ants.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 <ctype.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/time.h>
#include <dirent.h>
#include <fcntl.h>
#include <host.h>
#include <ants.h>
#include <http.h>
#include <config.h>
	
int buffer_size(int size, int *thread) {
	int i, q, n;
	if(!thread)
		return 0;
	n = *thread;
	if(n < 1 )
		n = 1;
	else if(n > 20)
		n = MAX_THREAD;
	i = size / n;
	i >>= 4;
	if(!i) {	/*fixup very tiny file size( < thread*16) */
		n = 1;
		i = size;
	}
	while(i < MIN_BUF_SIZE && n > 1) {
		i <<= 1;
		n >>= 1;
	}
	if(i < MIN_BUF_SIZE)
		i = MIN_BUF_SIZE;
	else if(i > MAX_BUF_SIZE)
		i = MAX_BUF_SIZE;
	if(n != *thread)
		*thread = n;
	if(i > PACKSIZE) {
		if((q = i % PACKSIZE))
			i -= q;
	}
	return i;
}	
	
		
int statistic(struct ants *owner) {
	int i, left, this_read, total, thread;
	long long cost;
	double percent, speed;
	static struct timeval tv, last;
	static int show;
	struct mission *pms = owner->pms;
	struct ants *ant = pms->first_ant;
	if(++show >= 10)
		show = 0;
	else
		return -1;
	
	total = pms->size;
	thread = pms->thread;
	gettimeofday(&tv, NULL);
	speed = -1;
	
	left = 0;
	if(pms->oneshot) {
		pms->oneshot = 0;
		last = tv;
		for(i = 0; i < thread; i++)
			left += (ant[i].end - ant[i].position + 1);
		pms->count = total - left;
	}
	else {
		for(i = 0; i < thread; i++)
			left += (ant[i].end - ant[i].position + 1);
		this_read = (total - left) - pms->count;
		pms->count = total - left;
		
		cost = (tv.tv_sec - last.tv_sec) * 1000000 + (tv.tv_usec + last.tv_usec);
		last = tv;
		cost /= 1000;
		percent = pms->count / (total / 100);
		this_read /= 1024;
		speed = (this_read * 1000) /cost;
		printf("thread %d get skip_lock - - -DOWNLOAD: %4.1f %%- - -DOWNLOAD SPEED :  %4.1f Kb/s .\n", owner->thread, percent, speed);
	}
	return (int)speed;
}	
	
void fill_ants(struct ants *ant, struct mission *pms, int size) {
	int i, bytes, thread, start;
	start = 0;
	thread = pms->thread;
	bytes = pms->size / thread;
	for(i = 0; i < thread; i++) {
		ant[i].thread = i + 1;
		ant[i].pms = pms;
		ant[i].buf_size = size;
		ant[i].start = start;
		ant[i].position = start;
		ant[i].end = ant[i].start + bytes -1;
		start = ant[i].end + 1;
	}
	ant[thread - 1].end = pms->size - 1;
}
	
void state_init(struct mission *pms) {
	int i, fd, thread;
	int num[MAX_THREAD];
	struct ants *ant = pms->first_ant;
	fd = pms->fd;
	thread = pms->thread;
	for(i = 0; i < thread; i++)
		num[i] = ant[i].end;
	lseek(fd, 0, 0);
	write(fd, pms, sizeof(struct mission));
	write(fd, num, sizeof(int) * thread);
}
	
void state_save(struct mission *pms) {
	int i, fd, thread, offset;
	int num[MAX_THREAD];
	struct ants *ant = pms->first_ant;
	fd = pms->fd;
	thread = pms->thread;
	offset = sizeof(struct mission) + (pms->thread * sizeof(int));
	for(i = 0; i < thread; i++)
		num[i] = ant[i].position;
	lseek(fd, offset, 0);
	write(fd, num, sizeof(int) * thread);
}
	
	
int scan_temp(char *path) {
	int i, num, fd;
	char *p;
	char filename[MAX_HOSTNAME];
	struct dirent **namelist;
	
	chdir(path);
	if(( num = scandir(".", &namelist, 0 , alphasort)) < 0)
		return -1;
	for(i = 0; i < num; i++) {
		strcpy(filename, namelist[i]->d_name);
		p = rindex(filename, '.');
		if(p++) {
			if(strcmp(p, "nat") == 0) {
				fd = open(filename, O_RDWR, 0644);
				if(fd)
					return fd;
			}
		}
	}
	return -1;
}	
	
int build_ants(struct mission *pms, char *name, int *thread) {
	int size, fd;
	struct ants *ant;
	char file[MAX_HOSTNAME];
	if(!fill_mission(pms, name))
		return 0;
	size = get_http_size(pms);
	if(size == -1)
		return 0;
	sprintf(file, "%s%s.nat",pms->file_path, pms->file);
	fd = open(file, O_WRONLY|O_CREAT, 0644);
	if(fd <= 0) {
		printf("can't open temp file\n");
		return 0;
	}
	pms->fd = fd;
	pms ->size = size;
	size = buffer_size(size, thread);   /* and fixup thread number*/
	if(!size)
		return 0;
	printf("buffer size is %d.\n", size);
	pms->thread = *thread;
	pms->oneshot = 1;
	pms->count = 0;
	ant = malloc(sizeof(struct ants) * (*thread));
	pms->first_ant = ant;
	pms->skip_lock.lock = 0;
	fill_ants(ant, pms, size);
	state_init(pms);
	return 1;
}	
	
int rebuild_ants(int fd, struct mission *pms) {
	int i, n, one, thread;
	int num[MAX_THREAD * 2];
	int *p;
	p = num;
	struct ants *ant;
	n = 0;
	one = 1;
	lseek(fd, 0, 0);
	read(fd, pms, sizeof(struct mission));
	thread = pms->thread;
	read(fd, num, (sizeof(int) * thread * 2));
	pms->fd = fd;
	for(i = 0; i < thread; i++) {
		int j;
		j = i;
		while((i < thread) && (num[i] == num[i + thread]))	/*exclude download 100% thread*/
			i++;
		if(i >= thread)
			break;
		if(i != j) {
			p[n] = num[i];
			p[n + thread] = num[n + thread];
			p++;
		}
		n++;
	}
	if(!n)
		return 0;
	thread = n;
	
	ant = malloc(sizeof(struct ants) * thread);
	pms->first_ant = ant;
	pms->skip_lock.lock = 0;
	pms->oneshot = 1;
	pms->thread = thread;
	for(i = 0; i < thread; i++) {
		ant[i].thread = i + 1;
		ant[i].pms = pms;
		ant[i].start = num[i + thread];
		ant[i].position = num[i + thread];
		ant[i].end = num[i];
		ant[i].buf_size = buffer_size((ant[i].end - ant[i].position + 1), &one);
	}
	return 1;
}	
	
int del_file(char *file) {	/* ugly!!! I don't know how to delete file */
	char del[MAX_HOSTNAME + 6];
	sprintf(del, "rm -f %s",file);
	system(del);
	return 1;
}