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opentracker/ot_sync.c

175 lines
4.7 KiB
C

/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
It is considered beerware. Prost. Skol. Cheers or whatever.
$id$ */
/* System */
#include <pthread.h>
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/uio.h>
/* Libowfat */
#include "byte.h"
#include "io.h"
#include "scan.h"
/* Opentracker */
#include "ot_iovec.h"
#include "ot_mutex.h"
#include "ot_stats.h"
#include "ot_sync.h"
#include "trackerlogic.h"
#ifdef WANT_SYNC_BATCH
#define OT_SYNC_CHUNK_SIZE (512 * 1024)
/* Import Changeset from an external authority
format: d4:syncd[..]ee
[..]: ( 20:01234567890abcdefghij16:XXXXYYYY )+
*/
int add_changeset_to_tracker(uint8_t *data, size_t len) {
ot_hash *hash;
uint8_t *end = data + len;
unsigned long peer_count;
/* We do know, that the string is \n terminated, so it cant
overflow */
if (byte_diff(data, 8, "d4:syncd"))
return -1;
data += 8;
while (1) {
if (byte_diff(data, 3, "20:")) {
if (byte_diff(data, 2, "ee"))
return -1;
return 0;
}
data += 3;
hash = (ot_hash *)data;
data += sizeof(ot_hash);
/* Scan string length indicator */
data += (len = scan_ulong((char *)data, &peer_count));
/* If no long was scanned, it is not divisible by 8, it is not
followed by a colon or claims to need to much memory, we fail */
if (!len || !peer_count || (peer_count & 7) || (*data++ != ':') || (data + peer_count > end))
return -1;
while (peer_count > 0) {
add_peer_to_torrent(hash, (ot_peer *)data, 1);
data += 8;
peer_count -= 8;
}
}
return 0;
}
/* Proposed output format
d4:syncd20:<info_hash>8*N:(xxxxyyyy)*Nee
*/
static void sync_make(int *iovec_entries, struct iovec **iovector) {
int bucket;
char *r, *re;
/* Setup return vector... */
*iovec_entries = 0;
*iovector = NULL;
if (!(r = iovec_increase(iovec_entries, iovector, OT_SYNC_CHUNK_SIZE)))
return;
/* ... and pointer to end of current output buffer.
This works as a low watermark */
re = r + OT_SYNC_CHUNK_SIZE;
memmove(r, "d4:syncd", 8);
r += 8;
/* For each bucket... */
for (bucket = 0; bucket < OT_BUCKET_COUNT; ++bucket) {
/* Get exclusive access to that bucket */
ot_vector *torrents_list = mutex_bucket_lock(bucket);
size_t tor_offset;
/* For each torrent in this bucket.. */
for (tor_offset = 0; tor_offset < torrents_list->size; ++tor_offset) {
/* Address torrents members */
ot_peerlist *peer_list = (((ot_torrent *)(torrents_list->data))[tor_offset]).peer_list;
ot_hash *hash = &(((ot_torrent *)(torrents_list->data))[tor_offset]).hash;
const size_t byte_count = sizeof(ot_peer) * peer_list->changeset.size;
/* If we reached our low watermark in buffer... */
if (re - r <= (ssize_t)(/* strlen( "20:" ) == */ 3 + sizeof(ot_hash) + /* strlen_max( "%zd" ) == */ 12 + byte_count)) {
/* Allocate a fresh output buffer at the end of our buffers list
release bucket and return, if that fails */
if (!(r = iovec_fix_increase_or_free(iovec_entries, iovector, r, OT_SYNC_CHUNK_SIZE)))
return mutex_bucket_unlock(bucket);
/* Adjust new end of output buffer */
re = r + OT_SYNC_CHUNK_SIZE;
}
*r++ = '2';
*r++ = '0';
*r++ = ':';
memmove(r, hash, sizeof(ot_hash));
r += sizeof(ot_hash);
r += sprintf(r, "%zd:", byte_count);
memmove(r, peer_list->changeset.data, byte_count);
r += byte_count;
}
/* All torrents done: release lock on currenct bucket */
mutex_bucket_unlock(bucket);
}
/* Close bencoded sync dictionary */
*r++ = 'e';
*r++ = 'e';
/* Release unused memory in current output buffer */
iovec_fixlast(iovec_entries, iovector, r);
}
/* This is the entry point into this worker thread
It grabs tasks from mutex_tasklist and delivers results back
*/
static void *sync_worker(void *args) {
int iovec_entries;
struct iovec *iovector;
args = args;
while (1) {
ot_tasktype tasktype = TASK_SYNC_OUT;
ot_taskid taskid = mutex_workqueue_poptask(&tasktype);
sync_make(&iovec_entries, &iovector);
stats_issue_event(EVENT_SYNC_OUT, FLAG_TCP, iovec_length(&iovec_entries, &iovector));
if (mutex_workqueue_pushresult(taskid, iovec_entries, iovector))
iovec_free(&iovec_entries, &iovector);
}
return NULL;
}
static pthread_t thread_id;
void sync_init( ) {
pthread_create( &thread_id, NULL, sync_worker, NULL );
}
void sync_deinit( ) {
pthread_cancel( thread_id );
}
void sync_deliver( int64 socket ) {
mutex_workqueue_pushtask( socket, TASK_SYNC_OUT );
}
#endif
const char *g_version_sync_c = "$Source$: $Revision$\n";