hydra-queue-runner: Handle $HYDRA_DBI

Dependencies

• [2] 24BMQDZA Start of single-process hydra-queue-runner
• [3] UQQ4IL55 Add a error type for "unsupported system type"
• [4] ENXUSMSV Make concurrency more robust

Change contents

• replacement in src/hydra-queue-runner/hydra-queue-runner.cc at line 63
  [2.5364]→[2.5364:5421](∅→∅)
  − Connection() : pqxx::connection("dbname=hydra") { };
  [2.5364]

  [2.5421]
  + Connection() : pqxx::connection(getFlags()) { };

  +

  + string getFlags()

  + {

  + string s = getEnv("HYDRA_DBI", "dbi:Pg:dbname=hydra;");

  + string prefix = "dbi:Pg:";

  + if (string(s, 0, prefix.size()) != prefix)

  + throw Error("$HYDRA_DBI does not denote a PostgreSQL database");

  + return concatStringsSep(" ", tokenizeString<Strings>(string(s, prefix.size()), ";"));

  + }