Function ParseRelativeTimespan

cvmfs/receiver/commit_processor.cc:102–172

See commit_processor.h for the contract. `now` is injected so the parser is deterministic and unit-testable.

// See commit_processor.h for the contract. `now` is injected so the parser is
// deterministic and unit-testable.
time_t ParseRelativeTimespan(const std::string &timespan, time_t now) {
  // Tokenize on whitespace, lower-casing as we go.
  std::vector<std::string> tokens;
  std::string current;
  for (size_t i = 0; i < timespan.size(); ++i) {
    const unsigned char c = static_cast<unsigned char>(timespan[i]);
    if (isspace(c)) {
      if (!current.empty()) {
        tokens.push_back(current);
        current.clear();
      }
    } else {
      current += static_cast<char>(tolower(c));
    }
  }
  if (!current.empty()) {
    tokens.push_back(current);
  }

  // Expect exactly "<number> <unit> ago".
  if (tokens.size() != 3 || tokens[2] != "ago") {
    return 0;
  }
  const std::string &number = tokens[0];
  if (number.empty()) {
    return 0;
  }
  for (size_t i = 0; i < number.size(); ++i) {
    if (!isdigit(static_cast<unsigned char>(number[i]))) {
      return 0;
    }
  }
  const int64_t count = String2Int64(number);

  // De-pluralize the unit.
  std::string unit = tokens[1];
  if (!unit.empty() && unit[unit.size() - 1] == 's') {
    unit.resize(unit.size() - 1);
  }

  // Fixed-length units can be subtracted directly.
  int64_t factor = 0;
  if (unit == "sec" || unit == "second") {
    factor = 1;
  } else if (unit == "min" || unit == "minute") {
    factor = 60;
  } else if (unit == "hour") {
    factor = 3600;
  } else if (unit == "day") {
    factor = 86400;
  } else if (unit == "week") {
    factor = 604800;
  }
  if (factor > 0) {
    return now - static_cast<time_t>(count * factor);
  }

  // Calendar units: let mktime() normalize the broken-down time.