headers/shared/common.h

   1 /* Shoggoth - Distributed File System
   2  * Common utils
   3  *
   4  * Copyright (C) 2012 Pawel Dziepak
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, version 3 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #ifndef COMMON_H_
  17 #define COMMON_H_
  18
  19 #include <arpa/inet.h>
  20
  21 static inline int min(int a, int b) {
  22         return a > b ? b : a;
  23 }
  24
  25 static inline int max(int a, int b) {
  26         return a < b ? b : a;
  27 }
  28
  29 #define to_be16(x) htons(x)
  30 #define to_be32(x) htonl(x)
  31
  32 static inline uint64_t to_be64(uint64_t x) {
  33         uint64_t y;
  34         unsigned char *py = (unsigned char*)&y;
  35
  36         py[0] = x >> 56;
  37         py[1] = x >> 48;
  38         py[2] = x >> 40;
  39         py[3] = x >> 32;
  40         py[4] = x >> 24;
  41         py[5] = x >> 16;
  42         py[6] = x >> 8;
  43         py[7] = x;
  44
  45         return y;
  46 }
  47
  48 #define from_be16(x) ntohs(x)
  49 #define from_be32(x) ntohl(x)
  50
  51 static inline uint64_t form_be64(uint64_t x) {
  52         unsigned char *px = (unsigned char*)&x;
  53
  54         return (uint64_t)px[0] << 56 | (uint64_t)px[1] << 48 |
  55                 (uint64_t)px[2] << 40 | (uint64_t)px[3] << 32 |
  56                 (uint64_t)px[4] << 24 | (uint64_t)px[5] << 16 |
  57                 (uint64_t)px[6] << 8 | (uint64_t)px[7];
  58 }
  59
  60 #endif