http.c

下载程序,多线程下载,断点续传. 目前只能下http

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <fcntl.h>
#include <pthread.h>
#include <sys/time.h>
#include <host.h>
#include <http.h>
#include <ants.h>
#include <wait_read.h>
#include <skip_lock.h>
#include <config.h>
	
int get_http_size(struct mission *pms) {
	signed long i;
	int s, err = 0;
	char cmd[256];
	char msg_hdr[1024];
	char *p;
	
	sprintf(cmd, "GET %s HTTP/1.1\r\nHost: %s:%d\r\nReferer: %s\r\nConnection: close\r\n\r\n", pms->path, pms->host, pms->port, pms->referer);
#ifdef DEBUG
	printf("cmd line is \n%s.\n", cmd);
#endif
	
	for(i = 0; i < TIMES; i++) {	
		while(1) {
			if((s = connect_host(pms->host, pms->port)) <= 0) sleep(1);
			else{
				break;
			}
			printf("connect host again.\n");
		}
		if(send(s, cmd, strlen(cmd), 0) != strlen(cmd)) {
			printf("write error.\n");
			err = 1;
		}
		else {	
			int state;
#ifdef DEBUG
			printf("writes ok\n");
#endif
			_wait_read(s, state, 20);	/*macro*/
			if(state < 1) {
				sleep(2);
				continue;
			}
			if(recv(s, msg_hdr, 1024, 0) < 0) {
				printf("read error.\n");
				err = 1;
			}
			else
				err = 0;
		}
		if(!(err))
			break;
		sleep(2);
	}
	
	if(err)
		return 0;
	
#ifdef DEBUG
	printf("size read ok\n");
#endif
	
	close(s);
#ifdef DEBUG
	i = find_start(msg_hdr, 1024);
	msg_hdr[i - 2] = 0;
	printf("%s", msg_hdr);
#endif
	i = (int)(strstr(msg_hdr, "200") - msg_hdr);
	if( (i <= 0) || i > 20) {	
		/*add error handler code here.*/
		
		return 0;
	}
	
	if((p = strstr(msg_hdr, "Content-Length")) || (p = strstr(msg_hdr, "Content-length:")))
		p+= 16;
	else {
		p = msg_hdr;
		while((p = strstr(p, "\r\n"))) {	/*fixup some file don't have string "Content-Length", I hope it works ok! */
			p = p + 2;
			if((*p <= '9') && (*p >= '0'))
				break;
		}
		if(!p)
			return 0;
	}
	s = atoi(p);
	printf("Content-length: %d\n", s);
	return s;
	
}
	
	
static void down_http_fragment(struct ants *ant) {
	char cmd[256];
	char data[PACKSIZE];
	char *buffer_start;
	char *buffer;
	int s, fd, size, speed, offset, packsize;
	int first, read, state, bytesleft;
	struct mission *pms;
	
	first = 1;
	pms = ant->pms;
	size = ant->buf_size;
	buffer_start = malloc(size);
	
	sprintf(cmd, "GET %s HTTP/1.1\r\nRange: bytes=%d-\r\nHost: %s:%d\r\nReferer: %s\r\n\r\n",pms->path, ant->position, pms->host, pms->port, pms->referer);
	
	do {
		while(1) {
			if((s = connect_host(pms->host, pms->port)) <= 0)
				sleep(1);
			else{
				ant->s = s;
				break;
			}
			printf("connect host again.\n");
		}
	
		if(send(s, cmd, strlen(cmd), 0) != strlen(cmd)) {
			close(s);
			sleep(5);
			continue;
		}
	} while (0);
	
	chdir(pms->file_path);
	fd = open(pms->file, O_WRONLY|O_CREAT, 0644);
	
retry:
	offset = 0;
	packsize = PACKSIZE;
	buffer = buffer_start;
	bytesleft = ant->end - ant->position + 1 ;
	lseek(fd, ant->position, 0);
	
	while(bytesleft) {
		_wait_read(s, state, 30);	/*macro*/
		if(state < 1){
			sleep(2);
			continue;
		}
	
		if(offset + packsize > size)
			packsize = size - offset;
		if(packsize > bytesleft)
			packsize = bytesleft;
	
		if(first) {
			int start_text;
			first = 0;	
			read = recv(s, data, packsize, MSG_WAITALL);
			/*extract head of http connect*/
			start_text = find_start(data, read);
			if(start_text == -1) {
				ant->ret = -1;
				goto bad_head;
			}
			read -= start_text;
			memcpy(buffer, data + start_text, read);
		}
		else {
			read = recv(s, data, packsize, MSG_WAITALL);
			memcpy(buffer, data, read);
		}
	
		buffer += read;
		bytesleft -= read;
		offset += read;
		speed = -1; /*skip save buffer flag*/
		if(bytesleft && ((offset + packsize) <= size))
			continue;
	
		write(fd, buffer_start, offset);
		ant->position += offset;
		if(!skip_lock(&pms->skip_lock)) {	/*save download state, if abort, we can continue*/
			state_save(pms);
			speed = statistic(ant);
			skip_unlock(&pms->skip_lock);
		}
	
		if(bytesleft)
			goto retry;
		else
			break;
	}
	ant->ret = 0;
bad_head:
	close(s);
	close(fd);
	free(buffer_start);
#ifdef DEBUG
	printf("thread %d exit.\n", ant->thread);
#endif
	pthread_exit(NULL);
}
	
	
void down_http(struct mission *pms) {
	int i, time, thread;
	struct timeval now, last;
	struct ants *ant;
	char file[MAX_HOSTNAME];
	pthread_t *pthread;
	ant = pms->first_ant;
	thread = pms->thread;
	pthread = malloc(sizeof(pthread_t) * thread);
	gettimeofday(&last, NULL);
	for(i = 0; i < thread; i++) {
		pthread_create(&pthread[i], NULL, (void *)down_http_fragment, (void *)&ant[i]);
	}
	
	for(i = 0; i < thread; i++) {
		if(ant[i].ret == -1) {
			printf("the %d thread error.\n", i);
		}
		pthread_join(pthread[i], NULL);
	}
	gettimeofday(&now, NULL);
	time = (now.tv_sec - last.tv_sec) * 1000000 +(now.tv_usec - last.tv_usec);
	time /= 1000;
	printf("cost time %d.%d s\n", (time / 1000), (time / 10));
	printf("100%% download\n");
	free(pthread);
	free(pms->first_ant);
	close(pms->fd);
	sprintf(file, "%s%s.nat",pms->file_path, pms->file);
	del_file(file);
}