为什么是utorrents磁铁Torrent文件抓取比我的python脚本快

Question

我正在尝试使用python脚本转换.torrent文件中的种子磁铁url。python脚本连接到dht并等待元数据，然后从它创建torrent文件。

。

#!/usr/bin/env python
'''
Created on Apr 19, 2012
@author: dan, Faless
    GNU GENERAL PUBLIC LICENSE - Version 3
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
    http://www.gnu.org/licenses/gpl-3.0.txt
'''
import shutil
import tempfile
import os.path as pt
import sys
import libtorrent as lt
from time import sleep

def magnet2torrent(magnet, output_name=None):
    if output_name and 
            not pt.isdir(output_name) and 
            not pt.isdir(pt.dirname(pt.abspath(output_name))):
        print("Invalid output folder: " + pt.dirname(pt.abspath(output_name)))
        print("")
        sys.exit(0)
    tempdir = tempfile.mkdtemp()
    ses = lt.session()
    params = {
        'save_path': tempdir,
        'duplicate_is_error': True,
        'storage_mode': lt.storage_mode_t(2),
        'paused': False,
        'auto_managed': True,
        'duplicate_is_error': True
    }
    handle = lt.add_magnet_uri(ses, magnet, params)
    print("Downloading Metadata (this may take a while)")
    while (not handle.has_metadata()):
        try:
            sleep(1)
        except KeyboardInterrupt:
            print("Aborting...")
            ses.pause()
            print("Cleanup dir " + tempdir)
            shutil.rmtree(tempdir)
            sys.exit(0)
    ses.pause()
    print("Done")
    torinfo = handle.get_torrent_info()
    torfile = lt.create_torrent(torinfo)
    output = pt.abspath(torinfo.name() + ".torrent")
    if output_name:
        if pt.isdir(output_name):
            output = pt.abspath(pt.join(
                output_name, torinfo.name() + ".torrent"))
        elif pt.isdir(pt.dirname(pt.abspath(output_name))):
            output = pt.abspath(output_name)
    print("Saving torrent file here : " + output + " ...")
    torcontent = lt.bencode(torfile.generate())
    f = open(output, "wb")
    f.write(lt.bencode(torfile.generate()))
    f.close()
    print("Saved! Cleaning up dir: " + tempdir)
    ses.remove_torrent(handle)
    shutil.rmtree(tempdir)
    return output

def showHelp():
    print("")
    print("USAGE: " + pt.basename(sys.argv[0]) + " MAGNET [OUTPUT]")
    print("  MAGNETt- the magnet url")
    print("  OUTPUTt- the output torrent file name")
    print("")

def main():
    if len(sys.argv) < 2:
        showHelp()
        sys.exit(0)
    magnet = sys.argv[1]
    output_name = None
    if len(sys.argv) >= 3:
        output_name = sys.argv[2]
    magnet2torrent(magnet, output_name)

if __name__ == "__main__":
    main()

上面的脚本需要大约1+分钟来获取元数据并创建.torrent文件，而utorrent客户端只需要几秒钟，为什么?

如何使我的脚本更快?

我想为大约1k+种子获取元数据。

。磁铁链接

magnet:?xt=urn:btih:BFEFB51F4670D682E98382ADF81014638A25105A&dn=openSUSE+13.2+DVD+x86_64.iso&tr=udp%3A%2F%2Ftracker.openbittorrent.com%3A80&tr=udp%3A%2F%2Ftracker.publicbt.com%3A80&tr=udp%3A%2F%2Ftracker.ccc.de%3A80

---

update:

我已经在脚本中像这样指定了已知的DHT路由器url。

session = lt.session()
session.listen_on(6881, 6891)
session.add_dht_router("router.utorrent.com", 6881)
session.add_dht_router("router.bittorrent.com", 6881)
session.add_dht_router("dht.transmissionbt.com", 6881)
session.add_dht_router("router.bitcomet.com", 6881)
session.add_dht_router("dht.aelitis.com", 6881)
session.start_dht()

但是仍然很慢，有时会出现

这样的错误

DHT error [hostname lookup] (1) Host not found (authoritative)
could not map port using UPnP: no router found

---

update:

我写了这个小脚本，从DB中获取十六进制信息哈希，并试图从dht中获取元数据，然后在DB中插入torrent文件。

我让它无限期地运行，因为我不知道如何保存状态，所以保持它运行将获得更多的对等体和获取元数据将更快。

#!/usr/bin/env python
# this file will run as client or daemon and fetch torrent meta data i.e. torrent files from magnet uri
import libtorrent as lt # libtorrent library
import tempfile # for settings parameters while fetching metadata as temp dir
import sys #getting arguiments from shell or exit script
from time import sleep #sleep
import shutil # removing directory tree from temp directory 
import os.path # for getting pwd and other things
from pprint import pprint # for debugging, showing object data
import MySQLdb # DB connectivity 
import os
from datetime import date, timedelta
#create lock file to make sure only single instance is running
lock_file_name = "/daemon.lock"
if(os.path.isfile(lock_file_name)):
    sys.exit('another instance running')
#else:
    #f = open(lock_file_name, "w")
    #f.close()
session = lt.session()
session.listen_on(6881, 6891)
session.add_dht_router("router.utorrent.com", 6881)
session.add_dht_router("router.bittorrent.com", 6881)
session.add_dht_router("dht.transmissionbt.com", 6881)
session.add_dht_router("router.bitcomet.com", 6881)
session.add_dht_router("dht.aelitis.com", 6881)
session.start_dht()
alive = True
while alive:
    db_conn = MySQLdb.connect(  host = 'localhost',     user = '',  passwd = '',    db = 'basesite',    unix_socket='') # Open database connection
    #print('reconnecting')
    #get all records where enabled = 0 and uploaded within yesterday 
    subset_count = 5 ;
    yesterday = date.today() - timedelta(1)
    yesterday = yesterday.strftime('%Y-%m-%d %H:%M:%S')
    #print(yesterday)
    total_count_query = ("SELECT COUNT(*) as total_count FROM content WHERE upload_date > '"+ yesterday +"' AND enabled = '0' ")
    #print(total_count_query)
    try:
        total_count_cursor = db_conn.cursor()# prepare a cursor object using cursor() method
        total_count_cursor.execute(total_count_query) # Execute the SQL command
        total_count_results = total_count_cursor.fetchone() # Fetch all the rows in a list of lists.
        total_count = total_count_results[0]
        print(total_count)
    except:
            print "Error: unable to select data"
    total_pages = total_count/subset_count
    #print(total_pages)
    current_page = 1
    while(current_page <= total_pages):
        from_count = (current_page * subset_count) - subset_count
        #print(current_page)
        #print(from_count)
        hashes = []
        get_mysql_data_query = ("SELECT hash FROM content WHERE upload_date > '" + yesterday +"' AND enabled = '0' ORDER BY record_num ASC LIMIT "+ str(from_count) +" , " + str(subset_count) +" ")
        #print(get_mysql_data_query)
        try:
            get_mysql_data_cursor = db_conn.cursor()# prepare a cursor object using cursor() method
            get_mysql_data_cursor.execute(get_mysql_data_query) # Execute the SQL command
            get_mysql_data_results = get_mysql_data_cursor.fetchall() # Fetch all the rows in a list of lists.
            for row in get_mysql_data_results:
                hashes.append(row[0].upper())
        except:
            print "Error: unable to select data"
        print(hashes)
        handles = []
        for hash in hashes:
            tempdir = tempfile.mkdtemp()
            add_magnet_uri_params = {
                'save_path': tempdir,
                'duplicate_is_error': True,
                'storage_mode': lt.storage_mode_t(2),
                'paused': False,
                'auto_managed': True,
                'duplicate_is_error': True
            }
            magnet_uri = "magnet:?xt=urn:btih:" + hash.upper() + "&tr=udp%3A%2F%2Ftracker.openbittorrent.com%3A80&tr=udp%3A%2F%2Ftracker.publicbt.com%3A80&tr=udp%3A%2F%2Ftracker.ccc.de%3A80"
            #print(magnet_uri)
            handle = lt.add_magnet_uri(session, magnet_uri, add_magnet_uri_params)
            handles.append(handle) #push handle in handles list
        #print("handles length is :")
        #print(len(handles))
        while(len(handles) != 0):
            for h in handles:
                #print("inside handles for each loop")
                if h.has_metadata():
                    torinfo = h.get_torrent_info()
                    final_info_hash = str(torinfo.info_hash())
                    final_info_hash = final_info_hash.upper()
                    torfile = lt.create_torrent(torinfo)
                    torcontent = lt.bencode(torfile.generate())
                    tfile_size = len(torcontent)
                    try:
                        insert_cursor = db_conn.cursor()# prepare a cursor object using cursor() method
                        insert_cursor.execute("""INSERT INTO dht_tfiles (hash, tdata) VALUES (%s, %s)""",  [final_info_hash , torcontent] )
                        db_conn.commit()
                        #print "data inserted in DB"
                    except MySQLdb.Error, e:
                        try:
                            print "MySQL Error [%d]: %s" % (e.args[0], e.args[1])
                        except IndexError:
                            print "MySQL Error: %s" % str(e)    
                    shutil.rmtree(h.save_path())    #   remove temp data directory
                    session.remove_torrent(h) # remove torrnt handle from session   
                    handles.remove(h) #remove handle from list
                else:
                    if(h.status().active_time > 600):   # check if handle is more than 10 minutes old i.e. 600 seconds
                        #print('remove_torrent')
                        shutil.rmtree(h.save_path())    #   remove temp data directory
                        session.remove_torrent(h) # remove torrnt handle from session   
                        handles.remove(h) #remove handle from list
                sleep(1)        
                #print('sleep1')
        print('sleep10')
        sleep(10)
        current_page = current_page + 1
    #print('sleep20')
    sleep(20)
os.remove(lock_file_name);

现在我需要按照Arvid的建议实现新的东西。

---

我已经设法实现了Arvid的建议。和一些更多的扩展我发现在洪水支持论坛http://forum.deluge-torrent.org/viewtopic.php?f=7&t=42299&start=10

#!/usr/bin/env python
import libtorrent as lt # libtorrent library
import tempfile # for settings parameters while fetching metadata as temp dir
import sys #getting arguiments from shell or exit script
from time import sleep #sleep
import shutil # removing directory tree from temp directory 
import os.path # for getting pwd and other things
from pprint import pprint # for debugging, showing object data
import MySQLdb # DB connectivity 
import os
from datetime import date, timedelta
def var_dump(obj):
  for attr in dir(obj):
    print "obj.%s = %s" % (attr, getattr(obj, attr))
session = lt.session()
session.add_extension('ut_pex')
session.add_extension('ut_metadata')
session.add_extension('smart_ban')
session.add_extension('metadata_transfer')  
#session = lt.session(lt.fingerprint("DE", 0, 1, 0, 0), flags=1)
session_save_filename = "/tmp/new.client.save_state"
if(os.path.isfile(session_save_filename)):
    fileread = open(session_save_filename, 'rb')
    session.load_state(lt.bdecode(fileread.read()))
    fileread.close()
    print('session loaded from file')
else:
    print('new session started')
session.add_dht_router("router.utorrent.com", 6881)
session.add_dht_router("router.bittorrent.com", 6881)
session.add_dht_router("dht.transmissionbt.com", 6881)
session.add_dht_router("router.bitcomet.com", 6881)
session.add_dht_router("dht.aelitis.com", 6881)
session.start_dht()
alerts = [] 
alive = True
while alive:
    a = session.pop_alert()
    alerts.append(a)
    print('----------')
    for a in alerts:
        var_dump(a)
        alerts.remove(a)

    print('sleep10')
    sleep(10)
    filewrite = open(session_save_filename, "wb")
    filewrite.write(lt.bencode(session.save_state()))
    filewrite.close()

让它运行一分钟并收到警报

obj.msg = no router found 

---

update:

经过一些测试后看起来像

session.add_dht_router("router.bitcomet.com", 6881)

造成

('%s: %s', 'alert', 'DHT error [hostname lookup] (1) Host not found (authoritative)')

---

更新:我加了

session.start_dht()
session.start_lsd()
session.start_upnp()
session.start_natpmp()

and got alert

('%s: %s', 'portmap_error_alert', 'could not map port using UPnP: no router found')

Answer 1

正如MatteoItalia所指出的，引导DHT不是瞬间的，有时可能需要一段时间。当引导过程完成时，没有明确定义的时间点，它是一个不断与网络连接的连续体。

连接得越多，你知道的好的、稳定的节点越多，查找就会越快。分解大多数引导过程的一种方法(以获得更多的苹果与苹果的比较)是在获得dht_bootstrap_alert之后开始对进行定时器(并且在此之前不要添加磁铁链接)。

添加dht引导节点将主要使能够引导，但它仍然不一定特别快。您通常需要大约270个节点(包括替换节点)被认为是自引导的。

要加快引导过程，您可以做的一件事是确保保存和加载会话状态，其中包括dht路由表。这将重新加载前一个会话中的所有节点到路由表中，并且(假设您没有更改IP并且一切正常工作)引导应该更快。

确保没有在会话构造函数中启动DHT(作为flags参数，只需传入add_default_plugins)，加载状态，添加路由器节点，然后启动DHT。

不幸的是，在内部工作时涉及到很多活动部分，排序很重要，可能存在微妙的问题。

另外，请注意保持DHT连续运行会更快，因为重新加载状态仍然需要经过引导，它只会有更多的节点在前面ping并尝试"连接"。

禁用start_default_features标志也意味着UPnP和NAT-PMP将不会启动，如果您使用这些，您将不得不手动启动它们