上传文件块client实现

首先由内容阻止所有文件（块大小的约束），然后对于每一个chunk构造单独的一个UDP 数据报进行传输，在应用层的開始是自己定义的包头，有块号，块长度，块指纹等元数据信息，这些信息便于接收端可以按序正确接收。

/*--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 2500

typedef 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<IPaddress>;\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));
}

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