X-Git-Url: http://git.tdb.fi/?p=libs%2Fcore.git;a=blobdiff_plain;f=source%2Fio%2Fwindows%2Feventreader.cpp;fp=source%2Fio%2Fwindows%2Feventreader.cpp;h=62c9763d9fa92595385f658b36710d68087e09b8;hp=0000000000000000000000000000000000000000;hb=609c9a508cfdc7b42c46c4f21d17639204165a00;hpb=b4806214e905752617691f851717033fd3f266c2

diff --git a/source/io/windows/eventreader.cpp b/source/io/windows/eventreader.cpp
new file mode 100644
index 0000000..62c9763
--- /dev/null
+++ b/source/io/windows/eventreader.cpp
@@ -0,0 +1,115 @@
+#include <windows.h>
+#include <algorithm>
+#include <msp/core/systemerror.h>
+#include "eventreader.h"
+#include "handle_private.h"
+
+using namespace std;
+
+namespace Msp {
+namespace IO {
+
+struct EventReader::Private
+{
+	OVERLAPPED *overlapped;
+	Handle event;
+	unsigned buf_size;
+	char *buffer;
+	unsigned buf_avail;
+	char *buf_next;
+};
+
+
+EventReader::EventReader(Handle &h, unsigned size):
+	handle(h),
+	priv(new Private)
+{
+	priv->overlapped = 0;
+	*priv->event = CreateEvent(0, true, false, 0);
+	priv->buf_size = size;
+	priv->buffer = new char[priv->buf_size];
+	priv->buf_avail = 0;
+	priv->buf_next = priv->buffer;
+}
+
+EventReader::~EventReader()
+{
+	CloseHandle(*priv->event);
+	delete priv->overlapped;
+	delete[] priv->buffer;
+	delete priv;
+}
+
+const Handle &EventReader::get_event()
+{
+	start();
+	return priv->event;
+}
+
+void EventReader::start()
+{
+	if(priv->buf_avail || priv->overlapped)
+		return;
+
+	priv->overlapped = new OVERLAPPED;
+	memset(priv->overlapped, 0, sizeof(OVERLAPPED));
+	priv->overlapped->hEvent = *priv->event;
+
+	DWORD ret;
+	priv->buf_next = priv->buffer;
+	if(!ReadFile(*handle, priv->buffer, priv->buf_size, &ret, priv->overlapped))
+	{
+		unsigned err = GetLastError();
+		if(err!=ERROR_IO_PENDING)
+			throw system_error("ReadFile");
+	}
+	else
+	{
+		priv->buf_avail = ret;
+		delete priv->overlapped;
+		priv->overlapped = 0;
+		SetEvent(*priv->event);
+	}
+}
+
+void EventReader::wait()
+{
+	if(!priv->overlapped)
+		return;
+
+	DWORD ret;
+	if(!GetOverlappedResult(*handle, priv->overlapped, &ret, true))
+		throw system_error("GetOverlappedResult");
+	else
+	{
+		priv->buf_avail = ret;
+		delete priv->overlapped;
+		priv->overlapped = 0;
+	}
+}
+
+unsigned EventReader::read(char *buf, unsigned len)
+{
+	if(!priv->buf_avail)
+	{
+		// No data in buffer, try to get some
+		start();
+		wait();
+	}
+
+	len = min(len, priv->buf_avail);
+	memcpy(buf, priv->buf_next, len);
+	priv->buf_next += len;
+	priv->buf_avail -= len;
+
+	if(!priv->buf_avail)
+	{
+		ResetEvent(*priv->event);
+		start();
+	}
+
+	return len;
+}
+
+} // namespace IO
+} // namespace Msp