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):
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. You can pick up the announcements later by calling
95 get_all_connections_for() or get_permuted_peers().
98 def get_all_connections():
99 """Return a frozenset of (nodeid, service_name, rref) tuples, one for
100 each active connection we've established to a remote service. This is
101 mostly useful for unit tests that need to wait until a certain number
102 of connections have been made."""
104 def get_all_connectors():
105 """Return a dict that maps from (nodeid, service_name) to a
106 RemoteServiceConnector instance for all services that we are actively
107 trying to connect to. Each RemoteServiceConnector has the following
110 service_name: the type of service provided, like 'storage'
111 announcement_time: when we first heard about this service
112 last_connect_time: when we last established a connection
113 last_loss_time: when we last lost a connection
115 version: the peer's version, from the most recent connection
116 oldest_supported: the peer's oldest supported version, same
118 rref: the RemoteReference, if connected, otherwise None
119 remote_host: the IAddress, if connected, otherwise None
121 This method is intended for monitoring interfaces, such as a web page
122 which describes connecting and connected peers.
125 def get_all_peerids():
126 """Return a frozenset of all peerids to whom we have a connection (to
127 one or more services) established. Mostly useful for unit tests."""
129 def get_all_connections_for(service_name):
130 """Return a frozenset of (nodeid, service_name, rref) tuples, one
131 for each active connection that provides the given SERVICE_NAME."""
133 def get_permuted_peers(service_name, key):
134 """Returns an ordered list of (peerid, rref) tuples, selecting from
135 the connections that provide SERVICE_NAME, using a hash-based
136 permutation keyed by KEY. This randomizes the service list in a
137 repeatable way, to distribute load over many peers.
140 def connected_to_introducer():
141 """Returns a boolean, True if we are currently connected to the
142 introducer, False if not."""