38a54df863
People keep tripping over the old copyrights and copy-pasting them to new files. Search and replace "Cloudius Systems" with "ScyllaDB". Message-Id: <1460013664-25966-1-git-send-email-penberg@scylladb.com>
98 lines
2.9 KiB
C++
98 lines
2.9 KiB
C++
/*
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* Copyright (C) 2015 ScyllaDB
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*/
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/*
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* This file is part of Scylla.
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*
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* Scylla is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Scylla is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "big_decimal.hh"
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#include <regex>
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#include "types.hh"
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big_decimal::big_decimal(sstring_view text)
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{
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std::string str = text.to_string();
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static const std::regex big_decimal_re("^([\\+\\-]?)([0-9]*)(\\.([0-9]*))?([eE]([\\+\\-]?[0-9]+))?");
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std::smatch sm;
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if (!std::regex_match(str, sm, big_decimal_re)) {
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throw marshal_exception();
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}
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bool negative = sm[1] == "-";
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auto integer = sm[2].str();
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auto fraction = sm[4].str();
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auto exponent = sm[6].str();
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if (integer.empty() && fraction.empty()) {
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throw marshal_exception();
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}
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integer.append(fraction);
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unsigned i;
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for (i = 0; i < integer.size() - 1 && integer[i] == '0'; i++);
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integer = integer.substr(i);
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_unscaled_value = boost::multiprecision::cpp_int(integer);
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if (negative) {
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_unscaled_value *= -1;
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}
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_scale = exponent.empty() ? 0 : -boost::lexical_cast<int32_t>(exponent);
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_scale += fraction.size();
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}
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sstring big_decimal::to_string() const
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{
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if (!_unscaled_value) {
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return "0";
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}
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boost::multiprecision::cpp_int num = boost::multiprecision::abs(_unscaled_value);
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auto str = num.str();
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if (_scale < 0) {
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for (int i = 0; i > _scale; i--) {
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str.push_back('0');
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}
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} else if (_scale > 0) {
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if (str.size() > unsigned(_scale)) {
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str.insert(str.size() - _scale, 1, '.');
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} else {
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std::string nstr = "0.";
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nstr.append(_scale - str.size(), '0');
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nstr.append(str);
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str = std::move(nstr);
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}
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while (str.back() == '0') {
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str.pop_back();
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}
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if (str.back() == '.') {
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str.pop_back();
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}
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}
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if (_unscaled_value < 0) {
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str.insert(0, 1, '-');
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}
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return str;
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}
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int big_decimal::compare(const big_decimal& other) const
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{
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auto max_scale = std::max(_scale, other._scale);
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boost::multiprecision::cpp_int rescale(10);
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boost::multiprecision::cpp_int x = _unscaled_value * boost::multiprecision::pow(rescale, max_scale - _scale);
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boost::multiprecision::cpp_int y = other._unscaled_value * boost::multiprecision::pow(rescale, max_scale - other._scale);
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return x == y ? 0 : x < y ? -1 : 1;
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}
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