Function replicationFeedSlave

src/replication.cpp:470–525

sds catCommandForAofAndActiveReplication(sds buf, struct redisCommand *cmd, robj **argv, int argc);

void replicationFeedSlave(client *replica, int dictid, robj **argv, int argc, bool fSendRaw)
{
    char llstr[LONG_STR_SIZE];
    std::unique_lock<decltype(replica->lock)> lock(replica->lock);

    /* Send SELECT command to every replica if needed. */
    if (g_pserver->replicaseldb != dictid) {
        robj *selectcmd;

        /* For a few DBs we have pre-computed SELECT command. */
        if (dictid >= 0 && dictid < PROTO_SHARED_SELECT_CMDS) {
            selectcmd = shared.select[dictid];
        } else {
            int dictid_len;

            dictid_len = ll2string(llstr,sizeof(llstr),dictid);
            selectcmd = createObject(OBJ_STRING,
                sdscatprintf(sdsempty(),
                "*2\r\n$6\r\nSELECT\r\n$%d\r\n%s\r\n",
                dictid_len, llstr));
        }

        /* Add the SELECT command into the backlog. */
        /* We don't do this for advanced replication because this will be done later when it adds the whole RREPLAY command */
        if (g_pserver->repl_backlog && fSendRaw) feedReplicationBacklogWithObject(selectcmd);

        /* Send it to slaves */
        addReply(replica,selectcmd);

        if (dictid < 0 || dictid >= PROTO_SHARED_SELECT_CMDS)
            decrRefCount(selectcmd);
    }
    g_pserver->replicaseldb = dictid;

    /* Feed slaves that are waiting for the initial SYNC (so these commands
     * are queued in the output buffer until the initial SYNC completes),
     * or are already in sync with the master. */

    if (fSendRaw)
    {
        /* Add the multi bulk length. */
        addReplyArrayLen(replica,argc);

        /* Finally any additional argument that was not stored inside the
            * static buffer if any (from j to argc). */
        for (int j = 0; j < argc; j++)
            addReplyBulk(replica,argv[j]);
    }
    else
    {
        struct redisCommand *cmd = lookupCommand(szFromObj(argv[0]));
        sds buf = catCommandForAofAndActiveReplication(sdsempty(), cmd, argv, argc);
        addReplyProto(replica, buf, sdslen(buf));
        sdsfree(buf);
    }
}

static int writeProtoNum(char *dst, const size_t cchdst, long long num)