[Spice-devel] [PATCH 13/22] Convert message writing from C style to C++ style
Christophe de Dinechin
christophe at dinechin.org
Wed Feb 28 15:43:16 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
- Classes, FormatMessage, FrameMessage, CapabilitiesMessage and
X11CursorMessage represent individual messages
The various classes should be moved to separate headers in a
subsequent operation
The design uses the "curiously recurring template pattern" (CRTP) to
defer some of the code to a derived class. This is done to avoid
runtime overhead: all the calls are static.
Signed-off-by: Christophe de Dinechin <dinechin at redhat.com>
---
src/spice-streaming-agent.cpp | 279 +++++++++++++++++++-----------------------
1 file changed, 128 insertions(+), 151 deletions(-)
diff --git a/src/spice-streaming-agent.cpp b/src/spice-streaming-agent.cpp
index 23ee824..8bbd457 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
{
typedef std::set<SpiceVideoCodecType> codecs_t;
@@ -87,13 +69,17 @@ public:
const codecs_t &client_codecs() { return codecs; }
bool streaming_requested() { return is_streaming; }
+ template <typename Message, typename ...PayloadArgs>
+ void send(PayloadArgs... payload)
+ {
+ Message message(payload...);
+ std::lock_guard<std::mutex> stream_guard(mutex);
+ message.write_header(*this);
+ message.write_message_body(*this, payload...);
+ }
+
int read_command(bool blocking);
- 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);
+ void write_all(const char *operation, const void *buf, const size_t len);
private:
int have_something_to_read(int timeout);
@@ -109,6 +95,117 @@ private:
bool is_streaming = false;
};
+template <typename Payload, typename Info, unsigned Type>
+class Message
+{
+public:
+ template <typename ...PayloadArgs>
+ Message(PayloadArgs... payload)
+ : hdr(StreamDevHeader {
+ .protocol_version = STREAM_DEVICE_PROTOCOL,
+ .padding = 0, // Workaround GCC bug "sorry: not implemented"
+ .type = Type,
+ .size = (uint32_t) Info::size(payload...)
+ })
+ { }
+ void write_header(Stream &stream)
+ {
+ stream.write_all("header", &hdr, sizeof(hdr));
+ }
+
+protected:
+ StreamDevHeader hdr;
+ typedef Payload payload_t;
+};
+
+class FormatMessage : public Message<StreamMsgFormat, FormatMessage, STREAM_TYPE_FORMAT>
+{
+public:
+ FormatMessage(unsigned w, unsigned h, uint8_t c) : Message(w, h, c) {}
+ static size_t size(unsigned width, unsigned height, uint8_t codec)
+ {
+ return sizeof(payload_t);
+ }
+ void write_message_body(Stream &stream, unsigned w, unsigned h, uint8_t c)
+ {
+ StreamMsgFormat msg = { .width = w, .height = h, .codec = c, .padding1 = {} };
+ stream.write_all("format", &msg, sizeof(msg));
+ }
+};
+
+class FrameMessage : public Message<StreamMsgData, FrameMessage, STREAM_TYPE_DATA>
+{
+public:
+ FrameMessage(const void *frame, size_t length) : Message(frame, length) {}
+ static size_t size(const void *frame, size_t length)
+ {
+ return sizeof(payload_t) + length;
+ }
+ void write_message_body(Stream &stream, const void *frame, size_t length)
+ {
+ stream.write_all("frame", frame, length);
+ }
+};
+
+class CapabilitiesMessage : public Message<StreamMsgData, CapabilitiesMessage, STREAM_TYPE_CAPABILITIES>
+{
+public:
+ CapabilitiesMessage() : Message() {}
+ static size_t size()
+ {
+ return sizeof(payload_t);
+ }
+ void write_message_body(Stream &stream)
+ {
+ /* No body for capabilities message */
+ }
+};
+
+class X11CursorMessage : public Message<StreamMsgCursorSet, X11CursorMessage, STREAM_TYPE_CURSOR_SET>
+{
+public:
+ X11CursorMessage(XFixesCursorImage *cursor): Message(cursor) {}
+ static size_t size(XFixesCursorImage *cursor)
+ {
+ return sizeof(payload_t) + sizeof(uint32_t) * pixel_count(cursor);
+ }
+
+ void write_message_body(Stream &stream, XFixesCursorImage *cursor)
+ {
+ StreamMsgCursorSet msg = {
+ .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 pixcount = pixel_count(cursor);
+ size_t pixsize = pixcount * sizeof(uint32_t);
+ std::unique_ptr<uint32_t[]> pixels(new uint32_t[pixcount]);
+ uint32_t *pixbuf = pixels.get();
+ fill_pixels(cursor, pixcount, pixbuf);
+
+ stream.write_all("cursor message", &msg, sizeof(msg));
+ stream.write_all("cursor pixels", pixbuf, pixsize);
+ }
+
+private:
+ static size_t pixel_count(XFixesCursorImage *cursor)
+ {
+ return cursor->width * cursor->height;
+ }
+
+ void fill_pixels(XFixesCursorImage *cursor, unsigned count, uint32_t *pixbuf)
+ {
+ for (unsigned i = 0; i < count; ++i) {
+ pixbuf[i] = cursor->pixels[i];
+ }
+ }
+};
+
}} // namespace spice::streaming_agent
static bool quit_requested = false;
@@ -166,15 +263,7 @@ void Stream::handle_stream_capabilities(uint32_t len)
}
// we currently do not support extensions so just reply so
- StreamDevHeader hdr = {
- STREAM_DEVICE_PROTOCOL,
- 0,
- STREAM_TYPE_CAPABILITIES,
- 0
- };
- if (write_all(&hdr, sizeof(hdr)) != sizeof(hdr)) {
- throw std::runtime_error("error writing capabilities");
- }
+ send<CapabilitiesMessage>();
}
void Stream::handle_stream_error(uint32_t len)
@@ -228,7 +317,7 @@ int Stream::read_command(bool blocking)
return 1;
}
-size_t Stream::write_all(const void *buf, const size_t len)
+void Stream::write_all(const char *operation, const void *buf, const size_t len)
{
size_t written = 0;
while (written < len) {
@@ -237,73 +326,11 @@ size_t Stream::write_all(const void *buf, const size_t len)
if (errno == EINTR) {
continue;
}
- syslog(LOG_ERR, "write failed - %m");
- return l;
+ throw WriteError("write failed", operation, errno).syslog();
}
written += l;
}
- syslog(LOG_DEBUG, "write_all -- %u bytes written\n", (unsigned)written);
- 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;
+ syslog(LOG_DEBUG, "write_all -- %zu bytes written\n", written);
}
/* returns current time in micro-seconds */
@@ -350,46 +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 msgsize = sizeof(CursorMessage) + width * height * sizeof(uint32_t);
- const uint32_t hdrsize = sizeof(StreamDevHeader);
-
- std::unique_ptr<uint8_t[]> storage(new uint8_t[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 = 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(), msgsize);
-}
-
static void cursor_changes(Stream *stream, Display *display, int event_base)
{
unsigned long last_serial = 0;
@@ -411,12 +398,7 @@ static void cursor_changes(Stream *stream, Display *display, int event_base)
}
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);
+ stream->send<X11CursorMessage>(cursor);
}
}
@@ -471,9 +453,7 @@ 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) {
- throw std::runtime_error("FAILED to send format message");
- }
+ stream.send<FormatMessage>(width, height, codec);
}
if (f_log) {
if (log_binary) {
@@ -484,10 +464,7 @@ 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) {
- syslog(LOG_ERR, "FAILED to send a frame\n");
- break;
- }
+ stream.send<FrameMessage>(frame.buffer, frame.buffer_size);
//usleep(1);
if (stream.read_command(false) < 0) {
syslog(LOG_ERR, "FAILED to read command\n");
--
2.13.5 (Apple Git-94)
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