Implement `strbuf_insertf()` and `strbuf_vinsertf()` to
insert data using a printf format string.
Original-idea-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
Signed-off-by: Paul-Sebastian Ungureanu <ungureanupaulsebastian@xxxxxxxxx>
---
strbuf.c | 36 ++++++++++++++++++++++++++++++++++++
strbuf.h | 9 +++++++++
2 files changed, 45 insertions(+)
diff --git a/strbuf.c b/strbuf.c
index 82e90f1dfe..bfbbdadbf3 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -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, sb->alloc - sb->len, 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);
diff --git a/strbuf.h b/strbuf.h
index be02150df3..8f8fe01e68 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -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.
*/
--
2.20.1.441.g764a526393
