[Spice-devel] [PATCH v2 12/24] Convert message writing from C style to C++ style
Christophe de Dinechin
christophe at dinechin.org
Wed Feb 21 17:46:24 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 | 255 ++++++++++++++++++++----------------------
1 file changed, 122 insertions(+), 133 deletions(-)
diff --git a/src/spice-streaming-agent.cpp b/src/spice-streaming-agent.cpp
index 9f4183c..85d055b 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:
@@ -79,7 +61,6 @@ public:
{
close(streamfd);
}
- operator int() { return streamfd; }
int have_something_to_read(int timeout);
void handle_stream_start_stop(uint32_t len);
@@ -88,18 +69,131 @@ public:
void 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;
+ typedef Message message_t; // Used to compute sizes easily
+};
+
+
+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(message_t);
+ }
+ 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(message_t));
+ }
+};
+
+
+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(message_t) + 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(this, sizeof(message_t))
+ + stream.write_all(frame, length);
+ }
+};
+
+struct X11CursorMessage : Message<StreamMsgCursorSet, X11CursorMessage>
+{
+ X11CursorMessage(XFixesCursorImage *cursor)
+ : Message(cursor),
+ pixels(new uint32_t[pixel_count(cursor)])
+ {
+ fill_pixels(cursor);
+ }
+ static const StreamMsgType type = STREAM_TYPE_CURSOR_SET;
+ static size_t pixel_count(XFixesCursorImage *cursor)
+ {
+ return cursor->width * cursor->height;
+ }
+ static size_t size(XFixesCursorImage *cursor)
+ {
+ return sizeof(message_t) + sizeof(uint32_t) * pixel_count(cursor);
+ }
+ 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)
+ {
+ unsigned pixel_size = pixel_count(cursor) * sizeof(uint32_t);
+ return stream.write_all(this, sizeof(message_t))
+ + stream.write_all(pixels.get(), pixel_size);
+ }
+ void fill_pixels(XFixesCursorImage *cursor)
+ {
+ uint32_t *pixbuf = pixels.get();
+ unsigned count = pixel_count(cursor);
+ for (unsigned i = 0; i < count; ++i) {
+ pixbuf[i] = cursor->pixels[i];
+ }
+ }
+private:
+ std::unique_ptr<uint32_t[]> pixels;
+};
+
}} // namespace spice::streaming_agent
@@ -240,66 +334,6 @@ 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)
{
@@ -343,47 +377,6 @@ 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;
@@ -402,12 +395,8 @@ 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");
}
}
@@ -461,7 +450,7 @@ 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) {
@@ -473,7 +462,7 @@ 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;
}
--
2.13.5 (Apple Git-94)
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