Line data    Source code

       1             : /*
       2             :  * Copyright (c) 2015 Cisco and/or its affiliates.
       3             :  * Licensed under the Apache License, Version 2.0 (the "License");
       4             :  * you may not use this file except in compliance with the License.
       5             :  * You may obtain a copy of the License at:
       6             :  *
       7             :  *     http://www.apache.org/licenses/LICENSE-2.0
       8             :  *
       9             :  * Unless required by applicable law or agreed to in writing, software
      10             :  * distributed under the License is distributed on an "AS IS" BASIS,
      11             :  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      12             :  * See the License for the specific language governing permissions and
      13             :  * limitations under the License.
      14             :  */
      15             : /*
      16             :   Original license for the code used to construct
      17             :   clib_xxhash(...).
      18             : 
      19             :   xxHash - Fast Hash algorithm
      20             :   Copyright (C) 2012-2014, Yann Collet.
      21             :   BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
      22             : 
      23             :   Redistribution and use in source and binary forms, with or without
      24             :   modification, are permitted provided that the following conditions are
      25             :   met:
      26             : 
      27             :   * Redistributions of source code must retain the above copyright
      28             :   notice, this list of conditions and the following disclaimer.
      29             :   * Redistributions in binary form must reproduce the above
      30             :   copyright notice, this list of conditions and the following disclaimer
      31             :   in the documentation and/or other materials provided with the
      32             :   distribution.
      33             : 
      34             :   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      35             :   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      36             :   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      37             :   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
      38             :   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
      39             :   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
      40             :   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      41             :   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      42             :   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      43             :   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
      44             :   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
      45             : */
      46             : 
      47             : #ifndef __included_xxhash_h__
      48             : #define __included_xxhash_h__
      49             : 
      50             : #define PRIME64_1 11400714785074694791ULL
      51             : #define PRIME64_2 14029467366897019727ULL
      52             : #define PRIME64_3  1609587929392839161ULL
      53             : #define PRIME64_4  9650029242287828579ULL
      54             : #define PRIME64_5  2870177450012600261ULL
      55             : #define XXH_rotl64(x,r) ((x << r) | (x >> (64 - r)))
      56             : 
      57             : static inline u64
      58        3069 : clib_xxhash (u64 key)
      59             : {
      60             :   u64 k1, h64;
      61             : 
      62        3069 :   k1 = key;
      63        3069 :   h64 = 0x9e3779b97f4a7c13LL + PRIME64_5 + 8;
      64        3069 :   k1 *= PRIME64_2;
      65        3069 :   k1 = XXH_rotl64 (k1, 31);
      66        3069 :   k1 *= PRIME64_1;
      67        3069 :   h64 ^= k1;
      68        3069 :   h64 = XXH_rotl64 (h64, 27) * PRIME64_1 + PRIME64_4;
      69             : 
      70        3069 :   h64 ^= h64 >> 33;
      71        3069 :   h64 *= PRIME64_2;
      72        3069 :   h64 ^= h64 >> 29;
      73        3069 :   h64 *= PRIME64_3;
      74        3069 :   h64 ^= h64 >> 32;
      75        3069 :   return h64;
      76             : }
      77             : 
      78             : #endif /* __included_xxhash_h__ */
      79             : 
      80             : /*
      81             :  * fd.io coding-style-patch-verification: ON
      82             :  *
      83             :  * Local Variables:
      84             :  * eval: (c-set-style "gnu")
      85             :  * End:
      86             :  */