transmission/libtransmission/webseed.c

326 lines
8.9 KiB
C

/*
* This file Copyright (C) Mnemosyne LLC
*
* This file is licensed by the GPL version 2. Works owned by the
* Transmission project are granted a special exemption to clause 2(b)
* so that the bulk of its code can remain under the MIT license.
* This exemption does not extend to derived works not owned by
* the Transmission project.
*
* $Id$
*/
#include <string.h> /* strlen() */
#include <event2/buffer.h>
#include <event2/event.h>
#include "transmission.h"
#include "cache.h"
#include "inout.h" /* tr_ioFindFileLocation() */
#include "list.h"
#include "ratecontrol.h"
#include "peer-mgr.h"
#include "torrent.h"
#include "utils.h"
#include "web.h"
#include "webseed.h"
struct tr_webseed_task
{
tr_session * session;
struct evbuffer * content;
struct tr_webseed * webseed;
tr_block_index_t block;
tr_piece_index_t piece_index;
uint32_t piece_offset;
uint32_t length;
int torrent_id;
};
struct tr_webseed
{
tr_peer parent;
tr_ratecontrol download_rate;
tr_session * session;
tr_peer_callback * callback;
void * callback_data;
tr_list * tasks;
struct event * timer;
char * base_url;
size_t base_url_len;
int torrent_id;
tr_bool is_stopping;
};
enum
{
TR_IDLE_TIMER_MSEC = 2000
};
static void
webseed_free( struct tr_webseed * w )
{
tr_bitsetDestructor( &w->parent.have );
tr_free( w->parent.client );
event_free( w->timer );
tr_rcDestruct( &w->download_rate );
tr_free( w->base_url );
tr_free( w );
}
/***
****
***/
static const tr_peer_event blank_event = { 0, 0, 0, 0, 0.0f, 0, 0, 0 };
static void
publish( tr_webseed * w, tr_peer_event * e )
{
if( w->callback != NULL )
w->callback( &w->parent, e, w->callback_data );
}
static void
fire_client_got_block( tr_torrent * tor, tr_webseed * w, tr_block_index_t block )
{
tr_peer_event e = blank_event;
e.pieceIndex = tr_torBlockPiece( tor, block );
e.offset = tor->blockSize * block - tor->info.pieceSize * e.pieceIndex;
e.length = tr_torBlockCountBytes( tor, block );
e.eventType = TR_PEER_CLIENT_GOT_BLOCK;
publish( w, &e );
}
static void
fire_client_got_data( tr_webseed * w, uint32_t length )
{
tr_peer_event e = blank_event;
e.eventType = TR_PEER_CLIENT_GOT_DATA;
e.length = length;
e.wasPieceData = TRUE;
publish( w, &e );
}
/***
****
***/
static void
on_content_changed( struct evbuffer * buf UNUSED,
const struct evbuffer_cb_info * info,
void * vw )
{
tr_webseed * w = vw;
if( ( info->n_added > 0 ) && !w->is_stopping )
{
tr_rcTransferred( &w->download_rate, info->n_added );
fire_client_got_data( w, info->n_added );
}
}
static void task_request_next_chunk( struct tr_webseed_task * task );
static void
on_idle( tr_webseed * w )
{
tr_torrent * tor = tr_torrentFindFromId( w->session, w->torrent_id );
if( w->is_stopping && !tr_webseedIsActive( w ) )
{
webseed_free( w );
}
else if( !w->is_stopping && tor && tor->isRunning && !tr_torrentIsSeed( tor ) )
{
int i;
int got = 0;
const int max = tor->blockCountInPiece;
const int want = max - tr_list_size( w->tasks );
tr_block_index_t * blocks = NULL;
if( want > 0 )
{
blocks = tr_new( tr_block_index_t, want );
tr_peerMgrGetNextRequests( tor, &w->parent, want, blocks, &got );
}
for( i=0; i<got; ++i )
{
const tr_block_index_t b = blocks[i];
struct tr_webseed_task * task = tr_new( struct tr_webseed_task, 1 );
task->webseed = w;
task->session = w->session;
task->torrent_id = w->torrent_id;
task->block = b;
task->piece_index = tr_torBlockPiece( tor, b );
task->piece_offset = ( tor->blockSize * b )
- ( tor->info.pieceSize * task->piece_index );
task->length = tr_torBlockCountBytes( tor, b );
task->content = evbuffer_new( );
evbuffer_add_cb( task->content, on_content_changed, w );
tr_list_append( &w->tasks, task );
task_request_next_chunk( task );
}
tr_free( blocks );
}
}
static void
web_response_func( tr_session * session,
long response_code,
const void * response UNUSED,
size_t response_byte_count UNUSED,
void * vtask )
{
struct tr_webseed_task * t = vtask;
tr_torrent * tor = tr_torrentFindFromId( session, t->torrent_id );
const int success = ( response_code == 206 );
if( success && tor )
{
if( evbuffer_get_length( t->content ) < t->length )
{
task_request_next_chunk( t );
}
else
{
tr_webseed * w = t->webseed;
tr_cacheWriteBlock( session->cache, tor,
t->piece_index, t->piece_offset, t->length,
evbuffer_pullup( t->content, -1 ) );
fire_client_got_block( tor, w, t->block );
tr_list_remove_data( &w->tasks, t );
evbuffer_free( t->content );
tr_free( t );
on_idle( w );
}
}
}
static char*
make_url( tr_webseed * w, const tr_file * file )
{
struct evbuffer * out = evbuffer_new( );
evbuffer_add( out, w->base_url, w->base_url_len );
/* if url ends with a '/', add the torrent name */
if( w->base_url[w->base_url_len - 1] == '/' && file->name )
tr_http_escape( out, file->name, strlen(file->name), FALSE );
return evbuffer_free_to_str( out );
}
static void
task_request_next_chunk( struct tr_webseed_task * t )
{
tr_torrent * tor = tr_torrentFindFromId( t->session, t->torrent_id );
if( tor != NULL )
{
char * url;
char range[64];
const tr_info * inf = tr_torrentInfo( tor );
const uint32_t remain = t->length - evbuffer_get_length( t->content );
const uint64_t total_offset = inf->pieceSize * t->piece_index
+ t->piece_offset
+ evbuffer_get_length( t->content );
const tr_piece_index_t step_piece = total_offset / inf->pieceSize;
const uint32_t step_piece_offset
= total_offset - ( inf->pieceSize * step_piece );
tr_file_index_t file_index;
uint64_t file_offset;
const tr_file * file;
uint32_t this_pass;
tr_ioFindFileLocation( tor, step_piece, step_piece_offset,
&file_index, &file_offset );
file = &inf->files[file_index];
this_pass = MIN( remain, file->length - file_offset );
url = make_url( t->webseed, file );
tr_snprintf( range, sizeof range, "%"PRIu64"-%"PRIu64,
file_offset, file_offset + this_pass - 1 );
tr_webRunWithBuffer( t->session, url, range,
web_response_func, t, t->content );
tr_free( url );
}
}
tr_bool
tr_webseedIsActive( const tr_webseed * w )
{
return w->tasks != NULL;
}
tr_bool
tr_webseedGetSpeed_Bps( const tr_webseed * w, uint64_t now, int * setme_Bps )
{
const tr_bool is_active = tr_webseedIsActive( w );
*setme_Bps = is_active ? tr_rcRate_Bps( &w->download_rate, now ) : 0;
return is_active;
}
/***
****
***/
static void
webseed_timer_func( evutil_socket_t foo UNUSED, short bar UNUSED, void * vw )
{
tr_webseed * w = vw;
on_idle( w );
tr_timerAddMsec( w->timer, TR_IDLE_TIMER_MSEC );
}
tr_webseed*
tr_webseedNew( struct tr_torrent * tor,
const char * url,
tr_peer_callback * callback,
void * callback_data )
{
tr_webseed * w = tr_new0( tr_webseed, 1 );
tr_peer * peer = &w->parent;
peer->peerIsChoked = TRUE;
peer->clientIsInterested = !tr_torrentIsSeed( tor );
tr_bitsetConstructor( &peer->have, tor->info.pieceCount );
tr_bitsetSetHaveAll( &peer->have );
peer->progress = 1.0;
peer->client = tr_strdup( "webseed" );
w->torrent_id = tr_torrentId( tor );
w->session = tor->session;
w->base_url_len = strlen( url );
w->base_url = tr_strndup( url, w->base_url_len );
w->callback = callback;
w->callback_data = callback_data;
tr_rcConstruct( &w->download_rate );
w->timer = evtimer_new( w->session->event_base, webseed_timer_func, w );
tr_timerAddMsec( w->timer, TR_IDLE_TIMER_MSEC );
return w;
}
void
tr_webseedFree( tr_webseed * w )
{
if( w )
{
if( tr_webseedIsActive( w ) )
w->is_stopping = TRUE;
else
webseed_free( w );
}
}