From 55bef12cda37490ad3555ca0dc724697241c33f1 Mon Sep 17 00:00:00 2001
From: Wim Taymans <wtaymans@redhat.com>
Date: Wed, 29 Jul 2020 09:49:06 +0200
Subject: [PATCH] pulse: take queued data into account when asking for more

Don't use always ask for the maximum amount of data in the
write_callback but subtract the queued amount of data from it or else
we will queue too much and cause huge lag.

Fixes #258
---
 pipewire-pulseaudio/src/stream.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/pipewire-pulseaudio/src/stream.c b/pipewire-pulseaudio/src/stream.c
index 1ac0d2b8..7b529a95 100644
--- a/pipewire-pulseaudio/src/stream.c
+++ b/pipewire-pulseaudio/src/stream.c
@@ -552,10 +552,16 @@ static void stream_process(void *data)
 	update_timing_info(s);
 
 	if (s->direction == PA_STREAM_PLAYBACK) {
+		pa_timing_info *i = &s->timing_info;
+		uint64_t queued, writable;
+
 		queue_output(s);
 
-		if (s->write_callback && s->state == PA_STREAM_READY)
-			s->write_callback(s, s->maxblock, s->write_userdata);
+		queued = i->write_index - SPA_MIN(i->read_index, i->write_index);
+		writable = s->maxblock - SPA_MIN(queued, s->maxblock);
+
+		if (s->write_callback && s->state == PA_STREAM_READY && writable > 0)
+			s->write_callback(s, writable, s->write_userdata);
 	}
 	else {
 		pull_input(s);
@@ -1843,6 +1849,9 @@ int pa_stream_get_latency(pa_stream *s, pa_usec_t *r_usec, int *negative)
 	else
 		*r_usec = time_counter_diff(s, t, c, negative);
 
+	pw_log_debug("stream %p: now:%"PRIu64" stream:%"PRIu64
+			" res:%"PRIu64, s, t, c, *r_usec);
+
 	return 0;
 }
 
-- 
2.26.2