tahoe-lafs/src/allmydata/nodemaker.py
Brian Warner 7b7b0c9709 Rewrite immutable downloader (#798). This patch includes higher-level
integration into the NodeMaker, and updates the web-status display to handle
the new download events.
2010-08-04 00:27:02 -07:00

113 lines
5.0 KiB
Python

import weakref
from zope.interface import implements
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.dirnode import DirectoryNode, pack_children
from allmydata.unknown import UnknownNode
from allmydata import uri
class NodeMaker:
implements(INodeMaker)
def __init__(self, storage_broker, secret_holder, history,
uploader, terminator,
default_encoding_parameters, key_generator):
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.key_generator = key_generator
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, (str, type(None))), type(writecap)
assert isinstance(readcap, (str, 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 = "I" + bigcap
else:
memokey = "M" + bigcap
if memokey in self._node_cache:
return self._node_cache[memokey]
cap = uri.from_string(bigcap, deep_immutable=deep_immutable, name=name)
node = self._create_from_single_cap(cap)
if node:
self._node_cache[memokey] = node # note: WeakValueDictionary
else:
# don't cache UnknownNode
node = UnknownNode(writecap, readcap, deep_immutable=deep_immutable, name=name)
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)):
return self._create_mutable(cap)
if isinstance(cap, (uri.DirectoryURI,
uri.ReadonlyDirectoryURI,
uri.ImmutableDirectoryURI,
uri.LiteralDirectoryURI)):
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):
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)
d.addCallback(lambda res: n)
return d
def create_new_mutable_directory(self, initial_children={}):
d = self.create_mutable_file(lambda n:
pack_children(initial_children, n.get_writekey()))
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)
d = self.uploader.upload(uploadable, history=self.history)
d.addCallback(lambda results: self.create_from_cap(None, results.uri))
d.addCallback(self._create_dirnode)
return d