int main(int argc, char *argv[])
{
int ret;
if(argc != 2) {
printf("usage:%s metafile\n",argv[0]);
exit(-1);
}
// 设置信号处理函数
ret = set_signal_hander();
if(ret != 0) { printf("%s:%d error\n",__FILE__,__LINE__); return -1; }
// 解析种子文件
ret = parse_metafile(argv[1]);
if(ret != 0) { printf("%s:%d error\n",__FILE__,__LINE__); return -1; }
// 初始化非阻塞peer
init_unchoke_peers();
// 创建用于保存下载数据的文件
ret = create_files();
if(ret != 0) { printf("%s:%d error\n",__FILE__,__LINE__); return -1; }
// 创建位图
ret = create_bitfield();
if(ret != 0) { printf("%s:%d error\n",__FILE__,__LINE__); return -1; }
// 创建缓冲区
ret = create_btcache();
if(ret != 0) { printf("%s:%d error\n",__FILE__,__LINE__); return -1; }
// 负责与所有Peer收发数据、交换消息
download_upload_with_peers();
// 做一些清理工作,主要是释放动态分配的内存
do_clear_work();
return 0;
}
int main (int argc, char * argv[]) {
bt_args_t bt_args; // structure to capture command-line arguments
int i; // loop iterator
int leecher_sock; // leecher's connection socket
parse_args(&bt_args, argc, argv);
if (bt_args.verbose) { // if verbose mode is requested
printf("Args information from command line:\n");
printf("\tverbose: %d\n", bt_args.verbose);
printf("\tsave_file: %s\n", bt_args.save_file); // display name of file to save to
printf("\tlog_file: %s\n", bt_args.log_file); // display name of file to log information to
printf("\ttorrent_file: %s\n", bt_args.torrent_file); // metainfo or torrent file being used by bt client
// print information of all peers
/*for (i = 0; i < MAX_CONNECTIONS; i++) {
if(bt_args.peers[i] != NULL)
print_peer(bt_args.peers[i]);
else
break;
}*/
}
// instantiate & allocate memory to bt_info_t struct that's inside bt_args
bt_info_t *bt_info = (bt_info_t *) malloc(sizeof(bt_info_t));
// parse the torrent file to fill up contents of the bt_info structure with required information from the 'info' dictionary in .torrent file
parse_torrent_file(&bt_args, bt_info);
if (bt_args.bind == 1) { // bt client runs in seeder mode
/* separate IPaddr:port from string following '-b'; generate bt client's ID;
* get a handle on the seeder's data-exchange socket;
* make seeder listen for incoming leecher connections */
init_seeder(&bt_args);
create_bitfield(&bt_args, bt_info);
printf("BITFIELD at SEEDER: '%s'\n", bt_args.bitfield->bits);
// printf("testing, bt_args.bitfield->bits: '%s'\n", bt_args.bitfield->bits);
// printf("testing, inside main, bt_args.bitfield->size: %ld\n", bt_args.bitfield->size);
} else { // bt client runs in leecher mode
for (i = 0; i < MAX_CONNECTIONS; i++) {
if (bt_args.peers[i] != NULL) {
// write all client (leecher) code here
if (bt_args.verbose) {
printf("Creating a leecher socket...\n");
}
leecher_sock = init_leecher(bt_args.peers[i]); // run a leecher instance for each peer recorded in bt_args->peers[]
unsigned char *handshake = malloc(100); // handshake information to be exchanged between peers
init_handshake(bt_args.peers[i], handshake, bt_info);
// send handshake over to seeder
ssize_t bytes_written;
if ( (bytes_written = write(leecher_sock, handshake, 100)) < 0 ) {
fprintf(stderr, "ERROR: Could not write to leecher socket.\n");
exit(1);
}
} else
break;
}
}
// main client loop
// printf("Starting Main Loop\n");
/*
while(1){
// try to accept incoming connection from new peer
// poll current peers for incoming traffic
// write pieces to files
// update peers' choke or unchoke status
// responses to have/havenots/interested etc.
// for peers that are not choked
// request pieces from outcoming traffic
// check livelness of peers and replace dead (or useless) peers
// with new potentially useful peers
// update peers,
}
*/
return 0;
}
