[Spice-devel] [PATCH spice-streaming-agent 2/2] Do not use an encoding not supported by the client

[Frediano Ziglio]

> 
> On Tue, 2017-11-21 at 09:49 +0000, Frediano Ziglio wrote:
> > This allows for instance old clients to work correctly.
> > 
> > Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> > ---
> >  src/concrete-agent.cpp        | 5 ++++-
> >  src/concrete-agent.hpp        | 3 ++-
> >  src/spice-streaming-agent.cpp | 6 +++++-
> >  3 files changed, 11 insertions(+), 3 deletions(-)
> > 
> > diff --git a/src/concrete-agent.cpp b/src/concrete-agent.cpp
> > index 192054a..404ee74 100644
> > --- a/src/concrete-agent.cpp
> > +++ b/src/concrete-agent.cpp
> > @@ -98,7 +98,7 @@ void ConcreteAgent::LoadPlugin(const char
> > *plugin_filename)
> >      }
> >  }
> >  
> > -FrameCapture *ConcreteAgent::GetBestFrameCapture()
> > +FrameCapture *ConcreteAgent::GetBestFrameCapture(const
> > std::set<SpiceVideoCodecType>& codecs)
> 
> 
> I notice that there's a bit of inconsistency about specifying the std::
> namespace or just using the bare type. There is a "using namespace
> std;" statement in this file, and most standard library types are used
> without specifying the namespace. But there there is at least one place
> where we specify the namespace, and you've added another in this patch.
> 

Usually I tend to use in the header to avoid having a global
unwanted "using namespace" statement and avoid in the source (at least
for std). We can define to always use the explicit namespace for "std".

> (as a matter of personal preference, I generally dislike 'using
> namespace' statements, and I prefer to specify the std:: namespace
> explicitly)
> 
> 
> > 
> 
> >  {
> >      vector<pair<unsigned, shared_ptr<Plugin>>> sorted_plugins;
> >  
> > @@ -113,6 +113,9 @@ FrameCapture
> > *ConcreteAgent::GetBestFrameCapture()
> >          if (plugin.first == DontUse) {
> >              break;
> 
> Unrelated to this patch, but shouldn't the statement above be
> 'continue' rather than 'break'?
> 

They are sorted based on rank so all others are DontUse too.

> 
> >          }
> > +        // check client supports the codec
> > +        if (codecs.find(plugin.second->VideoCodecType()) ==
> > codecs.end())
> > +            continue;
> >          FrameCapture *capture = plugin.second->CreateCapture();
> >          if (capture) {
> >              return capture;
> > diff --git a/src/concrete-agent.hpp b/src/concrete-agent.hpp
> > index 828368b..6c300fa 100644
> > --- a/src/concrete-agent.hpp
> > +++ b/src/concrete-agent.hpp
> > @@ -7,6 +7,7 @@
> >  #define SPICE_STREAMING_AGENT_CONCRETE_AGENT_HPP
> >  
> >  #include <vector>
> > +#include <set>
> >  #include <memory>
> >  #include <spice-streaming-agent/plugin.hpp>
> >  
> > @@ -33,7 +34,7 @@ public:
> >      void LoadPlugins(const char *directory);
> >      // pointer must remain valid
> >      void AddOption(const char *name, const char *value);
> > -    FrameCapture *GetBestFrameCapture();
> > +    FrameCapture *GetBestFrameCapture(const
> > std::set<SpiceVideoCodecType>& codecs);
>      bool PluginVersionIsCompatible(unsigned pluginVersion) const
> > override;
> >  private:
> >      void LoadPlugin(const char *plugin_filename);
> > diff --git a/src/spice-streaming-agent.cpp b/src/spice-streaming-
> > agent.cpp
> > index 20f2925..5c0bbb9 100644
> > --- a/src/spice-streaming-agent.cpp
> > +++ b/src/spice-streaming-agent.cpp
> > @@ -52,6 +52,7 @@ struct SpiceStreamDataMessage
> >  };
> >  
> >  static int streaming_requested;
> > +static std::set<SpiceVideoCodecType> client_codecs;
> >  static bool quit;
> >  static int streamfd = -1;
> >  static bool stdin_ok;
> > @@ -143,6 +144,9 @@ static int read_command_from_device(void)
> >      streaming_requested = msg[0]; /* num_codecs */
> >      syslog(LOG_INFO, "GOT START_STOP message -- request to %s
> > streaming\n",
> >             streaming_requested ? "START" : "STOP");
> > +    client_codecs.clear();
> > +    for (int i = 1; i <= msg[0]; ++i)
> > +        client_codecs.insert((SpiceVideoCodecType) msg[i]);
> >      return 1;
> >  }
> >  
> > @@ -363,7 +367,7 @@ do_capture(const char *streamport, FILE *f_log)
> >          syslog(LOG_INFO, "streaming starts now\n");
> >          uint64_t time_last = 0;
> >  
> > -        std::unique_ptr<FrameCapture>
> > capture(agent.GetBestFrameCapture());
> > +        std::unique_ptr<FrameCapture>
> > capture(agent.GetBestFrameCapture(client_codecs));
> >          if (!capture)
> >              throw std::runtime_error("cannot find a suitable capture
> > system");
> >  
> 
> 
> Otherwise it looks ok to me
> 
> Reviewed-by: Jonathon Jongsma <jjongsma at redhat.com>
> 
> 

Frediano