tahoe-lafs/allmydata/upload.py

113 lines
3.8 KiB
Python

from twisted.python import failure
from twisted.internet import defer
class NotEnoughPeersError(Exception):
pass
class HaveAllPeersError(Exception):
# we use this to jump out of the loop
pass
# this wants to live in storage, not here
class TooFullError(Exception):
pass
class Uploader:
debug = False
def __init__(self, peer):
self._peer = peer
def set_encoder(self, encoder):
self._encoder = encoder
def set_verifierid(self, vid):
assert isinstance(vid, str)
self._verifierid = vid
def set_filesize(self, size):
self._size = size
def _calculate_parameters(self):
self._shares = 100
self._share_size = self._size / 25
def start(self):
# first step: who should we upload to?
# maybe limit max_peers to 2*len(self.shares), to reduce memory
# footprint
max_peers = None
self.permuted = self._peer.permute_peerids(self._verifierid, max_peers)
# we will shrink self.permuted as we give up on peers
self.peer_index = 0
self.goodness_points = 0
self.target_goodness = self._shares
self.landlords = [] # list of (peerid, bucket_num, remotebucket)
d = defer.maybeDeferred(self._check_next_peer)
d.addCallback(self._got_all_peers)
return d
def _check_next_peer(self):
if len(self.permuted) == 0:
# there are no more to check
raise NotEnoughPeersError
if self.peer_index >= len(self.permuted):
self.peer_index = 0
peerid = self.permuted[self.peer_index]
d = self._peer.get_remote_service(peerid, "storageserver")
def _got_peer(service):
bucket_num = len(self.landlords)
if self.debug: print "asking %s" % peerid
d2 = service.callRemote("allocate_bucket",
verifierid=self._verifierid,
bucket_num=bucket_num,
size=self._share_size,
leaser=self._peer.nodeid)
def _allocate_response(bucket):
if self.debug:
print " peerid %s will grant us a lease" % peerid
self.landlords.append( (peerid, bucket_num, bucket) )
self.goodness_points += 1
if self.goodness_points >= self.target_goodness:
if self.debug: print " we're done!"
raise HaveAllPeersError()
# otherwise we fall through to allocate more peers
d2.addCallback(_allocate_response)
return d2
d.addCallback(_got_peer)
def _done_with_peer(res):
if self.debug: print "done with peer %s:" % peerid
if isinstance(res, failure.Failure):
if res.check(HaveAllPeersError):
if self.debug: print " all done"
# we're done!
return
if res.check(TooFullError):
if self.debug: print " too full"
elif res.check(IndexError):
if self.debug: print " no connection"
else:
if self.debug: print " other error:", res
self.permuted.remove(peerid) # this peer was unusable
else:
if self.debug: print " they gave us a lease"
# we get here for either good peers (when we still need
# more), or after checking a bad peer (and thus still need
# more). So now we need to grab a new peer.
self.peer_index += 1
return self._check_next_peer()
d.addBoth(_done_with_peer)
return d
def _got_all_peers(self, res):
d = self._encoder.do_upload(self.landlords)
return d