Method ToShortString

be/src/gutil/strings/human_readable.cc:276–323

Abbreviations used here are acceptable English abbreviations without the ending period (".") for brevity, except for uncommon abbreviations, in which case the entire word is spelled out. ("mo" and "mos" are not good abbreviations for "months" -- with or without the period). If needed, one can add a HumanReadableTime::ToStringShort() for shorter abbreviations or one for always spelling out the unit

// HumanReadableTime::ToStringShort() for shorter abbreviations or one
// for always spelling out the unit, HumanReadableTime::ToStringLong().
string HumanReadableElapsedTime::ToShortString(double seconds) {
  string human_readable;

  if (seconds < 0) {
    human_readable = "-";
    seconds = -seconds;
  }

  // Start with ns and keep going up to years.
  if (seconds < 0.000001) {
    StringAppendF(&human_readable, "%0.3g ns", seconds * 1000000000.0);
    return human_readable;
  }
  if (seconds < 0.001) {
    StringAppendF(&human_readable, "%0.3g us", seconds * 1000000.0);
    return human_readable;
  }
  if (seconds < 1.0) {
    StringAppendF(&human_readable, "%0.3g ms", seconds * 1000.0);
    return human_readable;
  }
  if (seconds < 60.0) {
    StringAppendF(&human_readable, "%0.3g s", seconds);
    return human_readable;
  }
  seconds /= 60.0;
  if (seconds < 60.0) {
    StringAppendF(&human_readable, "%0.3g min", seconds);
    return human_readable;
  }
  seconds /= 60.0;
  if (seconds < 24.0) {
    StringAppendF(&human_readable, "%0.3g h", seconds);
    return human_readable;
  }
  seconds /= 24.0;
  if (seconds < 30.0) {
    StringAppendF(&human_readable, "%0.3g days", seconds);
    return human_readable;
  }
  if (seconds < 365.2425) {
    StringAppendF(&human_readable, "%0.3g months", seconds / 30.436875);
    return human_readable;
  }
  seconds /= 365.2425;
  StringAppendF(&human_readable, "%0.3g years", seconds);
  return human_readable;
}

bool HumanReadableElapsedTime::ToDouble(const string& str, double* value) {
  struct TimeUnits {