[Qemu-devel] [PULL 17/26] paaudio: get/put_buffer functions

[Gerd Hoffmann <kraxel@redhat.com>]

From: Kővágó, Zoltán <dirty.ice.hu@gmail.com>

This lets us avoid some buffer copying when using mixeng.

Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com>
Message-id: 4554ff54ad04f706ad0e9af87fe07650fd6d9ac1.1568574965.git.DirtY.iCE.hu@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 audio/paaudio.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)

diff --git a/audio/paaudio.c b/audio/paaudio.c
index ed31f863f7fe..6ccdf3141598 100644
--- a/audio/paaudio.c
+++ b/audio/paaudio.c
@@ -98,6 +98,59 @@ static inline int PA_STREAM_IS_GOOD(pa_stream_state_t x)
         }                                                               \
     } while (0)
 
+static void *qpa_get_buffer_in(HWVoiceIn *hw, size_t *size)
+{
+    PAVoiceIn *p = (PAVoiceIn *) hw;
+    PAConnection *c = p->g->conn;
+    int r;
+
+    pa_threaded_mainloop_lock(c->mainloop);
+
+    CHECK_DEAD_GOTO(c, p->stream, unlock_and_fail,
+                    "pa_threaded_mainloop_lock failed\n");
+
+    if (!p->read_length) {
+        r = pa_stream_peek(p->stream, &p->read_data, &p->read_length);
+        CHECK_SUCCESS_GOTO(c, r == 0, unlock_and_fail,
+                           "pa_stream_peek failed\n");
+    }
+
+    *size = MIN(p->read_length, *size);
+
+    pa_threaded_mainloop_unlock(c->mainloop);
+    return (void *) p->read_data;
+
+unlock_and_fail:
+    pa_threaded_mainloop_unlock(c->mainloop);
+    *size = 0;
+    return NULL;
+}
+
+static void qpa_put_buffer_in(HWVoiceIn *hw, void *buf, size_t size)
+{
+    PAVoiceIn *p = (PAVoiceIn *) hw;
+    PAConnection *c = p->g->conn;
+    int r;
+
+    pa_threaded_mainloop_lock(c->mainloop);
+
+    CHECK_DEAD_GOTO(c, p->stream, unlock,
+                    "pa_threaded_mainloop_lock failed\n");
+
+    assert(buf == p->read_data && size <= p->read_length);
+
+    p->read_data += size;
+    p->read_length -= size;
+
+    if (size && !p->read_length) {
+        r = pa_stream_drop(p->stream);
+        CHECK_SUCCESS_GOTO(c, r == 0, unlock, "pa_stream_drop failed\n");
+    }
+
+unlock:
+    pa_threaded_mainloop_unlock(c->mainloop);
+}
+
 static size_t qpa_read(HWVoiceIn *hw, void *data, size_t length)
 {
     PAVoiceIn *p = (PAVoiceIn *) hw;
@@ -136,6 +189,32 @@ unlock_and_fail:
     return 0;
 }
 
+static void *qpa_get_buffer_out(HWVoiceOut *hw, size_t *size)
+{
+    PAVoiceOut *p = (PAVoiceOut *) hw;
+    PAConnection *c = p->g->conn;
+    void *ret;
+    int r;
+
+    pa_threaded_mainloop_lock(c->mainloop);
+
+    CHECK_DEAD_GOTO(c, p->stream, unlock_and_fail,
+                    "pa_threaded_mainloop_lock failed\n");
+
+    *size = -1;
+    r = pa_stream_begin_write(p->stream, &ret, size);
+    CHECK_SUCCESS_GOTO(c, r >= 0, unlock_and_fail,
+                       "pa_stream_begin_write failed\n");
+
+    pa_threaded_mainloop_unlock(c->mainloop);
+    return ret;
+
+unlock_and_fail:
+    pa_threaded_mainloop_unlock(c->mainloop);
+    *size = 0;
+    return NULL;
+}
+
 static size_t qpa_write(HWVoiceOut *hw, void *data, size_t length)
 {
     PAVoiceOut *p = (PAVoiceOut *) hw;
@@ -698,11 +777,15 @@ static struct audio_pcm_ops qpa_pcm_ops = {
     .init_out = qpa_init_out,
     .fini_out = qpa_fini_out,
     .write    = qpa_write,
+    .get_buffer_out = qpa_get_buffer_out,
+    .put_buffer_out = qpa_write, /* pa handles it */
     .volume_out = qpa_volume_out,
 
     .init_in  = qpa_init_in,
     .fini_in  = qpa_fini_in,
     .read     = qpa_read,
+    .get_buffer_in = qpa_get_buffer_in,
+    .put_buffer_in = qpa_put_buffer_in,
     .volume_in = qpa_volume_in
 };
 
-- 
2.18.1