#include?
#include?
#include?
#include?
#include?
#include?
#include?
#include?“parse_metafile.h“
#include?“bitfield.h“

extern?int??pieces_length;
extern?char?*file_name;

Bitmap??????*bitmap?=?NULL;?????????//?指向位圖
int?????????download_piece_num?=?0;?//?當(dāng)前已下載的piece數(shù)?

//?如果存在一個(gè)位圖文件則讀位圖文件并把獲取的內(nèi)容保存到bitmap
//?如此一來就可以實(shí)現(xiàn)斷點(diǎn)續(xù)傳即上次下載的內(nèi)容不至于丟失
int?create_bitfield（）
{
	bitmap?=?（Bitmap?*）malloc（sizeof（Bitmap））;
	if（bitmap?==?NULL）?{?
		printf（“allocate?memory?for?bitmap?fiailed\n“）;?
		return?-1;
	}

	//?pieces_length除以20即為總的piece數(shù)
	bitmap->valid_length?=?pieces_length?/?20;
	bitmap->bitfield_length?=?pieces_length?/?20?/?8;
	if（?（pieces_length/20）?%?8?!=?0?）??bitmap->bitfield_length++;

	bitmap->bitfield?=?（unsigned?char?*）malloc（bitmap->bitfield_length）;
	if（bitmap->bitfield?==?NULL）??{?
		printf（“allocate?memory?for?bitmap->bitfield?fiailed\n“）;?
		if（bitmap?!=?NULL）??free（bitmap）;
		return?-1;
	}

	char?bitmapfile[64];
	sprintf（bitmapfile“%dbitmap“pieces_length）;
	
	int??i;
	FILE?*fp?=?fopen（bitmapfile“rb“）;
	if（fp?==?NULL）?{??//?若打開文件失敗說明開始的是一個(gè)全新的下載
		memset（bitmap->bitfield?0?bitmap->bitfield_length）;
	}?else?{
		fseek（fp0SEEK_SET）;
		for（i?=?0;?i?bitfield_length;?i++）
			（bitmap->bitfield）[i]?=?fgetc（fp）;
		fclose（fp）;?
		//?給download_piece_num賦新的初值
		download_piece_num?=?get_download_piece_num（）;
	}
	
	return?0;
}

int?get_bit_value（Bitmap?*bitmapint?index）??
{
	int???????????ret;
	int???????????byte_index;
	unsigned?char?byte_value;
	unsigned?char?inner_byte_index;

	if（index?>=?bitmap->valid_length）??return?-1;

	byte_index?=?index?/?8;
	byte_value?=?bitmap->bitfield[byte_index];
	inner_byte_index?=?index?%?8;

	byte_value?=?byte_value?>>?（7?-?inner_byte_index）;
	if（byte_value?%?2?==?0）?ret?=?0;
	else????????????????????ret?=?1;

	return?ret;
}

int?set_bit_value（Bitmap?*bitmapint?indexunsigned?char?v）
{
	int???????????byte_index;
	unsigned?char?inner_byte_index;

	if（index?>=?bitmap->valid_length）??return?-1;
	if（（v?!=?0）?&&?（v?!=?1））???return?-1;

	byte_index?=?index?/?8;
	inner_byte_index?=?index?%?8;

	v?=?v?<	bitmap->bitfield[byte_index]?=?bitmap->bitfield[byte_index]?|?v;

	return?0;
}

int?all_zero（Bitmap?*bitmap）
{
	if（bitmap->bitfield?==?NULL）??return?-1;
	memset（bitmap->bitfield0bitmap->bitfield_length）;
	return?0;
}
?
int?all_set（Bitmap?*bitmap）
{
	if（bitmap->bitfield?==?NULL）??return?-1;
	memset（bitmap->bitfield0xffbitmap->bitfield_length）;
	return?0;	
}

void?release_memory_in_bitfield（）
{
	if（bitmap->bitfield?!=?NULL）?free（bitmap->bitfield）;
	if（bitmap?!=?NULL）??free（bitmap）;
}

int?print_bitfield（Bitmap?*bitmap）
{
	int?i;

	for（i?=?0;?i?bitfield_length;?i++）?{
		printf（“%.2X?“bitmap->bitfield[i]）;
		if（?（i+1）?%?16?==?0）??printf（“\n“）;
	}
	printf（“\n“）;

	return?0;
}

int?

?屬性????????????大小?????日期????時(shí)間???名稱
-----------?---------??----------?-----??----

?????文件???????5422??2008-01-23?17:53??源代碼_BT下載程序\bitfield.c

?????文件???????1111??2008-01-23?17:53??源代碼_BT下載程序\bitfield.h

?????文件????????223??2008-01-23?17:53??源代碼_BT下載程序\bterror.c

?????文件????????925??2008-01-23?17:53??源代碼_BT下載程序\bterror.h

?????文件??????27176??2008-01-23?17:53??源代碼_BT下載程序\data.c

?????文件???????2779??2008-01-23?17:53??源代碼_BT下載程序\data.h

?????文件????????698??2008-01-23?17:53??源代碼_BT下載程序\log.c

?????文件????????245??2008-01-23?17:53??源代碼_BT下載程序\log.h

?????文件???????1258??2008-01-23?17:53??源代碼_BT下載程序\main.c

?????文件????????310??2008-01-23?17:53??源代碼_BT下載程序\Makefile

?????文件??????23106??2008-01-23?17:53??源代碼_BT下載程序\message.c

?????文件???????1460??2008-01-23?17:53??源代碼_BT下載程序\message.h

?????文件??????11606??2008-01-23?17:53??源代碼_BT下載程序\parse_metafile.c

?????文件???????1369??2008-01-23?17:53??源代碼_BT下載程序\parse_metafile.h

?????文件???????4230??2008-01-23?17:53??源代碼_BT下載程序\peer.c

?????文件???????3455??2008-01-23?17:53??源代碼_BT下載程序\peer.h

?????文件??????15738??2008-01-23?17:53??源代碼_BT下載程序\policy.c

?????文件???????1155??2008-01-23?17:53??源代碼_BT下載程序\policy.h

?????文件???????5443??2008-01-23?17:53??源代碼_BT下載程序\sha1.c

?????文件????????996??2008-01-23?17:53??源代碼_BT下載程序\sha1.h

?????文件???????1363??2008-01-23?17:53??源代碼_BT下載程序\signal_hander.c

?????文件????????224??2008-01-23?17:53??源代碼_BT下載程序\signal_hander.h

?????文件??????13921??2008-01-23?17:53??源代碼_BT下載程序\torrent.c

?????文件????????327??2008-01-23?17:53??源代碼_BT下載程序\torrent.h

?????文件??????11458??2008-01-23?17:53??源代碼_BT下載程序\tracker.c

?????文件???????1556??2008-01-23?17:53??源代碼_BT下載程序\tracker.h

?????文件?????227011??2008-01-23?17:53??源代碼_BT下載程序\ttorrent

?????文件????1736192??2008-01-23?17:51??BT軟件下載開發(fā)完整版-00.doc

?????文件????1602048??2008-01-23?17:52??BT軟件下載開發(fā)完整版-01.doc

?????目錄??????????0??2008-11-26?14:04??源代碼_BT下載程序

............此處省略3個(gè)文件信息