mirror of https://gitee.com/bigwinds/arangodb
93 lines
2.5 KiB
C++
93 lines
2.5 KiB
C++
////////////////////////////////////////////////////////////////////////////////
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/// @brief arithmetic helpers
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///
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/// @file
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///
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/// DISCLAIMER
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///
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/// Copyright 2010-2014 triagens GmbH, Cologne, Germany
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///
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/// Licensed under the Apache License, Version 2.0 (the "License");
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/// you may not use this file except in compliance with the License.
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/// You may obtain a copy of the License at
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///
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/// http://www.apache.org/licenses/LICENSE-2.0
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///
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/// Unless required by applicable law or agreed to in writing, software
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/// distributed under the License is distributed on an "AS IS" BASIS,
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/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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/// See the License for the specific language governing permissions and
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/// limitations under the License.
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///
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/// Copyright holder is triAGENS GmbH, Cologne, Germany
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///
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/// @author Max Neunhoeffer
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/// @author Copyright 2014, triagens GmbH, Cologne, Germany
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////////////////////////////////////////////////////////////////////////////////
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#ifndef ARANGODB_AQL_ARITHMETIC_H
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#define ARANGODB_AQL_ARITHMETIC_H 1
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#include "Basics/Common.h"
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namespace triagens {
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namespace aql {
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template<typename T>
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bool IsUnsafeAddition (T l, T r) {
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return ((r > 0 && l > (std::numeric_limits<T>::max)() - r) ||
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(r < 0 && l < (std::numeric_limits<T>::min)() - r));
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}
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template<typename T>
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bool IsUnsafeSubtraction (T l, T r) {
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return ((r > 0 && l < (std::numeric_limits<T>::min)() + r) || (r < 0 && l > (std::numeric_limits<T>::max)() + r));
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}
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template<typename T>
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bool IsUnsafeMultiplication (T l, T r) {
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if (l > 0) {
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if (r > 0) {
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if (l > ((std::numeric_limits<T>::max)() / r)) {
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return true;
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}
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}
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else {
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if (r < ((std::numeric_limits<T>::min)() / l)) {
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return true;
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}
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}
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}
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else {
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if (r > 0) {
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if (l < ((std::numeric_limits<T>::min)() / r)) {
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return true;
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}
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}
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else {
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if ( (l != 0) && (r < ((std::numeric_limits<T>::max)() / l))) {
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return true;
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}
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}
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}
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return false;
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}
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template<typename T>
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bool IsUnsafeDivision (T l, T r) {
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// note: the caller still has to check whether r is zero (division by zero)
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return (l == (std::numeric_limits<T>::min)() && r == -1);
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}
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}
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}
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#endif
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// Local Variables:
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// mode: outline-minor
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// outline-regexp: "^\\(/// @brief\\|/// {@inheritDoc}\\|/// @addtogroup\\|// --SECTION--\\|/// @\\}\\)"
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// End:
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