From 9be264e1762c2e7a5159479230ce98cae0721e07 Mon Sep 17 00:00:00 2001
From: Devaev Maxim <mdevaev@gmail.com>
Date: Mon, 18 Jan 2021 11:27:57 +0300
Subject: [PATCH] memsink magic

---
 src/libs/memsink.c | 34 +++++++++++++++++++---------------
 src/libs/memsink.h |  3 +++
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/src/libs/memsink.c b/src/libs/memsink.c
index f60f38b..548460a 100644
--- a/src/libs/memsink.c
+++ b/src/libs/memsink.c
@@ -146,6 +146,7 @@ int memsink_server_put(memsink_s *sink, const frame_s *frame) {
 		COPY(encode_end_ts);
 		sink->has_clients = (sink->mem->last_client_ts + sink->client_ttl > get_now_monotonic());
 		memcpy(sink->mem->data, frame->data, frame->used);
+		sink->mem->magic = MEMSINK_MAGIC;
 #		undef COPY
 
 		if (flock(sink->fd, LOCK_UN) < 0) {
@@ -176,22 +177,25 @@ int memsink_client_get(memsink_s *sink, frame_s *frame) { // cppcheck-suppress u
 		return -1;
 	}
 
-	bool updated = (sink->mem->id != sink->last_id);
-	if (updated) {
-#		define COPY(_field) frame->_field = sink->mem->_field
-		sink->last_id = sink->mem->id;
-		COPY(width);
-		COPY(height);
-		COPY(format);
-		COPY(stride);
-		COPY(online);
-		COPY(grab_ts);
-		COPY(encode_begin_ts);
-		COPY(encode_end_ts);
-		frame_set_data(frame, sink->mem->data, sink->mem->used);
-#		undef COPY
+	bool updated = false;
+	if (sink->mem->magic == MEMSINK_MAGIC) {
+		updated = (sink->mem->id != sink->last_id);
+		if (updated) {
+#			define COPY(_field) frame->_field = sink->mem->_field
+			sink->last_id = sink->mem->id;
+			COPY(width);
+			COPY(height);
+			COPY(format);
+			COPY(stride);
+			COPY(online);
+			COPY(grab_ts);
+			COPY(encode_begin_ts);
+			COPY(encode_end_ts);
+			frame_set_data(frame, sink->mem->data, sink->mem->used);
+#			undef COPY
+		}
+		sink->mem->last_client_ts = get_now_monotonic();
 	}
-	sink->mem->last_client_ts = get_now_monotonic();
 
 	if (flock(sink->fd, LOCK_UN) < 0) {
 		LOG_PERROR("%s-sink: Can't unlock memory", sink->name);
diff --git a/src/libs/memsink.h b/src/libs/memsink.h
index 637206f..ca13207 100644
--- a/src/libs/memsink.h
+++ b/src/libs/memsink.h
@@ -39,6 +39,8 @@
 #include "frame.h"
 
 
+#define MEMSINK_MAGIC ((uint64_t)0xCAFEBABECAFEBABE)
+
 #ifndef CFG_MEMSINK_MAX_DATA
 #	define CFG_MEMSINK_MAX_DATA 33554432
 #endif
@@ -46,6 +48,7 @@
 
 
 typedef struct {
+	uint64_t	magic;
 	uint64_t	id;
 	size_t		used;
 	unsigned	width;