Function createDumpPayload

src/cluster.cpp:5125–5156

Generates a DUMP-format representation of the object 'o', adding it to the * io stream pointed by 'rio'. This function can't fail. */

/* Generates a DUMP-format representation of the object 'o', adding it to the
 * io stream pointed by 'rio'. This function can't fail. */
void createDumpPayload(rio *payload, robj_roptr o, robj *key) {
    unsigned char buf[2];
    uint64_t crc;

    /* Serialize the object in an RDB-like format. It consist of an object type
     * byte followed by the serialized object. This is understood by RESTORE. */
    rioInitWithBuffer(payload,sdsempty());
    serverAssert(rdbSaveObjectType(payload,o));
    serverAssert(rdbSaveObject(payload,o,key));
    char szT[32];
    uint64_t mvcc = mvccFromObj(o);
    snprintf(szT, sizeof(szT), "%" PRIu64, mvcc);
    serverAssert(rdbSaveAuxFieldStrStr(payload,"mvcc-tstamp", szT) != -1);

    /* Write the footer, this is how it looks like:
     * ----------------+---------------------+---------------+
     * ... RDB payload | 2 bytes RDB version | 8 bytes CRC64 |
     * ----------------+---------------------+---------------+
     * RDB version and CRC are both in little endian.
     */

    /* RDB version */
    buf[0] = RDB_VERSION & 0xff;
    buf[1] = (RDB_VERSION >> 8) & 0xff;
    payload->io.buffer.ptr = sdscatlen(payload->io.buffer.ptr,buf,2);

    /* CRC64 */
    crc = crc64(0,(unsigned char*)payload->io.buffer.ptr,
                sdslen(payload->io.buffer.ptr));
    memrev64ifbe(&crc);
    payload->io.buffer.ptr = sdscatlen(payload->io.buffer.ptr,&crc,8);
}

/* Verify that the RDB version of the dump payload matches the one of this Redis
 * instance and that the checksum is ok.