3 #include <linux/kernel.h>
7 * Used as the default ->buf value, so that people can always assume
8 * buf is non NULL and ->buf is NUL terminated even for a freshly
11 char strbuf_slopbuf[1];
13 int strbuf_init(struct strbuf *sb, ssize_t hint)
15 sb->alloc = sb->len = 0;
16 sb->buf = strbuf_slopbuf;
18 return strbuf_grow(sb, hint);
22 void strbuf_release(struct strbuf *sb)
30 char *strbuf_detach(struct strbuf *sb, size_t *sz)
32 char *res = sb->alloc ? sb->buf : NULL;
39 int strbuf_grow(struct strbuf *sb, size_t extra)
42 size_t nr = sb->len + extra + 1;
50 if (alloc_nr(sb->alloc) > nr)
51 nr = alloc_nr(sb->alloc);
54 * Note that sb->buf == strbuf_slopbuf if sb->alloc == 0, and it is
55 * a static variable. Thus we have to avoid passing it to realloc.
57 buf = realloc(sb->alloc ? sb->buf : NULL, nr * sizeof(*buf));
66 int strbuf_addch(struct strbuf *sb, int c)
68 int ret = strbuf_grow(sb, 1);
72 sb->buf[sb->len++] = c;
73 sb->buf[sb->len] = '\0';
77 int strbuf_add(struct strbuf *sb, const void *data, size_t len)
79 int ret = strbuf_grow(sb, len);
83 memcpy(sb->buf + sb->len, data, len);
84 return strbuf_setlen(sb, sb->len + len);
87 static int strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap)
92 if (!strbuf_avail(sb)) {
93 ret = strbuf_grow(sb, 64);
98 va_copy(ap_saved, ap);
99 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
102 if (len > strbuf_avail(sb)) {
103 ret = strbuf_grow(sb, len);
106 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap_saved);
108 if (len > strbuf_avail(sb)) {
109 pr_debug("this should not happen, your vsnprintf is broken");
113 return strbuf_setlen(sb, sb->len + len);
116 int strbuf_addf(struct strbuf *sb, const char *fmt, ...)
122 ret = strbuf_addv(sb, fmt, ap);
127 ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
129 size_t oldlen = sb->len;
130 size_t oldalloc = sb->alloc;
133 ret = strbuf_grow(sb, hint ? hint : 8192);
140 cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
145 strbuf_setlen(sb, oldlen);
151 ret = strbuf_grow(sb, 8192);
156 sb->buf[sb->len] = '\0';
157 return sb->len - oldlen;