[lttng-tools.git] / src / common / compat / string.hpp

/*
 * Copyright (C) 2015 Michael Jeanson <mjeanson@efficios.com>
 * Copyright (C) 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * SPDX-License-Identifier: MIT
 *
 */

#ifndef _COMPAT_STRING_H
#define _COMPAT_STRING_H

#include <stdlib.h>
#include <string.h>

#ifdef HAVE_STRNLEN
static inline size_t lttng_strnlen(const char *str, size_t max)
{
	return strnlen(str, max);
}
#else
static inline size_t lttng_strnlen(const char *str, size_t max)
{
	size_t ret;
	const char *end;

	end = (const char *) memchr(str, 0, max);

	if (end) {
		ret = (size_t) (end - str);
	} else {
		ret = max;
	}

	return ret;
}
#endif /* HAVE_STRNLEN */

#ifdef HAVE_STRNDUP
static inline char *lttng_strndup(const char *s, size_t n)
{
	return strndup(s, n);
}
#else
static inline char *lttng_strndup(const char *s, size_t n)
{
	char *ret;
	size_t navail;

	if (!s) {
		ret = NULL;
		goto end;
	}

	/* min() */
	navail = strlen(s) + 1;
	if ((n + 1) < navail) {
		navail = n + 1;
	}

	ret = malloc<char>(navail);
	if (!ret) {
		goto end;
	}

	memcpy(ret, s, navail);
	ret[navail - 1] = '\0';
end:
	return ret;
}
#endif /* HAVE_STRNDUP */

#ifdef HAVE_FLS
static inline int lttng_fls(int val)
{
	return fls(val);
}
#else
static inline int lttng_fls(int val)
{
	int r = 32;
	unsigned int x = (unsigned int) val;

	if (!x)
		return 0;
	if (!(x & 0xFFFF0000U)) {
		x <<= 16;
		r -= 16;
	}
	if (!(x & 0xFF000000U)) {
		x <<= 8;
		r -= 8;
	}
	if (!(x & 0xF0000000U)) {
		x <<= 4;
		r -= 4;
	}
	if (!(x & 0xC0000000U)) {
		x <<= 2;
		r -= 2;
	}
	if (!(x & 0x80000000U)) {
		r -= 1;
	}
	return r;
}
#endif /* HAVE_FLS */

#ifdef HAVE_MEMRCHR
static inline void *lttng_memrchr(const void *s, int c, size_t n)
{
	return (void *) memrchr(s, c, n);
}
#else
static inline void *lttng_memrchr(const void *s, int c, size_t n)
{
	int i;
	const char *str = (const char *) s;
	for (i = n - 1; i >= 0; i--) {
		if (str[i] == (char) c) {
			return (void *) (str + i);
		}
	}
	return NULL;
}
#endif /* HAVE_MEMRCHR */

#endif /* _COMPAT_STRING_H */
Commit	Line	Data
	1	/*
	2	* Copyright (C) 2015 Michael Jeanson <mjeanson@efficios.com>
	3	* Copyright (C) 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
	4	*
	5	* SPDX-License-Identifier: MIT
	6	*
	7	*/
	8
	9	#ifndef _COMPAT_STRING_H
	10	#define _COMPAT_STRING_H
	11
	12	#include <stdlib.h>
	13	#include <string.h>
	14
	15	#ifdef HAVE_STRNLEN
	16	static inline size_t lttng_strnlen(const char *str, size_t max)
	17	{
	18	return strnlen(str, max);
	19	}
	20	#else
	21	static inline size_t lttng_strnlen(const char *str, size_t max)
	22	{
	23	size_t ret;
	24	const char *end;
	25
	26	end = (const char *) memchr(str, 0, max);
	27
	28	if (end) {
	29	ret = (size_t) (end - str);
	30	} else {
	31	ret = max;
	32	}
	33
	34	return ret;
	35	}
	36	#endif /* HAVE_STRNLEN */
	37
	38	#ifdef HAVE_STRNDUP
	39	static inline char lttng_strndup(const char s, size_t n)
	40	{
	41	return strndup(s, n);
	42	}
	43	#else
	44	static inline char lttng_strndup(const char s, size_t n)
	45	{
	46	char *ret;
	47	size_t navail;
	48
	49	if (!s) {
	50	ret = NULL;
	51	goto end;
	52	}
	53
	54	/* min() */
	55	navail = strlen(s) + 1;
	56	if ((n + 1) < navail) {
	57	navail = n + 1;
	58	}
	59
	60	ret = malloc<char>(navail);
	61	if (!ret) {
	62	goto end;
	63	}
	64
	65	memcpy(ret, s, navail);
	66	ret[navail - 1] = '\0';
	67	end:
	68	return ret;
	69	}
	70	#endif /* HAVE_STRNDUP */
	71
	72	#ifdef HAVE_FLS
	73	static inline int lttng_fls(int val)
	74	{
	75	return fls(val);
	76	}
	77	#else
	78	static inline int lttng_fls(int val)
	79	{
	80	int r = 32;
	81	unsigned int x = (unsigned int) val;
	82
	83	if (!x)
	84	return 0;
	85	if (!(x & 0xFFFF0000U)) {
	86	x <<= 16;
	87	r -= 16;
	88	}
	89	if (!(x & 0xFF000000U)) {
	90	x <<= 8;
	91	r -= 8;
	92	}
	93	if (!(x & 0xF0000000U)) {
	94	x <<= 4;
	95	r -= 4;
	96	}
	97	if (!(x & 0xC0000000U)) {
	98	x <<= 2;
	99	r -= 2;
	100	}
	101	if (!(x & 0x80000000U)) {
	102	r -= 1;
	103	}
	104	return r;
	105	}
	106	#endif /* HAVE_FLS */
	107
	108	#ifdef HAVE_MEMRCHR
	109	static inline void lttng_memrchr(const void s, int c, size_t n)
	110	{
	111	return (void *) memrchr(s, c, n);
	112	}
	113	#else
	114	static inline void lttng_memrchr(const void s, int c, size_t n)
	115	{
	116	int i;
	117	const char str = (const char ) s;
	118	for (i = n - 1; i >= 0; i--) {
	119	if (str[i] == (char) c) {
	120	return (void *) (str + i);
	121	}
	122	}
	123	return NULL;
	124	}
	125	#endif /* HAVE_MEMRCHR */
	126
	127	#endif /* _COMPAT_STRING_H */