/*
* 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
* \copyright 2-Clause BSD License
*/
#ifndef UCX_HASH_KEY_H
#define UCX_HASH_KEY_H
#include "common.h"
#ifdef __cplusplus
extern "C" {
#endif
/** Internal structure for a key within a hash map. */
struct cx_hash_key_s {
/** The key data. */
const void *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 murmur2 32 bit hash.
*
* You need to initialize \c data and \c len in the key struct.
* The hash is then directly written to that struct.
*
* \note If \c data is \c NULL, the hash is defined as 1574210520.
*
* @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(const char *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(
const unsigned char *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(
const void *obj,
size_t len
);
/**
* Computes a hash key from a UCX string.
*
* @param str the string
* @return the hash key
*/
#define cx_hash_key_cxstr(str) cx_hash_key((void*)(str).ptr, (str).length)
#ifdef __cplusplus
} // extern "C"
#endif
#endif // UCX_HASH_KEY_H