[Spice-devel] [PATCH 12/17] Convert message writing from C style to C++ style
Frediano Ziglio
fziglio at redhat.com
Tue Feb 20 16:14:10 UTC 2018
> From: Christophe de Dinechin <dinechin at redhat.com>
>
> - The Stream class now deals with locking and sending messages
> - The Message<> template class deals with the general writing mechanisms
> - Three classes, FormatMessage, FrameMessage and X11CursorMessage represent
> individual messages
>
> The various classes should be moved to separate headers in a subsequent
> operation
>
> The design uses templates to avoid any runtime overhead. All the calls are
> static.
>
> Signed-off-by: Christophe de Dinechin <dinechin at redhat.com>
> ---
> src/spice-streaming-agent.cpp | 250
> ++++++++++++++++++++----------------------
> 1 file changed, 117 insertions(+), 133 deletions(-)
>
> diff --git a/src/spice-streaming-agent.cpp b/src/spice-streaming-agent.cpp
> index a989ee7..c174ea4 100644
> --- a/src/spice-streaming-agent.cpp
> +++ b/src/spice-streaming-agent.cpp
> @@ -48,24 +48,6 @@ namespace spice
> namespace streaming_agent
> {
>
> -struct FormatMessage
> -{
> - StreamDevHeader hdr;
> - StreamMsgFormat msg;
> -};
> -
> -struct DataMessage
> -{
> - StreamDevHeader hdr;
> - StreamMsgData msg;
> -};
> -
> -struct CursorMessage
> -{
> - StreamDevHeader hdr;
> - StreamMsgCursorSet msg;
> -};
> -
> class Stream
> {
> public:
> @@ -79,24 +61,131 @@ public:
> {
> close(streamfd);
> }
> - operator int() { return streamfd; }
>
> int have_something_to_read(int timeout);
> int read_command_from_device(void);
> int read_command(bool blocking);
>
> +
> + template <typename Message, typename ...PayloadArgs>
> + bool send(PayloadArgs... payload)
> + {
> + Message message(payload...);
> + std::lock_guard<std::mutex> stream_guard(mutex);
> + size_t expected = message.size(payload...);
> + size_t written = message.write(*this, payload...);
> + return written == expected;
> + }
> +
> size_t write_all(const void *buf, const size_t len);
> - int send_format(unsigned w, unsigned h, uint8_t c);
> - int send_frame(const void *buf, const unsigned size);
> - void send_cursor(uint16_t width, uint16_t height,
> - uint16_t hotspot_x, uint16_t hotspot_y,
> - std::function<void(uint32_t *)> fill_cursor);
>
> private:
> int streamfd = -1;
> std::mutex mutex;
> };
>
> +
> +template <typename Payload, typename Info>
> +struct Message
> +{
> + template <typename ...PayloadArgs>
> + Message(PayloadArgs... payload)
> + : hdr(StreamDevHeader {
> + .protocol_version = STREAM_DEVICE_PROTOCOL,
> + .padding = 0, // Workaround GCC bug "sorry: not
> implemented"
> + .type = Info::type,
> + .size = (uint32_t) (Info::size(payload...) - sizeof(hdr))
> + }),
> + msg(Info::make(payload...))
> + { }
> +
> + StreamDevHeader hdr;
> + Payload msg;
style, no column indentation.
> +};
> +
> +
> +struct FormatMessage : Message<StreamMsgFormat, FormatMessage>
> +{
> + FormatMessage(unsigned w, unsigned h, uint8_t c) : Message(w, h, c) {}
> + static const StreamMsgType type = STREAM_TYPE_FORMAT;
> + static size_t size(unsigned width, unsigned height, uint8_t codec)
> + {
> + return sizeof(FormatMessage);
> + }
> + static StreamMsgFormat make(unsigned w, unsigned h, uint8_t c)
> + {
> + return StreamMsgFormat{ .width = w, .height = h, .codec = c,
> .padding1 = {} };
> + }
> + size_t write(Stream &stream, unsigned w, unsigned h, uint8_t c)
> + {
> + return stream.write_all(this, sizeof(*this));
> + }
> +};
> +
> +
> +struct FrameMessage : Message<StreamMsgData, FrameMessage>
> +{
> + FrameMessage(const void *frame, size_t length) : Message(frame, length)
> {}
> + static const StreamMsgType type = STREAM_TYPE_DATA;
> + static size_t size(const void *frame, size_t length)
> + {
> + return sizeof(FrameMessage) + length;
> + }
> + static StreamMsgData make(const void *frame, size_t length)
> + {
> + return StreamMsgData();
> + }
> + size_t write(Stream &stream, const void *frame, size_t length)
> + {
> + return stream.write_all(&hdr, sizeof(hdr)) + stream.write_all(frame,
> length);
> + }
> +};
> +
> +struct X11CursorMessage : Message<StreamMsgCursorSet, X11CursorMessage>
> +{
> + X11CursorMessage(XFixesCursorImage *cursor)
> + : Message(cursor),
> + pixels(new uint32_t[pixel_size(cursor)])
> + {
> + fill_pixels(cursor);
> + }
> + static const StreamMsgType type = STREAM_TYPE_CURSOR_SET;
> + static size_t pixel_size(XFixesCursorImage *cursor)
> + {
> + return cursor->width * cursor->height;
> + }
> + static size_t size(XFixesCursorImage *cursor)
> + {
> + return sizeof(X11CursorMessage) + sizeof(uint32_t) *
> pixel_size(cursor);
I think this is wrong as contains also the size of "pixels"
smart pointer.
Maybe you mean sizeof(Message<StreamMsgCursorSet, X11CursorMessage>) ?
> + }
> + static StreamMsgCursorSet make(XFixesCursorImage *cursor)
> + {
> + return StreamMsgCursorSet
> + {
> + .width = cursor->width,
> + .height = cursor->height,
> + .hot_spot_x = cursor->xhot,
> + .hot_spot_y = cursor->yhot,
> + .type = SPICE_CURSOR_TYPE_ALPHA,
> + .padding1 = { },
> + .data = { }
> + };
> + }
> + size_t write(Stream &stream, XFixesCursorImage *cursor)
> + {
> + return stream.write_all(&hdr, sizeof(hdr)) +
> stream.write_all(pixels.get(), hdr.size);
> + }
> + void fill_pixels(XFixesCursorImage *cursor)
> + {
> + uint32_t *pixbuf = pixels.get();
> + unsigned count = cursor->width * cursor->height;
you can reuse pixel_size here.
> + for (unsigned i = 0; i < count; ++i)
> + pixbuf[i] = cursor->pixels[i];
I know this is copied, would be best to fix and add brackets.
> + }
> +private:
> + std::unique_ptr<uint32_t[]> pixels;
> +};
> +
> }} // namespace spice::streaming_agent
>
>
> @@ -201,66 +290,6 @@ size_t Stream::write_all(const void *buf, const size_t
> len)
> return written;
> }
>
> -int Stream::send_format(unsigned w, unsigned h, uint8_t c)
> -{
> - const size_t msgsize = sizeof(FormatMessage);
> - const size_t hdrsize = sizeof(StreamDevHeader);
> - FormatMessage msg = {
> - .hdr = {
> - .protocol_version = STREAM_DEVICE_PROTOCOL,
> - .padding = 0, // Workaround GCC "not implemented" bug
> - .type = STREAM_TYPE_FORMAT,
> - .size = msgsize - hdrsize
> - },
> - .msg = {
> - .width = w,
> - .height = h,
> - .codec = c,
> - .padding1 = { }
> - }
> - };
> - syslog(LOG_DEBUG, "writing format\n");
> - std::lock_guard<std::mutex> stream_guard(mutex);
> - if (write_all(&msg, msgsize) != msgsize) {
> - return EXIT_FAILURE;
> - }
> - return EXIT_SUCCESS;
> -}
> -
> -int Stream::send_frame(const void *buf, const unsigned size)
> -{
> - ssize_t n;
> - const size_t msgsize = sizeof(FormatMessage);
> - DataMessage msg = {
> - .hdr = {
> - .protocol_version = STREAM_DEVICE_PROTOCOL,
> - .padding = 0, // Workaround GCC "not implemented" bug
> - .type = STREAM_TYPE_DATA,
> - .size = size /* includes only the body? */
> - },
> - .msg = {}
> - };
> -
> - std::lock_guard<std::mutex> stream_guard(mutex);
> - n = write_all(&msg, msgsize);
> - syslog(LOG_DEBUG,
> - "wrote %ld bytes of header of data msg with frame of size %u
> bytes\n",
> - n, msg.hdr.size);
> - if (n != msgsize) {
> - syslog(LOG_WARNING, "write_all header: wrote %ld expected %lu\n",
> - n, msgsize);
> - return EXIT_FAILURE;
> - }
> - n = write_all(buf, size);
> - syslog(LOG_DEBUG, "wrote data msg body of size %ld\n", n);
> - if (n != size) {
> - syslog(LOG_WARNING, "write_all header: wrote %ld expected %u\n",
> - n, size);
> - return EXIT_FAILURE;
> - }
> - return EXIT_SUCCESS;
> -}
> -
> /* returns current time in micro-seconds */
> static uint64_t get_time(void)
> {
> @@ -304,47 +333,6 @@ static void usage(const char *progname)
> exit(1);
> }
>
> -void
> -Stream::send_cursor(uint16_t width, uint16_t height,
> - uint16_t hotspot_x, uint16_t hotspot_y,
> - std::function<void(uint32_t *)> fill_cursor)
> -{
> - if (width >= STREAM_MSG_CURSOR_SET_MAX_WIDTH ||
> - height >= STREAM_MSG_CURSOR_SET_MAX_HEIGHT)
> - return;
> -
> - const uint32_t cursor_msgsize =
> - sizeof(CursorMessage) + width * height * sizeof(uint32_t);
> - const uint32_t hdrsize = sizeof(StreamDevHeader);
> -
> - std::unique_ptr<uint8_t[]> storage(new uint8_t[cursor_msgsize]);
> -
> - CursorMessage *cursor_msg =
> - new(storage.get()) CursorMessage {
> - .hdr = {
> - .protocol_version = STREAM_DEVICE_PROTOCOL,
> - .padding = 0, // Workaround GCC internal / not implemented
> compiler error
> - .type = STREAM_TYPE_CURSOR_SET,
> - .size = cursor_msgsize - hdrsize
> - },
> - .msg = {
> - .width = width,
> - .height = height,
> - .hot_spot_x = hotspot_x,
> - .hot_spot_y = hotspot_y,
> - .type = SPICE_CURSOR_TYPE_ALPHA,
> - .padding1 = { },
> - .data = { }
> - }
> - };
> -
> - uint32_t *pixels = reinterpret_cast<uint32_t *>(cursor_msg->msg.data);
> - fill_cursor(pixels);
> -
> - std::lock_guard<std::mutex> stream_guard(mutex);
> - write_all(storage.get(), cursor_msgsize);
> -}
> -
> static void cursor_changes(Stream *stream, Display *display, int event_base)
> {
> unsigned long last_serial = 0;
> @@ -363,12 +351,8 @@ static void cursor_changes(Stream *stream, Display
> *display, int event_base)
> continue;
>
> last_serial = cursor->cursor_serial;
> - auto fill_cursor = [cursor](uint32_t *pixels) {
> - for (unsigned i = 0; i < cursor->width * cursor->height; ++i)
> - pixels[i] = cursor->pixels[i];
> - };
> - stream->send_cursor(cursor->width, cursor->height,
> - cursor->xhot, cursor->yhot, fill_cursor);
> + if (!stream->send<X11CursorMessage>(cursor))
> + syslog(LOG_WARNING, "FAILED to send cursor\n");
brackets.
> }
> }
>
> @@ -422,7 +406,7 @@ do_capture(Stream &stream, const char *streamport, FILE
> *f_log)
>
> syslog(LOG_DEBUG, "wXh %uX%u codec=%u\n", width, height,
> codec);
>
> - if (stream.send_format(width, height, codec) ==
> EXIT_FAILURE)
> + if (!stream.send<FormatMessage>(width, height, codec))
> throw std::runtime_error("FAILED to send format
> message");
> }
> if (f_log) {
> @@ -434,7 +418,7 @@ do_capture(Stream &stream, const char *streamport, FILE
> *f_log)
> hexdump(frame.buffer, frame.buffer_size, f_log);
> }
> }
> - if (stream.send_frame(frame.buffer, frame.buffer_size) ==
> EXIT_FAILURE) {
> + if (!stream.send<FrameMessage>(frame.buffer, frame.buffer_size))
> {
> syslog(LOG_ERR, "FAILED to send a frame\n");
> break;
> }
Frediano
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