strbuf.c: add strbuf_insertf() and strbuf_vinsertf()

Implement `strbuf_insertf()` and `strbuf_vinsertf()` to
insert data using a printf format string.

Original-idea-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Paul-Sebastian Ungureanu <ungureanupaulsebastian@gmail.com>
Helped-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Paul-Sebastian Ungureanu 2019-02-25 23:16:07 +00:00 committed by Junio C Hamano
parent e71c4a88f6
commit 5ef264dbdb
2 changed files with 45 additions and 0 deletions

View file

@ -249,6 +249,42 @@ void strbuf_insert(struct strbuf *sb, size_t pos, const void *data, size_t len)
strbuf_splice(sb, pos, 0, data, len);
}
void strbuf_vinsertf(struct strbuf *sb, size_t pos, const char *fmt, va_list ap)
{
int len, len2;
char save;
va_list cp;
if (pos > sb->len)
die("`pos' is too far after the end of the buffer");
va_copy(cp, ap);
len = vsnprintf(sb->buf + sb->len, 0, fmt, cp);
va_end(cp);
if (len < 0)
BUG("your vsnprintf is broken (returned %d)", len);
if (!len)
return; /* nothing to do */
if (unsigned_add_overflows(sb->len, len))
die("you want to use way too much memory");
strbuf_grow(sb, len);
memmove(sb->buf + pos + len, sb->buf + pos, sb->len - pos);
/* vsnprintf() will append a NUL, overwriting one of our characters */
save = sb->buf[pos + len];
len2 = vsnprintf(sb->buf + pos, len + 1, fmt, ap);
sb->buf[pos + len] = save;
if (len2 != len)
BUG("your vsnprintf is broken (returns inconsistent lengths)");
strbuf_setlen(sb, sb->len + len);
}
void strbuf_insertf(struct strbuf *sb, size_t pos, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
strbuf_vinsertf(sb, pos, fmt, ap);
va_end(ap);
}
void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
{
strbuf_splice(sb, pos, len, "", 0);

View file

@ -244,6 +244,15 @@ void strbuf_addchars(struct strbuf *sb, int c, size_t n);
*/
void strbuf_insert(struct strbuf *sb, size_t pos, const void *, size_t);
/**
* Insert data to the given position of the buffer giving a printf format
* string. The contents will be shifted, not overwritten.
*/
void strbuf_vinsertf(struct strbuf *sb, size_t pos, const char *fmt,
va_list ap);
void strbuf_insertf(struct strbuf *sb, size_t pos, const char *fmt, ...);
/**
* Remove given amount of data from a given position of the buffer.
*/