Entry reads an entry from the provided reader. It also validates the checksum for every entry read. Returns error on failure.
(reader io.Reader)
| 352 | // Entry reads an entry from the provided reader. It also validates the checksum for every entry |
| 353 | // read. Returns error on failure. |
| 354 | func (r *safeRead) Entry(reader io.Reader) (*Entry, error) { |
| 355 | tee := newHashReader(reader) |
| 356 | var h header |
| 357 | hlen, err := h.DecodeFrom(tee) |
| 358 | if err != nil { |
| 359 | return nil, err |
| 360 | } |
| 361 | if h.klen > uint32(1<<16) { // Key length must be below uint16. |
| 362 | return nil, errTruncate |
| 363 | } |
| 364 | kl := int(h.klen) |
| 365 | if cap(r.k) < kl { |
| 366 | r.k = make([]byte, 2*kl) |
| 367 | } |
| 368 | vl := int(h.vlen) |
| 369 | if cap(r.v) < vl { |
| 370 | r.v = make([]byte, 2*vl) |
| 371 | } |
| 372 | |
| 373 | e := &Entry{} |
| 374 | e.offset = r.recordOffset |
| 375 | e.hlen = hlen |
| 376 | buf := make([]byte, h.klen+h.vlen) |
| 377 | if _, err := io.ReadFull(tee, buf[:]); err != nil { |
| 378 | if err == io.EOF { |
| 379 | err = errTruncate |
| 380 | } |
| 381 | return nil, err |
| 382 | } |
| 383 | if r.lf.encryptionEnabled() { |
| 384 | if buf, err = r.lf.decryptKV(buf[:], r.recordOffset); err != nil { |
| 385 | return nil, err |
| 386 | } |
| 387 | } |
| 388 | e.Key = buf[:h.klen] |
| 389 | e.Value = buf[h.klen:] |
| 390 | var crcBuf [crc32.Size]byte |
| 391 | if _, err := io.ReadFull(reader, crcBuf[:]); err != nil { |
| 392 | if err == io.EOF { |
| 393 | err = errTruncate |
| 394 | } |
| 395 | return nil, err |
| 396 | } |
| 397 | crc := y.BytesToU32(crcBuf[:]) |
| 398 | if crc != tee.Sum32() { |
| 399 | return nil, errTruncate |
| 400 | } |
| 401 | e.meta = h.meta |
| 402 | e.UserMeta = h.userMeta |
| 403 | e.ExpiresAt = h.expiresAt |
| 404 | return e, nil |
| 405 | } |
| 406 | |
| 407 | // iterate iterates over log file. It doesn't not allocate new memory for every kv pair. |
| 408 | // Therefore, the kv pair is only valid for the duration of fn call. |