[net-next-2.6.git] / tools / perf / util / strbuf.h

#ifndef __PERF_STRBUF_H
#define __PERF_STRBUF_H

/*
 * Strbuf's can be use in many ways: as a byte array, or to store arbitrary
 * long, overflow safe strings.
 *
 * Strbufs has some invariants that are very important to keep in mind:
 *
 * 1. the ->buf member is always malloc-ed, hence strbuf's can be used to
 *    build complex strings/buffers whose final size isn't easily known.
 *
 *    It is NOT legal to copy the ->buf pointer away.
 *    `strbuf_detach' is the operation that detachs a buffer from its shell
 *    while keeping the shell valid wrt its invariants.
 *
 * 2. the ->buf member is a byte array that has at least ->len + 1 bytes
 *    allocated. The extra byte is used to store a '\0', allowing the ->buf
 *    member to be a valid C-string. Every strbuf function ensure this
 *    invariant is preserved.
 *
 *    Note that it is OK to "play" with the buffer directly if you work it
 *    that way:
 *
 *    strbuf_grow(sb, SOME_SIZE);
 *       ... Here, the memory array starting at sb->buf, and of length
 *       ... strbuf_avail(sb) is all yours, and you are sure that
 *       ... strbuf_avail(sb) is at least SOME_SIZE.
 *    strbuf_setlen(sb, sb->len + SOME_OTHER_SIZE);
 *
 *    Of course, SOME_OTHER_SIZE must be smaller or equal to strbuf_avail(sb).
 *
 *    Doing so is safe, though if it has to be done in many places, adding the
 *    missing API to the strbuf module is the way to go.
 *
 *    XXX: do _not_ assume that the area that is yours is of size ->alloc - 1
 *         even if it's true in the current implementation. Alloc is somehow a
 *         "private" member that should not be messed with.
 */

#include <assert.h>

extern char strbuf_slopbuf[];
struct strbuf {
	size_t alloc;
	size_t len;
	char *buf;
};

#define STRBUF_INIT  { 0, 0, strbuf_slopbuf }

/*----- strbuf life cycle -----*/
extern void strbuf_init(struct strbuf *buf, ssize_t hint);
extern void strbuf_release(struct strbuf *);
extern char *strbuf_detach(struct strbuf *, size_t *);

/*----- strbuf size related -----*/
static inline ssize_t strbuf_avail(const struct strbuf *sb) {
	return sb->alloc ? sb->alloc - sb->len - 1 : 0;
}

extern void strbuf_grow(struct strbuf *, size_t);

static inline void strbuf_setlen(struct strbuf *sb, size_t len) {
	if (!sb->alloc)
		strbuf_grow(sb, 0);
	assert(len < sb->alloc);
	sb->len = len;
	sb->buf[len] = '\0';
}

/*----- add data in your buffer -----*/
static inline void strbuf_addch(struct strbuf *sb, int c) {
	strbuf_grow(sb, 1);
	sb->buf[sb->len++] = c;
	sb->buf[sb->len] = '\0';
}

extern void strbuf_remove(struct strbuf *, size_t pos, size_t len);

extern void strbuf_add(struct strbuf *, const void *, size_t);
static inline void strbuf_addstr(struct strbuf *sb, const char *s) {
	strbuf_add(sb, s, strlen(s));
}

__attribute__((format(printf,2,3)))
extern void strbuf_addf(struct strbuf *sb, const char *fmt, ...);

/* XXX: if read fails, any partial read is undone */
extern ssize_t strbuf_read(struct strbuf *, int fd, ssize_t hint);

#endif /* __PERF_STRBUF_H */
Commit	Line	Data
8b40f521 JK	1	#ifndef __PERF_STRBUF_H
8b40f521 JK	2	#define __PERF_STRBUF_H
07800601 IM	3
	4	/*
	5	* Strbuf's can be use in many ways: as a byte array, or to store arbitrary
	6	* long, overflow safe strings.
	7	*
	8	* Strbufs has some invariants that are very important to keep in mind:
	9	*
	10	* 1. the ->buf member is always malloc-ed, hence strbuf's can be used to
	11	* build complex strings/buffers whose final size isn't easily known.
	12	*
	13	* It is NOT legal to copy the ->buf pointer away.
	14	* `strbuf_detach' is the operation that detachs a buffer from its shell
	15	* while keeping the shell valid wrt its invariants.
	16	*
	17	* 2. the ->buf member is a byte array that has at least ->len + 1 bytes
	18	* allocated. The extra byte is used to store a '\0', allowing the ->buf
	19	* member to be a valid C-string. Every strbuf function ensure this
	20	* invariant is preserved.
	21	*
	22	* Note that it is OK to "play" with the buffer directly if you work it
	23	* that way:
	24	*
	25	* strbuf_grow(sb, SOME_SIZE);
	26	* ... Here, the memory array starting at sb->buf, and of length
	27	* ... strbuf_avail(sb) is all yours, and you are sure that
	28	* ... strbuf_avail(sb) is at least SOME_SIZE.
	29	* strbuf_setlen(sb, sb->len + SOME_OTHER_SIZE);
	30	*
	31	* Of course, SOME_OTHER_SIZE must be smaller or equal to strbuf_avail(sb).
	32	*
	33	* Doing so is safe, though if it has to be done in many places, adding the
	34	* missing API to the strbuf module is the way to go.
	35	*
	36	* XXX: do _not_ assume that the area that is yours is of size ->alloc - 1
	37	* even if it's true in the current implementation. Alloc is somehow a
	38	* "private" member that should not be messed with.
	39	*/
	40
	41	#include <assert.h>
	42
	43	extern char strbuf_slopbuf[];
	44	struct strbuf {
	45	size_t alloc;
	46	size_t len;
	47	char *buf;
	48	};
	49
	50	#define STRBUF_INIT { 0, 0, strbuf_slopbuf }
	51
	52	/----- strbuf life cycle -----/
f37a291c	53	extern void strbuf_init(struct strbuf *buf, ssize_t hint);
07800601 IM	54	extern void strbuf_release(struct strbuf *);
07800601 IM	55	extern char strbuf_detach(struct strbuf , size_t *);
07800601 IM	56
07800601 IM	57	/----- strbuf size related -----/
f37a291c	58	static inline ssize_t strbuf_avail(const struct strbuf *sb) {
07800601 IM	59	return sb->alloc ? sb->alloc - sb->len - 1 : 0;
	60	}
	61
	62	extern void strbuf_grow(struct strbuf *, size_t);
	63
	64	static inline void strbuf_setlen(struct strbuf *sb, size_t len) {
	65	if (!sb->alloc)
	66	strbuf_grow(sb, 0);
	67	assert(len < sb->alloc);
	68	sb->len = len;
	69	sb->buf[len] = '\0';
	70	}
07800601 IM	71
	72	/----- add data in your buffer -----/
	73	static inline void strbuf_addch(struct strbuf *sb, int c) {
	74	strbuf_grow(sb, 1);
	75	sb->buf[sb->len++] = c;
	76	sb->buf[sb->len] = '\0';
	77	}
	78
07800601 IM	79	extern void strbuf_remove(struct strbuf *, size_t pos, size_t len);
07800601 IM	80
07800601 IM	81	extern void strbuf_add(struct strbuf , const void , size_t);
	82	static inline void strbuf_addstr(struct strbuf sb, const char s) {
	83	strbuf_add(sb, s, strlen(s));
	84	}
07800601 IM	85
	86	__attribute__((format(printf,2,3)))
	87	extern void strbuf_addf(struct strbuf sb, const char fmt, ...);
	88
07800601	89	/* XXX: if read fails, any partial read is undone */
f37a291c	90	extern ssize_t strbuf_read(struct strbuf *, int fd, ssize_t hint);
07800601	91
8b40f521	92	#endif /* __PERF_STRBUF_H */