Ejemplo n.º 1
0
class Encoder(object):
    def __init__(self, log_parent=None, upload_status=None, progress=None):
        object.__init__(self)
        self.uri_extension_data = {}
        self._codec = None
        self._status = None
        if upload_status:
            self._status = IUploadStatus(upload_status)
        precondition(log_parent is None or isinstance(log_parent, int),
                     log_parent)
        self._log_number = log.msg("creating Encoder %s" % self,
                                   facility="tahoe.encoder",
                                   parent=log_parent)
        self._aborted = False
        self._progress = progress

    def __repr__(self):
        if hasattr(self, "_storage_index"):
            return "<Encoder for %s>" % si_b2a(self._storage_index)[:5]
        return "<Encoder for unknown storage index>"

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

    @log_call_deferred(action_type=u"immutable:encode:set-encrypted-uploadable"
                       )
    def set_encrypted_uploadable(self, uploadable):
        eu = self._uploadable = IEncryptedUploadable(uploadable)
        d = eu.get_size()

        def _got_size(size):
            self.log(format="file size: %(size)d", size=size)
            self.file_size = size
            if self._progress:
                self._progress.set_progress_total(self.file_size)

        d.addCallback(_got_size)
        d.addCallback(lambda res: eu.get_all_encoding_parameters())
        d.addCallback(self._got_all_encoding_parameters)
        d.addCallback(lambda res: eu.get_storage_index())

        def _done(storage_index):
            self._storage_index = storage_index
            return self

        d.addCallback(_done)
        return d

    def _got_all_encoding_parameters(self, params):
        assert not self._codec
        k, happy, n, segsize = params
        self.required_shares = k
        self.min_happiness = happy
        self.num_shares = n
        self.segment_size = segsize
        self.log("got encoding parameters: %d/%d/%d %d" %
                 (k, happy, n, segsize))
        self.log("now setting up codec")

        assert self.segment_size % self.required_shares == 0

        self.num_segments = mathutil.div_ceil(self.file_size,
                                              self.segment_size)

        self._codec = CRSEncoder()
        self._codec.set_params(self.segment_size, self.required_shares,
                               self.num_shares)

        data = self.uri_extension_data
        data['codec_name'] = self._codec.get_encoder_type()
        data['codec_params'] = self._codec.get_serialized_params()

        data['size'] = self.file_size
        data['segment_size'] = self.segment_size
        self.share_size = mathutil.div_ceil(self.file_size,
                                            self.required_shares)
        data['num_segments'] = self.num_segments
        data['needed_shares'] = self.required_shares
        data['total_shares'] = self.num_shares

        # the "tail" is the last segment. This segment may or may not be
        # shorter than all other segments. We use the "tail codec" to handle
        # it. If the tail is short, we use a different codec instance. In
        # addition, the tail codec must be fed data which has been padded out
        # to the right size.
        tail_size = self.file_size % self.segment_size
        if not tail_size:
            tail_size = self.segment_size

        # the tail codec is responsible for encoding tail_size bytes
        padded_tail_size = mathutil.next_multiple(tail_size,
                                                  self.required_shares)
        self._tail_codec = CRSEncoder()
        self._tail_codec.set_params(padded_tail_size, self.required_shares,
                                    self.num_shares)
        data['tail_codec_params'] = self._tail_codec.get_serialized_params()

    def _get_share_size(self):
        share_size = mathutil.div_ceil(self.file_size, self.required_shares)
        overhead = self._compute_overhead()
        return share_size + overhead

    def _compute_overhead(self):
        return 0

    def get_param(self, name):
        assert self._codec

        if name == "storage_index":
            return self._storage_index
        elif name == "share_counts":
            return (self.required_shares, self.min_happiness, self.num_shares)
        elif name == "num_segments":
            return self.num_segments
        elif name == "segment_size":
            return self.segment_size
        elif name == "block_size":
            return self._codec.get_block_size()
        elif name == "share_size":
            return self._get_share_size()
        elif name == "serialized_params":
            return self._codec.get_serialized_params()
        else:
            raise KeyError("unknown parameter name '%s'" % name)

    def set_shareholders(self, landlords, servermap):
        assert isinstance(landlords, dict)
        for k in landlords:
            assert IStorageBucketWriter.providedBy(landlords[k])
        self.landlords = landlords.copy()
        assert isinstance(servermap, dict)
        for v in servermap.values():
            assert isinstance(v, set)
        self.servermap = servermap.copy()

    @log_call_deferred(action_type=u"immutable:encode:start")
    def start(self):
        """ Returns a Deferred that will fire with the verify cap (an instance of
        uri.CHKFileVerifierURI)."""
        self.log("%s starting" % (self, ))
        #paddedsize = self._size + mathutil.pad_size(self._size, self.needed_shares)
        assert self._codec
        self._crypttext_hasher = hashutil.crypttext_hasher()
        self._crypttext_hashes = []
        self.segment_num = 0
        self.block_hashes = [[] for x in range(self.num_shares)]
        # block_hashes[i] is a list that will be accumulated and then send
        # to landlord[i]. This list contains a hash of each segment_share
        # that we sent to that landlord.
        self.share_root_hashes = [None] * self.num_shares

        self._times = {
            "cumulative_encoding": 0.0,
            "cumulative_sending": 0.0,
            "hashes_and_close": 0.0,
            "total_encode_and_push": 0.0,
        }
        self._start_total_timestamp = time.time()

        d = fireEventually()

        d.addCallback(lambda res: self.start_all_shareholders())

        for i in range(self.num_segments - 1):
            # note to self: this form doesn't work, because lambda only
            # captures the slot, not the value
            #d.addCallback(lambda res: self.do_segment(i))
            # use this form instead:
            d.addCallback(lambda res, i=i: self._encode_segment(i))
            d.addCallback(self._send_segment, i)
            d.addCallback(self._turn_barrier)
        last_segnum = self.num_segments - 1
        d.addCallback(lambda res: self._encode_tail_segment(last_segnum))
        d.addCallback(self._send_segment, last_segnum)
        d.addCallback(self._turn_barrier)

        d.addCallback(lambda res: self.finish_hashing())

        d.addCallback(
            lambda res: self.send_crypttext_hash_tree_to_all_shareholders())
        d.addCallback(lambda res: self.send_all_block_hash_trees())
        d.addCallback(lambda res: self.send_all_share_hash_trees())
        d.addCallback(
            lambda res: self.send_uri_extension_to_all_shareholders())

        d.addCallback(lambda res: self.close_all_shareholders())
        d.addCallbacks(self.done, self.err)
        return d

    def set_status(self, status):
        if self._status:
            self._status.set_status(status)

    def set_encode_and_push_progress(self, sent_segments=None, extra=0.0):
        if self._status:
            # we treat the final hash+close as an extra segment
            if sent_segments is None:
                sent_segments = self.num_segments
            progress = float(sent_segments + extra) / (self.num_segments + 1)
            self._status.set_progress(2, progress)

    def abort(self):
        self.log("aborting upload", level=log.UNUSUAL)
        assert self._codec, "don't call abort before start"
        self._aborted = True
        # the next segment read (in _gather_data inside _encode_segment) will
        # raise UploadAborted(), which will bypass the rest of the upload
        # chain. If we've sent the final segment's shares, it's too late to
        # abort. TODO: allow abort any time up to close_all_shareholders.

    def _turn_barrier(self, res):
        # putting this method in a Deferred chain imposes a guaranteed
        # reactor turn between the pre- and post- portions of that chain.
        # This can be useful to limit memory consumption: since Deferreds do
        # not do tail recursion, code which uses defer.succeed(result) for
        # consistency will cause objects to live for longer than you might
        # normally expect.

        return fireEventually(res)

    def start_all_shareholders(self):
        self.log("starting shareholders", level=log.NOISY)
        self.set_status("Starting shareholders")
        dl = []
        for shareid in list(self.landlords):
            d = self.landlords[shareid].put_header()
            d.addErrback(self._remove_shareholder, shareid, "start")
            dl.append(d)
        return self._gather_responses(dl)

    def _encode_segment(self, segnum):
        codec = self._codec
        start = time.time()

        # the ICodecEncoder API wants to receive a total of self.segment_size
        # bytes on each encode() call, broken up into a number of
        # identically-sized pieces. Due to the way the codec algorithm works,
        # these pieces need to be the same size as the share which the codec
        # will generate. Therefore we must feed it with input_piece_size that
        # equals the output share size.
        input_piece_size = codec.get_block_size()

        # as a result, the number of input pieces per encode() call will be
        # equal to the number of required shares with which the codec was
        # constructed. You can think of the codec as chopping up a
        # 'segment_size' of data into 'required_shares' shares (not doing any
        # fancy math at all, just doing a split), then creating some number
        # of additional shares which can be substituted if the primary ones
        # are unavailable

        # we read data from the source one segment at a time, and then chop
        # it into 'input_piece_size' pieces before handing it to the codec

        crypttext_segment_hasher = hashutil.crypttext_segment_hasher()

        # memory footprint: we only hold a tiny piece of the plaintext at any
        # given time. We build up a segment's worth of cryptttext, then hand
        # it to the encoder. Assuming 3-of-10 encoding (3.3x expansion) and
        # 1MiB max_segment_size, we get a peak memory footprint of 4.3*1MiB =
        # 4.3MiB. Lowering max_segment_size to, say, 100KiB would drop the
        # footprint to 430KiB at the expense of more hash-tree overhead.

        d = self._gather_data(self.required_shares, input_piece_size,
                              crypttext_segment_hasher)

        def _done_gathering(chunks):
            for c in chunks:
                assert len(c) == input_piece_size
            self._crypttext_hashes.append(crypttext_segment_hasher.digest())
            # during this call, we hit 5*segsize memory
            return codec.encode(chunks)

        d.addCallback(_done_gathering)

        def _done(res):
            elapsed = time.time() - start
            self._times["cumulative_encoding"] += elapsed
            return res

        d.addCallback(_done)
        return d

    def _encode_tail_segment(self, segnum):

        start = time.time()
        codec = self._tail_codec
        input_piece_size = codec.get_block_size()

        crypttext_segment_hasher = hashutil.crypttext_segment_hasher()

        d = self._gather_data(self.required_shares,
                              input_piece_size,
                              crypttext_segment_hasher,
                              allow_short=True)

        def _done_gathering(chunks):
            for c in chunks:
                # a short trailing chunk will have been padded by
                # _gather_data
                assert len(c) == input_piece_size
            self._crypttext_hashes.append(crypttext_segment_hasher.digest())
            return codec.encode(chunks)

        d.addCallback(_done_gathering)

        def _done(res):
            elapsed = time.time() - start
            self._times["cumulative_encoding"] += elapsed
            return res

        d.addCallback(_done)
        return d

    def _gather_data(self,
                     num_chunks,
                     input_chunk_size,
                     crypttext_segment_hasher,
                     allow_short=False):
        """Return a Deferred that will fire when the required number of
        chunks have been read (and hashed and encrypted). The Deferred fires
        with a list of chunks, each of size input_chunk_size."""

        # I originally built this to allow read_encrypted() to behave badly:
        # to let it return more or less data than you asked for. It would
        # stash the leftovers until later, and then recurse until it got
        # enough. I don't think that was actually useful.
        #
        # who defines read_encrypted?
        #  offloaded.LocalCiphertextReader: real disk file: exact
        #  upload.EncryptAnUploadable: Uploadable, but a wrapper that makes
        #    it exact. The return value is a list of 50KiB chunks, to reduce
        #    the memory footprint of the encryption process.
        #  repairer.Repairer: immutable.filenode.CiphertextFileNode: exact
        #
        # This has been redefined to require read_encrypted() to behave like
        # a local file: return exactly the amount requested unless it hits
        # EOF.
        #  -warner

        if self._aborted:
            raise UploadAborted()

        read_size = num_chunks * input_chunk_size
        d = self._uploadable.read_encrypted(read_size, hash_only=False)

        def _got(data):
            assert isinstance(data, (list, tuple))
            if self._aborted:
                raise UploadAborted()
            data = b"".join(data)
            precondition(len(data) <= read_size, len(data), read_size)
            if not allow_short:
                precondition(len(data) == read_size, len(data), read_size)
            crypttext_segment_hasher.update(data)
            self._crypttext_hasher.update(data)
            if allow_short and len(data) < read_size:
                # padding
                data += b"\x00" * (read_size - len(data))
            encrypted_pieces = [
                data[i:i + input_chunk_size]
                for i in range(0, len(data), input_chunk_size)
            ]
            return encrypted_pieces

        d.addCallback(_got)
        return d

    def _send_segment(self, shares_and_shareids, segnum):
        # To generate the URI, we must generate the roothash, so we must
        # generate all shares, even if we aren't actually giving them to
        # anybody. This means that the set of shares we create will be equal
        # to or larger than the set of landlords. If we have any landlord who
        # *doesn't* have a share, that's an error.
        (shares, shareids) = shares_and_shareids
        _assert(set(self.landlords.keys()).issubset(set(shareids)),
                shareids=shareids,
                landlords=self.landlords)
        start = time.time()
        dl = []
        self.set_status("Sending segment %d of %d" %
                        (segnum + 1, self.num_segments))
        self.set_encode_and_push_progress(segnum)
        lognum = self.log("send_segment(%d)" % segnum, level=log.NOISY)
        for i in range(len(shares)):
            block = shares[i]
            shareid = shareids[i]
            d = self.send_block(shareid, segnum, block, lognum)
            dl.append(d)

            block_hash = hashutil.block_hash(block)
            #from allmydata.util import base32
            #log.msg("creating block (shareid=%d, blocknum=%d) "
            #        "len=%d %r .. %r: %s" %
            #        (shareid, segnum, len(block),
            #         block[:50], block[-50:], base32.b2a(block_hash)))
            self.block_hashes[shareid].append(block_hash)

        dl = self._gather_responses(dl)

        def do_progress(ign):
            done = self.segment_size * (segnum + 1)
            if self._progress:
                self._progress.set_progress(done)
            return ign

        dl.addCallback(do_progress)

        def _logit(res):
            self.log("%s uploaded %s / %s bytes (%d%%) of your file." % (
                self,
                self.segment_size * (segnum + 1),
                self.segment_size * self.num_segments,
                100 * (segnum + 1) / self.num_segments,
            ),
                     level=log.OPERATIONAL)
            elapsed = time.time() - start
            self._times["cumulative_sending"] += elapsed
            return res

        dl.addCallback(_logit)
        return dl

    def send_block(self, shareid, segment_num, block, lognum):
        if shareid not in self.landlords:
            return defer.succeed(None)
        sh = self.landlords[shareid]
        lognum2 = self.log("put_block to %s" % self.landlords[shareid],
                           parent=lognum,
                           level=log.NOISY)
        d = sh.put_block(segment_num, block)

        def _done(res):
            self.log("put_block done", parent=lognum2, level=log.NOISY)
            return res

        d.addCallback(_done)
        d.addErrback(self._remove_shareholder, shareid,
                     "segnum=%d" % segment_num)
        return d

    def _remove_shareholder(self, why, shareid, where):
        ln = self.log(
            format="error while sending %(method)s to shareholder=%(shnum)d",
            method=where,
            shnum=shareid,
            level=log.UNUSUAL,
            failure=why)
        if shareid in self.landlords:
            self.landlords[shareid].abort()
            peerid = self.landlords[shareid].get_peerid()
            assert peerid
            del self.landlords[shareid]
            self.servermap[shareid].remove(peerid)
            if not self.servermap[shareid]:
                del self.servermap[shareid]
        else:
            # even more UNUSUAL
            self.log("they weren't in our list of landlords",
                     parent=ln,
                     level=log.WEIRD,
                     umid="TQGFRw")
        happiness = happinessutil.servers_of_happiness(self.servermap)
        if happiness < self.min_happiness:
            peerids = set(
                happinessutil.shares_by_server(self.servermap).keys())
            msg = happinessutil.failure_message(len(peerids),
                                                self.required_shares,
                                                self.min_happiness, happiness)
            msg = "%s: %s" % (msg, why)
            raise UploadUnhappinessError(msg)
        self.log("but we can still continue with %s shares, we'll be happy "
                 "with at least %s" % (happiness, self.min_happiness),
                 parent=ln)

    def _gather_responses(self, dl):
        d = defer.DeferredList(dl, fireOnOneErrback=True)

        def _eatUploadUnhappinessError(f):
            # all exceptions that occur while talking to a peer are handled
            # in _remove_shareholder. That might raise UploadUnhappinessError,
            # which will cause the DeferredList to errback but which should
            # otherwise be consumed. Allow non-UploadUnhappinessError exceptions
            # to pass through as an unhandled errback. We use this in lieu of
            # consumeErrors=True to allow coding errors to be logged.
            f.trap(UploadUnhappinessError)
            return None

        for d0 in dl:
            d0.addErrback(_eatUploadUnhappinessError)
        return d

    def finish_hashing(self):
        self._start_hashing_and_close_timestamp = time.time()
        self.set_status("Finishing hashes")
        self.set_encode_and_push_progress(extra=0.0)
        crypttext_hash = self._crypttext_hasher.digest()
        self.uri_extension_data["crypttext_hash"] = crypttext_hash
        self._uploadable.close()

    def send_crypttext_hash_tree_to_all_shareholders(self):
        self.log("sending crypttext hash tree", level=log.NOISY)
        self.set_status("Sending Crypttext Hash Tree")
        self.set_encode_and_push_progress(extra=0.3)
        t = HashTree(self._crypttext_hashes)
        all_hashes = list(t)
        self.uri_extension_data["crypttext_root_hash"] = t[0]
        dl = []
        for shareid in list(self.landlords):
            dl.append(self.send_crypttext_hash_tree(shareid, all_hashes))
        return self._gather_responses(dl)

    def send_crypttext_hash_tree(self, shareid, all_hashes):
        if shareid not in self.landlords:
            return defer.succeed(None)
        sh = self.landlords[shareid]
        d = sh.put_crypttext_hashes(all_hashes)
        d.addErrback(self._remove_shareholder, shareid, "put_crypttext_hashes")
        return d

    def send_all_block_hash_trees(self):
        self.log("sending block hash trees", level=log.NOISY)
        self.set_status("Sending Subshare Hash Trees")
        self.set_encode_and_push_progress(extra=0.4)
        dl = []
        for shareid, hashes in enumerate(self.block_hashes):
            # hashes is a list of the hashes of all blocks that were sent
            # to shareholder[shareid].
            dl.append(self.send_one_block_hash_tree(shareid, hashes))
        return self._gather_responses(dl)

    def send_one_block_hash_tree(self, shareid, block_hashes):
        t = HashTree(block_hashes)
        all_hashes = list(t)
        # all_hashes[0] is the root hash, == hash(ah[1]+ah[2])
        # all_hashes[1] is the left child, == hash(ah[3]+ah[4])
        # all_hashes[n] == hash(all_hashes[2*n+1] + all_hashes[2*n+2])
        self.share_root_hashes[shareid] = t[0]
        if shareid not in self.landlords:
            return defer.succeed(None)
        sh = self.landlords[shareid]
        d = sh.put_block_hashes(all_hashes)
        d.addErrback(self._remove_shareholder, shareid, "put_block_hashes")
        return d

    def send_all_share_hash_trees(self):
        # Each bucket gets a set of share hash tree nodes that are needed to validate their
        # share. This includes the share hash itself, but does not include the top-level hash
        # root (which is stored securely in the URI instead).
        self.log("sending all share hash trees", level=log.NOISY)
        self.set_status("Sending Share Hash Trees")
        self.set_encode_and_push_progress(extra=0.6)
        dl = []
        for h in self.share_root_hashes:
            assert h
        # create the share hash tree
        t = HashTree(self.share_root_hashes)
        # the root of this hash tree goes into our URI
        self.uri_extension_data['share_root_hash'] = t[0]
        # now send just the necessary pieces out to each shareholder
        for i in range(self.num_shares):
            # the HashTree is given a list of leaves: 0,1,2,3..n .
            # These become nodes A+0,A+1,A+2.. of the tree, where A=n-1
            needed_hash_indices = t.needed_hashes(i, include_leaf=True)
            hashes = [(hi, t[hi]) for hi in needed_hash_indices]
            dl.append(self.send_one_share_hash_tree(i, hashes))
        return self._gather_responses(dl)

    def send_one_share_hash_tree(self, shareid, needed_hashes):
        if shareid not in self.landlords:
            return defer.succeed(None)
        sh = self.landlords[shareid]
        d = sh.put_share_hashes(needed_hashes)
        d.addErrback(self._remove_shareholder, shareid, "put_share_hashes")
        return d

    def send_uri_extension_to_all_shareholders(self):
        lp = self.log("sending uri_extension", level=log.NOISY)
        self.set_status("Sending URI Extensions")
        self.set_encode_and_push_progress(extra=0.8)
        for k in (
                'crypttext_root_hash',
                'crypttext_hash',
        ):
            assert k in self.uri_extension_data
        uri_extension = uri.pack_extension(self.uri_extension_data)
        ed = {}
        for k, v in self.uri_extension_data.items():
            if k.endswith("hash"):
                ed[k] = base32.b2a(v)
            else:
                ed[k] = v
        self.log("uri_extension_data is %s" % (ed, ),
                 level=log.NOISY,
                 parent=lp)
        self.uri_extension_hash = hashutil.uri_extension_hash(uri_extension)
        dl = []
        for shareid in list(self.landlords):
            dl.append(self.send_uri_extension(shareid, uri_extension))
        return self._gather_responses(dl)

    def send_uri_extension(self, shareid, uri_extension):
        sh = self.landlords[shareid]
        d = sh.put_uri_extension(uri_extension)
        d.addErrback(self._remove_shareholder, shareid, "put_uri_extension")
        return d

    def close_all_shareholders(self):
        self.log("closing shareholders", level=log.NOISY)
        self.set_status("Closing Shareholders")
        self.set_encode_and_push_progress(extra=0.9)
        dl = []
        for shareid in list(self.landlords):
            d = self.landlords[shareid].close()
            d.addErrback(self._remove_shareholder, shareid, "close")
            dl.append(d)
        return self._gather_responses(dl)

    def done(self, res):
        self.log("upload done", level=log.OPERATIONAL)
        self.set_status("Finished")
        self.set_encode_and_push_progress(extra=1.0)  # done
        now = time.time()
        h_and_c_elapsed = now - self._start_hashing_and_close_timestamp
        self._times["hashes_and_close"] = h_and_c_elapsed
        total_elapsed = now - self._start_total_timestamp
        self._times["total_encode_and_push"] = total_elapsed

        # update our sharemap
        self._shares_placed = set(self.landlords.keys())
        return uri.CHKFileVerifierURI(self._storage_index,
                                      self.uri_extension_hash,
                                      self.required_shares, self.num_shares,
                                      self.file_size)

    def err(self, f):
        self.log("upload failed", failure=f, level=log.UNUSUAL)
        self.set_status("Failed")
        # we need to abort any remaining shareholders, so they'll delete the
        # partial share, allowing someone else to upload it again.
        self.log("aborting shareholders", level=log.UNUSUAL)
        for shareid in list(self.landlords):
            self.landlords[shareid].abort()
        if f.check(defer.FirstError):
            return f.value.subFailure
        return f

    def get_shares_placed(self):
        # return a set of share numbers that were successfully placed.
        return self._shares_placed

    def get_times(self):
        # return a dictionary of encode+push timings
        return self._times

    def get_uri_extension_data(self):
        return self.uri_extension_data

    def get_uri_extension_hash(self):
        return self.uri_extension_hash
Ejemplo n.º 2
0
    def do_test(self, size, required_shares, max_shares, fewer_shares=None):
        data0s = [os.urandom(mathutil.div_ceil(size, required_shares)) for i in range(required_shares)]
        enc = CRSEncoder()
        enc.set_params(size, required_shares, max_shares)
        params = enc.get_params()
        assert params == (size, required_shares, max_shares)
        serialized_params = enc.get_serialized_params()
        self.assertEqual(parse_params(serialized_params), params)
        log.msg("params: %s" % (params,))
        d = enc.encode(data0s)
        def _done_encoding_all(shares_and_shareids):
            (shares, shareids) = shares_and_shareids
            self.failUnlessEqual(len(shares), max_shares)
            self.shares = shares
            self.shareids = shareids
        d.addCallback(_done_encoding_all)
        if fewer_shares is not None:
            # also validate that the desired_shareids= parameter works
            desired_shareids = random.sample(list(range(max_shares)), fewer_shares)
            d.addCallback(lambda res: enc.encode(data0s, desired_shareids))
            def _check_fewer_shares(some_shares_and_their_shareids):
                (some_shares, their_shareids) = some_shares_and_their_shareids
                self.failUnlessEqual(tuple(their_shareids), tuple(desired_shareids))
            d.addCallback(_check_fewer_shares)

        def _decode(shares_and_shareids):
            (shares, shareids) = shares_and_shareids
            dec = CRSDecoder()
            dec.set_params(*params)
            d1 = dec.decode(shares, shareids)
            return d1

        def _check_data(decoded_shares):
            self.failUnlessEqual(len(b''.join(decoded_shares)), len(b''.join(data0s)))
            self.failUnlessEqual(len(decoded_shares), len(data0s))
            for (i, (x, y)) in enumerate(zip(data0s, decoded_shares)):
                self.failUnlessEqual(x, y, "%s: %r != %r....  first share was %r" % (str(i), x, y, data0s[0],))
            self.failUnless(b''.join(decoded_shares) == b''.join(data0s), "%s" % ("???",))
            # 0data0sclipped = tuple(data0s)
            # data0sclipped[-1] =
            # self.failUnless(tuple(decoded_shares) == tuple(data0s))

        def _decode_some(res):
            log.msg("_decode_some")
            # decode with a minimal subset of the shares
            some_shares = self.shares[:required_shares]
            some_shareids = self.shareids[:required_shares]
            return _decode((some_shares, some_shareids))
        d.addCallback(_decode_some)
        d.addCallback(_check_data)

        def _decode_some_random(res):
            log.msg("_decode_some_random")
            # use a randomly-selected minimal subset
            l = random.sample(list(zip(self.shares, self.shareids)), required_shares)
            some_shares = [ x[0] for x in l ]
            some_shareids = [ x[1] for x in l ]
            return _decode((some_shares, some_shareids))
        d.addCallback(_decode_some_random)
        d.addCallback(_check_data)

        def _decode_multiple(res):
            log.msg("_decode_multiple")
            # make sure we can re-use the decoder object
            shares1 = random.sample(self.shares, required_shares)
            sharesl1 = random.sample(list(zip(self.shares, self.shareids)), required_shares)
            shares1 = [ x[0] for x in sharesl1 ]
            shareids1 = [ x[1] for x in sharesl1 ]
            sharesl2 = random.sample(list(zip(self.shares, self.shareids)), required_shares)
            shares2 = [ x[0] for x in sharesl2 ]
            shareids2 = [ x[1] for x in sharesl2 ]
            dec = CRSDecoder()
            dec.set_params(*params)
            d1 = dec.decode(shares1, shareids1)
            d1.addCallback(_check_data)
            d1.addCallback(lambda res: dec.decode(shares2, shareids2))
            d1.addCallback(_check_data)
            return d1
        d.addCallback(_decode_multiple)

        return d
Ejemplo n.º 3
0
class Encoder(object):
    implements(IEncoder)

    def __init__(self, log_parent=None, upload_status=None):
        object.__init__(self)
        self.uri_extension_data = {}
        self._codec = None
        self._status = None
        if upload_status:
            self._status = IUploadStatus(upload_status)
        precondition(log_parent is None or isinstance(log_parent, int),
                     log_parent)
        self._log_number = log.msg("creating Encoder %s" % self,
                                   facility="tahoe.encoder", parent=log_parent)
        self._aborted = False

    def __repr__(self):
        if hasattr(self, "_storage_index"):
            return "<Encoder for %s>" % si_b2a(self._storage_index)[:5]
        return "<Encoder for unknown storage index>"

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

    def set_encrypted_uploadable(self, uploadable):
        eu = self._uploadable = IEncryptedUploadable(uploadable)
        d = eu.get_size()
        def _got_size(size):
            self.log(format="file size: %(size)d", size=size)
            self.file_size = size
        d.addCallback(_got_size)
        d.addCallback(lambda res: eu.get_all_encoding_parameters())
        d.addCallback(self._got_all_encoding_parameters)
        d.addCallback(lambda res: eu.get_storage_index())
        def _done(storage_index):
            self._storage_index = storage_index
            return self
        d.addCallback(_done)
        return d

    def _got_all_encoding_parameters(self, params):
        assert not self._codec
        k, happy, n, segsize = params
        self.required_shares = k
        self.servers_of_happiness = happy
        self.num_shares = n
        self.segment_size = segsize
        self.log("got encoding parameters: %d/%d/%d %d" % (k,happy,n, segsize))
        self.log("now setting up codec")

        assert self.segment_size % self.required_shares == 0

        self.num_segments = mathutil.div_ceil(self.file_size,
                                              self.segment_size)

        self._codec = CRSEncoder()
        self._codec.set_params(self.segment_size,
                               self.required_shares, self.num_shares)

        data = self.uri_extension_data
        data['codec_name'] = self._codec.get_encoder_type()
        data['codec_params'] = self._codec.get_serialized_params()

        data['size'] = self.file_size
        data['segment_size'] = self.segment_size
        self.share_size = mathutil.div_ceil(self.file_size,
                                            self.required_shares)
        data['num_segments'] = self.num_segments
        data['needed_shares'] = self.required_shares
        data['total_shares'] = self.num_shares

        # the "tail" is the last segment. This segment may or may not be
        # shorter than all other segments. We use the "tail codec" to handle
        # it. If the tail is short, we use a different codec instance. In
        # addition, the tail codec must be fed data which has been padded out
        # to the right size.
        tail_size = self.file_size % self.segment_size
        if not tail_size:
            tail_size = self.segment_size

        # the tail codec is responsible for encoding tail_size bytes
        padded_tail_size = mathutil.next_multiple(tail_size,
                                                  self.required_shares)
        self._tail_codec = CRSEncoder()
        self._tail_codec.set_params(padded_tail_size,
                                    self.required_shares, self.num_shares)
        data['tail_codec_params'] = self._tail_codec.get_serialized_params()

    def _get_share_size(self):
        share_size = mathutil.div_ceil(self.file_size, self.required_shares)
        overhead = self._compute_overhead()
        return share_size + overhead

    def _compute_overhead(self):
        return 0

    def get_param(self, name):
        assert self._codec

        if name == "storage_index":
            return self._storage_index
        elif name == "share_counts":
            return (self.required_shares, self.servers_of_happiness,
                    self.num_shares)
        elif name == "num_segments":
            return self.num_segments
        elif name == "segment_size":
            return self.segment_size
        elif name == "block_size":
            return self._codec.get_block_size()
        elif name == "share_size":
            return self._get_share_size()
        elif name == "serialized_params":
            return self._codec.get_serialized_params()
        else:
            raise KeyError("unknown parameter name '%s'" % name)

    def set_shareholders(self, landlords, servermap):
        assert isinstance(landlords, dict)
        for k in landlords:
            assert IStorageBucketWriter.providedBy(landlords[k])
        self.landlords = landlords.copy()
        assert isinstance(servermap, dict)
        for v in servermap.itervalues():
            assert isinstance(v, set)
        self.servermap = servermap.copy()

    def start(self):
        """ Returns a Deferred that will fire with the verify cap (an instance of
        uri.CHKFileVerifierURI)."""
        self.log("%s starting" % (self,))
        #paddedsize = self._size + mathutil.pad_size(self._size, self.needed_shares)
        assert self._codec
        self._crypttext_hasher = hashutil.crypttext_hasher()
        self._crypttext_hashes = []
        self.segment_num = 0
        self.block_hashes = [[] for x in range(self.num_shares)]
        # block_hashes[i] is a list that will be accumulated and then send
        # to landlord[i]. This list contains a hash of each segment_share
        # that we sent to that landlord.
        self.share_root_hashes = [None] * self.num_shares

        self._times = {
            "cumulative_encoding": 0.0,
            "cumulative_sending": 0.0,
            "hashes_and_close": 0.0,
            "total_encode_and_push": 0.0,
            }
        self._start_total_timestamp = time.time()

        d = fireEventually()

        d.addCallback(lambda res: self.start_all_shareholders())

        for i in range(self.num_segments-1):
            # note to self: this form doesn't work, because lambda only
            # captures the slot, not the value
            #d.addCallback(lambda res: self.do_segment(i))
            # use this form instead:
            d.addCallback(lambda res, i=i: self._encode_segment(i))
            d.addCallback(self._send_segment, i)
            d.addCallback(self._turn_barrier)
        last_segnum = self.num_segments - 1
        d.addCallback(lambda res: self._encode_tail_segment(last_segnum))
        d.addCallback(self._send_segment, last_segnum)
        d.addCallback(self._turn_barrier)

        d.addCallback(lambda res: self.finish_hashing())

        d.addCallback(lambda res:
                      self.send_crypttext_hash_tree_to_all_shareholders())
        d.addCallback(lambda res: self.send_all_block_hash_trees())
        d.addCallback(lambda res: self.send_all_share_hash_trees())
        d.addCallback(lambda res: self.send_uri_extension_to_all_shareholders())

        d.addCallback(lambda res: self.close_all_shareholders())
        d.addCallbacks(self.done, self.err)
        return d

    def set_status(self, status):
        if self._status:
            self._status.set_status(status)

    def set_encode_and_push_progress(self, sent_segments=None, extra=0.0):
        if self._status:
            # we treat the final hash+close as an extra segment
            if sent_segments is None:
                sent_segments = self.num_segments
            progress = float(sent_segments + extra) / (self.num_segments + 1)
            self._status.set_progress(2, progress)

    def abort(self):
        self.log("aborting upload", level=log.UNUSUAL)
        assert self._codec, "don't call abort before start"
        self._aborted = True
        # the next segment read (in _gather_data inside _encode_segment) will
        # raise UploadAborted(), which will bypass the rest of the upload
        # chain. If we've sent the final segment's shares, it's too late to
        # abort. TODO: allow abort any time up to close_all_shareholders.

    def _turn_barrier(self, res):
        # putting this method in a Deferred chain imposes a guaranteed
        # reactor turn between the pre- and post- portions of that chain.
        # This can be useful to limit memory consumption: since Deferreds do
        # not do tail recursion, code which uses defer.succeed(result) for
        # consistency will cause objects to live for longer than you might
        # normally expect.

        return fireEventually(res)


    def start_all_shareholders(self):
        self.log("starting shareholders", level=log.NOISY)
        self.set_status("Starting shareholders")
        dl = []
        for shareid in list(self.landlords):
            d = self.landlords[shareid].put_header()
            d.addErrback(self._remove_shareholder, shareid, "start")
            dl.append(d)
        return self._gather_responses(dl)

    def _encode_segment(self, segnum):
        codec = self._codec
        start = time.time()

        # the ICodecEncoder API wants to receive a total of self.segment_size
        # bytes on each encode() call, broken up into a number of
        # identically-sized pieces. Due to the way the codec algorithm works,
        # these pieces need to be the same size as the share which the codec
        # will generate. Therefore we must feed it with input_piece_size that
        # equals the output share size.
        input_piece_size = codec.get_block_size()

        # as a result, the number of input pieces per encode() call will be
        # equal to the number of required shares with which the codec was
        # constructed. You can think of the codec as chopping up a
        # 'segment_size' of data into 'required_shares' shares (not doing any
        # fancy math at all, just doing a split), then creating some number
        # of additional shares which can be substituted if the primary ones
        # are unavailable

        crypttext_segment_hasher = hashutil.crypttext_segment_hasher()

        # memory footprint: we only hold a tiny piece of the plaintext at any
        # given time. We build up a segment's worth of cryptttext, then hand
        # it to the encoder. Assuming 3-of-10 encoding (3.3x expansion) and
        # 1MiB max_segment_size, we get a peak memory footprint of 4.3*1MiB =
        # 4.3MiB. Lowering max_segment_size to, say, 100KiB would drop the
        # footprint to 430KiB at the expense of more hash-tree overhead.

        d = self._gather_data(self.required_shares, input_piece_size,
                              crypttext_segment_hasher)
        def _done_gathering(chunks):
            for c in chunks:
                assert len(c) == input_piece_size
            self._crypttext_hashes.append(crypttext_segment_hasher.digest())
            # during this call, we hit 5*segsize memory
            return codec.encode(chunks)
        d.addCallback(_done_gathering)
        def _done(res):
            elapsed = time.time() - start
            self._times["cumulative_encoding"] += elapsed
            return res
        d.addCallback(_done)
        return d

    def _encode_tail_segment(self, segnum):

        start = time.time()
        codec = self._tail_codec
        input_piece_size = codec.get_block_size()

        crypttext_segment_hasher = hashutil.crypttext_segment_hasher()

        d = self._gather_data(self.required_shares, input_piece_size,
                              crypttext_segment_hasher,
                              allow_short=True)
        def _done_gathering(chunks):
            for c in chunks:
                # a short trailing chunk will have been padded by
                # _gather_data
                assert len(c) == input_piece_size
            self._crypttext_hashes.append(crypttext_segment_hasher.digest())
            return codec.encode(chunks)
        d.addCallback(_done_gathering)
        def _done(res):
            elapsed = time.time() - start
            self._times["cumulative_encoding"] += elapsed
            return res
        d.addCallback(_done)
        return d

    def _gather_data(self, num_chunks, input_chunk_size,
                     crypttext_segment_hasher,
                     allow_short=False,
                     previous_chunks=[]):
        """Return a Deferred that will fire when the required number of
        chunks have been read (and hashed and encrypted). The Deferred fires
        with the combination of any 'previous_chunks' and the new chunks
        which were gathered."""

        if self._aborted:
            raise UploadAborted()

        if not num_chunks:
            return defer.succeed(previous_chunks)

        d = self._uploadable.read_encrypted(input_chunk_size, False)
        def _got(data):
            if self._aborted:
                raise UploadAborted()
            encrypted_pieces = []
            length = 0
            while data:
                encrypted_piece = data.pop(0)
                length += len(encrypted_piece)
                crypttext_segment_hasher.update(encrypted_piece)
                self._crypttext_hasher.update(encrypted_piece)
                encrypted_pieces.append(encrypted_piece)

            precondition(length <= input_chunk_size,
                         "length=%d > input_chunk_size=%d" %
                         (length, input_chunk_size))
            if allow_short:
                if length < input_chunk_size:
                    # padding
                    pad_size = input_chunk_size - length
                    encrypted_pieces.append('\x00' * pad_size)
            else:
                # non-tail segments should be the full segment size
                if length != input_chunk_size:
                    log.msg("non-tail segment should be full segment size: %d!=%d"
                            % (length, input_chunk_size),
                            level=log.BAD, umid="jNk5Yw")
                precondition(length == input_chunk_size,
                             "length=%d != input_chunk_size=%d" %
                             (length, input_chunk_size))

            encrypted_piece = "".join(encrypted_pieces)
            return previous_chunks + [encrypted_piece]

        d.addCallback(_got)
        d.addCallback(lambda chunks:
                      self._gather_data(num_chunks-1, input_chunk_size,
                                        crypttext_segment_hasher,
                                        allow_short, chunks))
        return d

    def _send_segment(self, (shares, shareids), segnum):
        # To generate the URI, we must generate the roothash, so we must
        # generate all shares, even if we aren't actually giving them to
        # anybody. This means that the set of shares we create will be equal
        # to or larger than the set of landlords. If we have any landlord who
        # *doesn't* have a share, that's an error.
        _assert(set(self.landlords.keys()).issubset(set(shareids)),
                shareids=shareids, landlords=self.landlords)
        start = time.time()
        dl = []
        self.set_status("Sending segment %d of %d" % (segnum+1,
                                                      self.num_segments))
        self.set_encode_and_push_progress(segnum)
        lognum = self.log("send_segment(%d)" % segnum, level=log.NOISY)
        for i in range(len(shares)):
            block = shares[i]
            shareid = shareids[i]
            d = self.send_block(shareid, segnum, block, lognum)
            dl.append(d)
            block_hash = hashutil.block_hash(block)
            #from allmydata.util import base32
            #log.msg("creating block (shareid=%d, blocknum=%d) "
            #        "len=%d %r .. %r: %s" %
            #        (shareid, segnum, len(block),
            #         block[:50], block[-50:], base32.b2a(block_hash)))
            self.block_hashes[shareid].append(block_hash)

        dl = self._gather_responses(dl)
        def _logit(res):
            self.log("%s uploaded %s / %s bytes (%d%%) of your file." %
                     (self,
                      self.segment_size*(segnum+1),
                      self.segment_size*self.num_segments,
                      100 * (segnum+1) / self.num_segments,
                      ),
                     level=log.OPERATIONAL)
            elapsed = time.time() - start
            self._times["cumulative_sending"] += elapsed
            return res
        dl.addCallback(_logit)
        return dl
Ejemplo n.º 4
0
class Encoder(object):
    implements(IEncoder)

    def __init__(self, log_parent=None, upload_status=None):
        object.__init__(self)
        self.uri_extension_data = {}
        self._codec = None
        self._status = None
        if upload_status:
            self._status = IUploadStatus(upload_status)
        precondition(log_parent is None or isinstance(log_parent, int),
                     log_parent)
        self._log_number = log.msg("creating Encoder %s" % self,
                                   facility="tahoe.encoder",
                                   parent=log_parent)
        self._aborted = False

    def __repr__(self):
        if hasattr(self, "_storage_index"):
            return "<Encoder for %s>" % si_b2a(self._storage_index)[:5]
        return "<Encoder for unknown storage index>"

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

    def set_encrypted_uploadable(self, uploadable):
        eu = self._uploadable = IEncryptedUploadable(uploadable)
        d = eu.get_size()

        def _got_size(size):
            self.log(format="file size: %(size)d", size=size)
            self.file_size = size

        d.addCallback(_got_size)
        d.addCallback(lambda res: eu.get_all_encoding_parameters())
        d.addCallback(self._got_all_encoding_parameters)
        d.addCallback(lambda res: eu.get_storage_index())

        def _done(storage_index):
            self._storage_index = storage_index
            return self

        d.addCallback(_done)
        return d

    def _got_all_encoding_parameters(self, params):
        assert not self._codec
        k, happy, n, segsize = params
        self.required_shares = k
        self.servers_of_happiness = happy
        self.num_shares = n
        self.segment_size = segsize
        self.log("got encoding parameters: %d/%d/%d %d" %
                 (k, happy, n, segsize))
        self.log("now setting up codec")

        assert self.segment_size % self.required_shares == 0

        self.num_segments = mathutil.div_ceil(self.file_size,
                                              self.segment_size)

        self._codec = CRSEncoder()
        self._codec.set_params(self.segment_size, self.required_shares,
                               self.num_shares)

        data = self.uri_extension_data
        data['codec_name'] = self._codec.get_encoder_type()
        data['codec_params'] = self._codec.get_serialized_params()

        data['size'] = self.file_size
        data['segment_size'] = self.segment_size
        self.share_size = mathutil.div_ceil(self.file_size,
                                            self.required_shares)
        data['num_segments'] = self.num_segments
        data['needed_shares'] = self.required_shares
        data['total_shares'] = self.num_shares

        # the "tail" is the last segment. This segment may or may not be
        # shorter than all other segments. We use the "tail codec" to handle
        # it. If the tail is short, we use a different codec instance. In
        # addition, the tail codec must be fed data which has been padded out
        # to the right size.
        tail_size = self.file_size % self.segment_size
        if not tail_size:
            tail_size = self.segment_size

        # the tail codec is responsible for encoding tail_size bytes
        padded_tail_size = mathutil.next_multiple(tail_size,
                                                  self.required_shares)
        self._tail_codec = CRSEncoder()
        self._tail_codec.set_params(padded_tail_size, self.required_shares,
                                    self.num_shares)
        data['tail_codec_params'] = self._tail_codec.get_serialized_params()

    def _get_share_size(self):
        share_size = mathutil.div_ceil(self.file_size, self.required_shares)
        overhead = self._compute_overhead()
        return share_size + overhead

    def _compute_overhead(self):
        return 0

    def get_param(self, name):
        assert self._codec

        if name == "storage_index":
            return self._storage_index
        elif name == "share_counts":
            return (self.required_shares, self.servers_of_happiness,
                    self.num_shares)
        elif name == "num_segments":
            return self.num_segments
        elif name == "segment_size":
            return self.segment_size
        elif name == "block_size":
            return self._codec.get_block_size()
        elif name == "share_size":
            return self._get_share_size()
        elif name == "serialized_params":
            return self._codec.get_serialized_params()
        else:
            raise KeyError("unknown parameter name '%s'" % name)

    def set_shareholders(self, landlords, servermap):
        assert isinstance(landlords, dict)
        for k in landlords:
            assert IStorageBucketWriter.providedBy(landlords[k])
        self.landlords = landlords.copy()
        assert isinstance(servermap, dict)
        for v in servermap.itervalues():
            assert isinstance(v, set)
        self.servermap = servermap.copy()

    def start(self):
        """ Returns a Deferred that will fire with the verify cap (an instance of
        uri.CHKFileVerifierURI)."""
        self.log("%s starting" % (self, ))
        #paddedsize = self._size + mathutil.pad_size(self._size, self.needed_shares)
        assert self._codec
        self._crypttext_hasher = hashutil.crypttext_hasher()
        self._crypttext_hashes = []
        self.segment_num = 0
        self.block_hashes = [[] for x in range(self.num_shares)]
        # block_hashes[i] is a list that will be accumulated and then send
        # to landlord[i]. This list contains a hash of each segment_share
        # that we sent to that landlord.
        self.share_root_hashes = [None] * self.num_shares

        self._times = {
            "cumulative_encoding": 0.0,
            "cumulative_sending": 0.0,
            "hashes_and_close": 0.0,
            "total_encode_and_push": 0.0,
        }
        self._start_total_timestamp = time.time()

        d = fireEventually()

        d.addCallback(lambda res: self.start_all_shareholders())

        for i in range(self.num_segments - 1):
            # note to self: this form doesn't work, because lambda only
            # captures the slot, not the value
            #d.addCallback(lambda res: self.do_segment(i))
            # use this form instead:
            d.addCallback(lambda res, i=i: self._encode_segment(i))
            d.addCallback(self._send_segment, i)
            d.addCallback(self._turn_barrier)
        last_segnum = self.num_segments - 1
        d.addCallback(lambda res: self._encode_tail_segment(last_segnum))
        d.addCallback(self._send_segment, last_segnum)
        d.addCallback(self._turn_barrier)

        d.addCallback(lambda res: self.finish_hashing())

        d.addCallback(
            lambda res: self.send_crypttext_hash_tree_to_all_shareholders())
        d.addCallback(lambda res: self.send_all_block_hash_trees())
        d.addCallback(lambda res: self.send_all_share_hash_trees())
        d.addCallback(
            lambda res: self.send_uri_extension_to_all_shareholders())

        d.addCallback(lambda res: self.close_all_shareholders())
        d.addCallbacks(self.done, self.err)
        return d

    def set_status(self, status):
        if self._status:
            self._status.set_status(status)

    def set_encode_and_push_progress(self, sent_segments=None, extra=0.0):
        if self._status:
            # we treat the final hash+close as an extra segment
            if sent_segments is None:
                sent_segments = self.num_segments
            progress = float(sent_segments + extra) / (self.num_segments + 1)
            self._status.set_progress(2, progress)

    def abort(self):
        self.log("aborting upload", level=log.UNUSUAL)
        assert self._codec, "don't call abort before start"
        self._aborted = True
        # the next segment read (in _gather_data inside _encode_segment) will
        # raise UploadAborted(), which will bypass the rest of the upload
        # chain. If we've sent the final segment's shares, it's too late to
        # abort. TODO: allow abort any time up to close_all_shareholders.

    def _turn_barrier(self, res):
        # putting this method in a Deferred chain imposes a guaranteed
        # reactor turn between the pre- and post- portions of that chain.
        # This can be useful to limit memory consumption: since Deferreds do
        # not do tail recursion, code which uses defer.succeed(result) for
        # consistency will cause objects to live for longer than you might
        # normally expect.

        return fireEventually(res)

    def start_all_shareholders(self):
        self.log("starting shareholders", level=log.NOISY)
        self.set_status("Starting shareholders")
        dl = []
        for shareid in list(self.landlords):
            d = self.landlords[shareid].put_header()
            d.addErrback(self._remove_shareholder, shareid, "start")
            dl.append(d)
        return self._gather_responses(dl)

    def _encode_segment(self, segnum):
        codec = self._codec
        start = time.time()

        # the ICodecEncoder API wants to receive a total of self.segment_size
        # bytes on each encode() call, broken up into a number of
        # identically-sized pieces. Due to the way the codec algorithm works,
        # these pieces need to be the same size as the share which the codec
        # will generate. Therefore we must feed it with input_piece_size that
        # equals the output share size.
        input_piece_size = codec.get_block_size()

        # as a result, the number of input pieces per encode() call will be
        # equal to the number of required shares with which the codec was
        # constructed. You can think of the codec as chopping up a
        # 'segment_size' of data into 'required_shares' shares (not doing any
        # fancy math at all, just doing a split), then creating some number
        # of additional shares which can be substituted if the primary ones
        # are unavailable

        # we read data from the source one segment at a time, and then chop
        # it into 'input_piece_size' pieces before handing it to the codec

        crypttext_segment_hasher = hashutil.crypttext_segment_hasher()

        # memory footprint: we only hold a tiny piece of the plaintext at any
        # given time. We build up a segment's worth of cryptttext, then hand
        # it to the encoder. Assuming 3-of-10 encoding (3.3x expansion) and
        # 1MiB max_segment_size, we get a peak memory footprint of 4.3*1MiB =
        # 4.3MiB. Lowering max_segment_size to, say, 100KiB would drop the
        # footprint to 430KiB at the expense of more hash-tree overhead.

        d = self._gather_data(self.required_shares, input_piece_size,
                              crypttext_segment_hasher)

        def _done_gathering(chunks):
            for c in chunks:
                assert len(c) == input_piece_size
            self._crypttext_hashes.append(crypttext_segment_hasher.digest())
            # during this call, we hit 5*segsize memory
            return codec.encode(chunks)

        d.addCallback(_done_gathering)

        def _done(res):
            elapsed = time.time() - start
            self._times["cumulative_encoding"] += elapsed
            return res

        d.addCallback(_done)
        return d

    def _encode_tail_segment(self, segnum):

        start = time.time()
        codec = self._tail_codec
        input_piece_size = codec.get_block_size()

        crypttext_segment_hasher = hashutil.crypttext_segment_hasher()

        d = self._gather_data(self.required_shares,
                              input_piece_size,
                              crypttext_segment_hasher,
                              allow_short=True)

        def _done_gathering(chunks):
            for c in chunks:
                # a short trailing chunk will have been padded by
                # _gather_data
                assert len(c) == input_piece_size
            self._crypttext_hashes.append(crypttext_segment_hasher.digest())
            return codec.encode(chunks)

        d.addCallback(_done_gathering)

        def _done(res):
            elapsed = time.time() - start
            self._times["cumulative_encoding"] += elapsed
            return res

        d.addCallback(_done)
        return d

    def _gather_data(self,
                     num_chunks,
                     input_chunk_size,
                     crypttext_segment_hasher,
                     allow_short=False):
        """Return a Deferred that will fire when the required number of
        chunks have been read (and hashed and encrypted). The Deferred fires
        with a list of chunks, each of size input_chunk_size."""

        # I originally built this to allow read_encrypted() to behave badly:
        # to let it return more or less data than you asked for. It would
        # stash the leftovers until later, and then recurse until it got
        # enough. I don't think that was actually useful.
        #
        # who defines read_encrypted?
        #  offloaded.LocalCiphertextReader: real disk file: exact
        #  upload.EncryptAnUploadable: Uploadable, but a wrapper that makes
        #    it exact. The return value is a list of 50KiB chunks, to reduce
        #    the memory footprint of the encryption process.
        #  repairer.Repairer: immutable.filenode.CiphertextFileNode: exact
        #
        # This has been redefined to require read_encrypted() to behave like
        # a local file: return exactly the amount requested unless it hits
        # EOF.
        #  -warner

        if self._aborted:
            raise UploadAborted()

        read_size = num_chunks * input_chunk_size
        d = self._uploadable.read_encrypted(read_size, hash_only=False)

        def _got(data):
            assert isinstance(data, (list, tuple))
            if self._aborted:
                raise UploadAborted()
            data = "".join(data)
            precondition(len(data) <= read_size, len(data), read_size)
            if not allow_short:
                precondition(len(data) == read_size, len(data), read_size)
            crypttext_segment_hasher.update(data)
            self._crypttext_hasher.update(data)
            if allow_short and len(data) < read_size:
                # padding
                data += "\x00" * (read_size - len(data))
            encrypted_pieces = [
                data[i:i + input_chunk_size]
                for i in range(0, len(data), input_chunk_size)
            ]
            return encrypted_pieces

        d.addCallback(_got)
        return d

    def _send_segment(self, (shares, shareids), segnum):
        # To generate the URI, we must generate the roothash, so we must
        # generate all shares, even if we aren't actually giving them to
        # anybody. This means that the set of shares we create will be equal
        # to or larger than the set of landlords. If we have any landlord who
        # *doesn't* have a share, that's an error.
        _assert(set(self.landlords.keys()).issubset(set(shareids)),
                shareids=shareids,
                landlords=self.landlords)
        start = time.time()
        dl = []
        self.set_status("Sending segment %d of %d" %
                        (segnum + 1, self.num_segments))
        self.set_encode_and_push_progress(segnum)
        lognum = self.log("send_segment(%d)" % segnum, level=log.NOISY)
        for i in range(len(shares)):
            block = shares[i]
            shareid = shareids[i]
            d = self.send_block(shareid, segnum, block, lognum)
            dl.append(d)
            block_hash = hashutil.block_hash(block)
            #from allmydata.util import base32
            #log.msg("creating block (shareid=%d, blocknum=%d) "
            #        "len=%d %r .. %r: %s" %
            #        (shareid, segnum, len(block),
            #         block[:50], block[-50:], base32.b2a(block_hash)))
            self.block_hashes[shareid].append(block_hash)

        dl = self._gather_responses(dl)

        def _logit(res):
            self.log("%s uploaded %s / %s bytes (%d%%) of your file." % (
                self,
                self.segment_size * (segnum + 1),
                self.segment_size * self.num_segments,
                100 * (segnum + 1) / self.num_segments,
            ),
                     level=log.OPERATIONAL)
            elapsed = time.time() - start
            self._times["cumulative_sending"] += elapsed
            return res

        dl.addCallback(_logit)
        return dl
Ejemplo n.º 5
0
class Encoder(object):

    def __init__(self, log_parent=None, upload_status=None, progress=None):
        object.__init__(self)
        self.uri_extension_data = {}
        self._codec = None
        self._status = None
        if upload_status:
            self._status = IUploadStatus(upload_status)
        precondition(log_parent is None or isinstance(log_parent, int),
                     log_parent)
        self._log_number = log.msg("creating Encoder %s" % self,
                                   facility="tahoe.encoder", parent=log_parent)
        self._aborted = False
        self._progress = progress

    def __repr__(self):
        if hasattr(self, "_storage_index"):
            return "<Encoder for %s>" % si_b2a(self._storage_index)[:5]
        return "<Encoder for unknown storage index>"

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

    @log_call_deferred(action_type=u"immutable:encode:set-encrypted-uploadable")
    def set_encrypted_uploadable(self, uploadable):
        eu = self._uploadable = IEncryptedUploadable(uploadable)
        d = eu.get_size()
        def _got_size(size):
            self.log(format="file size: %(size)d", size=size)
            self.file_size = size
            if self._progress:
                self._progress.set_progress_total(self.file_size)
        d.addCallback(_got_size)
        d.addCallback(lambda res: eu.get_all_encoding_parameters())
        d.addCallback(self._got_all_encoding_parameters)
        d.addCallback(lambda res: eu.get_storage_index())
        def _done(storage_index):
            self._storage_index = storage_index
            return self
        d.addCallback(_done)
        return d

    def _got_all_encoding_parameters(self, params):
        assert not self._codec
        k, happy, n, segsize = params
        self.required_shares = k
        self.min_happiness = happy
        self.num_shares = n
        self.segment_size = segsize
        self.log("got encoding parameters: %d/%d/%d %d" % (k,happy,n, segsize))
        self.log("now setting up codec")

        assert self.segment_size % self.required_shares == 0

        self.num_segments = mathutil.div_ceil(self.file_size,
                                              self.segment_size)

        self._codec = CRSEncoder()
        self._codec.set_params(self.segment_size,
                               self.required_shares, self.num_shares)

        data = self.uri_extension_data
        data['codec_name'] = self._codec.get_encoder_type()
        data['codec_params'] = self._codec.get_serialized_params()

        data['size'] = self.file_size
        data['segment_size'] = self.segment_size
        self.share_size = mathutil.div_ceil(self.file_size,
                                            self.required_shares)
        data['num_segments'] = self.num_segments
        data['needed_shares'] = self.required_shares
        data['total_shares'] = self.num_shares

        # the "tail" is the last segment. This segment may or may not be
        # shorter than all other segments. We use the "tail codec" to handle
        # it. If the tail is short, we use a different codec instance. In
        # addition, the tail codec must be fed data which has been padded out
        # to the right size.
        tail_size = self.file_size % self.segment_size
        if not tail_size:
            tail_size = self.segment_size

        # the tail codec is responsible for encoding tail_size bytes
        padded_tail_size = mathutil.next_multiple(tail_size,
                                                  self.required_shares)
        self._tail_codec = CRSEncoder()
        self._tail_codec.set_params(padded_tail_size,
                                    self.required_shares, self.num_shares)
        data['tail_codec_params'] = self._tail_codec.get_serialized_params()

    def _get_share_size(self):
        share_size = mathutil.div_ceil(self.file_size, self.required_shares)
        overhead = self._compute_overhead()
        return share_size + overhead

    def _compute_overhead(self):
        return 0

    def get_param(self, name):
        assert self._codec

        if name == "storage_index":
            return self._storage_index
        elif name == "share_counts":
            return (self.required_shares, self.min_happiness,
                    self.num_shares)
        elif name == "num_segments":
            return self.num_segments
        elif name == "segment_size":
            return self.segment_size
        elif name == "block_size":
            return self._codec.get_block_size()
        elif name == "share_size":
            return self._get_share_size()
        elif name == "serialized_params":
            return self._codec.get_serialized_params()
        else:
            raise KeyError("unknown parameter name '%s'" % name)

    def set_shareholders(self, landlords, servermap):
        assert isinstance(landlords, dict)
        for k in landlords:
            assert IStorageBucketWriter.providedBy(landlords[k])
        self.landlords = landlords.copy()
        assert isinstance(servermap, dict)
        for v in servermap.itervalues():
            assert isinstance(v, set)
        self.servermap = servermap.copy()

    @log_call_deferred(action_type=u"immutable:encode:start")
    def start(self):
        """ Returns a Deferred that will fire with the verify cap (an instance of
        uri.CHKFileVerifierURI)."""
        self.log("%s starting" % (self,))
        #paddedsize = self._size + mathutil.pad_size(self._size, self.needed_shares)
        assert self._codec
        self._crypttext_hasher = hashutil.crypttext_hasher()
        self._crypttext_hashes = []
        self.segment_num = 0
        self.block_hashes = [[] for x in range(self.num_shares)]
        # block_hashes[i] is a list that will be accumulated and then send
        # to landlord[i]. This list contains a hash of each segment_share
        # that we sent to that landlord.
        self.share_root_hashes = [None] * self.num_shares

        self._times = {
            "cumulative_encoding": 0.0,
            "cumulative_sending": 0.0,
            "hashes_and_close": 0.0,
            "total_encode_and_push": 0.0,
            }
        self._start_total_timestamp = time.time()

        d = fireEventually()

        d.addCallback(lambda res: self.start_all_shareholders())

        for i in range(self.num_segments-1):
            # note to self: this form doesn't work, because lambda only
            # captures the slot, not the value
            #d.addCallback(lambda res: self.do_segment(i))
            # use this form instead:
            d.addCallback(lambda res, i=i: self._encode_segment(i))
            d.addCallback(self._send_segment, i)
            d.addCallback(self._turn_barrier)
        last_segnum = self.num_segments - 1
        d.addCallback(lambda res: self._encode_tail_segment(last_segnum))
        d.addCallback(self._send_segment, last_segnum)
        d.addCallback(self._turn_barrier)

        d.addCallback(lambda res: self.finish_hashing())

        d.addCallback(lambda res:
                      self.send_crypttext_hash_tree_to_all_shareholders())
        d.addCallback(lambda res: self.send_all_block_hash_trees())
        d.addCallback(lambda res: self.send_all_share_hash_trees())
        d.addCallback(lambda res: self.send_uri_extension_to_all_shareholders())

        d.addCallback(lambda res: self.close_all_shareholders())
        d.addCallbacks(self.done, self.err)
        return d

    def set_status(self, status):
        if self._status:
            self._status.set_status(status)

    def set_encode_and_push_progress(self, sent_segments=None, extra=0.0):
        if self._status:
            # we treat the final hash+close as an extra segment
            if sent_segments is None:
                sent_segments = self.num_segments
            progress = float(sent_segments + extra) / (self.num_segments + 1)
            self._status.set_progress(2, progress)

    def abort(self):
        self.log("aborting upload", level=log.UNUSUAL)
        assert self._codec, "don't call abort before start"
        self._aborted = True
        # the next segment read (in _gather_data inside _encode_segment) will
        # raise UploadAborted(), which will bypass the rest of the upload
        # chain. If we've sent the final segment's shares, it's too late to
        # abort. TODO: allow abort any time up to close_all_shareholders.

    def _turn_barrier(self, res):
        # putting this method in a Deferred chain imposes a guaranteed
        # reactor turn between the pre- and post- portions of that chain.
        # This can be useful to limit memory consumption: since Deferreds do
        # not do tail recursion, code which uses defer.succeed(result) for
        # consistency will cause objects to live for longer than you might
        # normally expect.

        return fireEventually(res)


    def start_all_shareholders(self):
        self.log("starting shareholders", level=log.NOISY)
        self.set_status("Starting shareholders")
        dl = []
        for shareid in list(self.landlords):
            d = self.landlords[shareid].put_header()
            d.addErrback(self._remove_shareholder, shareid, "start")
            dl.append(d)
        return self._gather_responses(dl)

    def _encode_segment(self, segnum):
        codec = self._codec
        start = time.time()

        # the ICodecEncoder API wants to receive a total of self.segment_size
        # bytes on each encode() call, broken up into a number of
        # identically-sized pieces. Due to the way the codec algorithm works,
        # these pieces need to be the same size as the share which the codec
        # will generate. Therefore we must feed it with input_piece_size that
        # equals the output share size.
        input_piece_size = codec.get_block_size()

        # as a result, the number of input pieces per encode() call will be
        # equal to the number of required shares with which the codec was
        # constructed. You can think of the codec as chopping up a
        # 'segment_size' of data into 'required_shares' shares (not doing any
        # fancy math at all, just doing a split), then creating some number
        # of additional shares which can be substituted if the primary ones
        # are unavailable

        # we read data from the source one segment at a time, and then chop
        # it into 'input_piece_size' pieces before handing it to the codec

        crypttext_segment_hasher = hashutil.crypttext_segment_hasher()

        # memory footprint: we only hold a tiny piece of the plaintext at any
        # given time. We build up a segment's worth of cryptttext, then hand
        # it to the encoder. Assuming 3-of-10 encoding (3.3x expansion) and
        # 1MiB max_segment_size, we get a peak memory footprint of 4.3*1MiB =
        # 4.3MiB. Lowering max_segment_size to, say, 100KiB would drop the
        # footprint to 430KiB at the expense of more hash-tree overhead.

        d = self._gather_data(self.required_shares, input_piece_size,
                              crypttext_segment_hasher)
        def _done_gathering(chunks):
            for c in chunks:
                assert len(c) == input_piece_size
            self._crypttext_hashes.append(crypttext_segment_hasher.digest())
            # during this call, we hit 5*segsize memory
            return codec.encode(chunks)
        d.addCallback(_done_gathering)
        def _done(res):
            elapsed = time.time() - start
            self._times["cumulative_encoding"] += elapsed
            return res
        d.addCallback(_done)
        return d

    def _encode_tail_segment(self, segnum):

        start = time.time()
        codec = self._tail_codec
        input_piece_size = codec.get_block_size()

        crypttext_segment_hasher = hashutil.crypttext_segment_hasher()

        d = self._gather_data(self.required_shares, input_piece_size,
                              crypttext_segment_hasher, allow_short=True)
        def _done_gathering(chunks):
            for c in chunks:
                # a short trailing chunk will have been padded by
                # _gather_data
                assert len(c) == input_piece_size
            self._crypttext_hashes.append(crypttext_segment_hasher.digest())
            return codec.encode(chunks)
        d.addCallback(_done_gathering)
        def _done(res):
            elapsed = time.time() - start
            self._times["cumulative_encoding"] += elapsed
            return res
        d.addCallback(_done)
        return d

    def _gather_data(self, num_chunks, input_chunk_size,
                     crypttext_segment_hasher,
                     allow_short=False):
        """Return a Deferred that will fire when the required number of
        chunks have been read (and hashed and encrypted). The Deferred fires
        with a list of chunks, each of size input_chunk_size."""

        # I originally built this to allow read_encrypted() to behave badly:
        # to let it return more or less data than you asked for. It would
        # stash the leftovers until later, and then recurse until it got
        # enough. I don't think that was actually useful.
        #
        # who defines read_encrypted?
        #  offloaded.LocalCiphertextReader: real disk file: exact
        #  upload.EncryptAnUploadable: Uploadable, but a wrapper that makes
        #    it exact. The return value is a list of 50KiB chunks, to reduce
        #    the memory footprint of the encryption process.
        #  repairer.Repairer: immutable.filenode.CiphertextFileNode: exact
        #
        # This has been redefined to require read_encrypted() to behave like
        # a local file: return exactly the amount requested unless it hits
        # EOF.
        #  -warner

        if self._aborted:
            raise UploadAborted()

        read_size = num_chunks * input_chunk_size
        d = self._uploadable.read_encrypted(read_size, hash_only=False)
        def _got(data):
            assert isinstance(data, (list,tuple))
            if self._aborted:
                raise UploadAborted()
            data = "".join(data)
            precondition(len(data) <= read_size, len(data), read_size)
            if not allow_short:
                precondition(len(data) == read_size, len(data), read_size)
            crypttext_segment_hasher.update(data)
            self._crypttext_hasher.update(data)
            if allow_short and len(data) < read_size:
                # padding
                data += "\x00" * (read_size - len(data))
            encrypted_pieces = [data[i:i+input_chunk_size]
                                for i in range(0, len(data), input_chunk_size)]
            return encrypted_pieces
        d.addCallback(_got)
        return d

    def _send_segment(self, shares_and_shareids, segnum):
        # To generate the URI, we must generate the roothash, so we must
        # generate all shares, even if we aren't actually giving them to
        # anybody. This means that the set of shares we create will be equal
        # to or larger than the set of landlords. If we have any landlord who
        # *doesn't* have a share, that's an error.
        (shares, shareids) = shares_and_shareids
        _assert(set(self.landlords.keys()).issubset(set(shareids)),
                shareids=shareids, landlords=self.landlords)
        start = time.time()
        dl = []
        self.set_status("Sending segment %d of %d" % (segnum+1,
                                                      self.num_segments))
        self.set_encode_and_push_progress(segnum)
        lognum = self.log("send_segment(%d)" % segnum, level=log.NOISY)
        for i in range(len(shares)):
            block = shares[i]
            shareid = shareids[i]
            d = self.send_block(shareid, segnum, block, lognum)
            dl.append(d)

            block_hash = hashutil.block_hash(block)
            #from allmydata.util import base32
            #log.msg("creating block (shareid=%d, blocknum=%d) "
            #        "len=%d %r .. %r: %s" %
            #        (shareid, segnum, len(block),
            #         block[:50], block[-50:], base32.b2a(block_hash)))
            self.block_hashes[shareid].append(block_hash)

        dl = self._gather_responses(dl)

        def do_progress(ign):
            done = self.segment_size * (segnum + 1)
            if self._progress:
                self._progress.set_progress(done)
            return ign
        dl.addCallback(do_progress)

        def _logit(res):
            self.log("%s uploaded %s / %s bytes (%d%%) of your file." %
                     (self,
                      self.segment_size*(segnum+1),
                      self.segment_size*self.num_segments,
                      100 * (segnum+1) / self.num_segments,
                      ),
                     level=log.OPERATIONAL)
            elapsed = time.time() - start
            self._times["cumulative_sending"] += elapsed
            return res
        dl.addCallback(_logit)
        return dl

    def send_block(self, shareid, segment_num, block, lognum):
        if shareid not in self.landlords:
            return defer.succeed(None)
        sh = self.landlords[shareid]
        lognum2 = self.log("put_block to %s" % self.landlords[shareid],
                           parent=lognum, level=log.NOISY)
        d = sh.put_block(segment_num, block)
        def _done(res):
            self.log("put_block done", parent=lognum2, level=log.NOISY)
            return res
        d.addCallback(_done)
        d.addErrback(self._remove_shareholder, shareid,
                     "segnum=%d" % segment_num)
        return d

    def _remove_shareholder(self, why, shareid, where):
        ln = self.log(format="error while sending %(method)s to shareholder=%(shnum)d",
                      method=where, shnum=shareid,
                      level=log.UNUSUAL, failure=why)
        if shareid in self.landlords:
            self.landlords[shareid].abort()
            peerid = self.landlords[shareid].get_peerid()
            assert peerid
            del self.landlords[shareid]
            self.servermap[shareid].remove(peerid)
            if not self.servermap[shareid]:
                del self.servermap[shareid]
        else:
            # even more UNUSUAL
            self.log("they weren't in our list of landlords", parent=ln,
                     level=log.WEIRD, umid="TQGFRw")
        happiness = happinessutil.servers_of_happiness(self.servermap)
        if happiness < self.min_happiness:
            peerids = set(happinessutil.shares_by_server(self.servermap).keys())
            msg = happinessutil.failure_message(len(peerids),
                                                self.required_shares,
                                                self.min_happiness,
                                                happiness)
            msg = "%s: %s" % (msg, why)
            raise UploadUnhappinessError(msg)
        self.log("but we can still continue with %s shares, we'll be happy "
                 "with at least %s" % (happiness,
                                       self.min_happiness),
                 parent=ln)

    def _gather_responses(self, dl):
        d = defer.DeferredList(dl, fireOnOneErrback=True)
        def _eatUploadUnhappinessError(f):
            # all exceptions that occur while talking to a peer are handled
            # in _remove_shareholder. That might raise UploadUnhappinessError,
            # which will cause the DeferredList to errback but which should
            # otherwise be consumed. Allow non-UploadUnhappinessError exceptions
            # to pass through as an unhandled errback. We use this in lieu of
            # consumeErrors=True to allow coding errors to be logged.
            f.trap(UploadUnhappinessError)
            return None
        for d0 in dl:
            d0.addErrback(_eatUploadUnhappinessError)
        return d

    def finish_hashing(self):
        self._start_hashing_and_close_timestamp = time.time()
        self.set_status("Finishing hashes")
        self.set_encode_and_push_progress(extra=0.0)
        crypttext_hash = self._crypttext_hasher.digest()
        self.uri_extension_data["crypttext_hash"] = crypttext_hash
        self._uploadable.close()

    def send_crypttext_hash_tree_to_all_shareholders(self):
        self.log("sending crypttext hash tree", level=log.NOISY)
        self.set_status("Sending Crypttext Hash Tree")
        self.set_encode_and_push_progress(extra=0.3)
        t = HashTree(self._crypttext_hashes)
        all_hashes = list(t)
        self.uri_extension_data["crypttext_root_hash"] = t[0]
        dl = []
        for shareid in list(self.landlords):
            dl.append(self.send_crypttext_hash_tree(shareid, all_hashes))
        return self._gather_responses(dl)

    def send_crypttext_hash_tree(self, shareid, all_hashes):
        if shareid not in self.landlords:
            return defer.succeed(None)
        sh = self.landlords[shareid]
        d = sh.put_crypttext_hashes(all_hashes)
        d.addErrback(self._remove_shareholder, shareid, "put_crypttext_hashes")
        return d

    def send_all_block_hash_trees(self):
        self.log("sending block hash trees", level=log.NOISY)
        self.set_status("Sending Subshare Hash Trees")
        self.set_encode_and_push_progress(extra=0.4)
        dl = []
        for shareid,hashes in enumerate(self.block_hashes):
            # hashes is a list of the hashes of all blocks that were sent
            # to shareholder[shareid].
            dl.append(self.send_one_block_hash_tree(shareid, hashes))
        return self._gather_responses(dl)

    def send_one_block_hash_tree(self, shareid, block_hashes):
        t = HashTree(block_hashes)
        all_hashes = list(t)
        # all_hashes[0] is the root hash, == hash(ah[1]+ah[2])
        # all_hashes[1] is the left child, == hash(ah[3]+ah[4])
        # all_hashes[n] == hash(all_hashes[2*n+1] + all_hashes[2*n+2])
        self.share_root_hashes[shareid] = t[0]
        if shareid not in self.landlords:
            return defer.succeed(None)
        sh = self.landlords[shareid]
        d = sh.put_block_hashes(all_hashes)
        d.addErrback(self._remove_shareholder, shareid, "put_block_hashes")
        return d

    def send_all_share_hash_trees(self):
        # Each bucket gets a set of share hash tree nodes that are needed to validate their
        # share. This includes the share hash itself, but does not include the top-level hash
        # root (which is stored securely in the URI instead).
        self.log("sending all share hash trees", level=log.NOISY)
        self.set_status("Sending Share Hash Trees")
        self.set_encode_and_push_progress(extra=0.6)
        dl = []
        for h in self.share_root_hashes:
            assert h
        # create the share hash tree
        t = HashTree(self.share_root_hashes)
        # the root of this hash tree goes into our URI
        self.uri_extension_data['share_root_hash'] = t[0]
        # now send just the necessary pieces out to each shareholder
        for i in range(self.num_shares):
            # the HashTree is given a list of leaves: 0,1,2,3..n .
            # These become nodes A+0,A+1,A+2.. of the tree, where A=n-1
            needed_hash_indices = t.needed_hashes(i, include_leaf=True)
            hashes = [(hi, t[hi]) for hi in needed_hash_indices]
            dl.append(self.send_one_share_hash_tree(i, hashes))
        return self._gather_responses(dl)

    def send_one_share_hash_tree(self, shareid, needed_hashes):
        if shareid not in self.landlords:
            return defer.succeed(None)
        sh = self.landlords[shareid]
        d = sh.put_share_hashes(needed_hashes)
        d.addErrback(self._remove_shareholder, shareid, "put_share_hashes")
        return d

    def send_uri_extension_to_all_shareholders(self):
        lp = self.log("sending uri_extension", level=log.NOISY)
        self.set_status("Sending URI Extensions")
        self.set_encode_and_push_progress(extra=0.8)
        for k in ('crypttext_root_hash', 'crypttext_hash',
                  ):
            assert k in self.uri_extension_data
        uri_extension = uri.pack_extension(self.uri_extension_data)
        ed = {}
        for k,v in self.uri_extension_data.items():
            if k.endswith("hash"):
                ed[k] = base32.b2a(v)
            else:
                ed[k] = v
        self.log("uri_extension_data is %s" % (ed,), level=log.NOISY, parent=lp)
        self.uri_extension_hash = hashutil.uri_extension_hash(uri_extension)
        dl = []
        for shareid in list(self.landlords):
            dl.append(self.send_uri_extension(shareid, uri_extension))
        return self._gather_responses(dl)

    def send_uri_extension(self, shareid, uri_extension):
        sh = self.landlords[shareid]
        d = sh.put_uri_extension(uri_extension)
        d.addErrback(self._remove_shareholder, shareid, "put_uri_extension")
        return d

    def close_all_shareholders(self):
        self.log("closing shareholders", level=log.NOISY)
        self.set_status("Closing Shareholders")
        self.set_encode_and_push_progress(extra=0.9)
        dl = []
        for shareid in list(self.landlords):
            d = self.landlords[shareid].close()
            d.addErrback(self._remove_shareholder, shareid, "close")
            dl.append(d)
        return self._gather_responses(dl)

    def done(self, res):
        self.log("upload done", level=log.OPERATIONAL)
        self.set_status("Finished")
        self.set_encode_and_push_progress(extra=1.0) # done
        now = time.time()
        h_and_c_elapsed = now - self._start_hashing_and_close_timestamp
        self._times["hashes_and_close"] = h_and_c_elapsed
        total_elapsed = now - self._start_total_timestamp
        self._times["total_encode_and_push"] = total_elapsed

        # update our sharemap
        self._shares_placed = set(self.landlords.keys())
        return uri.CHKFileVerifierURI(self._storage_index, self.uri_extension_hash,
                                      self.required_shares, self.num_shares, self.file_size)

    def err(self, f):
        self.log("upload failed", failure=f, level=log.UNUSUAL)
        self.set_status("Failed")
        # we need to abort any remaining shareholders, so they'll delete the
        # partial share, allowing someone else to upload it again.
        self.log("aborting shareholders", level=log.UNUSUAL)
        for shareid in list(self.landlords):
            self.landlords[shareid].abort()
        if f.check(defer.FirstError):
            return f.value.subFailure
        return f

    def get_shares_placed(self):
        # return a set of share numbers that were successfully placed.
        return self._shares_placed

    def get_times(self):
        # return a dictionary of encode+push timings
        return self._times

    def get_uri_extension_data(self):
        return self.uri_extension_data
    def get_uri_extension_hash(self):
        return self.uri_extension_hash