btcontent.h

linux系统下bt的客户端实现。 采用的是c++

#ifndef BTCONTENT_H
#define BTCONTENT_H

#include "Btfiles.h"
#include "Bitfield.h"
struct BTCACHE {
    uint64_t bc_off;
    size_t bc_len;

    unsigned char bc_f_flush:1;
    unsigned char bc_f_reserved:7;

    char *bc_buf;

    struct BTCACHE *bc_next;
    struct BTCACHE *bc_prev;
    struct BTCACHE *age_next;
    struct BTCACHE *age_prev;
};

class btContent {
  private:
    unsigned char *m_announce, *m_hash_table;
    unsigned char m_shake_buffer[68];
	unsigned char*m_sha_buffer;
	char *m_announce_list[20];

    size_t m_hash_table_length;
    size_t m_piece_length;
    size_t m_npieces;
    time_t m_create_date;

    uint64_t m_left_bytes;
    btFiles m_btfiles;
    bitfield *m_pbitmap;
	
	BTCACHE** m_cache;
	BTCACHE* m_cache_oldest, *m_cache_newest;
	uint64_t m_cache_size, m_cache_used;

	void empty_cache();

  public:
     btContent();
    ~btContent();

    void FlushCache() { FlushCache(m_npieces); };
    void FlushCache(size_t idx);
	void CacheClean(size_t need);
	void Uncache(size_t idx);
    void printout();
	void free_announce_list();

    int InitialFromMI(Bencode *);
    ssize_t CacheIO(unsigned char *buf, uint64_t off, size_t len, int method);
	ssize_t ReadSlice(unsigned char *buf, size_t idx, size_t off, size_t len);
	ssize_t WriteSlice(unsigned char *buf, size_t idx, size_t off, size_t len);
	ssize_t ReadPiece(size_t idx, unsigned char* buff);
	int APieceComplete(size_t idx);
	int GetHashValue(size_t idx, unsigned char* md);
	int GetAPiece(size_t idx, unsigned char* buf);

	size_t GetCacheSize() { return m_cache_size; }
	size_t GetCacheUsed() { return m_cache_used; }
	size_t GetPieceLength() { return m_piece_length; }
	size_t GetPieceLength(size_t idx);
	size_t GetNPieces() const { return m_npieces; }
	unsigned char* GetAnnounce() { return m_announce; }
	unsigned char* GetPeerId()  { return m_shake_buffer + 48; }
	unsigned char* GetInfoHash() { return m_shake_buffer + 28; } 
	         char** GetAnnounceList() { return m_announce_list; }
	uint64_t GetTotalFilesLength() 
		{ return m_btfiles.GetTotalLength(); }
	uint64_t GetLeftBytes() const { return m_left_bytes; }
	
};

extern btContent BTCONTENT;
#endif