til_stream: first stab at implementing til_stream_t

Until now there's just been a forward declared type for
til_fb_fragment_t.stream's type, and it's been completely unused.

The purpose of the stream is to provide a continous inter-frame
object where information can be stored pertaining to the stream
of frames.

Right now, that information is limited to emergent "pipes" formed
by using taps against a given stream.  Taps at new paths in the
stream become added as pipes for those paths, with the
responsible tap hooked in as the driving tap.  Taps at existing
paths become diverted to the driving taps, enabling potential for
external drivers for tapped variables.

This commit only adds the implementation, nothing is actually
using it yet.

1 files changed, 27 insertions, 0 deletions

diff --git a/src/til_stream.h b/src/til_stream.h
new file mode 100644
index 0000000..91eaa55
--- /dev/null
+++ b/src/til_stream.h
@@ -0,0 +1,27 @@
+#ifndef _TIL_STREAM_H
+#define _TIL_STREAM_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "til_module_context.h"
+
+typedef struct til_stream_t til_stream_t;
+typedef struct til_tap_t til_tap_t;
+
+til_stream_t * til_stream_new(void);
+til_stream_t * til_stream_free(til_stream_t *stream);
+
+/* bare interface for non-module-context owned taps */
+int til_stream_tap(til_stream_t *stream, const void *tap_owner, const char *parent_path, uint32_t parent_hash, const til_tap_t *tap);
+
+/* convenience helper for use within modules */
+static inline int til_stream_tap_context(til_stream_t *stream, const til_module_context_t *module_context, const til_tap_t *tap)
+{
+	return til_stream_tap(stream, module_context, module_context->path, module_context->path_hash, tap);
+}
+
+void til_stream_untap_owner(til_stream_t *stream, const void *owner);
+void til_stream_fprint(til_stream_t *stream, FILE *out);
+
+#endif