diff options
| -rw-r--r-- | weed/storage/memory_map_windows.go | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/weed/storage/memory_map_windows.go b/weed/storage/memory_map_windows.go new file mode 100644 index 000000000..a6c96caaf --- /dev/null +++ b/weed/storage/memory_map_windows.go @@ -0,0 +1,216 @@ +// +build windows + +package storage + +import ( + "reflect" + "syscall" + "unsafe" + + "golang.org/x/sys/windows" +) + +type DWORD = uint32 +type WORD = uint16 + +type memory_buffer struct { + aligned_length uint64 + length uint64 + aligned_ptr uintptr + ptr uintptr + buffer []byte +} + +type memory_map struct { + file_handle windows.Handle + file_memory_map_handle windows.Handle + write_map_views []memory_buffer + max_length uint64 + // read_map_views []memory_buffer +} + +var ( + procGetSystemInfo = syscall.NewLazyDLL("kernel32.dll").NewProc("GetSystemInfo") +) + +var system_info, err = getSystemInfo() + +var chunk_size = uint64(system_info.dwAllocationGranularity) * 512 + +func CreateMemoryMap(hFile windows.Handle, maxlength uint64) memory_map { + + mem_map := memory_map{} + maxlength_high := uint32(maxlength >> 32) + maxlength_low := uint32(maxlength & 0xFFFFFFFF) + file_memory_map_handle, err := windows.CreateFileMapping(hFile, nil, windows.PAGE_READWRITE, maxlength_high, maxlength_low, nil) + + if err != nil { + mem_map.file_handle = hFile + mem_map.file_memory_map_handle = file_memory_map_handle + mem_map.max_length = maxlength + } + + return mem_map +} + +func DeleteFileAndMemoryMap(mem_map memory_map) { + windows.CloseHandle(mem_map.file_memory_map_handle) + windows.CloseHandle(mem_map.file_handle) + + for _, view := range mem_map.write_map_views { + ReleaseMemory(view) + } + + mem_map.write_map_views = nil + mem_map.max_length = 0 +} + +func min(x, y uint64) uint64 { + if x < y { + return x + } + return y +} + +func WriteMemory(mem_map memory_map, offset uint64, length uint64, data []byte) { + + for { + if ((offset+length)/chunk_size)+1 > uint64(len(mem_map.write_map_views)) { + allocateChunk(mem_map) + } else { + break + } + } + + remaining_length := length + slice_index := offset / chunk_size + slice_offset := offset - (slice_index * chunk_size) + data_offset := uint64(0) + + for { + write_end := min(remaining_length, chunk_size) + copy(mem_map.write_map_views[slice_index].buffer[slice_offset:write_end], data[data_offset:]) + remaining_length -= (write_end - slice_offset) + data_offset += (write_end - slice_offset) + + if remaining_length > 0 { + slice_index += 1 + slice_offset = 0 + } else { + break + } + } +} + +func ReadMemory(mem_map memory_map, offset uint64, length uint64) (memory_buffer, error) { + return allocate(mem_map.file_memory_map_handle, offset, length, false) +} + +func ReleaseMemory(mem_buffer memory_buffer) { + windows.UnmapViewOfFile(mem_buffer.aligned_ptr) + + mem_buffer.ptr = 0 + mem_buffer.aligned_ptr = 0 + mem_buffer.length = 0 + mem_buffer.aligned_length = 0 + mem_buffer.buffer = nil +} + +func allocateChunk(mem_map memory_map) { + + start := uint64(len(mem_map.write_map_views)-1) * chunk_size + mem_buffer, err := allocate(mem_map.file_memory_map_handle, start, chunk_size, true) + + if err == nil { + mem_map.write_map_views = append(mem_map.write_map_views, mem_buffer) + } +} + +func allocate(hMapFile windows.Handle, offset uint64, length uint64, write bool) (memory_buffer, error) { + + mem_buffer := memory_buffer{} + + dwSysGran := system_info.dwAllocationGranularity + + start := (offset / uint64(dwSysGran)) * uint64(dwSysGran) + diff := offset - start + aligned_length := diff + length + + offset_high := uint32(start >> 32) + offset_low := uint32(start & 0xFFFFFFFF) + + access := windows.FILE_MAP_READ + + if write { + access = windows.FILE_MAP_WRITE + } + + addr_ptr, errno := windows.MapViewOfFile(hMapFile, + uint32(access), // read/write permission + offset_high, + offset_low, + uintptr(aligned_length)) + + if addr_ptr == 0 { + return mem_buffer, errno + } + + mem_buffer.aligned_ptr = addr_ptr + mem_buffer.aligned_length = aligned_length + mem_buffer.ptr = addr_ptr + uintptr(diff) + mem_buffer.length = length + + slice_header := (*reflect.SliceHeader)(unsafe.Pointer(&mem_buffer.buffer)) + slice_header.Data = addr_ptr + uintptr(diff) + slice_header.Len = int(length) + slice_header.Cap = int(length) + + return mem_buffer, nil +} + +// typedef struct _SYSTEM_INFO { +// union { +// DWORD dwOemId; +// struct { +// WORD wProcessorArchitecture; +// WORD wReserved; +// }; +// }; +// DWORD dwPageSize; +// LPVOID lpMinimumApplicationAddress; +// LPVOID lpMaximumApplicationAddress; +// DWORD_PTR dwActiveProcessorMask; +// DWORD dwNumberOfProcessors; +// DWORD dwProcessorType; +// DWORD dwAllocationGranularity; +// WORD wProcessorLevel; +// WORD wProcessorRevision; +// } SYSTEM_INFO; +// https://msdn.microsoft.com/en-us/library/ms724958(v=vs.85).aspx +type _SYSTEM_INFO struct { + dwOemId DWORD + dwPageSize DWORD + lpMinimumApplicationAddress uintptr + lpMaximumApplicationAddress uintptr + dwActiveProcessorMask uintptr + dwNumberOfProcessors DWORD + dwProcessorType DWORD + dwAllocationGranularity DWORD + wProcessorLevel WORD + wProcessorRevision WORD +} + +// void WINAPI GetSystemInfo( +// _Out_ LPSYSTEM_INFO lpSystemInfo +// ); +// https://msdn.microsoft.com/en-us/library/ms724381(VS.85).aspx +func getSystemInfo() (_SYSTEM_INFO, error) { + var si _SYSTEM_INFO + _, _, err := procGetSystemInfo.Call( + uintptr(unsafe.Pointer(&si)), + ) + if err != syscall.Errno(0) { + return si, err + } + return si, nil +} |