[PATCH RFCv3 49/51] alsa: Refactor computation of sleep usec

[pmeerw@xxxxxxxxxx (Peter Meerwald)]

From: Peter Meerwald <p.meerwald@xxxxxxxxxxxxxxxxxx>

avoids duplicate code in mmap_read/write() and unix_read/write()

Signed-off-by: Peter Meerwald <pmeerw at pmeerw.net>
---
 src/modules/alsa/alsa-sink.c   | 57 +++++++++++++++++-------------------------
 src/modules/alsa/alsa-source.c | 35 +++++++++++++-------------
 2 files changed, 40 insertions(+), 52 deletions(-)

diff --git a/src/modules/alsa/alsa-sink.c b/src/modules/alsa/alsa-sink.c
index 0d13716..aab7ee7 100644
--- a/src/modules/alsa/alsa-sink.c
+++ b/src/modules/alsa/alsa-sink.c
@@ -508,10 +508,29 @@ static size_t check_left_to_play(struct userdata *u, size_t n_bytes, bool on_tim
     return left_to_play;
 }
 
+static pa_usec_t compute_sleep(struct userdata *u, size_t left_to_play) {
+    size_t input_underrun = pa_sink_process_input_underruns(u->sink, left_to_play);
+    pa_usec_t sleep_usec = 0;
+
+    if (u->use_tsched) {
+        pa_usec_t underrun_sleep = pa_bytes_to_usec_round_up(input_underrun, &u->sink->sample_spec);
+        sleep_usec = PA_BYTES_TO_USEC(left_to_play, &u->sink->sample_spec);
+
+        if (sleep_usec > u->tsched_watermark_usec)
+            sleep_usec -= u->tsched_watermark_usec;
+        else
+            sleep_usec = 0;
+
+        sleep_usec = PA_MIN(sleep_usec, underrun_sleep);
+    }
+
+    return sleep_usec;
+}
+
 static int mmap_write(struct userdata *u, pa_usec_t *sleep_usec, bool polled, bool on_timeout) {
     bool work_done = false;
     pa_usec_t max_sleep_usec = 0, process_usec = 0;
-    size_t left_to_play, input_underrun;
+    size_t left_to_play;
     size_t sleep_bytes = 0;
     unsigned j = 0;
 
@@ -683,22 +702,7 @@ static int mmap_write(struct userdata *u, pa_usec_t *sleep_usec, bool polled, bo
     }
 
 done:
-    input_underrun = pa_sink_process_input_underruns(u->sink, left_to_play);
-
-    if (u->use_tsched) {
-        pa_usec_t underrun_sleep = pa_bytes_to_usec_round_up(input_underrun, &u->sink->sample_spec);
-
-        *sleep_usec = PA_BYTES_TO_USEC(left_to_play, &u->sink->sample_spec);
-        process_usec = u->tsched_watermark_usec;
-
-        if (*sleep_usec > process_usec)
-            *sleep_usec -= process_usec;
-        else
-            *sleep_usec = 0;
-
-        *sleep_usec = PA_MIN(*sleep_usec, underrun_sleep);
-    } else
-        *sleep_usec = 0;
+    *sleep_usec = compute_sleep(u, left_to_play);
 
     return work_done ? 1 : 0;
 }
@@ -706,7 +710,7 @@ done:
 static int unix_write(struct userdata *u, pa_usec_t *sleep_usec, bool polled, bool on_timeout) {
     bool work_done = false;
     pa_usec_t max_sleep_usec = 0, process_usec = 0;
-    size_t left_to_play, input_underrun;
+    size_t left_to_play;
     unsigned j = 0;
 
     pa_assert(u);
@@ -837,22 +841,7 @@ static int unix_write(struct userdata *u, pa_usec_t *sleep_usec, bool polled, bo
         }
     }
 
-    input_underrun = pa_sink_process_input_underruns(u->sink, left_to_play);
-
-    if (u->use_tsched) {
-        pa_usec_t underrun_sleep = pa_bytes_to_usec_round_up(input_underrun, &u->sink->sample_spec);
-
-        *sleep_usec = PA_BYTES_TO_USEC(left_to_play, &u->sink->sample_spec);
-        process_usec = u->tsched_watermark_usec;
-
-        if (*sleep_usec > process_usec)
-            *sleep_usec -= process_usec;
-        else
-            *sleep_usec = 0;
-
-        *sleep_usec = PA_MIN(*sleep_usec, underrun_sleep);
-    } else
-        *sleep_usec = 0;
+    *sleep_usec = compute_sleep(u, left_to_play);
 
     return work_done ? 1 : 0;
 }
diff --git a/src/modules/alsa/alsa-source.c b/src/modules/alsa/alsa-source.c
index f82f811..ac88e4b 100644
--- a/src/modules/alsa/alsa-source.c
+++ b/src/modules/alsa/alsa-source.c
@@ -477,6 +477,21 @@ static size_t check_left_to_record(struct userdata *u, size_t n_bytes, bool on_t
     return left_to_record;
 }
 
+static pa_usec_t compute_sleep(struct userdata *u, size_t left_to_record) {
+    pa_usec_t sleep_usec = 0;
+
+    if (u->use_tsched) {
+        sleep_usec = PA_BYTES_TO_USEC(left_to_record, &u->source->sample_spec);
+
+        if (sleep_usec > u->tsched_watermark_usec)
+            sleep_usec -= u->tsched_watermark_usec;
+        else
+            sleep_usec = 0;
+    }
+
+    return sleep_usec;
+}
+
 static int mmap_read(struct userdata *u, pa_usec_t *sleep_usec, bool polled, bool on_timeout) {
     bool work_done = false;
     pa_usec_t max_sleep_usec = 0, process_usec = 0;
@@ -625,15 +640,7 @@ static int mmap_read(struct userdata *u, pa_usec_t *sleep_usec, bool polled, boo
         }
     }
 
-    if (u->use_tsched) {
-        *sleep_usec = PA_BYTES_TO_USEC(left_to_record, &u->source->sample_spec);
-        process_usec = u->tsched_watermark_usec;
-
-        if (*sleep_usec > process_usec)
-            *sleep_usec -= process_usec;
-        else
-            *sleep_usec = 0;
-    }
+    *sleep_usec = compute_sleep(u, left_to_record);
 
     return work_done ? 1 : 0;
 }
@@ -755,15 +762,7 @@ static int unix_read(struct userdata *u, pa_usec_t *sleep_usec, bool polled, boo
         }
     }
 
-    if (u->use_tsched) {
-        *sleep_usec = PA_BYTES_TO_USEC(left_to_record, &u->source->sample_spec);
-        process_usec = u->tsched_watermark_usec;
-
-        if (*sleep_usec > process_usec)
-            *sleep_usec -= process_usec;
-        else
-            *sleep_usec = 0;
-    }
+    *sleep_usec = compute_sleep(u, left_to_record);
 
     return work_done ? 1 : 0;
 }
-- 
1.9.1