tahoe-lafs/src/allmydata/introducer/server.py

import time, os.path
from zope.interface import implements
from twisted.application import service
from foolscap import Referenceable
from allmydata import node
from allmydata.interfaces import RIIntroducerPublisherAndSubscriberService
from allmydata.util import log
from allmydata.introducer.common import make_index

class IntroducerNode(node.Node):
    PORTNUMFILE = "introducer.port"
    NODETYPE = "introducer"

    def __init__(self, basedir="."):
        node.Node.__init__(self, basedir)
        self.init_introducer()
        webport = self.get_config("webport")
        if webport:
            self.init_web(webport) # strports string

    def init_introducer(self):
        introducerservice = IntroducerService(self.basedir)
        self.add_service(introducerservice)

        d = self.when_tub_ready()
        def _publish(res):
            self.introducer_url = self.tub.registerReference(introducerservice,
                                                             "introducer")
            self.log(" introducer is at %s" % self.introducer_url)
            self.write_config("introducer.furl", self.introducer_url + "\n")
        d.addCallback(_publish)
        d.addErrback(log.err, facility="tahoe.init", level=log.BAD)

    def init_web(self, webport):
        self.log("init_web(webport=%s)", args=(webport,))

        from allmydata.webish import IntroducerWebishServer
        nodeurl_path = os.path.join(self.basedir, "node.url")
        ws = IntroducerWebishServer(webport, nodeurl_path)
        self.add_service(ws)

class IntroducerService(service.MultiService, Referenceable):
    implements(RIIntroducerPublisherAndSubscriberService)
    name = "introducer"

    def __init__(self, basedir="."):
        service.MultiService.__init__(self)
        self.introducer_url = None
        # 'index' is (tubid, service_name)
        self._announcements = {} # dict of index -> (announcement, timestamp)
        self._subscribers = {} # dict of (rref->timestamp) dicts

    def log(self, *args, **kwargs):
        if "facility" not in kwargs:
            kwargs["facility"] = "tahoe.introducer"
        return log.msg(*args, **kwargs)

    def get_announcements(self):
        return self._announcements
    def get_subscribers(self):
        return self._subscribers

    def remote_publish(self, announcement):
        self.log("introducer: announcement published: %s" % (announcement,) )
        index = make_index(announcement)
        if index in self._announcements:
            (old_announcement, timestamp) = self._announcements[index]
            if old_announcement == announcement:
                self.log("but we already knew it, ignoring", level=log.NOISY)
                return
            else:
                self.log("old announcement being updated", level=log.NOISY)
        self._announcements[index] = (announcement, time.time())
        (furl, service_name, ri_name, nickname, ver, oldest) = announcement
        for s in self._subscribers.get(service_name, []):
            s.callRemote("announce", set([announcement]))

    def remote_subscribe(self, subscriber, service_name):
        self.log("introducer: subscription[%s] request at %s" % (service_name,
                                                                 subscriber))
        if service_name not in self._subscribers:
            self._subscribers[service_name] = {}
        subscribers = self._subscribers[service_name]
        if subscriber in subscribers:
            self.log("but they're already subscribed, ignoring",
                     level=log.UNUSUAL)
            return
        subscribers[subscriber] = time.time()
        def _remove():
            self.log("introducer: unsubscribing[%s] %s" % (service_name,
                                                           subscriber))
            subscribers.pop(subscriber, None)
        subscriber.notifyOnDisconnect(_remove)

        announcements = set( [ ann
                               for idx,(ann,when) in self._announcements.items()
                               if idx[1] == service_name] )
        d = subscriber.callRemote("announce", announcements)
        d.addErrback(log.err, facility="tahoe.introducer", level=log.UNUSUAL)