[Spice-devel] [RFC PATCH spice-server v3 10/20] stream-channel: Allows to register callback to get new stream request

[Jonathon Jongsma]

I had a similar comment in a different patch during the last version of
the series, but I personally would prefer a signal to handle this
situation. For example, StreamChannel could have a "supported-codecs"
property, Then when a new client connected, or a client disconnected,
it would update this property. The StreamDevice would connect to the
"notify::supported-codecs" signal, and then it would start and stop the
stream as necessary. I think that encapsulates the logic of starting
and stopping the stream a little bit better within the device class as
well. 

After writing the above paragraph, I did a little more investigation
and I noticed that DisplayChannel already has a similar design -- it
has a "video-codecs" property.

Reviewed-by: Jonathon Jongsma <jjongsma at redhat.com>



On Wed, 2017-08-23 at 10:14 +0100, Frediano Ziglio wrote:
> The channel needs to communicate when it receive a new
> stream request from the guest.
> 
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> ---
>  server/stream-channel.c | 12 ++++++++++++
>  server/stream-channel.h |  6 ++++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/server/stream-channel.c b/server/stream-channel.c
> index 08c51272..a89a8f8e 100644
> --- a/server/stream-channel.c
> +++ b/server/stream-channel.c
> @@ -68,6 +68,10 @@ struct StreamChannel {
>      int stream_id;
>      /* size of the current video stream */
>      unsigned width, height;
> +
> +    /* callback to notify when a stream should be started or stopped
> */
> +    stream_channel_start_proc start_cb;
> +    void *start_opaque;
>  };
>  
>  struct StreamChannelClass {
> @@ -383,3 +387,11 @@ stream_channel_send_data(StreamChannel *channel,
> const void *data, size_t size,
>      red_channel_pipes_new_add(red_channel, pipe_item_new_ref, item);
>      red_pipe_item_unref(&item->base);
>  }
> +
> +void
> +stream_channel_register_start_cb(StreamChannel *channel,
> +                                 stream_channel_start_proc cb, void
> *opaque)
> +{
> +    channel->start_cb = cb;
> +    channel->start_opaque = opaque;
> +}
> diff --git a/server/stream-channel.h b/server/stream-channel.h
> index 6257f806..37b9e327 100644
> --- a/server/stream-channel.h
> +++ b/server/stream-channel.h
> @@ -49,6 +49,7 @@ GType stream_channel_get_type(void) G_GNUC_CONST;
>  StreamChannel* stream_channel_new(RedsState *server);
>  
>  struct StreamMsgFormat;
> +struct StreamMsgStartStop;
>  
>  void stream_channel_change_format(StreamChannel *channel,
>                                    const struct StreamMsgFormat
> *fmt);
> @@ -56,6 +57,11 @@ void stream_channel_send_data(StreamChannel
> *channel,
>                                const void *data, size_t size,
>                                uint32_t mm_time);
>  
> +typedef void (*stream_channel_start_proc)(void *opaque, struct
> StreamMsgStartStop *start,
> +                                          StreamChannel *channel);
> +void stream_channel_register_start_cb(StreamChannel *channel,
> +                                      stream_channel_start_proc cb,
> void *opaque);
> +
>  G_END_DECLS
>  
>  #endif /* STREAM_CHANNEL_H_ */