From c75bd39e6a9c9f6cb98de48f681b86285570858b Mon Sep 17 00:00:00 2001
From: Devaev Maxim <mdevaev@gmail.com>
Date: Sun, 10 Jan 2021 19:21:29 +0300
Subject: [PATCH] using hashes to enumerate frames in memsink

---
 src/libs/memsink.c |  6 +++---
 src/libs/memsink.h |  4 ++--
 src/libs/tools.h   | 49 +++++++++++++++++++++++++++++++++-------------
 3 files changed, 40 insertions(+), 19 deletions(-)

diff --git a/src/libs/memsink.c b/src/libs/memsink.c
index 4d739bb..27a8295 100644
--- a/src/libs/memsink.c
+++ b/src/libs/memsink.c
@@ -102,7 +102,7 @@ int memsink_server_put(memsink_s *sink, const frame_s *frame) {
 		LOG_VERBOSE("%s sink: >>>>> Exposing new frame ...", sink->name);
 
 #		define COPY(_field) sink->mem->_field = frame->_field
-		sink->mem->seq += 1;
+		sink->mem->id = get_now_id();
 		COPY(used);
 		COPY(width);
 		COPY(height);
@@ -145,11 +145,11 @@ int memsink_client_get(memsink_s *sink, frame_s *frame) { // cppcheck-suppress u
 
 	bool same = false;
 
-	if (sink->client_seq == sink->mem->seq) {
+	if (sink->mem->id == sink->consumed_id) {
 		same = true;
 	} else {
 #		define COPY(_field) frame->_field = sink->mem->_field
-		sink->client_seq = sink->mem->seq;
+		sink->consumed_id = sink->mem->id;
 		COPY(width);
 		COPY(height);
 		COPY(format);
diff --git a/src/libs/memsink.h b/src/libs/memsink.h
index 2576c75..8dca2ef 100644
--- a/src/libs/memsink.h
+++ b/src/libs/memsink.h
@@ -46,7 +46,7 @@
 
 
 typedef struct {
-	uint64_t	seq;
+	uint64_t	id;
 	size_t		used;
 	unsigned	width;
 	unsigned	height;
@@ -68,7 +68,7 @@ typedef struct {
 
 	int					fd;
 	memsink_shared_s	*mem;
-	uint64_t			client_seq;
+	uint64_t			consumed_id; // Client only
 } memsink_s;
 
 
diff --git a/src/libs/tools.h b/src/libs/tools.h
index d4d3d4f..946994b 100644
--- a/src/libs/tools.h
+++ b/src/libs/tools.h
@@ -23,6 +23,7 @@
 #pragma once
 
 #include <stdio.h>
+#include <stdint.h>
 #include <stdlib.h>
 #include <stdbool.h>
 #include <unistd.h>
@@ -62,12 +63,23 @@ INLINE long long floor_ms(long double now) {
 	return (long long)now - (now < (long long)now); // floor()
 }
 
-INLINE void get_now(clockid_t clk_id, time_t *sec, long *msec) {
-	struct timespec spec;
+INLINE uint32_t triple_u32(uint32_t x) {
+	// https://nullprogram.com/blog/2018/07/31/
+	x ^= x >> 17;
+	x *= UINT32_C(0xED5AD4BB);
+	x ^= x >> 11;
+	x *= UINT32_C(0xAC4C1B51);
+	x ^= x >> 15;
+	x *= UINT32_C(0x31848BAB);
+	x ^= x >> 14;
+	return x;
+}
 
-	assert(!clock_gettime(clk_id, &spec));
-	*sec = spec.tv_sec;
-	*msec = round(spec.tv_nsec / 1.0e6);
+INLINE void get_now(clockid_t clk_id, time_t *sec, long *msec) {
+	struct timespec ts;
+	assert(!clock_gettime(clk_id, &ts));
+	*sec = ts.tv_sec;
+	*msec = round(ts.tv_nsec / 1.0e6);
 
 	if (*msec > 999) {
 		*sec += 1;
@@ -75,24 +87,33 @@ INLINE void get_now(clockid_t clk_id, time_t *sec, long *msec) {
 	}
 }
 
+#if defined(CLOCK_MONOTONIC_RAW)
+#	define X_CLOCK_MONOTONIC CLOCK_MONOTONIC_RAW
+#elif defined(CLOCK_MONOTONIC_FAST)
+#	define X_CLOCK_MONOTONIC CLOCK_MONOTONIC_FAST
+#else
+#	define X_CLOCK_MONOTONIC CLOCK_MONOTONIC
+#endif
+
 INLINE long double get_now_monotonic(void) {
 	time_t sec;
 	long msec;
-
-#	if defined(CLOCK_MONOTONIC_RAW)
-	get_now(CLOCK_MONOTONIC_RAW, &sec, &msec);
-#	elif defined(CLOCK_MONOTONIC_FAST)
-	get_now(CLOCK_MONOTONIC_FAST, &sec, &msec);
-#	else
-	get_now(CLOCK_MONOTONIC, &sec, &msec);
-#	endif
+	get_now(X_CLOCK_MONOTONIC, &sec, &msec);
 	return (long double)sec + ((long double)msec) / 1000;
 }
 
+INLINE uint64_t get_now_id(void) {
+	struct timespec ts;
+	assert(!clock_gettime(X_CLOCK_MONOTONIC, &ts));
+	uint64_t now = (uint64_t)(ts.tv_nsec / 1000) + (uint64_t)ts.tv_sec * 1000000;
+	return (uint64_t)triple_u32(now) | ((uint64_t)triple_u32(now + 12345) << 32);
+}
+
+#undef X_CLOCK_MONOTONIC
+
 INLINE long double get_now_real(void) {
 	time_t sec;
 	long msec;
-
 	get_now(CLOCK_REALTIME, &sec, &msec);
 	return (long double)sec + ((long double)msec) / 1000;
 }