File multipart upload client implementation

First, the file is segmented by content (with block size constraints), and then a separate UDP datagram is constructed for each chunk for transmission. At the beginning of the application layer, it is a custom header, metadata information, such as block numbers, block lengths, and block fingerprints, can be received in order by the receiving end.

/*--vonzhou ---this project is to upload file after chunking using     rabin fingerprint, here use UDP so that every packet nodelay.    but we need to ensure the reliability.*/#include "global.h"#define SERV_PORT 2500typedef struct {        unsigned char fp[20];        int chunk_id;        short flags;        short chunk_len; // The max is 32767 enough        char data[MAX_CHUNK_SIZE];}TransferUnit;// some flags for this chunk transfered.enum{        CHUNK_NEED_DEDU = 0x0001,   // need deduplication        CHUNK_OTHER = 0x0002      // other for extension};FileInfo *fi;int sendUDP(FileInfo *fi,int sockfd,struct sockaddr *pservaddr,socklen_t servlen){    char buf[sizeof(TransferUnit)];    fd_set wrset;    struct timeval tv;    int rlen,wlen, len = 1;    int fd;    int ret;    int i,j;    FingerChunk *p;    TransferUnit unit;    //connect to server    if(connect(sockfd,(struct sockaddr *)pservaddr,servlen) == -1)        err_quit("connet error");    else        printf("connect server ok!\n");    fd = open(fi->file_path, O_RDONLY);    if(fd==-1)        err_quit("fopen error %s\n",strerror(errno));    // begin to transfer the file to the server;                i=0;    p = fi->first;    while(1){        tv.tv_sec = 1;// tell select to wait 1 second;        tv.tv_usec = 0;        FD_ZERO(&wrset);        FD_SET(sockfd,&wrset);        // wait for the socket can write                ret = select(sockfd+1,NULL,&wrset,NULL,&tv);        if(ret == -1)            err_quit("select error %s\n",strerror(errno));        else if(ret==0){            printf("select timeout,continue circle\n");            continue;        }        //prepare for writing the socket                memset(&unit, 0, sizeof(unit));        if(FD_ISSET(sockfd,&wrset)){            /* we should first transfer some medadata,like filename,filter feature vector,            *FIXME: file fingerprint to controller? to make a packetin,            *here just let the fp = 20 1s            */            if(i == 0){                for(j=0;j<20;j++)                    unit.fp[j] = 0xff;                unit.chunk_id = 0;                //need not dedu                unit.chunk_len = strlen(fi->file_path);                wlen = write(sockfd, &unit, 28 + strlen(fi->file_path));                if(wlen != (28 + strlen(fi->file_path)))                     err_quit("write data to sockfd error:%s\n",strerror(errno));                memset(&unit, 0, sizeof(unit));            }            if(p != NULL)                len = p->chunklen;            // the last read , p is null, so cannnot use p->chu            rlen = read(fd, unit.data, len);            if(rlen < 0)                err_quit("fread data error %s\n",strerror(errno));            else if(rlen==0){                //indicate the transfer completed                for(j=0;j<20;j++)                    unit.fp[j] = 0xff;                unit.chunk_id = 0;                //need not dedu                unit.chunk_len = 3;                strncpy(unit.data,"end", 3);                wlen = write(sockfd,&unit,28 + 3);                if(wlen !=31)                    err_quit("write end flag error:%s\n",strerror(errno));                printf("File %s Transfer Success!\n", fi->file_path);                close(fd);                return 0;            }            // construct this tranfer unit we cannot before read            //bcos the following p pointer used.            for(j=0; j< 20;j++)                unit.fp[j] = p->chunk_hash[j];// 20B fingerprint;            unit.chunk_id = i; // 4B chunk ID            unit.chunk_len = p->chunklen;            unit.flags = CHUNK_NEED_DEDU;            //write to socket            wlen = write(sockfd, &unit, 28+p->chunklen);            if(wlen != (rlen + 28))                err_quit("write data to sockfd error:%s\n",strerror(errno));            i++;            p = p->next;            memset(&unit, 0, sizeof(unit));            usleep(500);            printf("The %d times read\n",i);        }    }// end while(1)}int main(int argc ,char *argv[]){        char *fh;        struct sysinfo s_info;        long time1,time2;        int error1,error2;        int sockfd;        struct stat fsize;        struct sockaddr_in servaddr;        error1= sysinfo(&s_info);        time1 = s_info.uptime;        int r;        //  FileInfo *fi;        fi = file_new();        if(argc != 3)        err_quit("useage:udpclient
 
  ;\n");        bzero(&servaddr,sizeof(servaddr));        servaddr.sin_family= AF_INET;        servaddr.sin_port = htons(SERV_PORT);        if(inet_pton(AF_INET,argv[1],&servaddr.sin_addr) <= 0)            err_quit("[%s]is not a valid IPaddress\n",argv[1]);        sockfd =socket(AF_INET,SOCK_DGRAM,0);        r = fcntl(sockfd, F_GETFL, 0);        fcntl(sockfd, F_SETFL, r & ~O_NONBLOCK);        // chunking file         strcpy(fi->file_path, argv[2]);        chunk_file(fi);        printf("File size : %lld\n",fi->file_size);        printf("Chunk Num : %d\n",fi->chunknum);        sendUDP(fi, sockfd, (struct sockaddr *)&servaddr,sizeof(servaddr));        close(sockfd);        fprintf(stderr,"ServerIP:\t%s\n",argv[1]);        if(stat(argv[2],&fsize) == -1)                perror("failed to get fiel statusi\n");        else                fprintf(stderr,"file name:\t%s\nfile size:\t%dK\n",argv[2],fsize.st_size/1024);        error2=sysinfo(&s_info);        time2 = s_info.uptime;        printf("tranfice file time =%ld seconds\n",(time2-time1));}