Move most platform-specific code into overlay directories

[libs/core.git] / source / io / windows / seekable.cpp

diff --git a/source/io/windows/seekable.cpp b/source/io/windows/seekable.cpp
new file mode 100644 (file)
index 0000000..73c5cc5
--- /dev/null
+++ b/source/io/windows/seekable.cpp
@@ -0,0 +1,45 @@
+#include <windows.h>
+#include <msp/core/systemerror.h>
+#include "handle.h"
+#include "handle_private.h"
+#include "seekable.h"
+
+using namespace std;
+
+namespace {
+
+using namespace Msp::IO;
+
+int sys_seek_type(SeekType st)
+{
+       if(st==S_BEG)
+               return FILE_BEGIN;
+       else if(st==S_CUR)
+               return FILE_CURRENT;
+       else if(st==S_END)
+               return FILE_END;
+
+       throw invalid_argument("sys_seek_type");
+}
+
+}
+
+namespace Msp {
+namespace IO {
+
+SeekOffset sys_seek(Handle &handle, SeekOffset offset, SeekType type)
+{
+       LONG high = offset>>32;
+       DWORD ret = SetFilePointer(*handle, offset, &high, sys_seek_type(type));
+       if(ret==INVALID_SET_FILE_POINTER)
+       {
+               DWORD err = GetLastError();
+               if(err!=NO_ERROR)
+                       throw system_error("SetFilePointer");
+       }
+
+       return (SeekOffset(high)<<32) | ret;
+}
+
+} // namespace IO
+} // namespace Msp