ucx: src/cx/hash_key.h@475335643af4

increase version number to 3.1

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from Doxygen output

     1 /*

     2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

     3  *

     4  * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.

     5  *

     6  * Redistribution and use in source and binary forms, with or without

     7  * modification, are permitted provided that the following conditions are met:

     8  *

     9  *   1. Redistributions of source code must retain the above copyright

    10  *      notice, this list of conditions and the following disclaimer.

    11  *

    12  *   2. Redistributions in binary form must reproduce the above copyright

    13  *      notice, this list of conditions and the following disclaimer in the

    14  *      documentation and/or other materials provided with the distribution.

    15  *

    16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

    17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

    18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

    19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

    20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

    21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

    22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

    23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

    24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

    25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

    26  * POSSIBILITY OF SUCH DAMAGE.

    27  */

    28 /**

    29  * \file hash_key.h

    30  * \brief Interface for map implementations.

    31  * \author Mike Becker

    32  * \author Olaf Wintermann

    33  * \copyright 2-Clause BSD License

    34  */

    37 #ifndef UCX_HASH_KEY_H

    38 #define UCX_HASH_KEY_H

    40 #include "common.h"

    42 #ifdef __cplusplus

    43 extern "C" {

    44 #endif

    46 /** Internal structure for a key within a hash map. */

    47 struct cx_hash_key_s {

    48     /** The key data. */

    49     void const *data;

    50     /**

    51      * The key data length.

    52      */

    53     size_t len;

    54     /** The hash value of the key data. */

    55     unsigned hash;

    56 };

    58 /**

    59  * Type for a hash key.

    60  */

    61 typedef struct cx_hash_key_s CxHashKey;

    63 /**

    64  * Computes a murmur2 32 bit hash.

    65  *

    66  * You need to initialize \c data and \c len in the key struct.

    67  * The hash is then directly written to that struct.

    68  *

    69  * \note If \c data is \c NULL, the hash is defined as 1574210520.

    70  *

    71  * @param key the key, the hash shall be computed for

    72  */

    73 void cx_hash_murmur(CxHashKey *key);

    75 /**

    76  * Computes a hash key from a string.

    77  *

    78  * The string needs to be zero-terminated.

    79  *

    80  * @param str the string

    81  * @return the hash key

    82  */

    83 __attribute__((__warn_unused_result__))

    84 CxHashKey cx_hash_key_str(char const *str);

    86 /**

    87  * Computes a hash key from a byte array.

    88  *

    89  * @param bytes the array

    90  * @param len the length

    91  * @return the hash key

    92  */

    93 __attribute__((__warn_unused_result__))

    94 CxHashKey cx_hash_key_bytes(

    95         unsigned char const *bytes,

    96         size_t len

    97 );

    99 /**

   100  * Computes a hash key for an arbitrary object.

   101  *

   102  * The computation uses the in-memory representation that might not be

   103  * the same on different platforms. Therefore, this hash should not be

   104  * used for data exchange with different machines.

   105  *

   106  * @param obj a pointer to an arbitrary object

   107  * @param len the length of object in memory

   108  * @return the hash key

   109  */

   110 __attribute__((__warn_unused_result__))

   111 CxHashKey cx_hash_key(

   112         void const *obj,

   113         size_t len

   114 );

   116 /**

   117  * Computes a hash key from a UCX string.

   118  *

   119  * @param str the string

   120  * @return the hash key

   121  */

   122 #define cx_hash_key_cxstr(str) cx_hash_key((void*)(str).ptr, (str).length)

   124 #ifdef __cplusplus

   125 } // extern "C"

   126 #endif

   128 #endif // UCX_HASH_KEY_H

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