diff options
Diffstat (limited to 'src/mongo/db/commands.h')
| -rw-r--r-- | src/mongo/db/commands.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/src/mongo/db/commands.h b/src/mongo/db/commands.h index 485deeb61e4..e8c1a91d5b5 100644 --- a/src/mongo/db/commands.h +++ b/src/mongo/db/commands.h @@ -37,6 +37,7 @@ #include "mongo/db/auth/resource_pattern.h" #include "mongo/db/client_basic.h" #include "mongo/db/jsobj.h" +#include "mongo/db/query/explain.h" namespace mongo { @@ -138,6 +139,26 @@ namespace mutablebson { virtual void help( std::stringstream& help ) const; /** + * Commands which can be explained override this method. Any operation which has a query + * part and executes as a tree of execution stages can be explained. A command should + * implement explain by: + * + * 1) Calling its custom parse function in order to parse the command. The output of + * this function should be a CanonicalQuery (representing the query part of the + * operation), and a PlanExecutor which wraps the tree of execution stages. + * + * 2) Calling Explain::explainStages(...) on the PlanExecutor. This is the function + * which knows how to convert an execution stage tree into explain output. + */ + virtual Status explain(OperationContext* txn, + const std::string& dbname, + const BSONObj& cmdObj, + Explain::Verbosity verbosity, + BSONObjBuilder* out) const { + return Status(ErrorCodes::IllegalOperation, "Cannot explain cmd: " + name); + } + + /** * Checks if the given client is authorized to run this command on database "dbname" * with the invocation described by "cmdObj". */ |