import copy, os.path, stat from cStringIO import StringIO from zope.interface import implements from twisted.internet import defer from twisted.internet.interfaces import IPushProducer, IConsumer from twisted.protocols import basic from foolscap.eventual import eventually from allmydata.interfaces import IFileNode, IFileURI, ICheckable, \ IDownloadTarget, IUploadResults from allmydata.util import dictutil, log, base32 from allmydata.util.assertutil import precondition from allmydata import uri as urimodule from allmydata.immutable.checker import Checker from allmydata.check_results import CheckResults, CheckAndRepairResults from allmydata.immutable.repairer import Repairer from allmydata.immutable import download class _ImmutableFileNodeBase(object): implements(IFileNode, ICheckable) def __init__(self, uri, client): precondition(urimodule.IImmutableFileURI.providedBy(uri), uri) self.u = IFileURI(uri) self._client = client def get_readonly_uri(self): return self.get_uri() def is_mutable(self): return False def is_readonly(self): return True def __hash__(self): return self.u.__hash__() def __eq__(self, other): if IFileNode.providedBy(other): return self.u.__eq__(other.u) else: return False def __ne__(self, other): if IFileNode.providedBy(other): return self.u.__eq__(other.u) else: return True class PortionOfFile: # like a list slice (things[2:14]), but for a file on disk def __init__(self, fn, offset=0, size=None): self.f = open(fn, "rb") self.f.seek(offset) self.bytes_left = size def read(self, size=None): # bytes_to_read = min(size, self.bytes_left), but None>anything if size is None: bytes_to_read = self.bytes_left elif self.bytes_left is None: bytes_to_read = size else: bytes_to_read = min(size, self.bytes_left) data = self.f.read(bytes_to_read) if self.bytes_left is not None: self.bytes_left -= len(data) return data class DownloadCache: implements(IDownloadTarget) def __init__(self, node, cachefile): self._downloader = node._client.getServiceNamed("downloader") self._uri = node.get_uri() self._storage_index = node.get_storage_index() self.milestones = set() # of (offset,size,Deferred) self.cachefile = cachefile self.download_in_progress = False # five states: # new FileNode, no downloads ever performed # new FileNode, leftover file (partial) # new FileNode, leftover file (whole) # download in progress, not yet complete # download complete def when_range_available(self, offset, size): assert isinstance(offset, (int,long)) assert isinstance(size, (int,long)) d = defer.Deferred() self.milestones.add( (offset,size,d) ) self._check_milestones() if self.milestones and not self.download_in_progress: self.download_in_progress = True log.msg(format=("immutable filenode read [%(si)s]: " + "starting download"), si=base32.b2a(self._storage_index), umid="h26Heg", level=log.OPERATIONAL) d2 = self._downloader.download(self._uri, self) d2.addBoth(self._download_done) d2.addErrback(self._download_failed) d2.addErrback(log.err, umid="cQaM9g") return d def read(self, consumer, offset, size): assert offset+size <= self.get_filesize() f = PortionOfFile(self.cachefile.get_filename(), offset, size) d = basic.FileSender().beginFileTransfer(f, consumer) d.addCallback(lambda lastSent: consumer) return d def _download_done(self, res): # clear download_in_progress, so failed downloads can be re-tried self.download_in_progress = False return res def _download_failed(self, f): # tell anyone who's waiting that we failed for m in self.milestones: (offset,size,d) = m eventually(d.errback, f) self.milestones.clear() def _check_milestones(self): current_size = self.get_filesize() for m in list(self.milestones): (offset,size,d) = m if offset+size <= current_size: log.msg(format=("immutable filenode read [%(si)s] " + "%(offset)d+%(size)d vs %(filesize)d: " + "done"), si=base32.b2a(self._storage_index), offset=offset, size=size, filesize=current_size, umid="nuedUg", level=log.NOISY) self.milestones.discard(m) eventually(d.callback, None) else: log.msg(format=("immutable filenode read [%(si)s] " + "%(offset)d+%(size)d vs %(filesize)d: " + "still waiting"), si=base32.b2a(self._storage_index), offset=offset, size=size, filesize=current_size, umid="8PKOhg", level=log.NOISY) def get_filesize(self): try: filesize = os.stat(self.cachefile.get_filename())[stat.ST_SIZE] except OSError: filesize = 0 return filesize def open(self, size): self.f = open(self.cachefile.get_filename(), "wb") def write(self, data): self.f.write(data) self._check_milestones() def close(self): self.f.close() self._check_milestones() def fail(self, why): pass def register_canceller(self, cb): pass def finish(self): return None # The following methods are just because the target might be a repairer.DownUpConnector, # and just because the current CHKUpload object expects to find the storage index and # encoding parameters in its Uploadable. def set_storageindex(self, storageindex): pass def set_encodingparams(self, encodingparams): pass class FileNode(_ImmutableFileNodeBase, log.PrefixingLogMixin): def __init__(self, uri, client, cachefile): _ImmutableFileNodeBase.__init__(self, uri, client) self.download_cache = DownloadCache(self, cachefile) prefix = uri.get_verify_cap().to_string() log.PrefixingLogMixin.__init__(self, "allmydata.immutable.filenode", prefix=prefix) self.log("starting", level=log.OPERATIONAL) def get_uri(self): return self.u.to_string() def get_size(self): return self.u.get_size() def get_verify_cap(self): return self.u.get_verify_cap() def get_storage_index(self): return self.u.storage_index def check_and_repair(self, monitor, verify=False): verifycap = self.get_verify_cap() servers = self._client.get_servers("storage") c = Checker(client=self._client, verifycap=verifycap, servers=servers, verify=verify, monitor=monitor) d = c.start() def _maybe_repair(cr): crr = CheckAndRepairResults(self.u.storage_index) crr.pre_repair_results = cr if cr.is_healthy(): crr.post_repair_results = cr return defer.succeed(crr) else: crr.repair_attempted = True crr.repair_successful = False # until proven successful def _gather_repair_results(ur): assert IUploadResults.providedBy(ur), ur # clone the cr -- check results to form the basic of the prr -- post-repair results prr = CheckResults(cr.uri, cr.storage_index) prr.data = copy.deepcopy(cr.data) sm = prr.data['sharemap'] assert isinstance(sm, dictutil.DictOfSets), sm sm.update(ur.sharemap) servers_responding = set(prr.data['servers-responding']) servers_responding.union(ur.sharemap.iterkeys()) prr.data['servers-responding'] = list(servers_responding) prr.data['count-shares-good'] = len(sm) prr.data['count-good-share-hosts'] = len(sm) is_healthy = len(sm) >= self.u.total_shares prr.set_healthy(is_healthy) crr.repair_successful = is_healthy prr.set_needs_rebalancing(len(sm) >= self.u.total_shares) crr.post_repair_results = prr return crr def _repair_error(f): # as with mutable repair, I'm not sure if I want to pass # through a failure or not. TODO crr.repair_successful = False crr.repair_failure = f return f r = Repairer(client=self._client, verifycap=verifycap, monitor=monitor) d = r.start() d.addCallbacks(_gather_repair_results, _repair_error) return d d.addCallback(_maybe_repair) return d def check(self, monitor, verify=False): v = Checker(client=self._client, verifycap=self.get_verify_cap(), servers=self._client.get_servers("storage"), verify=verify, monitor=monitor) return v.start() def read(self, consumer, offset=0, size=None): if size is None: size = self.get_size() - offset size = min(size, self.get_size() - offset) if offset == 0 and size == self.get_size(): # don't use the cache, just do a normal streaming download self.log("doing normal full download", umid="VRSBwg", level=log.OPERATIONAL) return self.download(download.ConsumerAdapter(consumer)) d = self.download_cache.when_range_available(offset, size) d.addCallback(lambda res: self.download_cache.read(consumer, offset, size)) return d def download(self, target): downloader = self._client.getServiceNamed("downloader") return downloader.download(self.get_uri(), target, self._parentmsgid) def download_to_data(self): downloader = self._client.getServiceNamed("downloader") return downloader.download_to_data(self.get_uri()) class LiteralProducer: implements(IPushProducer) def resumeProducing(self): pass def stopProducing(self): pass class LiteralFileNode(_ImmutableFileNodeBase): def __init__(self, uri, client): precondition(urimodule.IImmutableFileURI.providedBy(uri), uri) _ImmutableFileNodeBase.__init__(self, uri, client) def get_uri(self): return self.u.to_string() def get_size(self): return len(self.u.data) def get_verify_cap(self): return None def get_storage_index(self): return None def check(self, monitor, verify=False): return defer.succeed(None) def check_and_repair(self, monitor, verify=False): return defer.succeed(None) def read(self, consumer, offset=0, size=None): if size is None: data = self.u.data[offset:] else: data = self.u.data[offset:offset+size] # We use twisted.protocols.basic.FileSender, which only does # non-streaming, i.e. PullProducer, where the receiver/consumer must # ask explicitly for each chunk of data. There are only two places in # the Twisted codebase that can't handle streaming=False, both of # which are in the upload path for an FTP/SFTP server # (protocols.ftp.FileConsumer and # vfs.adapters.ftp._FileToConsumerAdapter), neither of which is # likely to be used as the target for a Tahoe download. d = basic.FileSender().beginFileTransfer(StringIO(data), consumer) d.addCallback(lambda lastSent: consumer) return d def download(self, target): # note that this does not update the stats_provider data = self.u.data if IConsumer.providedBy(target): target.registerProducer(LiteralProducer(), True) target.open(len(data)) target.write(data) if IConsumer.providedBy(target): target.unregisterProducer() target.close() return defer.maybeDeferred(target.finish) def download_to_data(self): data = self.u.data return defer.succeed(data)