From 97e4909d9e7c835b73c2eebdf4991d395c4ffb3f Mon Sep 17 00:00:00 2001 From: px4dev Date: Sun, 4 Aug 2013 19:40:57 -0700 Subject: Improvements to the HX stream protocol implementation. --- src/modules/systemlib/hx_stream.h | 42 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 41 insertions(+), 1 deletion(-) (limited to 'src/modules/systemlib/hx_stream.h') diff --git a/src/modules/systemlib/hx_stream.h b/src/modules/systemlib/hx_stream.h index 128689953..1f3927222 100644 --- a/src/modules/systemlib/hx_stream.h +++ b/src/modules/systemlib/hx_stream.h @@ -58,7 +58,8 @@ __BEGIN_DECLS * Allocate a new hx_stream object. * * @param fd The file handle over which the protocol will - * communicate. + * communicate, or -1 if the protocol will use + * hx_stream_start/hx_stream_send_next. * @param callback Called when a frame is received. * @param callback_arg Passed to the callback. * @return A handle to the stream, or NULL if memory could @@ -80,6 +81,7 @@ __EXPORT extern void hx_stream_free(hx_stream_t stream); * * Any counter may be set to NULL to disable counting that datum. * + * @param stream A handle returned from hx_stream_init. * @param tx_frames Counter for transmitted frames. * @param rx_frames Counter for received frames. * @param rx_errors Counter for short and corrupt received frames. @@ -89,6 +91,44 @@ __EXPORT extern void hx_stream_set_counters(hx_stream_t stream, perf_counter_t rx_frames, perf_counter_t rx_errors); +/** + * Reset a stream. + * + * Forces the local stream state to idle. + * + * @param stream A handle returned from hx_stream_init. + */ +__EXPORT extern void hx_stream_reset(hx_stream_t stream); + +/** + * Prepare to send a frame. + * + * Use this in conjunction with hx_stream_send_next to + * set the frame to be transmitted. + * + * Use hx_stream_send() to write to the stream fd directly. + * + * @param stream A handle returned from hx_stream_init. + * @param data Pointer to the data to send. + * @param count The number of bytes to send. + * @return Zero on success, -errno on error. + */ +__EXPORT extern int hx_stream_start(hx_stream_t stream, + const void *data, + size_t count); + +/** + * Get the next byte to send for a stream. + * + * This requires that the stream be prepared for sending by + * calling hx_stream_start first. + * + * @param stream A handle returned from hx_stream_init. + * @return The byte to send, or -1 if there is + * nothing left to send. + */ +__EXPORT extern int hx_stream_send_next(hx_stream_t stream); + /** * Send a frame. * -- cgit v1.2.3