ot_sync.c

   1 /* This software was written by Dirk Engling <erdgeist@erdgeist.org>
   2    It is considered beerware. Prost. Skol. Cheers or whatever.
   3
   4    $id$ */
   5
   6 /* System */
   7 #include <sys/types.h>
   8 #include <sys/mman.h>
   9 #include <sys/uio.h>
  10 #include <stdio.h>
  11 #include <string.h>
  12 #include <pthread.h>
  13
  14 /* Libowfat */
  15 #include "scan.h"
  16 #include "byte.h"
  17 #include "io.h"
  18
  19 /* Opentracker */
  20 #include "trackerlogic.h"
  21 #include "ot_mutex.h"
  22 #include "ot_sync.h"
  23 #include "ot_stats.h"
  24 #include "ot_iovec.h"
  25
  26 #ifdef WANT_SYNC_BATCH
  27
  28 #define OT_SYNC_CHUNK_SIZE (512*1024)
  29
  30 /* Import Changeset from an external authority
  31    format: d4:syncd[..]ee
  32    [..]:   ( 20:01234567890abcdefghij16:XXXXYYYY )+
  33 */
  34 int add_changeset_to_tracker( uint8_t *data, size_t len ) {
  35   ot_hash    *hash;
  36   uint8_t    *end = data + len;
  37   unsigned long      peer_count;
  38
  39   /* We do know, that the string is \n terminated, so it cant
  40      overflow */
  41   if( byte_diff( data, 8, "d4:syncd" ) ) return -1;
  42   data += 8;
  43
  44   while( 1 ) {
  45     if( byte_diff( data, 3, "20:" ) ) {
  46       if( byte_diff( data, 2, "ee" ) )
  47         return -1;
  48       return 0;
  49     }
  50     data += 3;
  51     hash = (ot_hash*)data;
  52     data += sizeof( ot_hash );
  53
  54     /* Scan string length indicator */
  55     data += ( len = scan_ulong( (char*)data, &peer_count ) );
  56
  57     /* If no long was scanned, it is not divisible by 8, it is not
  58        followed by a colon or claims to need to much memory, we fail */
  59     if( !len || !peer_count || ( peer_count & 7 ) || ( *data++ != ':' ) || ( data + peer_count > end ) )
  60       return -1;
  61
  62     while( peer_count > 0 ) {
  63       add_peer_to_torrent( hash, (ot_peer*)data, 1 );
  64       data += 8; peer_count -= 8;
  65     }
  66   }
  67   return 0;
  68 }
  69
  70 /* Proposed output format
  71    d4:syncd20:<info_hash>8*N:(xxxxyyyy)*Nee
  72 */
  73 static void sync_make( int *iovec_entries, struct iovec **iovector ) {
  74   int    bucket;
  75   char  *r, *re;
  76
  77   /* Setup return vector... */
  78   *iovec_entries = 0;
  79   *iovector = NULL;
  80   if( !( r = iovec_increase( iovec_entries, iovector, OT_SYNC_CHUNK_SIZE ) ) )
  81     return;
  82
  83   /* ... and pointer to end of current output buffer.
  84      This works as a low watermark */
  85   re = r + OT_SYNC_CHUNK_SIZE;
  86
  87   memmove( r, "d4:syncd", 8 ); r += 8;
  88
  89   /* For each bucket... */
  90   for( bucket=0; bucket<OT_BUCKET_COUNT; ++bucket ) {
  91     /* Get exclusive access to that bucket */
  92     ot_vector *torrents_list = mutex_bucket_lock( bucket );
  93     size_t tor_offset;
  94
  95     /* For each torrent in this bucket.. */
  96     for( tor_offset=0; tor_offset<torrents_list->size; ++tor_offset ) {
  97       /* Address torrents members */
  98       ot_peerlist *peer_list = ( ((ot_torrent*)(torrents_list->data))[tor_offset] ).peer_list;
  99       ot_hash     *hash      =&( ((ot_torrent*)(torrents_list->data))[tor_offset] ).hash;
 100       const size_t byte_count = sizeof(ot_peer) * peer_list->changeset.size;
 101
 102       /* If we reached our low watermark in buffer... */
 103       if( re - r <= (ssize_t)(/* strlen( "20:" ) == */ 3 + sizeof( ot_hash ) + /* strlen_max( "%zd" ) == */ 12 + byte_count ) ) {
 104
 105         /* Allocate a fresh output buffer at the end of our buffers list
 106            release bucket and return, if that fails */
 107         if( !( r = iovec_fix_increase_or_free( iovec_entries, iovector, r, OT_SYNC_CHUNK_SIZE ) ) )
 108           return mutex_bucket_unlock( bucket );
 109
 110         /* Adjust new end of output buffer */
 111         re = r + OT_SYNC_CHUNK_SIZE;
 112       }
 113
 114       *r++ = '2'; *r++ = '0'; *r++ = ':';
 115       memmove( r, hash, sizeof( ot_hash ) ); r += sizeof( ot_hash );
 116       r += sprintf( r, "%zd:", byte_count );
 117       memmove( r, peer_list->changeset.data, byte_count ); r += byte_count;
 118     }
 119
 120     /* All torrents done: release lock on currenct bucket */
 121     mutex_bucket_unlock( bucket );
 122   }
 123
 124   /* Close bencoded sync dictionary */
 125   *r++='e'; *r++='e';
 126
 127   /* Release unused memory in current output buffer */
 128   iovec_fixlast( iovec_entries, iovector, r );
 129 }
 130
 131 /* This is the entry point into this worker thread
 132    It grabs tasks from mutex_tasklist and delivers results back
 133 */
 134 static void * sync_worker( void * args) {
 135   int iovec_entries;
 136   struct iovec *iovector;
 137
 138   args = args;
 139
 140   while( 1 ) {
 141     ot_tasktype tasktype = TASK_SYNC_OUT;
 142     ot_taskid   taskid   = mutex_workqueue_poptask( &tasktype );
 143     sync_make( &iovec_entries, &iovector );
 144     stats_issue_event( EVENT_SYNC_OUT, FLAG_TCP, iovec_length( &iovec_entries, &iovector) );
 145     if( mutex_workqueue_pushresult( taskid, iovec_entries, iovector ) )
 146       iovec_free( &iovec_entries, &iovector );
 147   }
 148   return NULL;
 149 }
 150
 151 static pthread_t thread_id;
 152 void sync_init( ) {
 153   pthread_create( &thread_id, NULL, sync_worker, NULL );
 154 }
 155
 156 void sync_deinit( ) {
 157   pthread_cancel( thread_id );
 158 }
 159
 160 void sync_deliver( int64 socket ) {
 161   mutex_workqueue_pushtask( socket, TASK_SYNC_OUT );
 162 }
 163
 164 #endif
 165
 166 const char *g_version_sync_c = "$Source$: $Revision$\n";