You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
95 lines
2.9 KiB
95 lines
2.9 KiB
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#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>
|
|
#include <stdarg.h>
|
|
#include <stddef.h>
|
|
#include <string.h>
|
|
#include <linux/compiler.h>
|
|
#include <sys/types.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 -----*/
|
|
int strbuf_init(struct strbuf *buf, ssize_t hint);
|
|
void strbuf_release(struct strbuf *buf);
|
|
char *strbuf_detach(struct strbuf *buf, size_t *);
|
|
|
|
/*----- strbuf size related -----*/
|
|
static inline ssize_t strbuf_avail(const struct strbuf *sb) {
|
|
return sb->alloc ? sb->alloc - sb->len - 1 : 0;
|
|
}
|
|
|
|
int strbuf_grow(struct strbuf *buf, size_t);
|
|
|
|
static inline int strbuf_setlen(struct strbuf *sb, size_t len) {
|
|
if (!sb->alloc) {
|
|
int ret = strbuf_grow(sb, 0);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
assert(len < sb->alloc);
|
|
sb->len = len;
|
|
sb->buf[len] = '\0';
|
|
return 0;
|
|
}
|
|
|
|
/*----- add data in your buffer -----*/
|
|
int strbuf_addch(struct strbuf *sb, int c);
|
|
|
|
int strbuf_add(struct strbuf *buf, const void *, size_t);
|
|
static inline int strbuf_addstr(struct strbuf *sb, const char *s) {
|
|
return strbuf_add(sb, s, strlen(s));
|
|
}
|
|
|
|
int strbuf_addf(struct strbuf *sb, const char *fmt, ...) __printf(2, 3);
|
|
|
|
/* XXX: if read fails, any partial read is undone */
|
|
ssize_t strbuf_read(struct strbuf *, int fd, ssize_t hint);
|
|
|
|
#endif /* __PERF_STRBUF_H */
|
|
|