tahoe-lafs/src/allmydata/nodemaker.py
Itamar Turner-Trauring 96fd1861d2 Port to Python 3.
2020-12-09 14:58:54 -05:00

163 lines
7.3 KiB
Python

"""
Ported to Python 3.
"""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals
from future.utils import PY2
if PY2:
from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min # noqa: F401
import weakref
from zope.interface import implementer
from allmydata.util.assertutil import precondition
from allmydata.interfaces import INodeMaker
from allmydata.immutable.literal import LiteralFileNode
from allmydata.immutable.filenode import ImmutableFileNode, CiphertextFileNode
from allmydata.immutable.upload import Data
from allmydata.mutable.filenode import MutableFileNode
from allmydata.mutable.publish import MutableData
from allmydata.dirnode import DirectoryNode, pack_children
from allmydata.unknown import UnknownNode
from allmydata.blacklist import ProhibitedNode
from allmydata import uri
@implementer(INodeMaker)
class NodeMaker(object):
def __init__(self, storage_broker, secret_holder, history,
uploader, terminator,
default_encoding_parameters, mutable_file_default,
key_generator, blacklist=None):
self.storage_broker = storage_broker
self.secret_holder = secret_holder
self.history = history
self.uploader = uploader
self.terminator = terminator
self.default_encoding_parameters = default_encoding_parameters
self.mutable_file_default = mutable_file_default
self.key_generator = key_generator
self.blacklist = blacklist
self._node_cache = weakref.WeakValueDictionary() # uri -> node
def _create_lit(self, cap):
return LiteralFileNode(cap)
def _create_immutable(self, cap):
return ImmutableFileNode(cap, self.storage_broker, self.secret_holder,
self.terminator, self.history)
def _create_immutable_verifier(self, cap):
return CiphertextFileNode(cap, self.storage_broker, self.secret_holder,
self.terminator, self.history)
def _create_mutable(self, cap):
n = MutableFileNode(self.storage_broker, self.secret_holder,
self.default_encoding_parameters,
self.history)
return n.init_from_cap(cap)
def _create_dirnode(self, filenode):
return DirectoryNode(filenode, self, self.uploader)
def create_from_cap(self, writecap, readcap=None, deep_immutable=False, name=u"<unknown name>"):
# this returns synchronously. It starts with a "cap string".
assert isinstance(writecap, (bytes, type(None))), type(writecap)
assert isinstance(readcap, (bytes, type(None))), type(readcap)
bigcap = writecap or readcap
if not bigcap:
# maybe the writecap was hidden because we're in a readonly
# directory, and the future cap format doesn't have a readcap, or
# something.
return UnknownNode(None, None) # deep_immutable and name not needed
# The name doesn't matter for caching since it's only used in the error
# attribute of an UnknownNode, and we don't cache those.
if deep_immutable:
memokey = b"I" + bigcap
else:
memokey = b"M" + bigcap
try:
node = self._node_cache[memokey]
except KeyError:
cap = uri.from_string(bigcap, deep_immutable=deep_immutable,
name=name)
node = self._create_from_single_cap(cap)
# node is None for an unknown URI, otherwise it is a type for which
# is_mutable() is known. We avoid cacheing mutable nodes due to
# ticket #1679.
if node is None:
# don't cache UnknownNode
node = UnknownNode(writecap, readcap,
deep_immutable=deep_immutable, name=name)
elif node.is_mutable():
self._node_cache[memokey] = node # note: WeakValueDictionary
if self.blacklist:
si = node.get_storage_index()
# if this node is blacklisted, return the reason, otherwise return None
reason = self.blacklist.check_storageindex(si)
if reason is not None:
# The original node object is cached above, not the ProhibitedNode wrapper.
# This ensures that removing the blacklist entry will make the node
# accessible if create_from_cap is called again.
node = ProhibitedNode(node, reason)
return node
def _create_from_single_cap(self, cap):
if isinstance(cap, uri.LiteralFileURI):
return self._create_lit(cap)
if isinstance(cap, uri.CHKFileURI):
return self._create_immutable(cap)
if isinstance(cap, uri.CHKFileVerifierURI):
return self._create_immutable_verifier(cap)
if isinstance(cap, (uri.ReadonlySSKFileURI, uri.WriteableSSKFileURI,
uri.WriteableMDMFFileURI, uri.ReadonlyMDMFFileURI)):
return self._create_mutable(cap)
if isinstance(cap, (uri.DirectoryURI,
uri.ReadonlyDirectoryURI,
uri.ImmutableDirectoryURI,
uri.LiteralDirectoryURI,
uri.MDMFDirectoryURI,
uri.ReadonlyMDMFDirectoryURI)):
filenode = self._create_from_single_cap(cap.get_filenode_cap())
return self._create_dirnode(filenode)
return None
def create_mutable_file(self, contents=None, keysize=None, version=None):
if version is None:
version = self.mutable_file_default
n = MutableFileNode(self.storage_broker, self.secret_holder,
self.default_encoding_parameters, self.history)
d = self.key_generator.generate(keysize)
d.addCallback(n.create_with_keys, contents, version=version)
d.addCallback(lambda res: n)
return d
def create_new_mutable_directory(self, initial_children={}, version=None):
# initial_children must have metadata (i.e. {} instead of None)
for (name, (node, metadata)) in initial_children.items():
precondition(isinstance(metadata, dict),
"create_new_mutable_directory requires metadata to be a dict, not None", metadata)
node.raise_error()
d = self.create_mutable_file(lambda n:
MutableData(pack_children(initial_children,
n.get_writekey())),
version=version)
d.addCallback(self._create_dirnode)
return d
def create_immutable_directory(self, children, convergence=None):
if convergence is None:
convergence = self.secret_holder.get_convergence_secret()
packed = pack_children(children, None, deep_immutable=True)
uploadable = Data(packed, convergence)
# XXX should pass reactor arg
d = self.uploader.upload(uploadable)
d.addCallback(lambda results:
self.create_from_cap(None, results.get_uri()))
d.addCallback(self._create_dirnode)
return d