Function UnixAndFromUnixPrepare

be/src/exprs/timestamp-functions.cc:228–254

The purpose of making this .cc only is to avoid moving the code of CastDirection into the .h file

// The purpose of making this .cc only is to avoid moving the code of
// CastDirection into the .h file
void UnixAndFromUnixPrepare(FunctionContext* context,
    FunctionContext::FunctionStateScope scope, CastDirection cast_mode) {
  if (scope != FunctionContext::THREAD_LOCAL) return;
  DateTimeFormatContext* dt_ctx = NULL;
  if (context->IsArgConstant(1)) {
    StringVal fmt_val = *reinterpret_cast<StringVal*>(context->GetConstantArg(1));
    const StringValue& fmt_ref = StringValue::FromStringVal(fmt_val);
    if (fmt_val.is_null || fmt_ref.Len() == 0) {
      ReportBadFormat(context, datetime_parse_util::GENERAL_ERROR, fmt_val, true);
      return;
    }
    dt_ctx = new DateTimeFormatContext(fmt_ref.Ptr(), fmt_ref.Len());
    bool parse_result = SimpleDateFormatTokenizer::Tokenize(dt_ctx, cast_mode);
    if (!parse_result) {
      delete dt_ctx;
      ReportBadFormat(context, datetime_parse_util::GENERAL_ERROR, fmt_val, true);
      return;
    }
  } else {
    // If our format string is constant, then we benefit from it only being parsed once in
    // the code above. If it's not constant, then we can reuse a context by resetting it.
    // This is much cheaper vs alloc/dealloc'ing a context for each evaluation.
    dt_ctx = new DateTimeFormatContext();
  }
  dt_ctx->SetCenturyBreakAndCurrentTime(*context->impl()->state()->now());
  context->SetFunctionState(scope, dt_ctx);
}

void TimestampFunctions::UnixAndFromUnixClose(FunctionContext* context,
    FunctionContext::FunctionStateScope scope) {