text: /*
   * bits.h - extract binary data from message buffer
   *
   * These macros extract bytes, words, longwords, floats, doubles, or
   * bitfields of arbitrary length and size from a message that contains
   * these items in either MSB-first or LSB-first byte order.
   *
   * We enforce data sizes of integral types in the casts on these.
   * Both 32- and 64-bit systems with gcc are OK with this set.
   *
   * This file is Copyright (c)2010 by the GPSD project
   * SPDX-License-Identifier: BSD-2-clause
   */
  #ifndef _GPSD_BITS_H_
  #define _GPSD_BITS_H_
  
  #include <stdint.h>
  #include <limits.h>
  
  /* number of bytes requited to contain a bit array of specified length */
  #define BITS_TO_BYTES(bitlen)	(((bitlen) + CHAR_BIT - 1) / CHAR_BIT)
  
  /* these are independent of byte order */
  #define getsb(buf, off)	((int8_t)buf[off])
  #define getub(buf, off)	((uint8_t)buf[off])
  #define putbyte(buf,off,b) do {buf[off] = (unsigned char)(b);} while (0)
  
  /* little-endian access */
  #define getles16(buf, off)	((int16_t)(((uint16_t)getub((buf),   (off)+1) << 8) | (uint16_t)getub((buf), (off))))
  #define getleu16(buf, off)	((uint16_t)(((uint16_t)getub((buf), (off)+1) << 8) | (uint16_t)getub((buf), (off))))
  #define getles32(buf, off)	((int32_t)(((uint16_t)getleu16((buf),  (off)+2) << 16) | (uint16_t)getleu16((buf), (off))))
  #define getleu32(buf, off)	((uint32_t)(((uint16_t)getleu16((buf),(off)+2) << 16) | (uint16_t)getleu16((buf), (off))))
  #define getles64(buf, off)	((int64_t)(((uint64_t)getleu32(buf, (off)+4) << 32) | getleu32(buf, (off))))
  #define getleu64(buf, off)	((uint64_t)(((uint64_t)getleu32(buf, (off)+4) << 32) | getleu32(buf, (off))))
  extern float getlef32(const char *, int);
  extern double getled64(const char *, int);
  
  #define putle16(buf, off, w) do {putbyte(buf, (off)+1, (unsigned int)(w) >> 8); putbyte(buf, (off), (w));} while (0)
  #define putle32(buf, off, l) do {putle16(buf, (off)+2, (unsigned int)(l) >> 16); putle16(buf, (off), (l));} while (0)
  
  /* big-endian access */
  #define getbes16(buf, off)	((int16_t)(((uint16_t)getub(buf, (off)) << 8) | (uint16_t)getub(buf, (off)+1)))
  #define getbeu16(buf, off)	((uint16_t)(((uint16_t)getub(buf, (off)) << 8) | (uint16_t)getub(buf, (off)+1)))
  #define getbeu24(buf, off)	((uint32_t)(((uint16_t)getbeu16(buf, (off)) << 8) | getub(buf, (off)+2)))
  #define getbes32(buf, off)	((int32_t)(((uint16_t)getbeu16(buf, (off)) << 16) | getbeu16(buf, (off)+2)))
  #define getbeu32(buf, off)	((uint32_t)(((uint16_t)getbeu16(buf, (off)) << 16) | getbeu16(buf, (off)+2)))
  #define getbes64(buf, off)	((int64_t)(((uint64_t)getbeu32(buf, (off)) << 32) | getbeu32(buf, (off)+4)))
  #define getbeu64(buf, off)	((uint64_t)(((uint64_t)getbeu32(buf, (off)) << 32) | getbeu32(buf, (off)+4)))
  extern float getbef32(const char *, int);
  extern double getbed64(const char *, int);
  
  #define putbe16(buf,off,w) do {putbyte(buf, (off), (w) >> 8); putbyte(buf, (off)+1, (w));} while (0)
  #define putbe32(buf,off,l) do {putbe16(buf, (off), (l) >> 16); putbe16(buf, (off)+2, (l));} while (0)
  
  extern void putbef32(char *, int, float);
  extern void putbed64(char *, int, double);
  
  extern void shiftleft(unsigned char *, int, unsigned short);
  
  /* bitfield extraction */
  extern uint64_t ubits(unsigned char buf[], unsigned int, unsigned int, bool);
  extern int64_t sbits(signed char buf[], unsigned int, unsigned int, bool);
  
  #endif /* _GPSD_BITS_H_ */
  