Overload createFile function, expose File in memory_map struct, delete from memory_map map on delete

weed/storage/volume_create_windows.go

@@ -0,0 +1,30 @@
+// +build windows
+
+package storage
+
+import (
+	"os"
+
+	"github.com/joeslay/seaweedfs/weed/storage/memory_map"
+	"golang.org/x/sys/windows"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/joeslay/seaweedfs/weed/os_overloads"
+)
+
+func createVolumeFile(fileName string, preallocate int64) (*os.File, error) {
+
+	mem_map, exists := memory_map.FileMemoryMap[fileName]
+	if !exists {
+		file, e := os_overloads.OpenFile(fileName, windows.O_RDWR|windows.O_CREAT, 0644, true)
+		new_mem_map := memory_map.CreateMemoryMap(file, 2^32)
+		memory_map.FileMemoryMap[fileName] = new_mem_map
+
+		if preallocate > 0 {
+			glog.V(0).Infof("Preallocated disk space for %s is not supported", fileName)
+		}
+		return file, e
+	} else {
+		return mem_map.File, nil
+	}
+}