ustream: add function ustream_read().

It can be used to fill caller-specified buffer with data already in
ustream read buffer.  Useful in the following use pattern.

	int available = ustream_pending_data(s, false);
	if (available >= sizeof(struct msghdr)) {
		struct msghdr h;
		ustream_read(s, &h, sizeof(h));
	}

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/ustream.h b/ustream.h
index 6431744..53e0828 100644
--- a/ustream.h
+++ b/ustream.h
@@ -143,6 +143,11 @@ void ustream_free(struct ustream *s);
 /* ustream_consume: remove data from the head of the read buffer */
 void ustream_consume(struct ustream *s, int len);
 
+/*
+ * ustream_read: read and consume data in read buffer into caller-specified
+ * area.  Return length of data read.
+ */
+int ustream_read(struct ustream *s, char *buf, int buflen);
 /* ustream_write: add data to the write buffer */
 int ustream_write(struct ustream *s, const char *buf, int len, bool more);
 int ustream_printf(struct ustream *s, const char *format, ...);