From 70a65f284257a4564cf80acb5b1e7a3b81efe149 Mon Sep 17 00:00:00 2001
From: erdgeist <>
Date: Sun, 4 Feb 2007 03:29:29 +0000
Subject: Add a lot of documentation for static functions in trackerlogic.c.
Make vector_remove_peer use hysteresis only, if pool is expected to grow
again. Remove too old torrents.
---
trackerlogic.c | 78 ++++++++++++++++++++++++++++++++++++++--------------------
1 file changed, 52 insertions(+), 26 deletions(-)
diff --git a/trackerlogic.c b/trackerlogic.c
index acd89b6..d112abd 100644
--- a/trackerlogic.c
+++ b/trackerlogic.c
@@ -34,6 +34,11 @@ int g_check_blacklist = 1;
static ot_torrent* const OT_TORRENT_ON_BLACKLIST = (ot_torrent*)2;
#endif
+/* Converter function from memory to human readable hex strings
+ - definitely not thread safe!!!
+*/
+static char ths[2+2*20]="-";static char*to_hex(ot_byte*s){const char*m="0123456789ABCDEF";char*e=ths+41;char*t=ths+1;while(t<e){*t++=m[*s>>4];*t++=m[*s++&15];}*t=0;return ths+1;}
+
/* This function gives us a binary search that returns a pointer, even if
no exact match is found. In that case it sets exactmatch 0 and gives
calling functions the chance to insert data
@@ -58,11 +63,13 @@ static void *binary_search( const void * const key, const void * base, const siz
return (void*)lookat;
}
-/* Converter function from memory to human readable hex strings
- - definitely not thread safe!!!
+/* This is the generic insert operation for our vector type.
+ It tries to locate the object at "key" with size "member_size" by comparing its first "compare_size" bytes with
+ those of objects in vector. Our special "binary_search" function does that and either returns the match or a
+ pointer to where the object is to be inserted. vector_find_or_insert makes space for the object and copies it,
+ if it wasn't found in vector. Caller needs to check the passed "exactmatch" variable to see, whether an insert
+ took place. If resizing the vector failed, NULL is returned, else the pointer to the object in vector.
*/
-char ths[2+2*20]="-";char*to_hex(ot_byte*s){char*m="0123456789ABCDEF";char*e=ths+41;char*t=ths+1;while(t<e){*t++=m[*s>>4];*t++=m[*s++&15];}*t=0;return ths+1;}
-
static void *vector_find_or_insert( ot_vector *vector, void *key, size_t member_size, size_t compare_size, int *exactmatch ) {
ot_byte *match = binary_search( key, vector->data, vector->size, member_size, compare_size, exactmatch );
@@ -83,9 +90,16 @@ static void *vector_find_or_insert( ot_vector *vector, void *key, size_t member_
vector->size++;
return match;
}
-
-static int vector_remove_peer( ot_vector *vector, ot_peer *peer ) {
- int exactmatch;
+
+/* This is the non-generic delete from vector-operation specialized for peers in pools.
+ Set hysteresis == 0 if you expect the vector not to ever grow again.
+ It returns 0 if no peer was found (and thus not removed)
+ 1 if a non-seeding peer was removed
+ 2 if a seeding peer was removed
+*/
+static int vector_remove_peer( ot_vector *vector, ot_peer *peer, int hysteresis ) {
+ int exactmatch;
+ size_t shrink_thresh = hysteresis ? OT_VECTOR_SHRINK_THRESH : OT_VECTOR_SHRINK_RATIO;
ot_peer *end = ((ot_peer*)vector->data) + vector->size;
ot_peer *match;
@@ -95,7 +109,7 @@ static int vector_remove_peer( ot_vector *vector, ot_peer *peer ) {
if( !exactmatch ) return 0;
exactmatch = ( OT_FLAG( match ) & PEER_FLAG_SEEDING ) ? 2 : 1;
memmove( match, match + 1, sizeof(ot_peer) * ( end - match - 1 ) );
- if( ( --vector->size * OT_VECTOR_SHRINK_THRESH < vector->space ) && ( vector->space > OT_VECTOR_MIN_MEMBERS ) ) {
+ if( ( --vector->size * shrink_thresh < vector->space ) && ( vector->space > OT_VECTOR_MIN_MEMBERS ) ) {
vector->space /= OT_VECTOR_SHRINK_RATIO;
vector->data = realloc( vector->data, vector->space * sizeof( ot_peer ) );
}
@@ -117,14 +131,18 @@ static void free_peerlist( ot_peerlist *peer_list ) {
free( peer_list );
}
+/* This is the non-generic delete from vector-operation specialized for torrents in buckets.
+ it returns 0 if the hash wasn't found in vector
+ 1 if the torrent was removed from vector
+*/
static int vector_remove_torrent( ot_vector *vector, ot_hash *hash ) {
int exactmatch;
ot_torrent *end = ((ot_torrent*)vector->data) + vector->size;
ot_torrent *match;
if( !vector->size ) return 0;
- match = binary_search( hash, vector->data, vector->size, sizeof( ot_torrent ), OT_HASH_COMPARE_SIZE, &exactmatch );
+ match = binary_search( hash, vector->data, vector->size, sizeof( ot_torrent ), OT_HASH_COMPARE_SIZE, &exactmatch );
if( !exactmatch ) return 0;
/* If this is being called after a unsuccessful malloc() for peer_list
@@ -139,8 +157,11 @@ static int vector_remove_torrent( ot_vector *vector, ot_hash *hash ) {
return 1;
}
-/* Returns 1, if torrent is gone, 0 otherwise
- We expect NOW as a parameter since calling time() may be expensive*/
+/* This function deallocates all timedouted pools and shifts all other pools
+ it Returns 1 if torrent itself has not seen an announce for more than OT_TORRENT_TIMEOUT time units
+ 0 if torrent is not yet timed out
+ Note: We expect NOW as a parameter since calling time() may be expensive
+*/
static int clean_peerlist( time_t time_now, ot_peerlist *peer_list ) {
int i, timedout = (int)( time_now - peer_list->base );
@@ -156,8 +177,11 @@ static int clean_peerlist( time_t time_now, ot_peerlist *peer_list ) {
memmove( peer_list->seed_count + timedout, peer_list->seed_count, sizeof( size_t ) * ( OT_POOLS_COUNT - timedout) );
byte_zero( peer_list->seed_count, sizeof( size_t ) * timedout );
- peer_list->base = NOW;
- return timedout == OT_POOLS_COUNT;
+ if( timedout == OT_POOLS_COUNT )
+ return time_now - peer_list->base > OT_TORRENT_TIMEOUT;
+
+ peer_list->base = time_now;
+ return 0;
}
ot_torrent *add_peer_to_torrent( ot_hash *hash, ot_peer *peer ) {
@@ -187,13 +211,12 @@ ot_torrent *add_peer_to_torrent( ot_hash *hash, ot_peer *peer ) {
/* Create a new torrent entry, then */
memmove( &torrent->hash, hash, sizeof( ot_hash ) );
- torrent->peer_list = malloc( sizeof (ot_peerlist) );
- if( !torrent->peer_list ) {
+ if( !( torrent->peer_list = malloc( sizeof (ot_peerlist) ) ) ) {
vector_remove_torrent( torrents_list, hash );
return NULL;
}
- byte_zero( torrent->peer_list, sizeof( ot_peerlist ));
+ byte_zero( torrent->peer_list, sizeof( ot_peerlist ) );
torrent->peer_list->base = NOW;
} else
clean_peerlist( NOW, torrent->peer_list );
@@ -201,7 +224,7 @@ ot_torrent *add_peer_to_torrent( ot_hash *hash, ot_peer *peer ) {
peer_pool = &torrent->peer_list->peers[0];
peer_dest = vector_find_or_insert( peer_pool, (void*)peer, sizeof( ot_peer ), OT_PEER_COMPARE_SIZE, &exactmatch );
- if( OT_FLAG(peer) & PEER_FLAG_COMPLETED )
+ if( OT_FLAG( peer ) & PEER_FLAG_COMPLETED )
torrent->peer_list->downloaded++;
/* If we hadn't had a match in current pool, create peer there and
@@ -213,7 +236,7 @@ ot_torrent *add_peer_to_torrent( ot_hash *hash, ot_peer *peer ) {
torrent->peer_list->seed_count[0]++;
for( i=1; i<OT_POOLS_COUNT; ++i ) {
- switch( vector_remove_peer( &torrent->peer_list->peers[i], peer ) ) {
+ switch( vector_remove_peer( &torrent->peer_list->peers[i], peer, 0 ) ) {
case 0: continue;
case 2: torrent->peer_list->seed_count[i]--;
case 1: default: return torrent;
@@ -231,7 +254,7 @@ ot_torrent *add_peer_to_torrent( ot_hash *hash, ot_peer *peer ) {
}
/* Compiles a list of random peers for a torrent
- * reply must have enough space to hold 24+6*amount bytes
+ * reply must have enough space to hold 92+6*amount bytes
* Selector function can be anything, maybe test for seeds, etc.
* RANDOM may return huge values
* does not yet check not to return self
@@ -349,7 +372,7 @@ size_t return_memstat_for_tracker( char **reply ) {
if( !( r = *reply = malloc( 256*32 + (43+OT_POOLS_COUNT*32)*torrent_count ) ) ) return 0;
for( i=0; i<256; ++i )
- r += sprintf( r, "%02X: %04X %04X\n", i, (ot_dword)all_torrents[i].size, (ot_dword)all_torrents[i].space );
+ r += sprintf( r, "%02X: %08X %08X\n", i, (unsigned int)all_torrents[i].size, (unsigned int)all_torrents[i].space );
for( i=0; i<256; ++i ) {
ot_vector *torrents_list = &all_torrents[i];
@@ -359,7 +382,7 @@ size_t return_memstat_for_tracker( char **reply ) {
r += sprintf( r, "\n%s:\n", to_hex( (ot_byte*)hash ) );
clean_peerlist( time_now, peer_list );
for( k=0; k<OT_POOLS_COUNT; ++k )
- r += sprintf( r, "\t%04X %04X\n", peer_list->peers[k].size, peer_list->peers[k].space );
+ r += sprintf( r, "\t%04X %04X\n", ((unsigned int)peer_list->peers[k].size), (unsigned int)peer_list->peers[k].space );
}
}
@@ -432,7 +455,13 @@ size_t return_stats_for_tracker( char *reply, int mode ) {
for( j=0; j<torrents_list->size; ++j ) {
ot_peerlist *peer_list = ( ((ot_torrent*)(torrents_list->data))[j] ).peer_list;
size_t local_peers = 0, local_seeds = 0;
- clean_peerlist( time_now, peer_list );
+
+ if( clean_peerlist( time_now, peer_list ) ) {
+ ot_hash *hash =&( ((ot_torrent*)(torrents_list->data))[j] ).hash;
+ vector_remove_torrent( torrents_list->data, hash );
+ --j;
+ continue;
+ }
for( k=0; k<OT_POOLS_COUNT; ++k ) {
local_peers += peer_list->peers[k].size;
local_seeds += peer_list->seed_count[k];
@@ -480,15 +509,12 @@ void remove_peer_from_torrent( ot_hash *hash, ot_peer *peer ) {
/* Maybe this does the job */
if( clean_peerlist( NOW, torrent->peer_list ) ) {
-#ifdef WANT_CLOSED_TRACKER
- if( !g_closedtracker )
-#endif
vector_remove_torrent( torrents_list, hash );
return;
}
for( i=0; i<OT_POOLS_COUNT; ++i )
- switch( vector_remove_peer( &torrent->peer_list->peers[i], peer ) ) {
+ switch( vector_remove_peer( &torrent->peer_list->peers[i], peer, i == 0 ) ) {
case 0: continue;
case 2: torrent->peer_list->seed_count[i]--;
case 1: default: return;
--
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