= Back-end utility functions =

The following functions can be used in your validator and assimilator code:

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{{{
int get_output_file_path(RESULT const&, std::string&);
}}}

Returns the path of a result's output file (parses result.xml_doc_out and computes the file's position in the  [DirHierarchy hierarchical directory structure]).

{{{
int get_output_file_paths(RESULT const&, vector<string>&);
}}}

Same, for multiple output files.

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{{{
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).

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{{{
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.