Feed the slave 'c' with the replication backlog starting from the * specified 'offset' up to the end of the backlog. */
| 419 | /* Feed the slave 'c' with the replication backlog starting from the |
| 420 | * specified 'offset' up to the end of the backlog. */ |
| 421 | long long addReplyReplicationBacklog(client *c, long long offset) { |
| 422 | long long j, skip, len; |
| 423 | |
| 424 | serverLog(LL_DEBUG, "[PSYNC] Replica request offset: %lld", offset); |
| 425 | |
| 426 | if (server.repl_backlog_histlen == 0) { |
| 427 | serverLog(LL_DEBUG, "[PSYNC] Backlog history len is zero"); |
| 428 | return 0; |
| 429 | } |
| 430 | |
| 431 | serverLog(LL_DEBUG, "[PSYNC] Backlog size: %lld", |
| 432 | server.repl_backlog_size); |
| 433 | serverLog(LL_DEBUG, "[PSYNC] First byte: %lld", |
| 434 | server.repl_backlog_off); |
| 435 | serverLog(LL_DEBUG, "[PSYNC] History len: %lld", |
| 436 | server.repl_backlog_histlen); |
| 437 | serverLog(LL_DEBUG, "[PSYNC] Current index: %lld", |
| 438 | server.repl_backlog_idx); |
| 439 | |
| 440 | /* Compute the amount of bytes we need to discard. */ |
| 441 | skip = offset - server.repl_backlog_off; |
| 442 | serverLog(LL_DEBUG, "[PSYNC] Skipping: %lld", skip); |
| 443 | |
| 444 | /* Point j to the oldest byte, that is actually our |
| 445 | * server.repl_backlog_off byte. */ |
| 446 | j = (server.repl_backlog_idx + |
| 447 | (server.repl_backlog_size-server.repl_backlog_histlen)) % |
| 448 | server.repl_backlog_size; |
| 449 | serverLog(LL_DEBUG, "[PSYNC] Index of first byte: %lld", j); |
| 450 | |
| 451 | /* Discard the amount of data to seek to the specified 'offset'. */ |
| 452 | j = (j + skip) % server.repl_backlog_size; |
| 453 | |
| 454 | /* Feed slave with data. Since it is a circular buffer we have to |
| 455 | * split the reply in two parts if we are cross-boundary. */ |
| 456 | len = server.repl_backlog_histlen - skip; |
| 457 | serverLog(LL_DEBUG, "[PSYNC] Reply total length: %lld", len); |
| 458 | while(len) { |
| 459 | long long thislen = |
| 460 | ((server.repl_backlog_size - j) < len) ? |
| 461 | (server.repl_backlog_size - j) : len; |
| 462 | |
| 463 | serverLog(LL_DEBUG, "[PSYNC] addReply() length: %lld", thislen); |
| 464 | addReplySds(c,sdsnewlen(server.repl_backlog + j, thislen)); |
| 465 | len -= thislen; |
| 466 | j = 0; |
| 467 | } |
| 468 | return server.repl_backlog_histlen - skip; |
| 469 | } |
| 470 | |
| 471 | /* Return the offset to provide as reply to the PSYNC command received |
| 472 | * from the slave. The returned value is only valid immediately after |
no test coverage detected