[PATCH 3/9] Add strbuf_printf() to do formatted printing to a strbuf.
Also, expose strbuf_add() and strbuf_add_char() to add raw data to the buffer.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
---
strbuf.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++------
strbuf.h | 3 ++
2 files changed, 65 insertions(+), 7 deletions(-)
diff --git a/strbuf.c b/strbuf.c
index e33d06b..2805c11 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -11,16 +11,26 @@ static void strbuf_begin(struct strbuf *sb) {
strbuf_init(sb);
}
-static void inline strbuf_add(struct strbuf *sb, int ch) {
- if (sb->alloc <= sb->len) {
- sb->alloc = sb->alloc * 3 / 2 + 16;
- sb->buf = xrealloc(sb->buf, sb->alloc);
- }
+static void inline strbuf_grow(struct strbuf *sb, size_t extra)
+{
+ ALLOC_GROW(sb->buf, sb->len + extra, sb->alloc);
+}
+
+void strbuf_add(struct strbuf *sb, const char *data, size_t len)
+{
+ strbuf_grow(sb, len);
+ memcpy(sb->buf + sb->len, data, len);
+ sb->len += len;
+}
+
+void strbuf_add_char(struct strbuf *sb, int ch)
+{
+ strbuf_grow(sb, 1);
sb->buf[sb->len++] = ch;
}
static void strbuf_end(struct strbuf *sb) {
- strbuf_add(sb, 0);
+ strbuf_add_char(sb, 0);
}
void read_line(struct strbuf *sb, FILE *fp, int term) {
@@ -33,9 +43,54 @@ void read_line(struct strbuf *sb, FILE *fp, int term) {
while ((ch = fgetc(fp)) != EOF) {
if (ch == term)
break;
- strbuf_add(sb, ch);
+ strbuf_add_char(sb, ch);
}
if (ch == EOF && sb->len == 0)
sb->eof = 1;
strbuf_end(sb);
}
+
+void strbuf_printf(struct strbuf *sb, const char *fmt, ...)
+{
+ char buffer[2048];
+ va_list args;
+ int len, size = 2 * sizeof buffer;
+
+ va_start(args, fmt);
+ len = vsnprintf(buffer, sizeof(buffer), fmt, args);
+ va_end(args);
+
+ if (len > sizeof(buffer)) {
+ /*
+ * Didn't fit in the buffer, but this vsnprintf at
+ * least gives us the required length back. Grow the
+ * buffer acccordingly and try again.
+ */
+ strbuf_grow(sb, len);
+ va_start(args, fmt);
+ len = vsnprintf(sb->buf + sb->len,
+ sb->alloc - sb->len, fmt, args);
+ va_end(args);
+ } else if (len >= 0) {
+ /*
+ * The initial vsnprintf fit in the temp buffer, just
+ * copy it to the strbuf.
+ */
+ strbuf_add(sb, buffer, len);
+ } else {
+ /*
+ * This vnsprintf sucks and just returns -1 when the
+ * buffer is too small. Keep doubling the size until
+ * it fits.
+ */
+ while (len < 0) {
+ strbuf_grow(sb, size);
+ va_start(args, fmt);
+ len = vsnprintf(sb->buf + sb->len,
+ sb->alloc - sb->len, fmt, args);
+ va_end(args);
+ size *= 2;
+ }
+ }
+}
+
diff --git a/strbuf.h b/strbuf.h
index 74cc012..1e5d09e 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -9,5 +9,8 @@ struct strbuf {
extern void strbuf_init(struct strbuf *);
extern void read_line(struct strbuf *, FILE *, int);
+extern void strbuf_add(struct strbuf *sb, const char *data, size_t len);
+extern void strbuf_add_char(struct strbuf *sb, int ch);
+extern void strbuf_printf(struct strbuf *sb, const char *fmt, ...);
#endif /* STRBUF_H */
--
1.5.2.GIT
Kristian Høgsberg <krh@redhat.com>