opentracker/trackerlogic.h

#ifndef __TRACKERLOGIC_H__
#define __TRACKERLOGIC_H__

#include <sys/types.h>
#include <sys/time.h>

/* Should be called BYTE, WORD, DWORD - but some OSs already have that and there's no #iftypedef */
/* They mark memory used as data instead of integer or human readable string -
   they should be cast before used as integer/text */
typedef unsigned char  ot_byte;
typedef unsigned short ot_word;
typedef unsigned long  ot_dword;

typedef ot_byte        ot_hash[20];
typedef ot_dword       ot_ip;
typedef time_t         ot_time;

#define MEMMOVE              memmove
#define BZERO                bzero
#define FORMAT_FIXED_STRING  sprintf
#define FORMAT_FORMAT_STRING sprintf
#define BINARY_FIND          binary_search

// We maintain a list of 256 pointers to sorted list of ot_torrent structs
// Sort key is, of course, its hash

// This list points to 9 pools of peers each grouped in five-minute-intervals
// thus achieving a timeout of 2700s or 45 minutes
// These pools are sorted by its binary content

#define OT_POOLS_COUNT   9
#define OT_POOLS_TIMEOUT 300
#define NOW              (time(NULL)/OT_POOLS_TIMEOUT)

#define OT_VECTOR_MIN_MEMBERS   128
#define OT_VECTOR_GROW_RATIO    2
#define OT_VECTOR_SHRINK_THRESH 3
#define OT_VECTOR_SHRINK_RATIO  2
typedef struct {
  void   *data;
  size_t  size;
  size_t  space;   
} ot_vector;

typedef struct {
  ot_byte data[8];
} ot_peer;
static const ot_byte PEER_FLAG_SEEDING   = 0x80;
static const ot_byte PEER_FLAG_COMPLETED = 0x40;
static const ot_byte PEER_FLAG_STOPPED   = 0x20;

#define OT_SETIP( peer, ip ) MEMMOVE((peer),(ip),4);
#define OT_SETPORT( peer, port ) MEMMOVE(((ot_byte*)peer)+4,(port),2);
#define OT_FLAG(peer) (((ot_byte*)(peer))[6])

#define OT_PEER_COMPARE_SIZE ((size_t)6)
#define OT_HASH_COMPARE_SIZE (sizeof(ot_hash))

typedef struct {
  ot_time        base;
  unsigned long  seed_count[ OT_POOLS_COUNT ];
  unsigned long  downloaded;
  ot_vector      peers[ OT_POOLS_COUNT ];
} ot_peerlist;

typedef struct {
  ot_hash      hash;
  ot_peerlist *peer_list;
} ot_torrent;

//
// Exported functions
//

int  init_logic( char *chdir_directory );
void deinit_logic( );

ot_torrent *add_peer_to_torrent( ot_hash *hash, ot_peer *peer );
size_t return_peers_for_torrent( ot_torrent *torrent, unsigned long amount, char *reply );
size_t return_scrape_for_torrent( ot_hash *hash, char *reply );
void  remove_peer_from_torrent( ot_hash *hash, ot_peer *peer );
void cleanup_torrents( void );

#endif