opentracker/ot_clean.c

/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
   It is considered beerware. Prost. Skol. Cheers or whatever. */

/* System */
#include <stdlib.h>
#include <string.h>

/* Libowfat */
#include "byte.h"

/* Opentracker */
#include "trackerlogic.h"
#include "ot_mutex.h"

/* To remember, when we last cleaned up */
static ot_time   all_torrents_clean[OT_BUCKET_COUNT];

/* Clean a single torrent
   return 1 if torrent timed out
*/
int clean_single_torrent( ot_torrent *torrent ) {
  ot_peerlist *peer_list = torrent->peer_list;
  size_t peers_count = 0, seeds_count;
  time_t timedout = (int)( NOW - peer_list->base );
  int i;
#ifdef WANT_TRACKER_SYNC
  char *new_peers;
#endif

  /* Torrent has idled out */
  if( timedout > OT_TORRENT_TIMEOUT )
    return 1;

  /* Nothing to be cleaned here? Test if torrent is worth keeping */
  if( timedout > OT_POOLS_COUNT ) {
    if( !peer_list->peer_count )
      return peer_list->down_count ? 0 : 1;
    timedout = OT_POOLS_COUNT;
  }

  /* Release vectors that have timed out */
  for( i = OT_POOLS_COUNT - timedout; i < OT_POOLS_COUNT; ++i )
    free( peer_list->peers[i].data);

  /* Shift vectors back by the amount of pools that were shifted out */
  memmove( peer_list->peers + timedout, peer_list->peers, sizeof( ot_vector ) * ( OT_POOLS_COUNT - timedout ) );
  byte_zero( peer_list->peers, sizeof( ot_vector ) * timedout );

  /* Shift back seed counts as well */
  memmove( peer_list->seed_counts + timedout, peer_list->seed_counts, sizeof( size_t ) * ( OT_POOLS_COUNT - timedout ) );
  byte_zero( peer_list->seed_counts, sizeof( size_t ) * timedout );

#ifdef WANT_TRACKER_SYNC
  /* Save the block modified within last OT_POOLS_TIMEOUT */
  if( peer_list->peers[1].size &&
    ( new_peers = realloc( peer_list->changeset.data, sizeof( ot_peer ) * peer_list->peers[1].size ) ) )
  {
    memmove( new_peers, peer_list->peers[1].data, peer_list->peers[1].size );
    peer_list->changeset.data = new_peers;
    peer_list->changeset.size = sizeof( ot_peer ) * peer_list->peers[1].size;
  } else {
    free( peer_list->changeset.data );

    memset( &peer_list->changeset, 0, sizeof( ot_vector ) );
  }
#endif

  peers_count = seeds_count = 0;
  for( i = 0; i < OT_POOLS_COUNT; ++i ) {
    peers_count += peer_list->peers[i].size;
    seeds_count += peer_list->seed_counts[i];
  }
  peer_list->seed_count = seeds_count;
  peer_list->peer_count = peers_count;

  if( peers_count )
    peer_list->base = NOW;
  else {
    /* When we got here, the last time that torrent
       has been touched is OT_POOLS_COUNT units before */
    peer_list->base = NOW - OT_POOLS_COUNT;
  }
  return 0;
}

/* Clean up all peers in current bucket, remove timedout pools and
   torrents */
void clean_all_torrents( void ) {
  ot_vector         *torrents_list;
  size_t             i;
  static int         bucket;
  ot_time time_now = NOW;

  /* Search for an uncleaned bucked */
  while( ( all_torrents_clean[bucket] == time_now ) && ( ++bucket < OT_BUCKET_COUNT ) );
  if( bucket >= OT_BUCKET_COUNT ) {
    bucket = 0; return;
  }

  all_torrents_clean[bucket] = time_now;

  torrents_list = mutex_bucket_lock( bucket );
  for( i=0; i<torrents_list->size; ++i ) {
    ot_torrent *torrent = ((ot_torrent*)(torrents_list->data)) + i;
    if( clean_single_torrent( torrent ) ) {
      vector_remove_torrent( torrents_list, torrent );
      --i; continue;
    }
  }
  mutex_bucket_unlock( bucket );
}

void clean_init( void ) {
  byte_zero( all_torrents_clean, sizeof( all_torrents_clean ) );
}

void clean_deinit( void ) {
  byte_zero( all_torrents_clean, sizeof( all_torrents_clean ) );
}