[esnacc-dev] [PATCH 2/2] cxx-lib/asn-buf: Stream buffer monitor

[Aaron Conole]

Sagara Wickramasekara <sagaraw at gmail.com> writes:

> Acked-by: Sagara Wickramasekara <sagaraw at gmail.com>

Thanks, I've applied both 1/2 and 2/2 (with some whitespace fix-up).

> On Fri, Aug 26, 2016 at 3:32 PM, Aaron Conole <aconole at bytheb.org> wrote:
>
>  Introduce a mechanism for monitoring and calling back stream buffer
>  objects.  This is useful for building busy-wait loops, which can perform
>  tasks as interleaved callbacks.
>
>  Signed-off-by: Aaron Conole <aconole at bytheb.org>
>  ---
>   cxx-lib/inc/asn-buf.h | 99
>  +++++++++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 99 insertions(+)
>
>  diff --git a/cxx-lib/inc/asn-buf.h b/cxx-lib/inc/asn-buf.h
>  index d316ba9..872484b 100644
>  --- a/cxx-lib/inc/asn-buf.h
>  +++ b/cxx-lib/inc/asn-buf.h
>  @@ -7,9 +7,11 @@
>   #pragma warning(push,3)
>   #endif
>
>  +#include <algorithm>
>   #include <deque>
>   #include <fstream>
>   #include <list>
>  +#include <map>
>   #include <ostream>
>   #include <sstream>
>   #include <streambuf>
>  @@ -413,6 +415,103 @@ private:
>
>   };
>
>  +
>  +class StreambufCallback
>  +{
>  +public:
>  +    enum Streambuf_CB_RESULT {
>  +        CB_NONE,
>  +        CB_DROP_STREAM
>  +    };
>  +
>  +    enum Streambuf_CB_STATUS {
>  +        CB_READ_OK,
>  +        CB_WRITE_OK,
>  +        CB_OPENED,
>  +        CB_CLOSED
>  +    };
>  +
>  +    StreambufCallback(){}
>  +    virtual ~StreambufCallback(){}
>  +    virtual Streambuf_CB_RESULT callback(Streambuf_CB_STATUS status,
>  +                                         std::streambuf *stream) = 0;
>  +};
>  +
>  +class StreambufMonitor
>  +{
>  +public:
>  +    typedef std::map<std::streambuf*,StreambufCallback&> callbackMap;
>  +
>  +private:
>  +    callbackMap                 callbacks;
>  +    std::list<std::streambuf*>  toDrop;
>  +
>  +    static void check_buffer(callbackMap::value_type t,
>  +                             std::list<std::streambuf*> &StreamDropList)
>  +    {
>  +        std::streambuf *Stream = t.first;
>  +        std::streamsize Bytes = Stream->in_avail();
>  +        StreambufCallback::Streambuf_CB_RESULT result =
>  +            StreambufCallback::CB_NONE;
>  +
>  +        if (Bytes == -1) {
>  +            result = (t.second).callback(StreambufCallback::CB_CLOSED, Stream);
>  +        } else if (Bytes > 0) {
>  +            result = (t.second).callback(StreambufCallback::CB_READ_OK,
>  +                                         Stream);
>  +        }
>  +
>  +        if (result == StreambufCallback::CB_DROP_STREAM) {
>  +            StreamDropList.push_back(Stream);
>  +        }
>  +    }
>  +
>  +    struct buffer_checker
>  +    {
>  +        StreambufMonitor *Mon;
>  +        void operator()(callbackMap::value_type t)
>  +        {
>  +            StreambufMonitor::check_buffer(t, Mon->toDrop);
>  +        }
>  +    };
>  +
>  +public:
>  +    StreambufMonitor() {}
>  +    ~StreambufMonitor() {}
>  +
>  +    /**
>  +     * Adds a streambuf to be monitored, with a specific callback instance. */
>  +    bool push(std::streambuf *Stream, StreambufCallback &CB, bool callOpen)
>  +    {
>  +        if (callOpen) {
>  +            StreambufCallback::Streambuf_CB_RESULT result =
>  +                CB.callback(StreambufCallback::CB_OPENED, Stream);
>  +            if (result == StreambufCallback::CB_DROP_STREAM)
>  +                return false;
>  +        }
>  +        callbacks.insert(
>  +            std::pair<std::streambuf*,StreambufCallback&>(Stream,CB));
>  +        return true;
>  +    }
>  +
>  +    /**
>  +     * Removes a streambuf from the monitor. */
>  +    bool pop(std::streambuf *Stream)
>  +    {
>  +        if (callbacks.erase(Stream))
>  +            return true;
>  +        return false;
>  +    }
>  +
>  +    void operator()()
>  +    {
>  +        buffer_checker bc;
>  +        bc.Mon = this;
>  +        std::for_each(callbacks.begin(), callbacks.end(), bc);
>  +        toDrop.clear();
>  +    }
>  +};
>  +
>   } // end namespace SNACC
>
>   SNACCDLL_API void sortSet(std::list<SNACC::AsnBuf> &bufList);
>  --
>  2.5.5
>
>  _______________________________________________
>  dev mailing list
>  dev at lists.esnacc.org
>  http://mail.esnacc.org/mailman/listinfo/dev