51 lines
1.6 KiB
C++
51 lines
1.6 KiB
C++
/* ******************************************************************************
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*
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*
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* This program and the accompanying materials are made available under the
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* terms of the Apache License, Version 2.0 which is available at
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* https://www.apache.org/licenses/LICENSE-2.0.
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*
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* See the NOTICE file distributed with this work for additional
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* information regarding copyright ownership.
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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, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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* SPDX-License-Identifier: Apache-2.0
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******************************************************************************/
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//
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// Stronger 64-bit hash function helper, as described here: http://www.javamex.com/tutorials/collections/strong_hash_code_implementation.shtml
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// @author raver119@gmail.com
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//
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#ifndef LIBND4J_HELPER_HASH_H
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#define LIBND4J_HELPER_HASH_H
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#include <string>
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#include <system/dll.h>
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#include <system/pointercast.h>
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#include <mutex>
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namespace sd {
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namespace ops {
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class ND4J_EXPORT HashHelper {
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private:
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Nd4jLong _byteTable[256];
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const Nd4jLong HSTART = 0xBB40E64DA205B064L;
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const Nd4jLong HMULT = 7664345821815920749L;
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bool _isInit = false;
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std::mutex _locker;
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public:
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static HashHelper& getInstance();
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Nd4jLong getLongHash(std::string& str);
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};
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}
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}
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#endif //LIBND4J_HELPER_HASH_H
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