utils.h

   1 /*
   2  * Copyright 2004 Timo Hirvonen
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  17  * 02111-1307, USA.
  18  */
  19
  20 #ifndef _UTILS_H
  21 #define _UTILS_H
  22
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <unistd.h>
  28 #include <time.h>
  29 #include <inttypes.h>
  30
  31 static inline int min(int a, int b)
  32 {
  33         return a < b ? a : b;
  34 }
  35
  36 static inline int max(int a, int b)
  37 {
  38         return a > b ? a : b;
  39 }
  40
  41 static inline int clamp(int val, int minval, int maxval)
  42 {
  43         if (val < minval)
  44                 return minval;
  45         if (val > maxval)
  46                 return maxval;
  47         return val;
  48 }
  49
  50 static inline int scale_from_percentage(int val, int max_val)
  51 {
  52         if (val < 0)
  53                 return (val * max_val - 50) / 100;
  54         return (val * max_val + 50) / 100;
  55 }
  56
  57 static inline int scale_to_percentage(int val, int max_val)
  58 {
  59         int half = max_val / 2;
  60
  61         if (max_val <= 0)
  62                 return 100;
  63
  64         if (val < 0)
  65                 return (val * 100 - half) / max_val;
  66         return (val * 100 + half) / max_val;
  67 }
  68
  69 static inline int str_to_int(const char *str, long int *val)
  70 {
  71         char *end;
  72
  73         *val = strtol(str, &end, 10);
  74         if (*str == 0 || *end != 0)
  75                 return -1;
  76         return 0;
  77 }
  78
  79 static inline time_t file_get_mtime(const char *filename)
  80 {
  81         struct stat s;
  82
  83         /* stat follows symlinks, lstat does not */
  84         if (stat(filename, &s) == -1)
  85                 return -1;
  86         return s.st_mtime;
  87 }
  88
  89 static inline void ns_sleep(int ns)
  90 {
  91         struct timespec req;
  92
  93         req.tv_sec = 0;
  94         req.tv_nsec = ns;
  95         nanosleep(&req, NULL);
  96 }
  97
  98 static inline void us_sleep(int us)
  99 {
 100         ns_sleep(us * 1e3);
 101 }
 102
 103 static inline void ms_sleep(int ms)
 104 {
 105         ns_sleep(ms * 1e6);
 106 }
 107
 108 static inline int is_url(const char *name)
 109 {
 110         return strncmp(name, "http://", 7) == 0;
 111 }
 112
 113 static inline uint32_t read_le32(const char *buf)
 114 {
 115         const unsigned char *b = (const unsigned char *)buf;
 116
 117         return b[0] | (b[1] << 8) | (b[2] << 16) | (b[3] << 24);
 118 }
 119
 120 static inline uint16_t read_le16(const char *buf)
 121 {
 122         const unsigned char *b = (const unsigned char *)buf;
 123
 124         return b[0] | (b[1] << 8);
 125 }
 126
 127 #endif