#include "debug.h"#include "util.h"#include <linux/kernel.h>#include <errno.h> /* * Used as the default ->buf value, so that people can always assume * buf is non NULL and ->buf is NUL terminated even for a freshly * initialized strbuf. */char strbuf_slopbuf[1]; int strbuf_init(struct strbuf *sb, ssize_t hint){	sb->alloc = sb->len = 0;	sb->buf = strbuf_slopbuf;	if (hint)		return strbuf_grow(sb, hint);	return 0;} void strbuf_release(struct strbuf *sb){	if (sb->alloc) {		zfree(&sb->buf);		strbuf_init(sb, 0);	}} char *strbuf_detach(struct strbuf *sb, size_t *sz){	char *res = sb->alloc ? sb->buf : NULL;	if (sz)		*sz = sb->len;	strbuf_init(sb, 0);	return res;} int strbuf_grow(struct strbuf *sb, size_t extra){	char *buf;	size_t nr = sb->len + extra + 1; 	if (nr < sb->alloc)		return 0; 	if (nr <= sb->len)		return -E2BIG; 	if (alloc_nr(sb->alloc) > nr)		nr = alloc_nr(sb->alloc); 	/*	 * Note that sb->buf == strbuf_slopbuf if sb->alloc == 0, and it is	 * a static variable. Thus we have to avoid passing it to realloc.	 */	buf = realloc(sb->alloc ? sb->buf : NULL, nr * sizeof(*buf));	if (!buf)		return -ENOMEM; 	sb->buf = buf;	sb->alloc = nr;	return 0;} int strbuf_addch(struct strbuf *sb, int c){	int ret = strbuf_grow(sb, 1);	if (ret)		return ret; 	sb->buf[sb->len++] = c;	sb->buf[sb->len] = '\0';	return 0;} int strbuf_add(struct strbuf *sb, const void *data, size_t len){	int ret = strbuf_grow(sb, len);	if (ret)		return ret; 	memcpy(sb->buf + sb->len, data, len);	return strbuf_setlen(sb, sb->len + len);} static int strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap){	int len, ret;	va_list ap_saved; 	if (!strbuf_avail(sb)) {		ret = strbuf_grow(sb, 64);		if (ret)			return ret;	} 	va_copy(ap_saved, ap);	len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);	if (len < 0)		return len;	if (len > strbuf_avail(sb)) {		ret = strbuf_grow(sb, len);		if (ret)			return ret;		len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap_saved);		va_end(ap_saved);		if (len > strbuf_avail(sb)) {			pr_debug("this should not happen, your vsnprintf is broken");			return -EINVAL;		}	}	return strbuf_setlen(sb, sb->len + len);} int strbuf_addf(struct strbuf *sb, const char *fmt, ...){	va_list ap;	int ret; 	va_start(ap, fmt);	ret = strbuf_addv(sb, fmt, ap);	va_end(ap);	return ret;} ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint){	size_t oldlen = sb->len;	size_t oldalloc = sb->alloc;	int ret; 	ret = strbuf_grow(sb, hint ? hint : 8192);	if (ret)		return ret; 	for (;;) {		ssize_t cnt; 		cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);		if (cnt < 0) {			if (oldalloc == 0)				strbuf_release(sb);			else				strbuf_setlen(sb, oldlen);			return cnt;		}		if (!cnt)			break;		sb->len += cnt;		ret = strbuf_grow(sb, 8192);		if (ret)			return ret;	} 	sb->buf[sb->len] = '\0';	return sb->len - oldlen;}