diff options
Diffstat (limited to 'src/mongo/db/pipeline/document_source.h')
| -rw-r--r-- | src/mongo/db/pipeline/document_source.h | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/src/mongo/db/pipeline/document_source.h b/src/mongo/db/pipeline/document_source.h index 2b014c37a61..7b724b555cd 100644 --- a/src/mongo/db/pipeline/document_source.h +++ b/src/mongo/db/pipeline/document_source.h @@ -366,11 +366,25 @@ public: kAllExcept, }; - GetModPathsReturn(Type type, std::set<std::string>&& paths) - : type(type), paths(std::move(paths)) {} + GetModPathsReturn(Type type, + std::set<std::string>&& paths, + StringMap<std::string>&& renames) + : type(type), paths(std::move(paths)), renames(std::move(renames)) {} Type type; std::set<std::string> paths; + + // Stages may fill out 'renames' to contain information about path renames. Each entry in + // 'renames' maps from the new name of the path (valid in documents flowing *out* of this + // stage) to the old name of the path (valid in documents flowing *into* this stage). + // + // For example, consider the stage + // + // {$project: {_id: 0, a: 1, b: "$c"}} + // + // This stage should return kAllExcept, since it modifies all paths other than "a". It can + // also fill out 'renames' with the mapping "b" => "c". + StringMap<std::string> renames; }; /** @@ -381,7 +395,7 @@ public: * See GetModPathsReturn above for the possible return values and what they mean. */ virtual GetModPathsReturn getModifiedPaths() const { - return {GetModPathsReturn::Type::kNotSupported, std::set<std::string>{}}; + return {GetModPathsReturn::Type::kNotSupported, std::set<std::string>{}, {}}; } /** |