| package bolt |
| |
| import ( |
| "fmt" |
| "os" |
| "syscall" |
| "time" |
| "unsafe" |
| ) |
| |
| var odirect int |
| |
| // fdatasync flushes written data to a file descriptor. |
| func fdatasync(db *DB) error { |
| return db.file.Sync() |
| } |
| |
| // flock acquires an advisory lock on a file descriptor. |
| func flock(f *os.File, _ time.Duration) error { |
| return nil |
| } |
| |
| // funlock releases an advisory lock on a file descriptor. |
| func funlock(f *os.File) error { |
| return nil |
| } |
| |
| // mmap memory maps a DB's data file. |
| // Based on: https://github.com/edsrzf/mmap-go |
| func mmap(db *DB, sz int) error { |
| // Truncate the database to the size of the mmap. |
| if err := db.file.Truncate(int64(sz)); err != nil { |
| return fmt.Errorf("truncate: %s", err) |
| } |
| |
| // Open a file mapping handle. |
| sizelo := uint32(sz >> 32) |
| sizehi := uint32(sz) & 0xffffffff |
| h, errno := syscall.CreateFileMapping(syscall.Handle(db.file.Fd()), nil, syscall.PAGE_READONLY, sizelo, sizehi, nil) |
| if h == 0 { |
| return os.NewSyscallError("CreateFileMapping", errno) |
| } |
| |
| // Create the memory map. |
| addr, errno := syscall.MapViewOfFile(h, syscall.FILE_MAP_READ, 0, 0, uintptr(sz)) |
| if addr == 0 { |
| return os.NewSyscallError("MapViewOfFile", errno) |
| } |
| |
| // Close mapping handle. |
| if err := syscall.CloseHandle(syscall.Handle(h)); err != nil { |
| return os.NewSyscallError("CloseHandle", err) |
| } |
| |
| // Convert to a byte array. |
| db.data = ((*[maxMapSize]byte)(unsafe.Pointer(addr))) |
| db.datasz = sz |
| |
| return nil |
| } |
| |
| // munmap unmaps a pointer from a file. |
| // Based on: https://github.com/edsrzf/mmap-go |
| func munmap(db *DB) error { |
| if db.data == nil { |
| return nil |
| } |
| |
| addr := (uintptr)(unsafe.Pointer(&db.data[0])) |
| if err := syscall.UnmapViewOfFile(addr); err != nil { |
| return os.NewSyscallError("UnmapViewOfFile", err) |
| } |
| return nil |
| } |