2 from zope.interface import Interface
3 from foolscap.api import StringConstraint, TupleOf, SetOf, DictOf, Any, \
5 FURL = StringConstraint(1000)
7 # Announcements are (FURL, service_name, remoteinterface_name,
8 # nickname, my_version, oldest_supported)
9 # the (FURL, service_name, remoteinterface_name) refer to the service being
10 # announced. The (nickname, my_version, oldest_supported) refer to the
11 # client as a whole. The my_version/oldest_supported strings can be parsed
12 # by an allmydata.util.version.Version instance, and then compared. The
13 # first goal is to make sure that nodes are not confused by speaking to an
14 # incompatible peer. The second goal is to enable the development of
15 # backwards-compatibility code.
17 Announcement = TupleOf(FURL, str, str,
20 class RIIntroducerSubscriberClient(RemoteInterface):
21 __remote_name__ = "RIIntroducerSubscriberClient.tahoe.allmydata.com"
23 def announce(announcements=SetOf(Announcement)):
24 """I accept announcements from the publisher."""
27 def set_encoding_parameters(parameters=(int, int, int)):
28 """Advise the client of the recommended k-of-n encoding parameters
29 for this grid. 'parameters' is a tuple of (k, desired, n), where 'n'
30 is the total number of shares that will be created for any given
31 file, while 'k' is the number of shares that must be retrieved to
32 recover that file, and 'desired' is the minimum number of shares that
33 must be placed before the uploader will consider its job a success.
34 n/k is the expansion ratio, while k determines the robustness.
36 Introducers should specify 'n' according to the expected size of the
37 grid (there is no point to producing more shares than there are
38 peers), and k according to the desired reliability-vs-overhead goals.
40 Note that setting k=1 is equivalent to simple replication.
44 # When Foolscap can handle multiple interfaces (Foolscap#17), the
45 # full-powered introducer will implement both RIIntroducerPublisher and
46 # RIIntroducerSubscriberService. Until then, we define
47 # RIIntroducerPublisherAndSubscriberService as a combination of the two, and
48 # make everybody use that.
50 class RIIntroducerPublisher(RemoteInterface):
51 """To publish a service to the world, connect to me and give me your
52 announcement message. I will deliver a copy to all connected subscribers."""
53 __remote_name__ = "RIIntroducerPublisher.tahoe.allmydata.com"
55 def publish(announcement=Announcement):
59 class RIIntroducerSubscriberService(RemoteInterface):
60 __remote_name__ = "RIIntroducerSubscriberService.tahoe.allmydata.com"
62 def subscribe(subscriber=RIIntroducerSubscriberClient, service_name=str):
63 """Give me a subscriber reference, and I will call its new_peers()
64 method will any announcements that match the desired service name. I
65 will ignore duplicate subscriptions.
69 class RIIntroducerPublisherAndSubscriberService(RemoteInterface):
70 __remote_name__ = "RIIntroducerPublisherAndSubscriberService.tahoe.allmydata.com"
72 return DictOf(str, Any())
73 def publish(announcement=Announcement):
75 def subscribe(subscriber=RIIntroducerSubscriberClient, service_name=str):
78 class IIntroducerClient(Interface):
79 """I provide service introduction facilities for a node. I help nodes
80 publish their services to the rest of the world, and I help them learn
81 about services available on other nodes."""
83 def publish(furl, service_name, remoteinterface_name):
84 """Once you call this, I will tell the world that the Referenceable
85 available at FURL is available to provide a service named
86 SERVICE_NAME. The precise definition of the service being provided is
87 identified by the Foolscap 'remote interface name' in the last
88 parameter: this is supposed to be a globally-unique string that
89 identifies the RemoteInterface that is implemented."""
91 def subscribe_to(service_name, callback, *args, **kwargs):
92 """Call this if you will eventually want to use services with the
93 given SERVICE_NAME. This will prompt me to subscribe to announcements
94 of those services. Your callback will be invoked with at least two
95 arguments: a serverid (binary string), and an announcement
96 dictionary, followed by any additional callback args/kwargs you give
97 me. I will run your callback for both new announcements and for
98 announcements that have changed, but you must be prepared to tolerate
101 The announcement dictionary that I give you will have the following
105 service-name: str('storage')
108 remoteinterface-name: str(ri_name)
112 oldest-supported: str
114 Note that app-version will be an empty dictionary until #466 is done
115 and both the introducer and the remote client have been upgraded. For
116 current (native) server types, the serverid will always be equal to
117 the binary form of the FURL's tubid.
120 def connected_to_introducer():
121 """Returns a boolean, True if we are currently connected to the
122 introducer, False if not."""