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

   1 package hotline
   2
   3 import (
   4         "bytes"
   5         "encoding/binary"
   6         "errors"
   7         "fmt"
   8         "io"
   9         "io/fs"
  10         "os"
  11         "path/filepath"
  12 )
  13
  14 const (
  15         incompleteFileSuffix = ".incomplete"
  16         infoForkNameTemplate = ".info_%s" // template string for info fork filenames
  17         rsrcForkNameTemplate = ".rsrc_%s" // template string for resource fork filenames
  18 )
  19
  20 // fileWrapper encapsulates the data, info, and resource forks of a Hotline file and provides methods to manage the files.
  21 type fileWrapper struct {
  22         fs             FileStore
  23         name           string // name of the file
  24         path           string // path to file directory
  25         dataPath       string // path to the file data fork
  26         dataOffset     int64
  27         rsrcPath       string // path to the file resource fork
  28         infoPath       string // path to the file information fork
  29         incompletePath string // path to partially transferred temp file
  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|os.O_TRUNC, 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 meta files to newPath.
 154 // Meta files include:
 155 // * Partially uploaded file ending with .incomplete
 156 // * Resource fork starting with .rsrc_
 157 // * Info fork starting with .info
 158 // During move of the meta files, os.ErrNotExist is ignored as these files may legitimately not exist.
 159 func (f *fileWrapper) move(newPath string) error {
 160         err := f.fs.Rename(f.dataPath, filepath.Join(newPath, f.name))
 161         if err != nil {
 162                 return err
 163         }
 164
 165         err = f.fs.Rename(f.incompletePath, filepath.Join(newPath, f.incompleteDataName()))
 166         if err != nil && !errors.Is(err, os.ErrNotExist) {
 167                 return err
 168         }
 169
 170         err = f.fs.Rename(f.rsrcPath, filepath.Join(newPath, f.rsrcForkName()))
 171         if err != nil && !errors.Is(err, os.ErrNotExist) {
 172                 return err
 173         }
 174
 175         err = f.fs.Rename(f.infoPath, filepath.Join(newPath, f.infoForkName()))
 176         if err != nil && !errors.Is(err, os.ErrNotExist) {
 177                 return err
 178         }
 179
 180         return nil
 181 }
 182
 183 // delete a fileWrapper and its associated metadata files if they exist
 184 func (f *fileWrapper) delete() error {
 185         err := f.fs.RemoveAll(f.dataPath)
 186         if err != nil {
 187                 return err
 188         }
 189
 190         err = f.fs.Remove(f.incompletePath)
 191         if err != nil && !errors.Is(err, os.ErrNotExist) {
 192                 return err
 193         }
 194
 195         err = f.fs.Remove(f.rsrcPath)
 196         if err != nil && !errors.Is(err, os.ErrNotExist) {
 197                 return err
 198         }
 199
 200         err = f.fs.Remove(f.infoPath)
 201         if err != nil && !errors.Is(err, os.ErrNotExist) {
 202                 return err
 203         }
 204
 205         return nil
 206 }
 207
 208 func (f *fileWrapper) flattenedFileObject() (*flattenedFileObject, error) {
 209         dataSize := make([]byte, 4)
 210         mTime := [8]byte{}
 211
 212         ft := defaultFileType
 213
 214         fileInfo, err := f.fs.Stat(f.dataPath)
 215         if err != nil && !errors.Is(err, fs.ErrNotExist) {
 216                 return nil, err
 217         }
 218         if errors.Is(err, fs.ErrNotExist) {
 219                 fileInfo, err = f.fs.Stat(f.incompletePath)
 220                 if err == nil {
 221                         mTime = toHotlineTime(fileInfo.ModTime())
 222                         binary.BigEndian.PutUint32(dataSize, uint32(fileInfo.Size()-f.dataOffset))
 223                         ft, _ = fileTypeFromInfo(fileInfo)
 224                 }
 225         } else {
 226                 mTime = toHotlineTime(fileInfo.ModTime())
 227                 binary.BigEndian.PutUint32(dataSize, uint32(fileInfo.Size()-f.dataOffset))
 228                 ft, _ = fileTypeFromInfo(fileInfo)
 229         }
 230
 231         f.ffo.FlatFileHeader = FlatFileHeader{
 232                 Format:    [4]byte{0x46, 0x49, 0x4c, 0x50}, // "FILP"
 233                 Version:   [2]byte{0, 1},
 234                 RSVD:      [16]byte{},
 235                 ForkCount: [2]byte{0, 2},
 236         }
 237
 238         _, err = f.fs.Stat(f.infoPath)
 239         if err == nil {
 240                 b, err := f.fs.ReadFile(f.infoPath)
 241                 if err != nil {
 242                         return nil, err
 243                 }
 244
 245                 f.ffo.FlatFileHeader.ForkCount[1] = 3
 246
 247                 _, err = io.Copy(&f.ffo.FlatFileInformationFork, bytes.NewReader(b))
 248                 if err != nil {
 249                         return nil, fmt.Errorf("error copying FlatFileInformationFork: %w", err)
 250                 }
 251         } else {
 252                 f.ffo.FlatFileInformationFork = FlatFileInformationFork{
 253                         Platform:         [4]byte{0x41, 0x4D, 0x41, 0x43}, // "AMAC" TODO: Remove hardcode to support "AWIN" Platform (maybe?)
 254                         TypeSignature:    [4]byte([]byte(ft.TypeCode)),
 255                         CreatorSignature: [4]byte([]byte(ft.CreatorCode)),
 256                         PlatformFlags:    [4]byte{0, 0, 1, 0}, // TODO: What is this?
 257                         CreateDate:       mTime,               // some filesystems don't support createTime
 258                         ModifyDate:       mTime,
 259                         Name:             []byte(f.name),
 260                         Comment:          []byte{},
 261                 }
 262
 263                 ns := make([]byte, 2)
 264                 binary.BigEndian.PutUint16(ns, uint16(len(f.name)))
 265                 f.ffo.FlatFileInformationFork.NameSize = [2]byte(ns[:])
 266         }
 267
 268         f.ffo.FlatFileInformationForkHeader = FlatFileForkHeader{
 269                 ForkType:        [4]byte{0x49, 0x4E, 0x46, 0x4F}, // "INFO"
 270                 CompressionType: [4]byte{},
 271                 RSVD:            [4]byte{},
 272                 DataSize:        f.ffo.FlatFileInformationFork.Size(),
 273         }
 274
 275         f.ffo.FlatFileDataForkHeader = FlatFileForkHeader{
 276                 ForkType:        [4]byte{0x44, 0x41, 0x54, 0x41}, // "DATA"
 277                 CompressionType: [4]byte{},
 278                 RSVD:            [4]byte{},
 279                 DataSize:        [4]byte{dataSize[0], dataSize[1], dataSize[2], dataSize[3]},
 280         }
 281         f.ffo.FlatFileResForkHeader = f.rsrcForkHeader()
 282
 283         return f.ffo, nil
 284 }