WIP: Add cubeb_stream_get_max_request_size API.get_max_req_size

This is intended to support https://github.com/mozilla/audioipc-2/issues/124

15 files changed, 62 insertions, 0 deletions

diff --git a/include/cubeb/cubeb.h b/include/cubeb/cubeb.h
index f653f5b..02539b9 100644
--- a/include/cubeb/cubeb.h
+++ b/include/cubeb/cubeb.h
@@ -607,6 +607,7 @@ cubeb_stream_get_latency(cubeb_stream * stream, uint32_t * latency);
     @retval CUBEB_ERROR */
 CUBEB_EXPORT int
 cubeb_stream_get_input_latency(cubeb_stream * stream, uint32_t * latency);
+
 /** Set the volume for a stream.
     @param stream the stream for which to adjust the volume.
     @param volume a float between 0.0 (muted) and 1.0 (maximum volume)
@@ -637,6 +638,20 @@ CUBEB_EXPORT int
 cubeb_stream_get_current_device(cubeb_stream * stm,
                                 cubeb_device ** const device);
 
+/** Get the maximum request size for this stream in frames.  This is the largest
+    value that will be presented or requested via `data_callback`'s `nframes`
+   parameter. Note: This value may change if the stream is automatically
+   reconfigured due to device changes. Callers of this API should use
+   cubeb_stream_register_device_changed_callback to monitor device changes and
+   requery this API after a device change.
+    @param stream the stream for which to retrieve max request size.
+    @param max_request_size the max request size in frames.
+    @retval CUBEB_OK
+    @retval CUBEB_ERROR_NOT_SUPPORTED */
+CUBEB_EXPORT int
+cubeb_stream_get_max_request_size(cubeb_stream * stream,
+                                  uint32_t * max_request_size);
+
 /** Destroy a cubeb_device structure.
     @param stream the stream passed in cubeb_stream_get_current_device
     @param devices the devices to destroy
diff --git a/src/cubeb-internal.h b/src/cubeb-internal.h
index 79326e1..3e03003 100644
--- a/src/cubeb-internal.h
+++ b/src/cubeb-internal.h
@@ -66,6 +66,8 @@ struct cubeb_ops {
   int (*stream_register_device_changed_callback)(
       cubeb_stream * stream,
       cubeb_device_changed_callback device_changed_callback);
+  int (*stream_get_max_request_size)(cubeb_stream * stream,
+                                     uint32_t * max_request_size);
   int (*register_device_collection_changed)(
       cubeb * context, cubeb_device_type devtype,
       cubeb_device_collection_changed_callback callback, void * user_ptr);
diff --git a/src/cubeb.c b/src/cubeb.c
index b3d32ee..6b542fc 100644
--- a/src/cubeb.c
+++ b/src/cubeb.c
@@ -501,6 +501,22 @@ cubeb_stream_get_current_device(cubeb_stream * stream,
 }
 
 int
+cubeb_stream_get_max_request_size(cubeb_stream * stream,
+                                  uint32_t * max_request_size)
+{
+  if (!stream || !max_request_size) {
+    return CUBEB_ERROR_INVALID_PARAMETER;
+  }
+
+  if (!stream->context->ops->stream_get_max_request_size) {
+    return CUBEB_ERROR_NOT_SUPPORTED;
+  }
+
+  return stream->context->ops->stream_get_max_request_size(stream,
+                                                           max_request_size);
+}
+
+int
 cubeb_stream_device_destroy(cubeb_stream * stream, cubeb_device * device)
 {
   if (!stream || !device) {
diff --git a/src/cubeb_aaudio.cpp b/src/cubeb_aaudio.cpp
index 448ea91..a72e671 100644
--- a/src/cubeb_aaudio.cpp
+++ b/src/cubeb_aaudio.cpp
@@ -1460,6 +1460,7 @@ const static struct cubeb_ops aaudio_ops = {
     /*.stream_get_current_device =*/NULL,
     /*.stream_device_destroy =*/NULL,
     /*.stream_register_device_changed_callback =*/NULL,
+    /*.stream_get_max_request_size =*/NULL,
     /*.register_device_collection_changed =*/NULL};
 
 extern "C" /*static*/ int
diff --git a/src/cubeb_alsa.c b/src/cubeb_alsa.c
index 08772dd..e367ced 100644
--- a/src/cubeb_alsa.c
+++ b/src/cubeb_alsa.c
@@ -1487,4 +1487,5 @@ static struct cubeb_ops const alsa_ops = {
     .stream_get_current_device = NULL,
     .stream_device_destroy = NULL,
     .stream_register_device_changed_callback = NULL,
+    .stream_get_max_request_size = NULL,
     .register_device_collection_changed = NULL};
diff --git a/src/cubeb_audiounit.cpp b/src/cubeb_audiounit.cpp
index 02cd134..2c5ec8b 100644
--- a/src/cubeb_audiounit.cpp
+++ b/src/cubeb_audiounit.cpp
@@ -3666,5 +3666,6 @@ cubeb_ops const audiounit_ops = {
     /*.stream_device_destroy =*/audiounit_stream_device_destroy,
     /*.stream_register_device_changed_callback =*/
     audiounit_stream_register_device_changed_callback,
+    /*.stream_get_max_request_size = */ NULL,
     /*.register_device_collection_changed =*/
     audiounit_register_device_collection_changed};
diff --git a/src/cubeb_jack.cpp b/src/cubeb_jack.cpp
index 3590235..70d0581 100644
--- a/src/cubeb_jack.cpp
+++ b/src/cubeb_jack.cpp
@@ -175,6 +175,7 @@ static struct cubeb_ops const cbjack_ops = {
     .stream_get_current_device = cbjack_stream_get_current_device,
     .stream_device_destroy = cbjack_stream_device_destroy,
     .stream_register_device_changed_callback = NULL,
+    .stream_get_max_request_size = NULL,
     .register_device_collection_changed = NULL};
 
 struct cubeb_stream {
diff --git a/src/cubeb_kai.c b/src/cubeb_kai.c
index 0a0d676..a88ad72 100644
--- a/src/cubeb_kai.c
+++ b/src/cubeb_kai.c
@@ -366,4 +366,5 @@ static struct cubeb_ops const kai_ops = {
     /*.stream_get_current_device =*/NULL,
     /*.stream_device_destroy =*/NULL,
     /*.stream_register_device_changed_callback=*/NULL,
+    /*.stream_get_max_request_size =*/NULL,
     /*.register_device_collection_changed=*/NULL};
diff --git a/src/cubeb_opensl.c b/src/cubeb_opensl.c
index 78096d5..68c2570 100644
--- a/src/cubeb_opensl.c
+++ b/src/cubeb_opensl.c
@@ -1792,4 +1792,5 @@ static struct cubeb_ops const opensl_ops = {
     .stream_get_current_device = NULL,
     .stream_device_destroy = NULL,
     .stream_register_device_changed_callback = NULL,
+    .stream_get_max_request_size = NULL,
     .register_device_collection_changed = NULL};
diff --git a/src/cubeb_oss.c b/src/cubeb_oss.c
index 083c37f..80e66da 100644
--- a/src/cubeb_oss.c
+++ b/src/cubeb_oss.c
@@ -1326,4 +1326,5 @@ static struct cubeb_ops const oss_ops = {
     .stream_get_current_device = oss_get_current_device,
     .stream_device_destroy = oss_stream_device_destroy,
     .stream_register_device_changed_callback = NULL,
+    .stream_get_max_request_size = NULL,
     .register_device_collection_changed = NULL};
diff --git a/src/cubeb_pulse.c b/src/cubeb_pulse.c
index 31a2f93..aafb616 100644
--- a/src/cubeb_pulse.c
+++ b/src/cubeb_pulse.c
@@ -1696,5 +1696,6 @@ static struct cubeb_ops const pulse_ops = {
     .stream_get_current_device = pulse_stream_get_current_device,
     .stream_device_destroy = pulse_stream_device_destroy,
     .stream_register_device_changed_callback = NULL,
+    .stream_get_max_request_size = NULL,
     .register_device_collection_changed =
         pulse_register_device_collection_changed};
diff --git a/src/cubeb_sndio.c b/src/cubeb_sndio.c
index d7fb792..db563b4 100644
--- a/src/cubeb_sndio.c
+++ b/src/cubeb_sndio.c
@@ -666,4 +666,5 @@ static struct cubeb_ops const sndio_ops = {
     .stream_get_current_device = NULL,
     .stream_device_destroy = NULL,
     .stream_register_device_changed_callback = NULL,
+    .stream_get_max_request_size = NULL,
     .register_device_collection_changed = NULL};
diff --git a/src/cubeb_sun.c b/src/cubeb_sun.c
index 3b7bef7..eeca190 100644
--- a/src/cubeb_sun.c
+++ b/src/cubeb_sun.c
@@ -730,4 +730,5 @@ static struct cubeb_ops const sun_ops = {
     .stream_get_current_device = sun_get_current_device,
     .stream_device_destroy = sun_stream_device_destroy,
     .stream_register_device_changed_callback = NULL,
+    .stream_get_max_request_size = NULL,
     .register_device_collection_changed = NULL};
diff --git a/src/cubeb_wasapi.cpp b/src/cubeb_wasapi.cpp
index 9cc8a26..6f42436 100644
--- a/src/cubeb_wasapi.cpp
+++ b/src/cubeb_wasapi.cpp
@@ -2965,6 +2965,23 @@ wasapi_stream_set_volume(cubeb_stream * stm, float volume)
   return CUBEB_OK;
 }
 
+// TODO: Need to implement stream_register_device_changed_callback.
+int
+wasapi_stream_get_max_request_size(cubeb_stream * stm,
+                                   uint32_t * max_request_size)
+{
+  auto_lock lock(stm->stream_reset_lock);
+
+  if (!stm->output_client && !stm->input_client) {
+    return CUBEB_ERROR;
+  }
+
+  *max_request_size =
+      std::max(stm->output_buffer_frame_count, stm->input_buffer_frame_count);
+
+  return CUBEB_OK;
+}
+
 static char const *
 wstr_to_utf8(LPCWSTR str)
 {
@@ -3382,6 +3399,7 @@ cubeb_ops const wasapi_ops = {
     /*.stream_get_current_device =*/NULL,
     /*.stream_device_destroy =*/NULL,
     /*.stream_register_device_changed_callback =*/NULL,
+    /*.stream_get_max_request_size =*/wasapi_stream_get_max_request_size,
     /*.register_device_collection_changed =*/
     wasapi_register_device_collection_changed,
 };
diff --git a/src/cubeb_winmm.c b/src/cubeb_winmm.c
index 169b743..1052da7 100644
--- a/src/cubeb_winmm.c
+++ b/src/cubeb_winmm.c
@@ -1179,4 +1179,5 @@ static struct cubeb_ops const winmm_ops = {
     /*.stream_get_current_device =*/NULL,
     /*.stream_device_destroy =*/NULL,
     /*.stream_register_device_changed_callback=*/NULL,
+    /*.stream_get_max_request_size = */ NULL,
     /*.register_device_collection_changed =*/NULL};