esos_utils.c

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/*
 * "Copyright (c) 2019 J. W. Bruce ("AUTHOR(S)")"
 * All rights reserved.
 * (J. W. Bruce, jwbruce_AT_tntech.edu, Tennessee Tech University)
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose, without fee, and without written agreement is
 * hereby granted, provided that the above copyright notice, the following
 * two paragraphs and the authors appear in all copies of this software.
 *
 * IN NO EVENT SHALL THE "AUTHORS" BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
 * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE "AUTHORS"
 * HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * THE "AUTHORS" SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE "AUTHORS" HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS."
 *
 * Please maintain this header in its entirety when copying/modifying
 * these files.
 *
 *
 */
 
#include    "esos.h"
#include    "esos_utils.h"
 
// ******** G L O B A L S ***************
uint32_t            __u32_esos_PRNG_Seed;
uint32_t            __esos_u32FNVHash = 2166136261uL;
 
/****************************************************************
** F U N C T I O N S
****************************************************************/
 
void __esos_set_PRNG_U32Seed(uint32_t u32_seed) {
   __u32_esos_PRNG_Seed = u32_seed;
} // end __esos_set_PRNG_U32Seed()
 
uint32_t   __esos_get_PRNG_RandomUint32(void) {
  uint32_t  hi, lo;
 
  lo = 16807 * ( __u32_esos_PRNG_Seed * 0xFFFF );
  hi = 16807 * ( __u32_esos_PRNG_Seed >> 16 );
  lo += (hi & 0x7FFF) << 16;
  lo += (hi >> 15);
  if (lo > 0x7FFFFFFF) lo -= 0x7FFFFFFF;
  return (__u32_esos_PRNG_Seed = (uint32_t) lo );
} // end __esos_get_PRNG_RandomUint32()
 
inline uint32_t    esos_GetRandomUint32(void) {
  return ( __esos_hw_PRNG_u32() );
} // end esos_getRandomUint32()
 
 
uint16_t    esos_taskname_hash_u16( void* buf, uint16_t len ) {
  unsigned char *bp = (unsigned char *)buf; /* start of buffer */
  unsigned char *be = bp + len;   /* beyond end of buffer */
  uint32_t        u32_temp = 2166136261uL;
 
  /*
   * FNV-1 hash each octet in the buffer
   */
  while (bp < be) {
    /* multiply by the 32 bit FNV magic prime mod 2^32 */
    u32_temp += (u32_temp<<1) + (u32_temp<<4) + (u32_temp<<7) + (u32_temp<<8) + (u32_temp<<24);
 
    /* xor the bottom with the current octet */
    u32_temp ^= (uint32_t)*bp++;
  } // end while
  return (uint16_t) ((u32_temp >> 16) ^ (u32_temp & 0xFFFF));
} // end esos_taskname_hash_u16
 
 
uint32_t esos_buffer_hash_u32(void *buf, uint16_t len) {
  unsigned char *bp = (unsigned char *)buf; /* start of buffer */
  unsigned char *be = bp + len;           /* beyond end of buffer */
 
  /*
   * FNV-1 hash each octet in the buffer
   */
  while (bp < be) {
 
    /* multiply by the 32 bit FNV magic prime mod 2^32 */
#if defined(NO_FNV_GCC_OPTIMIZATION)
    __esos_u32FNVHash *= FNV_32_PRIME;
#else
    __esos_u32FNVHash += (__esos_u32FNVHash<<1) + (__esos_u32FNVHash<<4) + (__esos_u32FNVHash<<7) + (__esos_u32FNVHash<<8) + (__esos_u32FNVHash<<24);
#endif
 
    /* xor the bottom with the current octet */
    __esos_u32FNVHash ^= (uint32_t)*bp++;
  }
 
  /* return our new hash value */
  return __esos_u32FNVHash;
}
 
 
uint32_t esos_string_hash_u32(char *psz_str) {
  unsigned char *ch_s = (unsigned char *)psz_str; /* unsigned string */
 
  /*
   * FNV-1 hash each octet in the buffer
   */
  while (*ch_s) {
 
    /* multiply by the 32 bit FNV magic prime mod 2^32 */
#if defined(NO_FNV_GCC_OPTIMIZATION)
    __esos_u32FNVHash *= FNV_32_PRIME;
#else
    __esos_u32FNVHash += (__esos_u32FNVHash<<1) + (__esos_u32FNVHash<<4) + (__esos_u32FNVHash<<7) + (__esos_u32FNVHash<<8) + (__esos_u32FNVHash<<24);
#endif
 
    /* xor the bottom with the current octet */
    __esos_u32FNVHash ^= (uint32_t)*ch_s++;
  }
 
  /* return our new hash value */
  return __esos_u32FNVHash;
}
 
inline uint16_t esos_hash_u32_to_u16(uint32_t u32_hash) {
  return  (uint16_t) ((u32_hash>>16) ^ (u32_hash&0xFFFF));
}