portable_io.h

   1 /*
   2  * Copyright (C) 2007-2009 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file portable_io.h Inline functions for endian-independent binary IO. */
   8
   9 static inline uint64_t read_portable(unsigned bits, const char *buf)
  10 {
  11         uint64_t ret = 0;
  12         int i, num_bytes = bits / 8;
  13
  14         for (i = 0; i < num_bytes; i++) {
  15                 unsigned char c = buf[i];
  16                 ret += ((uint64_t)c << (8 * i));
  17         }
  18         return ret;
  19 }
  20
  21 static inline uint64_t read_u64(const char *buf)
  22 {
  23         return read_portable(64, buf);
  24 }
  25
  26 static inline uint32_t read_u32(const char *buf)
  27 {
  28         return read_portable(32, buf);
  29 }
  30
  31 static inline uint16_t read_u16(const char *buf)
  32 {
  33         return read_portable(16, buf);
  34 }
  35
  36 static inline uint8_t read_u8(const char *buf)
  37 {
  38         return read_portable(8, buf);
  39 }
  40
  41 static inline void write_portable(unsigned bits, char *buf, uint64_t val)
  42 {
  43         int i, num_bytes = bits / 8;
  44 //      fprintf(stderr, "val: %lu\n", val);
  45         for (i = 0; i < num_bytes; i++) {
  46                 buf[i] = val & 0xff;
  47 //              fprintf(stderr, "buf[%d]=%x\n", i, buf[i]);
  48                 val = val >> 8;
  49         }
  50 }
  51
  52 static inline void write_u64(char *buf, uint64_t val)
  53 {
  54         write_portable(64, buf, val);
  55 }
  56
  57 static inline void write_u32(char *buf, uint32_t val)
  58 {
  59         write_portable(32, buf, (uint64_t) val);
  60 }
  61
  62 static inline void write_u16(char *buf, uint16_t val)
  63 {
  64         write_portable(16, buf, (uint64_t) val);
  65 }
  66
  67 static inline void write_u8(char *buf, uint8_t val)
  68 {
  69         write_portable(8, buf, (uint64_t) val);
  70 }