git.r.bdr.sh - rbdr/mobius/blob - hotline/file_wrapper.go

   1 package hotline
   2
   3 import (
   4         "encoding/binary"
   5         "errors"
   6         "fmt"
   7         "io"
   8         "io/fs"
   9         "os"
  10         "path/filepath"
  11 )
  12
  13 const (
  14         incompleteFileSuffix = ".incomplete"
  15         infoForkNameTemplate = ".info_%s" // template string for info fork filenames
  16         rsrcForkNameTemplate = ".rsrc_%s" // template string for resource fork filenames
  17 )
  18
  19 // fileWrapper encapsulates the data, info, and resource forks of a Hotline file and provides methods to manage the files.
  20 type fileWrapper struct {
  21         fs             FileStore
  22         name           string // name of the file
  23         path           string // path to file directory
  24         dataPath       string // path to the file data fork
  25         dataOffset     int64
  26         rsrcPath       string // path to the file resource fork
  27         infoPath       string // path to the file information fork
  28         incompletePath string // path to partially transferred temp file
  29         infoFork       *FlatFileInformationFork
  30         ffo            *flattenedFileObject
  31 }
  32
  33 func newFileWrapper(fs FileStore, path string, dataOffset int64) (*fileWrapper, error) {
  34         dir := filepath.Dir(path)
  35         fName := filepath.Base(path)
  36         f := fileWrapper{
  37                 fs:             fs,
  38                 name:           fName,
  39                 path:           dir,
  40                 dataPath:       path,
  41                 dataOffset:     dataOffset,
  42                 rsrcPath:       filepath.Join(dir, fmt.Sprintf(rsrcForkNameTemplate, fName)),
  43                 infoPath:       filepath.Join(dir, fmt.Sprintf(infoForkNameTemplate, fName)),
  44                 incompletePath: filepath.Join(dir, fName+incompleteFileSuffix),
  45                 ffo:            &flattenedFileObject{},
  46         }
  47
  48         var err error
  49         f.ffo, err = f.flattenedFileObject()
  50         if err != nil {
  51                 return nil, err
  52         }
  53
  54         return &f, nil
  55 }
  56
  57 func (f *fileWrapper) totalSize() []byte {
  58         var s int64
  59         size := make([]byte, 4)
  60
  61         info, err := f.fs.Stat(f.dataPath)
  62         if err == nil {
  63                 s += info.Size() - f.dataOffset
  64         }
  65
  66         info, err = f.fs.Stat(f.rsrcPath)
  67         if err == nil {
  68                 s += info.Size()
  69         }
  70
  71         binary.BigEndian.PutUint32(size, uint32(s))
  72
  73         return size
  74 }
  75
  76 func (f *fileWrapper) rsrcForkSize() (s [4]byte) {
  77         info, err := f.fs.Stat(f.rsrcPath)
  78         if err != nil {
  79                 return s
  80         }
  81
  82         binary.BigEndian.PutUint32(s[:], uint32(info.Size()))
  83         return s
  84 }
  85
  86 func (f *fileWrapper) rsrcForkHeader() FlatFileForkHeader {
  87         return FlatFileForkHeader{
  88                 ForkType:        [4]byte{0x4D, 0x41, 0x43, 0x52}, // "MACR"
  89                 CompressionType: [4]byte{},
  90                 RSVD:            [4]byte{},
  91                 DataSize:        f.rsrcForkSize(),
  92         }
  93 }
  94
  95 func (f *fileWrapper) incompleteDataName() string {
  96         return f.name + incompleteFileSuffix
  97 }
  98
  99 func (f *fileWrapper) rsrcForkName() string {
 100         return fmt.Sprintf(rsrcForkNameTemplate, f.name)
 101 }
 102
 103 func (f *fileWrapper) infoForkName() string {
 104         return fmt.Sprintf(infoForkNameTemplate, f.name)
 105 }
 106
 107 func (f *fileWrapper) rsrcForkWriter() (io.WriteCloser, error) {
 108         file, err := os.OpenFile(f.rsrcPath, os.O_CREATE|os.O_WRONLY, 0644)
 109         if err != nil {
 110                 return nil, err
 111         }
 112
 113         return file, nil
 114 }
 115
 116 func (f *fileWrapper) infoForkWriter() (io.WriteCloser, error) {
 117         file, err := os.OpenFile(f.infoPath, os.O_CREATE|os.O_WRONLY, 0644)
 118         if err != nil {
 119                 return nil, err
 120         }
 121
 122         return file, nil
 123 }
 124
 125 func (f *fileWrapper) incFileWriter() (io.WriteCloser, error) {
 126         file, err := os.OpenFile(f.incompletePath, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
 127         if err != nil {
 128                 return nil, err
 129         }
 130
 131         return file, nil
 132 }
 133
 134 func (f *fileWrapper) dataForkReader() (io.Reader, error) {
 135         return f.fs.Open(f.dataPath)
 136 }
 137
 138 func (f *fileWrapper) rsrcForkFile() (*os.File, error) {
 139         return f.fs.Open(f.rsrcPath)
 140 }
 141
 142 func (f *fileWrapper) dataFile() (os.FileInfo, error) {
 143         if fi, err := f.fs.Stat(f.dataPath); err == nil {
 144                 return fi, nil
 145         }
 146         if fi, err := f.fs.Stat(f.incompletePath); err == nil {
 147                 return fi, nil
 148         }
 149
 150         return nil, errors.New("file or directory not found")
 151 }
 152
 153 // move a fileWrapper and its associated metadata files to newPath
 154 func (f *fileWrapper) move(newPath string) error {
 155         err := f.fs.Rename(f.dataPath, filepath.Join(newPath, f.name))
 156         if err != nil {
 157                 // TODO
 158         }
 159
 160         err = f.fs.Rename(f.incompletePath, filepath.Join(newPath, f.incompleteDataName()))
 161         if err != nil {
 162                 // TODO
 163         }
 164
 165         err = f.fs.Rename(f.rsrcPath, filepath.Join(newPath, f.rsrcForkName()))
 166         if err != nil {
 167                 // TODO
 168         }
 169
 170         err = f.fs.Rename(f.infoPath, filepath.Join(newPath, f.infoForkName()))
 171         if err != nil {
 172                 // TODO
 173         }
 174
 175         return nil
 176 }
 177
 178 // delete a fileWrapper and its associated metadata files if they exist
 179 func (f *fileWrapper) delete() error {
 180         err := f.fs.RemoveAll(f.dataPath)
 181         if err != nil {
 182                 // TODO
 183         }
 184
 185         err = f.fs.Remove(f.incompletePath)
 186         if err != nil {
 187                 // TODO
 188         }
 189
 190         err = f.fs.Remove(f.rsrcPath)
 191         if err != nil {
 192                 // TODO
 193         }
 194
 195         err = f.fs.Remove(f.infoPath)
 196         if err != nil {
 197                 // TODO
 198         }
 199
 200         return nil
 201 }
 202
 203 func (f *fileWrapper) flattenedFileObject() (*flattenedFileObject, error) {
 204         dataSize := make([]byte, 4)
 205         mTime := make([]byte, 8)
 206
 207         ft := defaultFileType
 208
 209         fileInfo, err := f.fs.Stat(f.dataPath)
 210         if err != nil && !errors.Is(err, fs.ErrNotExist) {
 211                 return nil, err
 212         }
 213         if errors.Is(err, fs.ErrNotExist) {
 214                 fileInfo, err = f.fs.Stat(f.incompletePath)
 215                 if err == nil {
 216                         mTime = toHotlineTime(fileInfo.ModTime())
 217                         binary.BigEndian.PutUint32(dataSize, uint32(fileInfo.Size()-f.dataOffset))
 218                         ft, _ = fileTypeFromInfo(fileInfo)
 219                 }
 220         } else {
 221                 mTime = toHotlineTime(fileInfo.ModTime())
 222                 binary.BigEndian.PutUint32(dataSize, uint32(fileInfo.Size()-f.dataOffset))
 223                 ft, _ = fileTypeFromInfo(fileInfo)
 224         }
 225
 226         f.ffo.FlatFileHeader = FlatFileHeader{
 227                 Format:    [4]byte{0x46, 0x49, 0x4c, 0x50}, // "FILP"
 228                 Version:   [2]byte{0, 1},
 229                 RSVD:      [16]byte{},
 230                 ForkCount: [2]byte{0, 2},
 231         }
 232
 233         _, err = f.fs.Stat(f.infoPath)
 234         if err == nil {
 235                 b, err := f.fs.ReadFile(f.infoPath)
 236                 if err != nil {
 237                         return nil, err
 238                 }
 239
 240                 f.ffo.FlatFileHeader.ForkCount[1] = 3
 241
 242                 if err := f.ffo.FlatFileInformationFork.UnmarshalBinary(b); err != nil {
 243                         return nil, err
 244                 }
 245         } else {
 246                 f.ffo.FlatFileInformationFork = FlatFileInformationFork{
 247                         Platform:         []byte("AMAC"), // TODO: Remove hardcode to support "AWIN" Platform (maybe?)
 248                         TypeSignature:    []byte(ft.TypeCode),
 249                         CreatorSignature: []byte(ft.CreatorCode),
 250                         Flags:            []byte{0, 0, 0, 0},
 251                         PlatformFlags:    []byte{0, 0, 1, 0}, // TODO: What is this?
 252                         RSVD:             make([]byte, 32),
 253                         CreateDate:       mTime, // some filesystems don't support createTime
 254                         ModifyDate:       mTime,
 255                         NameScript:       []byte{0, 0},
 256                         Name:             []byte(f.name),
 257                         NameSize:         []byte{0, 0},
 258                         CommentSize:      []byte{0, 0},
 259                         Comment:          []byte{},
 260                 }
 261                 binary.BigEndian.PutUint16(f.ffo.FlatFileInformationFork.NameSize, uint16(len(f.name)))
 262         }
 263
 264         f.ffo.FlatFileInformationForkHeader = FlatFileForkHeader{
 265                 ForkType:        [4]byte{0x49, 0x4E, 0x46, 0x4F}, // "INFO"
 266                 CompressionType: [4]byte{},
 267                 RSVD:            [4]byte{},
 268                 DataSize:        f.ffo.FlatFileInformationFork.Size(),
 269         }
 270
 271         f.ffo.FlatFileDataForkHeader = FlatFileForkHeader{
 272                 ForkType:        [4]byte{0x44, 0x41, 0x54, 0x41}, // "DATA"
 273                 CompressionType: [4]byte{},
 274                 RSVD:            [4]byte{},
 275                 DataSize:        [4]byte{dataSize[0], dataSize[1], dataSize[2], dataSize[3]},
 276         }
 277         f.ffo.FlatFileResForkHeader = f.rsrcForkHeader()
 278
 279         return f.ffo, nil
 280 }