pkt-line: add packet_buf_write_len function

Add the 'packet_buf_write_len()' function which allows for writing an
arbitrary length buffer into a 'struct strbuf' and formatting it in
packet-line format.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/pkt-line.c b/pkt-line.c
index 7296731cf3..555eb2a507 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -215,6 +215,22 @@ void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 	va_end(args);
 }
 
+void packet_buf_write_len(struct strbuf *buf, const char *data, size_t len)
+{
+	size_t orig_len, n;
+
+	orig_len = buf->len;
+	strbuf_addstr(buf, "0000");
+	strbuf_add(buf, data, len);
+	n = buf->len - orig_len;
+
+	if (n > LARGE_PACKET_MAX)
+		die("protocol error: impossibly long line");
+
+	set_packet_header(&buf->buf[orig_len], n);
+	packet_trace(data, len, 1);
+}
+
 int write_packetized_from_fd(int fd_in, int fd_out)
 {
 	static char buf[LARGE_PACKET_DATA_MAX];