| 283 | } |
| 284 | |
| 285 | func (df *DataFile) readHeader() error { |
| 286 | header := DataFileHeader{} |
| 287 | |
| 288 | b := make([]byte, HEADER_SIZE) |
| 289 | n, err := df.file.ReadAt(b, 0) |
| 290 | if err != nil { |
| 291 | return err |
| 292 | } |
| 293 | if n != int(HEADER_SIZE) { |
| 294 | return fmt.Errorf("not full header read") |
| 295 | } |
| 296 | |
| 297 | buf := bytes.NewBuffer(b) |
| 298 | if err := binary.Read(buf, binary.BigEndian, &header.magic); err != nil { |
| 299 | return err |
| 300 | } |
| 301 | if err := binary.Read(buf, binary.BigEndian, &header.version); err != nil { |
| 302 | return err |
| 303 | } |
| 304 | if err := binary.Read(buf, binary.BigEndian, &header.chunkIdxStart); err != nil { |
| 305 | return err |
| 306 | } |
| 307 | if err := binary.Read(buf, binary.BigEndian, &header.chunkIdxLen); err != nil { |
| 308 | return err |
| 309 | } |
| 310 | if err := binary.Read(buf, binary.BigEndian, &header.encodeType); err != nil { |
| 311 | return err |
| 312 | } |
| 313 | if err := binary.Read(buf, binary.BigEndian, &header.maxKvSize); err != nil { |
| 314 | return err |
| 315 | } |
| 316 | if err := binary.Read(buf, binary.BigEndian, &header.chunkSize); err != nil { |
| 317 | return err |
| 318 | } |
| 319 | if err := binary.Read(buf, binary.BigEndian, &header.metaSize); err != nil { |
| 320 | return err |
| 321 | } |
| 322 | n, err = buf.Read(header.miner[:]) |
| 323 | if err != nil { |
| 324 | return err |
| 325 | } |
| 326 | if n != len(header.miner) { |
| 327 | return fmt.Errorf("short read for header.miner, n=%d", n) |
| 328 | } |
| 329 | if err := binary.Read(buf, binary.BigEndian, &header.status); err != nil { |
| 330 | return err |
| 331 | } |
| 332 | |
| 333 | // Sanity check |
| 334 | if header.magic != MAGIC { |
| 335 | return fmt.Errorf("magic error") |
| 336 | } |
| 337 | if header.version > VERSION { |
| 338 | return fmt.Errorf("unsupported version") |
| 339 | } |
| 340 | if header.encodeType > ENCODE_END { |
| 341 | return fmt.Errorf("unknown mask type") |
| 342 | } |