allmydata/encode.py

   1 from twisted.internet import defer
   2 import sha
   3 from allmydata.util import idlib
   4
   5 def netstring(s):
   6     return "%d:%s," % (len(s), s)
   7
   8 class Encoder(object):
   9     def __init__(self, infile, m):
  10         self.infile = infile
  11         self.k = 2
  12         self.m = m
  13
  14     def do_upload(self, landlords):
  15         dl = []
  16         data = self.infile.read()
  17         for (peerid, bucket_num, remotebucket) in landlords:
  18             dl.append(remotebucket.callRemote('write', data))
  19             dl.append(remotebucket.callRemote('close'))
  20
  21         return defer.DeferredList(dl)
  22
  23 class Decoder(object):
  24     def __init__(self, outfile, k, m, verifierid):
  25         self.outfile = outfile
  26         self.k = 2
  27         self.m = m
  28         self._verifierid = verifierid
  29
  30     def start(self, buckets):
  31         assert len(buckets) >= self.k
  32         dl = []
  33         for bucketnum, bucket in buckets[:self.k]:
  34             d = bucket.callRemote("read")
  35             dl.append(d)
  36         d2 = defer.DeferredList(dl)
  37         d2.addCallback(self._got_all_data)
  38         return d2
  39
  40     def _got_all_data(self, resultslist):
  41         shares = [results for success,results in resultslist if success]
  42         assert len(shares) >= self.k
  43         # here's where the Reed-Solomon magic takes place
  44         self.outfile.write(shares[0])
  45         hasher = sha.new(netstring("allmydata_v1_verifierid"))
  46         hasher.update(shares[0])
  47         vid = hasher.digest()
  48         if self._verifierid:
  49             assert self._verifierid == vid, "%s != %s" % (idlib.b2a(self._verifierid), idlib.b2a(vid))
  50