diff options
Diffstat (limited to 'src/mongo/db/pipeline/document_source_unwind.cpp')
| -rw-r--r-- | src/mongo/db/pipeline/document_source_unwind.cpp | 38 |
1 files changed, 22 insertions, 16 deletions
diff --git a/src/mongo/db/pipeline/document_source_unwind.cpp b/src/mongo/db/pipeline/document_source_unwind.cpp index 2161b0b9bbb..45ba4aed308 100644 --- a/src/mongo/db/pipeline/document_source_unwind.cpp +++ b/src/mongo/db/pipeline/document_source_unwind.cpp @@ -91,6 +91,10 @@ private: // Index into the _inputArray to return next. size_t _index = 0; + + // True if we are including the array index and it's path is a parent of the unwind path. If + // this is true, we will just return the array indices and ignore the array values. + bool _conflictingPaths; }; DocumentSourceUnwind::Unwinder::Unwinder(const FieldPath& unwindPath, @@ -100,7 +104,8 @@ DocumentSourceUnwind::Unwinder::Unwinder(const FieldPath& unwindPath, : _unwindPath(unwindPath), _preserveNullAndEmptyArrays(preserveNullAndEmptyArrays), _indexPath(indexPath), - _strict(strict) {} + _strict(strict), + _conflictingPaths(indexPath ? indexPath->isPrefixOf(unwindPath) : false) {} void DocumentSourceUnwind::Unwinder::resetDocument(const Document& document) { // Reset document specific attributes. @@ -141,8 +146,11 @@ DocumentSource::GetNextResult DocumentSourceUnwind::Unwinder::getNext() { // across documents that have come out of this pipeline operator. This is a partial deep // clone. Because the value at the end will be replaced, everything along the path // leading to that will be replaced in order not to share that change with any other - // clones (or the original). - _output.setNestedField(_unwindPathFieldIndexes, _inputArray[_index]); + // clones (or the original). If the array index path is a parent of the unwind path, we + // ignore the array value since it would be overwritten by the index. + if (!_conflictingPaths) { + _output.setNestedField(_unwindPathFieldIndexes, _inputArray[_index]); + } indexForOutput = _index; _index++; _haveNext = _index < length; @@ -232,19 +240,16 @@ bool DocumentSourceUnwind::canPushSortBack(const DocumentSourceSort* sort) const // otherwise when we swap the limit and unwind, we could end up providing fewer results to the // user than expected. if (!sort->hasLimit() || _preserveNullAndEmptyArrays) { - auto unwindPath = _unwindPath.fullPath(); + auto modifiedPaths = getModifiedPaths(); // Checks if any of the $sort's paths depend on the unwind path (or vice versa). SortPattern sortKeyPattern = sort->getSortKeyPattern(); - bool sortPathMatchesUnwindPath = + bool sortDependsOnUnwind = std::any_of(sortKeyPattern.begin(), sortKeyPattern.end(), [&](auto& sortKey) { // If 'sortKey' is a $meta expression, we can do the swap. - if (!sortKey.fieldPath) - return false; - return expression::bidirectionalPathPrefixOf(unwindPath, - sortKey.fieldPath->fullPath()); + return sortKey.fieldPath && modifiedPaths.canModify(*sortKey.fieldPath); }); - return !sortPathMatchesUnwindPath; + return !sortDependsOnUnwind; } return false; } @@ -293,12 +298,13 @@ Pipeline::SourceContainer::iterator DocumentSourceUnwind::doOptimizeAt( return std::next(itr); } -Value DocumentSourceUnwind::serialize(boost::optional<ExplainOptions::Verbosity> explain) const { - return Value(DOC(getSourceName() << DOC( - "path" << _unwindPath.fullPathWithPrefix() << "preserveNullAndEmptyArrays" - << (_preserveNullAndEmptyArrays ? Value(true) : Value()) - << "includeArrayIndex" - << (_indexPath ? Value((*_indexPath).fullPath()) : Value())))); +Value DocumentSourceUnwind::serialize(const SerializationOptions& opts) const { + return Value(DOC( + getSourceName() << DOC( + "path" << opts.serializeFieldPathWithPrefix(_unwindPath) << "preserveNullAndEmptyArrays" + << (_preserveNullAndEmptyArrays ? opts.serializeLiteral(true) : Value()) + << "includeArrayIndex" + << (_indexPath ? Value(opts.serializeFieldPath(*_indexPath)) : Value())))); } DepsTracker::State DocumentSourceUnwind::getDependencies(DepsTracker* deps) const { |