static clusterManagerNode *clusterManagerByIpPort(const char* ip, int port);
static int clusterManagerCommandMoveSlot(int argc, char **argv);

{"move-slot", clusterManagerCommandMoveSlot, ,

"from-host:from-port to-host:to-port slotNo", NULL},

// 根据ip和端口号来获取对应的redis集群节点
clusterManagerNode *clusterManagerByIpPort(const char* ip, int port)

{

    if (cluster_manager.nodes == NULL) return NULL;

    clusterManagerNode *found = NULL;

    sds lcip = sdsempty();

    lcip = sdscpy(lcip, ip);

    sdstolower(lcip);

    listIter li;

    listNode *ln;

    listRewind(cluster_manager.nodes, &li);

    while ((ln = listNext(&li)) != NULL) {

        clusterManagerNode *n = ln->value;

        if (n->ip && !sdscmp(n->ip, lcip) && (n->port == port)) {

            found = n;

            break;

        }

    }

    sdsfree(lcip);

    return found;

}

// 在redis集群中实现移动槽位功能
static int clusterManagerCommandMoveSlot(int argc, char **argv) {

    assert(argc == );

    char *to_ip = NULL, *from_ip = NULL;

    int to_port = , from_port = ;

    if (!getClusterHostFromCmdArgs(, argv + , &to_ip, &to_port))

        goto invalid_args;

    if (!getClusterHostFromCmdArgs(, argv, &from_ip, &from_port))

        goto invalid_args;

    char *end = NULL;

    char *slotStr = argv[];

    int slotNo = strtol(slotStr, &end, );

    if ((size_t)(end - slotStr) != strlen(slotStr)) {

        clusterManagerLogErr("*** the slotNo should be number.\n");

        return ;

    }

    clusterManagerLogInfo("Moving slot number: %d from node %s:%d to node %s:%d\n",

            slotNo, from_ip, from_port, to_ip, to_port);

    clusterManagerNode *tonode = clusterManagerNewNode(to_ip, to_port);

    if (!clusterManagerLoadInfoFromNode(tonode, )) return ;

    clusterManagerCheckCluster();

    if (cluster_manager.errors && listLength(cluster_manager.errors) > ) {

        fflush(stdout);

        fprintf(stderr,

                "*** Please fix your cluster problems before moving slot\n");

        return ;

    }

    clusterManagerNode *fromnode = clusterManagerByIpPort(from_ip, from_port);

    // check fromnode and tonode is valid

    const char *invalid_node_msg = "*** The specified node (%s:%d) is not known "

                                   "or not a master, please retry.\n";

    if (!fromnode || (fromnode->flags & CLUSTER_MANAGER_FLAG_SLAVE)) {

        clusterManagerLogErr(invalid_node_msg, from_ip, from_port);

        return ;

    } else if (!tonode || (tonode->flags & CLUSTER_MANAGER_FLAG_SLAVE)) {

        clusterManagerLogErr(invalid_node_msg, to_ip, to_port);

        return ;

    } else if (!strcmp(fromnode->name, tonode->name) && (fromnode->port == tonode->port)){

            clusterManagerLogErr( "*** It is not possible to use "

                                  "the target node as "

                                  "source node.\n");

            return ;

    }

    // check fromnode has the slot

    if (slotNo <  || slotNo >= CLUSTER_MANAGER_SLOTS) {

        // Don't give a range hint for using it when someone is familiar with redis

        clusterManagerLogErr("*** The slotNo is invalid, slotNo: %d\n", slotNo);

        return ;

    } else if (fromnode->slots[slotNo] == (uint8_t)()) {

        clusterManagerLogErr("*** From node don't have the slot: %d\n", slotNo);

        return ;

    }

    int opts = CLUSTER_MANAGER_OPT_VERBOSE | CLUSTER_MANAGER_OPT_UPDATE;

    char *err = NULL;

    int result = clusterManagerMoveSlot(fromnode, tonode, slotNo,

                                    opts, &err);

    if (!result) {

        if (err != NULL) {

            //clusterManagerLogErr("\n%s\n", err);

            zfree(err);

        }

    } else {

        clusterManagerLogInfo("Moving finished with success.\n");

    }

    return result;

invalid_args:

    fprintf(stderr, CLUSTER_MANAGER_INVALID_HOST_ARG);

    return ;

}