Files
scoutfs/utils/src/util.h
Zach Brown c0fdd37e5a scoutfs-utils: add get_unaligned helpers
Signed-off-by: Zach Brown <zab@versity.com>
2020-08-26 14:39:28 -07:00

115 lines
2.4 KiB
C

#ifndef _UTIL_H_
#define _UTIL_H_
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "sparse.h"
/*
* Generate build warnings if the condition is false but generate no
* code at run time if it's true.
*/
#define build_assert(cond) ((void)sizeof(char[1 - 2*!(cond)]))
#define min(a, b) \
({ \
__typeof__(a) _a = (a); \
__typeof__(b) _b = (b); \
\
_a < _b ? _a : _b; \
})
#define max(a, b) \
({ \
__typeof__(a) _a = (a); \
__typeof__(b) _b = (b); \
\
_a > _b ? _a : _b; \
})
#define swap(a, b) \
do { \
__typeof__(a) _t = (a); \
(a) = (b); \
(b) = (_t); \
} while (0)
#define array_size(arr) (sizeof(arr) / sizeof(arr[0]))
#define __packed __attribute__((packed))
/*
* Round the 'a' value up to the next 'b' power of two boundary. It
* casts the mask to the value type before masking to avoid truncation
* problems.
*/
#define round_up(a, b) \
({ \
__typeof__(a) _b = (b); \
\
((a) + _b - 1) & ~(_b - 1); \
})
#define round_down(a, b) \
({ \
__typeof__(a) _b = (b); \
\
((a) & ~(_b - 1)); \
})
#define DIV_ROUND_UP(x, y) (((x) + (y) - 1) / (y))
#define ALIGN(x, y) (((x) + (y) - 1) & ~((y) - 1))
#ifndef offsetof
#define offsetof(type, memb) ((unsigned long)&((type *)0)->memb)
#endif
#define container_of(ptr, type, memb) \
((type *)((void *)(ptr) - offsetof(type, memb)))
#define BITS_PER_LONG (sizeof(long) * 8)
#define U8_MAX ((u8)~0ULL)
#define U16_MAX ((u16)~0ULL)
#define U32_MAX ((u32)~0ULL)
#define U64_MAX ((u64)~0ULL)
#define flsll(x) \
({ \
unsigned long long _x = (x); \
\
(_x == 0 ? 0 : 64 - __builtin_clzll(_x)); \
})
#define ilog2(x) \
({ \
((unsigned long)log2l((long double)x)); \
})
#define emit_get_unaligned_le(nr) \
static inline __u##nr get_unaligned_le##nr(void *buf) \
{ \
__le##nr x; \
memcpy(&x, buf, sizeof(x)); \
return le##nr##_to_cpu(x); \
}
emit_get_unaligned_le(16)
emit_get_unaligned_le(32)
emit_get_unaligned_le(64)
/*
* return -1,0,+1 based on the memcmp comparison of the minimum of their
* two lengths. If their min shared bytes are equal but the lengths
* are not then the larger length is considered greater.
*/
static inline int memcmp_lens(const void *a, int a_len,
const void *b, int b_len)
{
unsigned int len = min(a_len, b_len);
return memcmp(a, b, len) ?: a_len - b_len;
}
#endif