ucx: src/cx/hash_key.h@69a83fad8a35 (annotated)

src/cx/hash_key.h@69a83fad8a35 (annotated)

src/cx/hash_key.h

Wed, 08 Jun 2022 21:33:31 +0200

author: Mike Becker <universe@uap-core.de>
date: Wed, 08 Jun 2022 21:33:31 +0200
changeset 563: 69a83fad8a35
child 603: c49104015a6b
permissions: -rw-r--r--

improve hash key handling

 /*
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
  *
  * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *   1. Redistributions of source code must retain the above copyright
  *      notice, this list of conditions and the following disclaimer.
  *
  *   2. Redistributions in binary form must reproduce the above copyright
  *      notice, this list of conditions and the following disclaimer in the
  *      documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 /**
  * \file hash_key.h
  * \brief Interface for map implementations.
  * \author Mike Becker
  * \author Olaf Wintermann
  * \version 3.0
  * \copyright 2-Clause BSD License
  */
 #ifndef UCX_HASH_KEY_H
 #define UCX_HASH_KEY_H
 #include "stddef.h"
 #ifdef __cplusplus
 extern "C" {
 #endif
 /** Internal structure for a key within a hash map. */
 struct cx_hash_key_s {
     /** The key data. */
     union {
         unsigned char *bytes;
         unsigned char const *cbytes;
         char const *cstr;
         char *str;
         void *obj;
     } data;
     /**
      * The key data length.
      */
     size_t len;
     /** The hash value of the key data. */
     unsigned hash;
 };
 /**
  * Type for a hash key.
  */
 typedef struct cx_hash_key_s CxHashKey;
 /**
  * Computes a murmur hash-2.
  *
  * You need to initialize data and len in the key struct.
  * The hash is then directly written to that struct.
  *
  * @param key the key, the hash shall be computed for
  */
 void cx_hash_murmur(CxHashKey *key);
 /**
  * Computes a hash key from a string.
  *
  * The string needs to be zero-terminated.
  *
  * @param str the string
  * @return the hash key
  */
 __attribute__((__warn_unused_result__))
 CxHashKey cx_hash_key_str(char const *str);
 /**
  * Computes a hash key from a byte array.
  *
  * @param bytes the array
  * @param len the length
  * @return the hash key
  */
 __attribute__((__warn_unused_result__))
 CxHashKey cx_hash_key_bytes(
         unsigned char const *bytes,
         size_t len
 );
 /**
  * Computes a hash key for an arbitrary object.
  *
  * The computation uses the in-memory representation that might not be
  * the same on different platforms. Therefore, this hash should not be
  * used for data exchange with different machines.
  *
  * @param obj a pointer to an arbitrary object
  * @param len the length of object in memory
  * @return the hash key
  */
 __attribute__((__warn_unused_result__))
 CxHashKey cx_hash_key(
         void *obj,
         size_t len
 );
 #ifdef __cplusplus
 } // extern "C"
 #endif
 #endif /* UCX_HASH_KEY_H */

Mercurial > hg > ucx / annotate

src/cx/hash_key.h@69a83fad8a35 (annotated)

src/cx/hash_key.h