51 lines
1.4 KiB
C
51 lines
1.4 KiB
C
/****************************************************************************
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* Copyright (C) 2024 Xiaomi Corporation
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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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#include "bt_hash.h"
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#define HASH4 h = ((h << 5) + h + *key++);
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uint32_t bt_hash4(const void* keyarg, size_t len)
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{
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const uint8_t* key = keyarg;
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uint32_t h = 0;
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size_t loop;
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if (len > 0) {
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loop = (len + 8 - 1) >> 3;
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switch (len & (8 - 1)) {
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case 0:
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do {
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HASH4;
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case 7:
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HASH4;
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case 6:
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HASH4;
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case 5:
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HASH4;
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case 4:
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HASH4;
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case 3:
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HASH4;
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case 2:
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HASH4;
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case 1:
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HASH4;
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} while (--loop);
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}
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}
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return h;
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} |