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(trunk libT) simplify the code in peer-mgr.c's rechokeDownloads(). 

The new code has fewer calls to malloc/free and, more importantly, has less copy-and-pasted code to handle the different rechoke states.
This commit is contained in:
Jordan Lee 2011-04-29 23:25:12 +00:00
parent 92ad42e10c
commit 841bfffff8
1 changed files with 68 additions and 73 deletions
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141
libtransmission/peer-mgr.c
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@ -2746,9 +2746,10 @@ tr_peerMgrPeerStats( const tr_torrent * tor, int * setmeCount )
return ret;
}
/**
***
**/
/***
****
****
***/
void
tr_peerMgrClearInterest( tr_torrent * tor )
@ -2795,24 +2796,46 @@ isPeerInteresting( const tr_torrent * tor, const tr_peer * peer )
return false;
}
typedef enum
{
RECHOKE_STATE_GOOD,
RECHOKE_STATE_UNTESTED,
RECHOKE_STATE_BAD
}
tr_rechoke_state;
struct tr_rechoke_info
{
tr_peer * peer;
int salt;
int rechoke_state;
};
static int
compare_rechoke_info( const void * va, const void * vb )
{
const struct tr_rechoke_info * a = va;
const struct tr_rechoke_info * b = vb;
if( a->rechoke_state != b->rechoke_state )
return a->rechoke_state - b->rechoke_state;
return a->salt - b->salt;
}
/* determines who we send "interested" messages to */
static void
rechokeDownloads( Torrent * t )
{
int i;
const time_t now = tr_time( );
int maxPeers = 0;
int rechoke_count = 0;
struct tr_rechoke_info * rechoke = NULL;
const int MIN_INTERESTING_PEERS = 5;
const int peerCount = tr_ptrArraySize( &t->peers );
int maxPeers = 0;
const time_t now = tr_time( );
int badCount = 0;
int goodCount = 0;
int untestedCount = 0;
tr_peer ** bad = tr_new( tr_peer*, peerCount );
tr_peer ** good = tr_new( tr_peer*, peerCount );
tr_peer ** untested = tr_new( tr_peer*, peerCount );
/* decide how many peers to be interested in */
/* decide HOW MANY peers to be interested in */
{
int blocks = 0;
int cancels = 0;
@ -2880,79 +2903,51 @@ rechokeDownloads( Torrent * t )
t->maxPeers = maxPeers;
/* separate the peers into "good" (ones with a low cancel-to-block ratio),
* untested peers, and "bad" (ones with a high cancel-to-block ratio).
* That's the order in which we'll choose who to show interest in */
/* decide WHICH peers to be interested in (based on their cancel-to-block ratio) */
for( i=0; i<peerCount; ++i )
{
/* Randomize the peer array so the peers in the three groups will be unsorted... */
int n = peerCount;
tr_peer ** peers = tr_memdup( tr_ptrArrayBase( &t->peers ), n * sizeof( tr_peer * ) );
tr_peer * peer = tr_ptrArrayNth( &t->peers, i );
while( n > 0 )
if( !isPeerInteresting( t->tor, peer ) )
{
const int i = tr_cryptoWeakRandInt( n );
tr_peer * peer = peers[i];
tr_peerMsgsSetInterested( peer->msgs, false );
}
else
{
tr_rechoke_state rechoke_state;
const int blocks = tr_historyGet( &peer->blocksSentToClient, now, CANCEL_HISTORY_SEC );
const int cancels = tr_historyGet( &peer->cancelsSentToPeer, now, CANCEL_HISTORY_SEC );
if( !isPeerInteresting( t->tor, peer ) )
{
tr_peerMsgsSetInterested( peer->msgs, false );
}
if( !blocks && !cancels )
rechoke_state = RECHOKE_STATE_UNTESTED;
else if( !cancels )
rechoke_state = RECHOKE_STATE_GOOD;
else if( !blocks )
rechoke_state = RECHOKE_STATE_BAD;
else if( ( cancels * 10 ) < blocks )
rechoke_state = RECHOKE_STATE_GOOD;
else
{
const int blocks = tr_historyGet( &peer->blocksSentToClient, now, CANCEL_HISTORY_SEC );
const int cancels = tr_historyGet( &peer->cancelsSentToPeer, now, CANCEL_HISTORY_SEC );
rechoke_state = RECHOKE_STATE_BAD;
if( !blocks && !cancels )
untested[untestedCount++] = peer;
else if( !cancels )
good[goodCount++] = peer;
else if( !blocks )
bad[badCount++] = peer;
else if( ( cancels * 10 ) < blocks )
good[goodCount++] = peer;
else
bad[badCount++] = peer;
}
if( rechoke == NULL )
rechoke = tr_new( struct tr_rechoke_info, peerCount );
/* remove 'peer' from the array 'peers' */
if( i != n - 1 )
peers[i] = peers[n-1];
--n;
rechoke[rechoke_count].peer = peer;
rechoke[rechoke_count].rechoke_state = rechoke_state;
rechoke[rechoke_count].salt = tr_cryptoWeakRandInt( INT_MAX );
rechoke_count++;
}
tr_free( peers );
}
t->interestedCount = 0;
/* We've decided (1) how many peers to be interested in,
* and (2) which peers are the best candidates,
* Now it's time to update our `interest' flags. */
for( i=0; i<goodCount; ++i ) {
const bool b = t->interestedCount < maxPeers;
tr_peerMsgsSetInterested( good[i]->msgs, b );
if( b )
++t->interestedCount;
}
for( i=0; i<untestedCount; ++i ) {
const bool b = t->interestedCount < maxPeers;
tr_peerMsgsSetInterested( untested[i]->msgs, b );
if( b )
++t->interestedCount;
}
for( i=0; i<badCount; ++i ) {
const bool b = t->interestedCount < maxPeers;
tr_peerMsgsSetInterested( bad[i]->msgs, b );
if( b )
++t->interestedCount;
}
/*fprintf( stderr, "num interested: %d\n", t->interestedCount );*/
/* now that we know which & how many peers to be interested in... update the peer interest */
qsort( rechoke, rechoke_count, sizeof( struct tr_rechoke_info ), compare_rechoke_info );
t->interestedCount = MIN( maxPeers, rechoke_count );
for( i=0; i<rechoke_count; ++i )
tr_peerMsgsSetInterested( rechoke[i].peer->msgs, i<t->interestedCount );
/* cleanup */
tr_free( untested );
tr_free( good );
tr_free( bad );
tr_free( rechoke );
}
/**