void Master::server_notify(pair <int, int> srv, bool extension) //notify server of server fail/chain extension
{
Server *prev = Search_Prev_Server(srv, !extension);
cal_next(srv.first);
if (prev == NULL)
{
printf("Head server fails, the successor automatically becomes the new head\n");
return;
}
else
{
//printf("previous server is %d\n", prev->GetserverName().second);
socklen_t len = sizeof(sockaddr_in);
char send_msg[MAXLINE];
Server *next = Search_Next_Server(prev);
if (next == NULL)
{
srv.second = -1;
}
else
{
srv.second = next->GetserverName().second;
}
packetize(send_msg, srv, false, extension);
Sendto(sockfd_udp, send_msg, MAXLINE, 0, (SA*)&(prev->Getsockaddr()), len);
if (extension)
printf("New server extended to the tail of chain %d\n%s\n", srv.first, seperator);
else if (srv.second == -1)
printf("Tail server fails, server notification sent out to its precessor: 127.0.0.1:%d\n", prev->GetserverName().second);
else
printf("Internal server fails, server notification sent out to its precessor: 127.0.0.1:%d, new next server is 127.0.0.1:%d\n", prev->GetserverName().second, srv.second);
}
}
int KMP(char *haystack, char *needle){
int l_h = strlen(haystack);
int l_n = strlen(needle);
vector<int> next(l_n, 0);
cal_next(next, needle);
int i_h = 0;
int i_n = 0;
while(i_h < l_h && i_n < l_n){
if(i_n == -1 || *(needle+i_n) == *(haystack+i_h)){
i_n++;
i_h++;
}else{
i_n = next[i_n];
}
}
return i_n==l_n ? i_h-i_n : -1;
}
