/*-------------------------------------------------------------------------
 *
 * pg_crc32c.h
 *	  Routines for computing CRC-32C checksums.
 *
 *
 * Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/port/pg_crc32c.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef PG_CRC32C_H
#define PG_CRC32C_H

typedef uint32 pg_crc32c;

#define INIT_CRC32C(crc) ((crc) = 0xFFFFFFFF)
#define EQ_CRC32C(c1, c2) ((c1) == (c2))

/*
 * Use slicing-by-8 algorithm.
 *
 * On big-endian systems, the intermediate value is kept in reverse byte
 * order, to avoid byte-swapping during the calculation. FIN_CRC32C reverses
 * the bytes to the final order.
 */
#define COMP_CRC32C(crc, data, len) \
	((crc) = pg_comp_crc32c_sb8((crc), (data), (len)))
#ifdef WORDS_BIGENDIAN

#ifdef HAVE__BUILTIN_BSWAP32
#define BSWAP32(x) __builtin_bswap32(x)
#else
#define BSWAP32(x) (((x << 24) & 0xff000000) | \
					((x << 8) & 0x00ff0000) | \
					((x >> 8) & 0x0000ff00) | \
					((x >> 24) & 0x000000ff))
#endif

#define FIN_CRC32C(crc) ((crc) = BSWAP32(crc) ^ 0xFFFFFFFF)
#else
#define FIN_CRC32C(crc) ((crc) ^= 0xFFFFFFFF)
#endif

extern pg_crc32c pg_comp_crc32c_sb8(pg_crc32c crc, const void *data, size_t len);

#endif /* PG_CRC32C_H */