to fields to check since it too is immutable
if (checkIdField)
changedImmutableFields.keepShortest(&idFieldRef);
else if (changedImmutableFields.empty()) {
// Return early if nothing changed which is immutable
return Status::OK();
}
LOG(4) << "Changed immutable fields: " << changedImmutableFields;
// 2.) Now compare values of the changed immutable fields (to make sure they haven't)
const mutablebson::ConstElement newIdElem = updated.root()[idFieldName];
FieldRefSet::const_iterator where = changedImmutableFields.begin();
const FieldRefSet::const_iterator end = changedImmutableFields.end();
for (; where != end; ++where) {
const FieldRef& current = **where;
// Find the updated field in the updated document.
mutablebson::ConstElement newElem = updated.root();
size_t currentPart = 0;
while (newElem.ok() && currentPart < current.numParts())
newElem = newElem[current.getPart(currentPart++)];
if (!newElem.ok()) {
if (original.isEmpty()) {
// If the _id is missing and not required, then skip this check
if (!(current.dottedField() == idFieldName))
return Status(ErrorCodes::NoSuchKey,
mongoutils::str::stream() << "After applying the update, the new"
<< " document was missing the '"
<< current.dottedField()
<< "' (required and immutable) field.");
} else {
if (current.dottedField() != idFieldName)
return Status(ErrorCodes::ImmutableField,
mongoutils::str::stream()
<< "After applying the update to the document with "
<< newIdElem.toString()
<< ", the '"
<< current.dottedField()
<< "' (required and immutable) field was "
"found to have been removed --"
<< original);
}
} else {
// Find the potentially affected field in the original document.
const BSONElement oldElem = dps::extractElementAtPath(original, current.dottedField());
const BSONElement oldIdElem = original.getField(idFieldName);
// Ensure no arrays since neither _id nor shard keys can be in an array, or one.
mb::ConstElement currElem = newElem;
while (currElem.ok()) {
if (currElem.getType() == Array) {
return Status(
ErrorCodes::NotSingleValueField,
mongoutils::str::stream()
<< "After applying the update to the document {"
<< (oldIdElem.ok() ? oldIdElem.toString() : newIdElem.toString())
<< " , ...}, the (immutable) field '"
<< current.dottedField()
<< "' was found to be an array or array descendant.");
}
currElem = currElem.parent();
}
// If we have both (old and new), compare them. If we just have new we are good
if (oldElem.ok() && newElem.compareWithBSONElement(oldElem, nullptr, false) != 0) {
return Status(ErrorCodes::ImmutableField,
mongoutils::str::stream()
<< "After applying the update to the document {"
<< oldElem.toString()
<< " , ...}, the (immutable) field '"
<< current.dottedField()
<< "' was found to have been altered to "
<< newElem.toString());
}
}
}
return Status::OK();
}