def _process_segment(self, segnum):
"""
I download, validate, decode, and decrypt one segment of the
file that this Retrieve is retrieving. This means coordinating
the process of getting k blocks of that file, validating them,
assembling them into one segment with the decoder, and then
decrypting them.
"""
self.log("processing segment %d" % segnum)
# TODO: The old code uses a marker. Should this code do that
# too? What did the Marker do?
# We need to ask each of our active readers for its block and
# salt. We will then validate those. If validation is
# successful, we will assemble the results into plaintext.
ds = []
for reader in self._active_readers:
started = time.time()
d1 = reader.get_block_and_salt(segnum)
d2,d3 = self._get_needed_hashes(reader, segnum)
d = deferredutil.gatherResults([d1,d2,d3])
d.addCallback(self._validate_block, segnum, reader, reader.server, started)
# _handle_bad_share takes care of recoverable errors (by dropping
# that share and returning None). Any other errors (i.e. code
# bugs) are passed through and cause the retrieve to fail.
d.addErrback(self._handle_bad_share, [reader])
ds.append(d)
dl = deferredutil.gatherResults(ds)
if self._verify:
dl.addCallback(lambda ignored: "")
dl.addCallback(self._set_segment)
else:
dl.addCallback(self._maybe_decode_and_decrypt_segment, segnum)
return dl
def _process_segment(self, segnum):
"""
I download, validate, decode, and decrypt one segment of the
file that this Retrieve is retrieving. This means coordinating
the process of getting k blocks of that file, validating them,
assembling them into one segment with the decoder, and then
decrypting them.
"""
self.log("processing segment %d" % segnum)
# TODO: The old code uses a marker. Should this code do that
# too? What did the Marker do?
# We need to ask each of our active readers for its block and
# salt. We will then validate those. If validation is
# successful, we will assemble the results into plaintext.
ds = []
for reader in self._active_readers:
started = time.time()
d1 = reader.get_block_and_salt(segnum)
d2,d3 = self._get_needed_hashes(reader, segnum)
d = deferredutil.gatherResults([d1,d2,d3])
d.addCallback(self._validate_block, segnum, reader, reader.server, started)
# _handle_bad_share takes care of recoverable errors (by dropping
# that share and returning None). Any other errors (i.e. code
# bugs) are passed through and cause the retrieve to fail.
d.addErrback(self._handle_bad_share, [reader])
ds.append(d)
dl = deferredutil.gatherResults(ds)
if self._verify:
dl.addCallback(lambda ignored: "")
dl.addCallback(self._set_segment)
else:
dl.addCallback(self._maybe_decode_and_decrypt_segment, segnum)
return dl
def _got_buckets(result):
bucketdict, success = result
shareverds = []
for (sharenum, bucket) in bucketdict.items():
d = self._download_and_verify(s, sharenum, bucket)
shareverds.append(d)
dl = deferredutil.gatherResults(shareverds)
def collect(results):
verified = set()
corrupt = set()
incompatible = set()
for succ, sharenum, whynot in results:
if succ:
verified.add(sharenum)
else:
if whynot == 'corrupt':
corrupt.add(sharenum)
elif whynot == 'incompatible':
incompatible.add(sharenum)
return (verified, s, corrupt, incompatible, success)
dl.addCallback(collect)
return dl
def get_block(self, blocknum):
# the first time we use this bucket, we need to fetch enough elements
# of the share hash tree to validate it from our share hash up to the
# hashroot.
if self.share_hash_tree.needed_hashes(self.sharenum):
d1 = self.bucket.get_share_hashes()
else:
d1 = defer.succeed([])
# We might need to grab some elements of our block hash tree, to
# validate the requested block up to the share hash.
blockhashesneeded = self.block_hash_tree.needed_hashes(blocknum, include_leaf=True)
# We don't need the root of the block hash tree, as that comes in the
# share tree.
blockhashesneeded.discard(0)
d2 = self.bucket.get_block_hashes(blockhashesneeded)
if blocknum < self.num_blocks-1:
thisblocksize = self.block_size
else:
thisblocksize = self.share_size % self.block_size
if thisblocksize == 0:
thisblocksize = self.block_size
d3 = self.bucket.get_block_data(blocknum,
self.block_size, thisblocksize)
dl = deferredutil.gatherResults([d1, d2, d3])
dl.addCallback(self._got_data, blocknum)
return dl
def _got_buckets(result):
bucketdict, success = result
shareverds = []
for (sharenum, bucket) in bucketdict.items():
d = self._download_and_verify(s, sharenum, bucket)
shareverds.append(d)
dl = deferredutil.gatherResults(shareverds)
def collect(results):
verified = set()
corrupt = set()
incompatible = set()
for succ, sharenum, whynot in results:
if succ:
verified.add(sharenum)
else:
if whynot == 'corrupt':
corrupt.add(sharenum)
elif whynot == 'incompatible':
incompatible.add(sharenum)
return (verified, s, corrupt, incompatible, success)
dl.addCallback(collect)
return dl
def get_block(self, blocknum):
# the first time we use this bucket, we need to fetch enough elements
# of the share hash tree to validate it from our share hash up to the
# hashroot.
if self.share_hash_tree.needed_hashes(self.sharenum):
d1 = self.bucket.get_share_hashes()
else:
d1 = defer.succeed([])
# We might need to grab some elements of our block hash tree, to
# validate the requested block up to the share hash.
blockhashesneeded = self.block_hash_tree.needed_hashes(
blocknum, include_leaf=True)
# We don't need the root of the block hash tree, as that comes in the
# share tree.
blockhashesneeded.discard(0)
d2 = self.bucket.get_block_hashes(blockhashesneeded)
if blocknum < self.num_blocks - 1:
thisblocksize = self.block_size
else:
thisblocksize = self.share_size % self.block_size
if thisblocksize == 0:
thisblocksize = self.block_size
d3 = self.bucket.get_block_data(blocknum, self.block_size,
thisblocksize)
dl = deferredutil.gatherResults([d1, d2, d3])
dl.addCallback(self._got_data, blocknum)
return dl
def _do_update(ignored):
new_data = MutableData("foo bar baz" * 100000)
new_small_data = MutableData("foo bar baz" * 10)
d1 = self.mdmf_node.overwrite(new_data)
d2 = self.sdmf_node.overwrite(new_small_data)
dl = gatherResults([d1, d2])
return dl
def _get_blocks(vrbp):
ds = []
for blocknum in range(veup.num_segments):
db = vrbp.get_block(blocknum)
db.addCallback(_discard_result)
ds.append(db)
# this gatherResults will fire once every block of this share has
# been downloaded and verified, or else it will errback.
return deferredutil.gatherResults(ds)
def start(self):
ds = []
if self._verify:
for s in self._servers:
ds.append(self._verify_server_shares(s))
else:
for s in self._servers:
ds.append(self._check_server_shares(s))
return deferredutil.gatherResults(ds).addCallback(self._format_results)
def start(self):
ds = []
if self._verify:
for s in self._servers:
ds.append(self._verify_server_shares(s))
else:
for s in self._servers:
ds.append(self._check_server_shares(s))
return deferredutil.gatherResults(ds).addCallback(self._format_results)
def test_gather_results(self):
d1 = defer.Deferred()
d2 = defer.Deferred()
res = deferredutil.gatherResults([d1, d2])
d1.errback(ValueError("BAD"))
def _callb(res):
self.fail("Should have errbacked, not resulted in %s" % (res,))
def _errb(thef):
thef.trap(ValueError)
res.addCallbacks(_callb, _errb)
return res
def _decode_and_decrypt_segments(self, ignored, data, offset):
"""
After the servermap update, I take the encrypted and encoded
data that the servermap fetched while doing its update and
transform it into decoded-and-decrypted plaintext that can be
used by the new uploadable. I return a Deferred that fires with
the segments.
"""
r = Retrieve(self._node, self._storage_broker, self._servermap,
self._version)
# decode: takes in our blocks and salts from the servermap,
# returns a Deferred that fires with the corresponding plaintext
# segments. Does not download -- simply takes advantage of
# existing infrastructure within the Retrieve class to avoid
# duplicating code.
sm = self._servermap
# XXX: If the methods in the servermap don't work as
# abstractions, you should rewrite them instead of going around
# them.
update_data = sm.update_data
start_segments = {} # shnum -> start segment
end_segments = {} # shnum -> end segment
blockhashes = {} # shnum -> blockhash tree
for (shnum, original_data) in update_data.iteritems():
data = [d[1] for d in original_data if d[0] == self._version]
# data is [(blockhashes,start,end)..]
# Every data entry in our list should now be share shnum for
# a particular version of the mutable file, so all of the
# entries should be identical.
datum = data[0]
assert [x for x in data if x != datum] == []
# datum is (blockhashes,start,end)
blockhashes[shnum] = datum[0]
start_segments[shnum] = datum[1] # (block,salt) bytestrings
end_segments[shnum] = datum[2]
d1 = r.decode(start_segments, self._start_segment)
d2 = r.decode(end_segments, self._end_segment)
d3 = defer.succeed(blockhashes)
return deferredutil.gatherResults([d1, d2, d3])
def _decode_and_decrypt_segments(self, ignored, data, offset):
"""
After the servermap update, I take the encrypted and encoded
data that the servermap fetched while doing its update and
transform it into decoded-and-decrypted plaintext that can be
used by the new uploadable. I return a Deferred that fires with
the segments.
"""
r = Retrieve(self._node, self._storage_broker, self._servermap,
self._version)
# decode: takes in our blocks and salts from the servermap,
# returns a Deferred that fires with the corresponding plaintext
# segments. Does not download -- simply takes advantage of
# existing infrastructure within the Retrieve class to avoid
# duplicating code.
sm = self._servermap
# XXX: If the methods in the servermap don't work as
# abstractions, you should rewrite them instead of going around
# them.
update_data = sm.update_data
start_segments = {} # shnum -> start segment
end_segments = {} # shnum -> end segment
blockhashes = {} # shnum -> blockhash tree
for (shnum, original_data) in update_data.iteritems():
data = [d[1] for d in original_data if d[0] == self._version]
# data is [(blockhashes,start,end)..]
# Every data entry in our list should now be share shnum for
# a particular version of the mutable file, so all of the
# entries should be identical.
datum = data[0]
assert [x for x in data if x != datum] == []
# datum is (blockhashes,start,end)
blockhashes[shnum] = datum[0]
start_segments[shnum] = datum[1] # (block,salt) bytestrings
end_segments[shnum] = datum[2]
d1 = r.decode(start_segments, self._start_segment)
d2 = r.decode(end_segments, self._end_segment)
d3 = defer.succeed(blockhashes)
return deferredutil.gatherResults([d1, d2, d3])
