= Back-end utility functions =

The following functions (in validate_util.C and sched_util.C)
can be used in your validator and assimilator code.


{{{
struct FILE_INFO {
    std::string path;
    bool optional;
};

extern int get_output_file_info(RESULT& result, FILE_INFO&);
extern int get_output_file_infos(RESULT& result, std::vector<FILE_INFO>&);
extern int get_output_file_path(RESULT& result, std::string&);
extern int get_output_file_paths(RESULT& result, std::vector<std::string>&);
}}}

Returns the paths of a result's output file(s).
The FILE_INFO variants also return each files "optional" attribute.


{{{
int try_fopen(char* path, FILE*& f, char* mode);
}}}

Open a file, distinguishing between recoverable and nonrecoverable errors.
Returns zero on success.
Returns ERR_FOPEN if the directory is present but not the file
(this is considered a nonrecoverable error).
Returns ERR_OPENDIR if the directory is not there
(this is generally a recoverable error, like NFS mount failure).


{{{
double median_mean_credit(vector<RESULT> const& results);
}}}

Given a vector of N correct results, computes a canonical credit as follows:

 * if N==1, return that result's claimed credit
 * if N==2, return min of claimed credits
 * if N>2, toss out high and low claimed credit, and return the average of the rest.