memory-util: move memeqbyte() & friends to src/fundamental/

This commit is contained in:
Lennart Poettering
2026-03-25 14:50:19 +01:00
parent 7e37e01768
commit e7b3a7bb24
5 changed files with 30 additions and 29 deletions
-21
View File
@@ -20,27 +20,6 @@ size_t page_size(void) {
return pgsz;
}
bool memeqbyte(uint8_t byte, const void *data, size_t length) {
/* Does the buffer consist entirely of the same specific byte value?
* Copied from https://github.com/systemd/casync/, copied in turn from
* https://github.com/rustyrussell/ccan/blob/master/ccan/mem/mem.c#L92,
* which is licensed CC-0.
*/
const uint8_t *p = data;
/* Check first 16 bytes manually */
for (size_t i = 0; i < 16; i++, length--) {
if (length == 0)
return true;
if (p[i] != byte)
return false;
}
/* Now we know first 16 bytes match, memcmp() with self. */
return memcmp(data, p + 16, length) == 0;
}
void* memdup_reverse(const void *mem, size_t size) {
assert(mem);
assert(size != 0);
-6
View File
@@ -57,12 +57,6 @@ static inline int memcmp_nn(const void *s1, size_t n1, const void *s2, size_t n2
#define zero(x) (memzero(&(x), sizeof(x)))
bool memeqbyte(uint8_t byte, const void *data, size_t length) _nonnull_if_nonzero_(2, 3);
#define memeqzero(data, length) memeqbyte(0x00, data, length)
#define eqzero(x) memeqzero(x, sizeof(x))
static inline void* mempset(void *s, int c, size_t n) {
memset(s, c, n);
return (uint8_t*) s + n;
+24
View File
@@ -0,0 +1,24 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include "memory-util-fundamental.h"
bool memeqbyte(uint8_t byte, const void *data, size_t length) {
/* Does the buffer consist entirely of the same specific byte value?
* Copied from https://github.com/systemd/casync/, copied in turn from
* https://github.com/rustyrussell/ccan/blob/master/ccan/mem/mem.c#L92,
* which is licensed CC-0.
*/
const uint8_t *p = data;
/* Check first 16 bytes manually */
for (size_t i = 0; i < 16; i++, length--) {
if (length == 0)
return true;
if (p[i] != byte)
return false;
}
/* Now we know first 16 bytes match, memcmp() with self. */
return memcmp(data, p + 16, length) == 0;
}
+5 -2
View File
@@ -9,8 +9,7 @@
# include <string.h>
#endif
#include "assert-fundamental.h"
#include "cleanup-fundamental.h"
#include "assert-fundamental.h" /* IWYU pragma: keep */
#include "macro-fundamental.h"
#define memzero(x, l) \
@@ -148,3 +147,7 @@ static inline uint64_t ALIGN_OFFSET_U64(uint64_t l, uint64_t ali) {
assert(((uintptr_t) _p) % alignof(t) == 0); \
(t *) _p; \
})
bool memeqbyte(uint8_t byte, const void *data, size_t length) _nonnull_if_nonzero_(2, 3);
#define memeqzero(data, length) memeqbyte(0x00, data, length)
#define eqzero(x) memeqzero(x, sizeof(x))
+1
View File
@@ -8,6 +8,7 @@ fundamental_sources = files(
'edid-fundamental.c',
'efivars-fundamental.c',
'iovec-util-fundamental.h',
'memory-util-fundamental.c',
'sha1-fundamental.c',
'sha256-fundamental.c',
'string-util-fundamental.c',