ChoiceOf, IntegerConstraint, Any, RemoteInterface, Referenceable
HASH_SIZE=32
+SALT_SIZE=16
+
+SDMF_VERSION=0
+MDMF_VERSION=1
Hash = StringConstraint(maxLength=HASH_SIZE,
minLength=HASH_SIZE)# binary format 32-byte SHA256 hash
MAX_BUCKETS = 256 # per peer -- zfec offers at most 256 shares per file
+DEFAULT_MAX_SEGMENT_SIZE = 128*1024
+
ShareData = StringConstraint(None)
URIExtensionData = StringConstraint(1000)
Number = IntegerConstraint(8) # 2**(8*8) == 16EiB ~= 18e18 ~= 18 exabytes
"""
return Any()
- def cancel_lease(storage_index=StorageIndex,
- cancel_secret=LeaseCancelSecret):
- """
- Cancel the lease on a given bucket. If this was the last lease on the
- bucket, the bucket will be deleted. If there is no bucket for the
- given storage_index, IndexError will be raised.
-
- For mutable shares, if the given cancel_secret does not match an
- existing lease, IndexError will be raised with a note listing the
- server-nodeids on the existing leases, so leases on migrated shares
- can be renewed or cancelled. For immutable shares, IndexError
- (without the note) will be raised.
- """
- return Any()
-
def get_buckets(storage_index=StorageIndex):
return DictOf(int, RIBucketReader, maxKeys=MAX_BUCKETS)
"""
class IStorageBroker(Interface):
- def get_servers_for_index(peer_selection_index):
+ def get_servers_for_psi(peer_selection_index):
+ """
+ @return: list of IServer instances
+ """
+ def get_connected_servers():
"""
- @return: list of (peerid, versioned-rref) tuples
+ @return: frozenset of connected IServer instances
"""
- def get_all_servers():
+ def get_known_servers():
"""
- @return: frozenset of (peerid, versioned-rref) tuples
+ @return: frozenset of IServer instances
"""
def get_all_serverids():
"""
- @return: iterator of serverid strings
+ @return: frozenset of serverid strings
"""
def get_nickname_for_serverid(serverid):
"""
@return: unicode nickname, or None
"""
+ # methods moved from IntroducerClient, need review
+ def get_all_connections():
+ """Return a frozenset of (nodeid, service_name, rref) tuples, one for
+ each active connection we've established to a remote service. This is
+ mostly useful for unit tests that need to wait until a certain number
+ of connections have been made."""
+
+ def get_all_connectors():
+ """Return a dict that maps from (nodeid, service_name) to a
+ RemoteServiceConnector instance for all services that we are actively
+ trying to connect to. Each RemoteServiceConnector has the following
+ public attributes::
+
+ service_name: the type of service provided, like 'storage'
+ announcement_time: when we first heard about this service
+ last_connect_time: when we last established a connection
+ last_loss_time: when we last lost a connection
+
+ version: the peer's version, from the most recent connection
+ oldest_supported: the peer's oldest supported version, same
+
+ rref: the RemoteReference, if connected, otherwise None
+ remote_host: the IAddress, if connected, otherwise None
+
+ This method is intended for monitoring interfaces, such as a web page
+ which describes connecting and connected peers.
+ """
+
+ def get_all_peerids():
+ """Return a frozenset of all peerids to whom we have a connection (to
+ one or more services) established. Mostly useful for unit tests."""
+
+ def get_all_connections_for(service_name):
+ """Return a frozenset of (nodeid, service_name, rref) tuples, one
+ for each active connection that provides the given SERVICE_NAME."""
+
+ def get_permuted_peers(service_name, key):
+ """Returns an ordered list of (peerid, rref) tuples, selecting from
+ the connections that provide SERVICE_NAME, using a hash-based
+ permutation keyed by KEY. This randomizes the service list in a
+ repeatable way, to distribute load over many peers.
+ """
+
+
+class IMutableSlotWriter(Interface):
+ """
+ The interface for a writer around a mutable slot on a remote server.
+ """
+ def set_checkstring(checkstring, *args):
+ """
+ Set the checkstring that I will pass to the remote server when
+ writing.
+
+ @param checkstring A packed checkstring to use.
+
+ Note that implementations can differ in which semantics they
+ wish to support for set_checkstring -- they can, for example,
+ build the checkstring themselves from its constituents, or
+ some other thing.
+ """
+
+ def get_checkstring():
+ """
+ Get the checkstring that I think currently exists on the remote
+ server.
+ """
+
+ def put_block(data, segnum, salt):
+ """
+ Add a block and salt to the share.
+ """
+
+ def put_encprivey(encprivkey):
+ """
+ Add the encrypted private key to the share.
+ """
+
+ def put_blockhashes(blockhashes=list):
+ """
+ Add the block hash tree to the share.
+ """
+
+ def put_sharehashes(sharehashes=dict):
+ """
+ Add the share hash chain to the share.
+ """
+
+ def get_signable():
+ """
+ Return the part of the share that needs to be signed.
+ """
+
+ def put_signature(signature):
+ """
+ Add the signature to the share.
+ """
+
+ def put_verification_key(verification_key):
+ """
+ Add the verification key to the share.
+ """
+
+ def finish_publishing():
+ """
+ Do anything necessary to finish writing the share to a remote
+ server. I require that no further publishing needs to take place
+ after this method has been called.
+ """
-# hm, we need a solution for forward references in schemas
-FileNode_ = Any() # TODO: foolscap needs constraints on copyables
-DirectoryNode_ = Any() # TODO: same
-AnyNode_ = ChoiceOf(FileNode_, DirectoryNode_)
-EncryptedThing = str
class IURI(Interface):
def init_from_string(uri):
"""Return True if the data can be modified by *somebody* (perhaps
someone who has a more powerful URI than this one)."""
+ # TODO: rename to get_read_cap()
def get_readonly():
"""Return another IURI instance, which represents a read-only form of
this one. If is_readonly() is True, this returns self."""
class IDirnodeURI(Interface):
"""I am a URI which represents a dirnode."""
-
class IFileURI(Interface):
"""I am a URI which represents a filenode."""
def get_size():
class IMutableFileURI(Interface):
"""I am a URI which represents a mutable filenode."""
-class INewDirectoryURI(Interface):
- pass
-class IReadonlyNewDirectoryURI(Interface):
- pass
+ def get_extension_params():
+ """Return the extension parameters in the URI"""
+ def set_extension_params():
+ """Set the extension parameters that should be in the URI"""
-class IFilesystemNode(Interface):
- def get_uri():
- """
- Return the URI that can be used by others to get access to this
- node. If this node is read-only, the URI will only offer read-only
- access. If this node is read-write, the URI will offer read-write
- access.
+class IDirectoryURI(Interface):
+ pass
- If you have read-write access to a node and wish to share merely
- read-only access with others, use get_readonly_uri().
- """
+class IReadonlyDirectoryURI(Interface):
+ pass
- def get_readonly_uri():
- """Return the directory URI that can be used by others to get
- read-only access to this directory node. The result is a read-only
- URI, regardless of whether this dirnode is read-only or read-write.
+class CapConstraintError(Exception):
+ """A constraint on a cap was violated."""
- If you have merely read-only access to this dirnode,
- get_readonly_uri() will return the same thing as get_uri().
- """
+class MustBeDeepImmutableError(CapConstraintError):
+ """Mutable children cannot be added to an immutable directory.
+ Also, caps obtained from an immutable directory can trigger this error
+ if they are later found to refer to a mutable object and then used."""
- def get_repair_cap():
- """Return an IURI instance that can be used to repair the file, or
- None if this node cannot be repaired (either because it is not
- distributed, like a LIT file, or because the node does not represent
- sufficient authority to create a repair-cap, like a read-only RSA
- mutable file node [which cannot create the correct write-enablers]).
- """
+class MustBeReadonlyError(CapConstraintError):
+ """Known write caps cannot be specified in a ro_uri field. Also,
+ caps obtained from a ro_uri field can trigger this error if they
+ are later found to be write caps and then used."""
- def get_verify_cap():
- """Return an IVerifierURI instance that represents the
- 'verifiy/refresh capability' for this node. The holder of this
- capability will be able to renew the lease for this node, protecting
- it from garbage-collection. They will also be able to ask a server if
- it holds a share for the file or directory.
- """
+class MustNotBeUnknownRWError(CapConstraintError):
+ """Cannot add an unknown child cap specified in a rw_uri field."""
- def get_storage_index():
- """Return a string with the (binary) storage index in use on this
- download. This may be None if there is no storage index (i.e. LIT
- files)."""
+
+class IReadable(Interface):
+ """I represent a readable object -- either an immutable file, or a
+ specific version of a mutable file.
+ """
def is_readonly():
"""Return True if this reference provides mutable access to the given
file or directory (i.e. if you can modify it), or False if not. Note
that even if this reference is read-only, someone else may hold a
- read-write reference to it."""
+ read-write reference to it.
+
+ For an IReadable returned by get_best_readable_version(), this will
+ always return True, but for instances of subinterfaces such as
+ IMutableFileVersion, it may return False."""
def is_mutable():
"""Return True if this file or directory is mutable (by *somebody*,
might be mutable overall, but your reference to it might be
read-only. On the other hand, all references to an immutable file
will be read-only; there are no read-write references to an immutable
- file.
- """
+ file."""
-class IMutableFilesystemNode(IFilesystemNode):
- pass
+ def get_storage_index():
+ """Return the storage index of the file."""
-class IFileNode(IFilesystemNode):
- def download(target):
- """Download the file's contents to a given IDownloadTarget"""
+ def get_size():
+ """Return the length (in bytes) of this readable object."""
def download_to_data():
- """Download the file's contents. Return a Deferred that fires
- with those contents."""
-
- def get_size():
- """Return the length (in bytes) of the data this node represents."""
+ """Download all of the file contents. I return a Deferred that fires
+ with the contents as a byte string."""
def read(consumer, offset=0, size=None):
"""Download a portion (possibly all) of the file's contents, making
p.stopProducing(), which will result in an exception being delivered
via deferred.errback().
- A simple download-to-memory consumer example would look like this::
-
- class MemoryConsumer:
- implements(IConsumer)
- def __init__(self):
- self.chunks = []
- self.done = False
- def registerProducer(self, p, streaming):
- assert streaming == False
- while not self.done:
- p.resumeProducing()
- def write(self, data):
- self.chunks.append(data)
- def unregisterProducer(self):
- self.done = True
- d = filenode.read(MemoryConsumer())
- d.addCallback(lambda mc: "".join(mc.chunks))
- return d
+ See src/allmydata/util/consumer.py for an example of a simple
+ download-to-memory consumer.
+ """
+
+
+class IWriteable(Interface):
+ """
+ I define methods that callers can use to update SDMF and MDMF
+ mutable files on a Tahoe-LAFS grid.
+ """
+ # XXX: For the moment, we have only this. It is possible that we
+ # want to move overwrite() and modify() in here too.
+ def update(data, offset):
+ """
+ I write the data from my data argument to the MDMF file,
+ starting at offset. I continue writing data until my data
+ argument is exhausted, appending data to the file as necessary.
+ """
+ # assert IMutableUploadable.providedBy(data)
+ # to append data: offset=node.get_size_of_best_version()
+ # do we want to support compacting MDMF?
+ # for an MDMF file, this can be done with O(data.get_size())
+ # memory. For an SDMF file, any modification takes
+ # O(node.get_size_of_best_version()).
+
+
+class IMutableFileVersion(IReadable):
+ """I provide access to a particular version of a mutable file. The
+ access is read/write if I was obtained from a filenode derived from
+ a write cap, or read-only if the filenode was derived from a read cap.
+ """
+
+ def get_sequence_number():
+ """Return the sequence number of this version."""
+
+ def get_servermap():
+ """Return the IMutableFileServerMap instance that was used to create
+ this object.
+ """
+
+ def get_writekey():
+ """Return this filenode's writekey, or None if the node does not have
+ write-capability. This may be used to assist with data structures
+ that need to make certain data available only to writers, such as the
+ read-write child caps in dirnodes. The recommended process is to have
+ reader-visible data be submitted to the filenode in the clear (where
+ it will be encrypted by the filenode using the readkey), but encrypt
+ writer-visible data using this writekey.
+ """
+
+ # TODO: Can this be overwrite instead of replace?
+ def replace(new_contents):
+ """Replace the contents of the mutable file, provided that no other
+ node has published (or is attempting to publish, concurrently) a
+ newer version of the file than this one.
+
+ I will avoid modifying any share that is different than the version
+ given by get_sequence_number(). However, if another node is writing
+ to the file at the same time as me, I may manage to update some shares
+ while they update others. If I see any evidence of this, I will signal
+ UncoordinatedWriteError, and the file will be left in an inconsistent
+ state (possibly the version you provided, possibly the old version,
+ possibly somebody else's version, and possibly a mix of shares from
+ all of these).
+
+ The recommended response to UncoordinatedWriteError is to either
+ return it to the caller (since they failed to coordinate their
+ writes), or to attempt some sort of recovery. It may be sufficient to
+ wait a random interval (with exponential backoff) and repeat your
+ operation. If I do not signal UncoordinatedWriteError, then I was
+ able to write the new version without incident.
+
+ I return a Deferred that fires (with a PublishStatus object) when the
+ update has completed.
+ """
+
+ def modify(modifier_cb):
+ """Modify the contents of the file, by downloading this version,
+ applying the modifier function (or bound method), then uploading
+ the new version. This will succeed as long as no other node
+ publishes a version between the download and the upload.
+ I return a Deferred that fires (with a PublishStatus object) when
+ the update is complete.
+
+ The modifier callable will be given three arguments: a string (with
+ the old contents), a 'first_time' boolean, and a servermap. As with
+ download_to_data(), the old contents will be from this version,
+ but the modifier can use the servermap to make other decisions
+ (such as refusing to apply the delta if there are multiple parallel
+ versions, or if there is evidence of a newer unrecoverable version).
+ 'first_time' will be True the first time the modifier is called,
+ and False on any subsequent calls.
+
+ The callable should return a string with the new contents. The
+ callable must be prepared to be called multiple times, and must
+ examine the input string to see if the change that it wants to make
+ is already present in the old version. If it does not need to make
+ any changes, it can either return None, or return its input string.
+
+ If the modifier raises an exception, it will be returned in the
+ errback.
+ """
+
+
+# The hierarchy looks like this:
+# IFilesystemNode
+# IFileNode
+# IMutableFileNode
+# IImmutableFileNode
+# IDirectoryNode
+class IFilesystemNode(Interface):
+ def get_cap():
+ """Return the strongest 'cap instance' associated with this node.
+ (writecap for writeable-mutable files/directories, readcap for
+ immutable or readonly-mutable files/directories). To convert this
+ into a string, call .to_string() on the result."""
+
+ def get_readcap():
+ """Return a readonly cap instance for this node. For immutable or
+ readonly nodes, get_cap() and get_readcap() return the same thing."""
+
+ def get_repair_cap():
+ """Return an IURI instance that can be used to repair the file, or
+ None if this node cannot be repaired (either because it is not
+ distributed, like a LIT file, or because the node does not represent
+ sufficient authority to create a repair-cap, like a read-only RSA
+ mutable file node [which cannot create the correct write-enablers]).
"""
-class IMutableFileNode(IFileNode, IMutableFilesystemNode):
+ def get_verify_cap():
+ """Return an IVerifierURI instance that represents the
+ 'verifiy/refresh capability' for this node. The holder of this
+ capability will be able to renew the lease for this node, protecting
+ it from garbage-collection. They will also be able to ask a server if
+ it holds a share for the file or directory.
+ """
+
+ def get_uri():
+ """Return the URI string corresponding to the strongest cap associated
+ with this node. If this node is read-only, the URI will only offer
+ read-only access. If this node is read-write, the URI will offer
+ read-write access.
+
+ If you have read-write access to a node and wish to share merely
+ read-only access with others, use get_readonly_uri().
+ """
+
+ def get_write_uri():
+ """Return the URI string that can be used by others to get write
+ access to this node, if it is writeable. If this is a read-only node,
+ return None."""
+
+ def get_readonly_uri():
+ """Return the URI string that can be used by others to get read-only
+ access to this node. The result is a read-only URI, regardless of
+ whether this node is read-only or read-write.
+
+ If you have merely read-only access to this node, get_readonly_uri()
+ will return the same thing as get_uri().
+ """
+
+ def get_storage_index():
+ """Return a string with the (binary) storage index in use on this
+ download. This may be None if there is no storage index (i.e. LIT
+ files and directories)."""
+
+ def is_readonly():
+ """Return True if this reference provides mutable access to the given
+ file or directory (i.e. if you can modify it), or False if not. Note
+ that even if this reference is read-only, someone else may hold a
+ read-write reference to it."""
+
+ def is_mutable():
+ """Return True if this file or directory is mutable (by *somebody*,
+ not necessarily you), False if it is is immutable. Note that a file
+ might be mutable overall, but your reference to it might be
+ read-only. On the other hand, all references to an immutable file
+ will be read-only; there are no read-write references to an immutable
+ file.
+ """
+
+ def is_unknown():
+ """Return True if this is an unknown node."""
+
+ def is_allowed_in_immutable_directory():
+ """Return True if this node is allowed as a child of a deep-immutable
+ directory. This is true if either the node is of a known-immutable type,
+ or it is unknown and read-only.
+ """
+
+ def raise_error():
+ """Raise any error associated with this node."""
+
+ # XXX: These may not be appropriate outside the context of an IReadable.
+ def get_size():
+ """Return the length (in bytes) of the data this node represents. For
+ directory nodes, I return the size of the backing store. I return
+ synchronously and do not consult the network, so for mutable objects,
+ I will return the most recently observed size for the object, or None
+ if I don't remember a size. Use get_current_size, which returns a
+ Deferred, if you want more up-to-date information."""
+
+ def get_current_size():
+ """I return a Deferred that fires with the length (in bytes) of the
+ data this node represents.
+ """
+
+class IFileNode(IFilesystemNode):
+ """I am a node which represents a file: a sequence of bytes. I am not a
+ container, like IDirectoryNode."""
+ def get_best_readable_version():
+ """Return a Deferred that fires with an IReadable for the 'best'
+ available version of the file. The IReadable provides only read
+ access, even if this filenode was derived from a write cap.
+
+ For an immutable file, there is only one version. For a mutable
+ file, the 'best' version is the recoverable version with the
+ highest sequence number. If no uncoordinated writes have occurred,
+ and if enough shares are available, then this will be the most
+ recent version that has been uploaded. If no version is recoverable,
+ the Deferred will errback with an UnrecoverableFileError.
+ """
+
+ def download_best_version():
+ """Download the contents of the version that would be returned
+ by get_best_readable_version(). This is equivalent to calling
+ download_to_data() on the IReadable given by that method.
+
+ I return a Deferred that fires with a byte string when the file
+ has been fully downloaded. To support streaming download, use
+ the 'read' method of IReadable. If no version is recoverable,
+ the Deferred will errback with an UnrecoverableFileError.
+ """
+
+ def get_size_of_best_version():
+ """Find the size of the version that would be returned by
+ get_best_readable_version().
+
+ I return a Deferred that fires with an integer. If no version
+ is recoverable, the Deferred will errback with an
+ UnrecoverableFileError.
+ """
+
+
+class IImmutableFileNode(IFileNode, IReadable):
+ """I am a node representing an immutable file. Immutable files have
+ only one version"""
+
+
+class IMutableFileNode(IFileNode):
"""I provide access to a 'mutable file', which retains its identity
regardless of what contents are put in it.
only be retrieved and updated all-at-once, as a single big string. Future
versions of our mutable files will remove this restriction.
"""
-
- def download_best_version():
- """Download the 'best' available version of the file, meaning one of
- the recoverable versions with the highest sequence number. If no
+ def get_best_mutable_version():
+ """Return a Deferred that fires with an IMutableFileVersion for
+ the 'best' available version of the file. The best version is
+ the recoverable version with the highest sequence number. If no
uncoordinated writes have occurred, and if enough shares are
- available, then this will be the most recent version that has been
- uploaded.
-
- I update an internal servermap with MODE_READ, determine which
- version of the file is indicated by
- servermap.best_recoverable_version(), and return a Deferred that
- fires with its contents. If no version is recoverable, the Deferred
- will errback with UnrecoverableFileError.
- """
+ available, then this will be the most recent version that has
+ been uploaded.
- def get_size_of_best_version():
- """Find the size of the version that would be downloaded with
- download_best_version(), without actually downloading the whole file.
-
- I return a Deferred that fires with an integer.
+ If no version is recoverable, the Deferred will errback with an
+ UnrecoverableFileError.
"""
def overwrite(new_contents):
errback.
"""
-
def get_servermap(mode):
"""Return a Deferred that fires with an IMutableFileServerMap
instance, updated using the given mode.
writer-visible data using this writekey.
"""
+ def get_version():
+ """Returns the mutable file protocol version."""
+
class NotEnoughSharesError(Exception):
- def __init__(self, msg, got, needed):
- Exception.__init__(self, msg)
- self.got = got
- self.needed = needed
- self.servermap = None
+ """Download was unable to get enough shares"""
+
+class NoSharesError(Exception):
+ """Download was unable to get any shares at all."""
+
+class DownloadStopped(Exception):
+ pass
+
+class UploadUnhappinessError(Exception):
+ """Upload was unable to satisfy 'servers_of_happiness'"""
class UnableToFetchCriticalDownloadDataError(Exception):
"""I was unable to fetch some piece of critical data which is supposed to
class NoSuchChildError(Exception):
"""A directory node was asked to fetch a child which does not exist."""
-class IDirectoryNode(IMutableFilesystemNode):
- """I represent a name-to-child mapping, holding the tahoe equivalent of a
- directory. All child names are unicode strings, and all children are some
- sort of IFilesystemNode (either files or subdirectories).
+class ChildOfWrongTypeError(Exception):
+ """An operation was attempted on a child of the wrong type (file or directory)."""
+
+class IDirectoryNode(IFilesystemNode):
+ """I represent a filesystem node that is a container, with a
+ name-to-child mapping, holding the tahoe equivalent of a directory. All
+ child names are unicode strings, and all children are some sort of
+ IFilesystemNode (a file, subdirectory, or unknown node).
"""
def get_uri():
def list():
"""I return a Deferred that fires with a dictionary mapping child
name (a unicode string) to (node, metadata_dict) tuples, in which
- 'node' is either an IFileNode or IDirectoryNode, and 'metadata_dict'
- is a dictionary of metadata."""
+ 'node' is an IFilesystemNode and 'metadata_dict' is a dictionary of
+ metadata."""
def has_child(name):
"""I return a Deferred that fires with a boolean, True if there
def get(name):
"""I return a Deferred that fires with a specific named child node,
- either an IFileNode or an IDirectoryNode. The child name must be a
- unicode string. I raise NoSuchChildError if I do not have a child by
- that name."""
+ which is an IFilesystemNode. The child name must be a unicode string.
+ I raise NoSuchChildError if I do not have a child by that name."""
def get_metadata_for(name):
- """I return a Deferred that fires with the metadata dictionary for a
- specific named child node. This metadata is stored in the *edge*, not
- in the child, so it is attached to the parent dirnode rather than the
- child dir-or-file-node. The child name must be a unicode string. I
- raise NoSuchChildError if I do not have a child by that name."""
+ """I return a Deferred that fires with the metadata dictionary for
+ a specific named child node. The child name must be a unicode string.
+ This metadata is stored in the *edge*, not in the child, so it is
+ attached to the parent dirnode rather than the child node.
+ I raise NoSuchChildError if I do not have a child by that name."""
def set_metadata_for(name, metadata):
"""I replace any existing metadata for the named child with the new
metadata. The child name must be a unicode string. This metadata is
stored in the *edge*, not in the child, so it is attached to the
- parent dirnode rather than the child dir-or-file-node. I return a
- Deferred (that fires with this dirnode) when the operation is
- complete. I raise NoSuchChildError if I do not have a child by that
- name."""
+ parent dirnode rather than the child node. I return a Deferred
+ (that fires with this dirnode) when the operation is complete.
+ I raise NoSuchChildError if I do not have a child by that name."""
def get_child_at_path(path):
- """Transform a child path into an IDirectoryNode or IFileNode.
+ """Transform a child path into an IFilesystemNode.
I perform a recursive series of 'get' operations to find the named
descendant node. I return a Deferred that fires with the node, or
"""
def get_child_and_metadata_at_path(path):
- """Transform a child path into an IDirectoryNode/IFileNode and
- metadata.
+ """Transform a child path into an IFilesystemNode and metadata.
I am like get_child_at_path(), but my Deferred fires with a tuple of
(node, metadata). The metadata comes from the last edge. If the path
is empty, the metadata will be an empty dictionary.
"""
- def set_uri(name, child_uri, metadata=None, overwrite=True):
- """I add a child (by URI) at the specific name. I return a Deferred
- that fires when the operation finishes. If overwrite= is True, I will
- replace any existing child of the same name, otherwise an existing
- child will cause me to return ExistingChildError. The child name must
- be a unicode string.
+ def set_uri(name, writecap, readcap=None, metadata=None, overwrite=True):
+ """I add a child (by writecap+readcap) at the specific name. I return
+ a Deferred that fires when the operation finishes. If overwrite= is
+ True, I will replace any existing child of the same name, otherwise
+ an existing child will cause me to return ExistingChildError. The
+ child name must be a unicode string.
- The child_uri could be for a file, or for a directory (either
- read-write or read-only, using a URI that came from get_uri() ).
+ The child caps could be for a file, or for a directory. If you have
+ both the writecap and readcap, you should provide both arguments.
+ If you have only one cap and don't know whether it is read-only,
+ provide it as the writecap argument and leave the readcap as None.
+ If you have only one cap that is known to be read-only, provide it
+ as the readcap argument and leave the writecap as None.
+ The filecaps are typically obtained from an IFilesystemNode with
+ get_uri() and get_readonly_uri().
If metadata= is provided, I will use it as the metadata for the named
edge. This will replace any existing metadata. If metadata= is left
as the default value of None, I will set ['mtime'] to the current
time, and I will set ['ctime'] to the current time if there was not
already a child by this name present. This roughly matches the
- ctime/mtime semantics of traditional filesystems.
+ ctime/mtime semantics of traditional filesystems. See the
+ "About the metadata" section of webapi.txt for futher information.
If this directory node is read-only, the Deferred will errback with a
- NotMutableError."""
+ NotWriteableError."""
def set_children(entries, overwrite=True):
- """Add multiple (name, child_uri) pairs (or (name, child_uri,
- metadata) triples) to a directory node. Returns a Deferred that fires
- (with None) when the operation finishes. This is equivalent to
- calling set_uri() multiple times, but is much more efficient. All
- child names must be unicode strings.
+ """Add multiple children (by writecap+readcap) to a directory node.
+ Takes a dictionary, with childname as keys and (writecap, readcap)
+ tuples (or (writecap, readcap, metadata) triples) as values. Returns
+ a Deferred that fires (with this dirnode) when the operation
+ finishes. This is equivalent to calling set_uri() multiple times, but
+ is much more efficient. All child names must be unicode strings.
"""
def set_node(name, child, metadata=None, overwrite=True):
when the operation finishes. This Deferred will fire with the child
node that was just added. I will replace any existing child of the
same name. The child name must be a unicode string. The 'child'
- instance must be an instance providing IDirectoryNode or IFileNode.
+ instance must be an instance providing IFilesystemNode.
If metadata= is provided, I will use it as the metadata for the named
edge. This will replace any existing metadata. If metadata= is left
as the default value of None, I will set ['mtime'] to the current
time, and I will set ['ctime'] to the current time if there was not
already a child by this name present. This roughly matches the
- ctime/mtime semantics of traditional filesystems.
+ ctime/mtime semantics of traditional filesystems. See the
+ "About the metadata" section of webapi.txt for futher information.
If this directory node is read-only, the Deferred will errback with a
- NotMutableError."""
+ NotWriteableError."""
def set_nodes(entries, overwrite=True):
- """Add multiple (name, child_node) pairs (or (name, child_node,
- metadata) triples) to a directory node. Returns a Deferred that fires
- (with None) when the operation finishes. This is equivalent to
- calling set_node() multiple times, but is much more efficient. All
- child names must be unicode strings."""
-
+ """Add multiple children to a directory node. Takes a dict mapping
+ unicode childname to (child_node, metdata) tuples. If metdata=None,
+ the original metadata is left unmodified. Returns a Deferred that
+ fires (with this dirnode) when the operation finishes. This is
+ equivalent to calling set_node() multiple times, but is much more
+ efficient."""
def add_file(name, uploadable, metadata=None, overwrite=True):
"""I upload a file (using the given IUploadable), then attach the
- resulting FileNode to the directory at the given name. I set metadata
- the same way as set_uri and set_node. The child name must be a
- unicode string.
+ resulting ImmutableFileNode to the directory at the given name. I set
+ metadata the same way as set_uri and set_node. The child name must be
+ a unicode string.
I return a Deferred that fires (with the IFileNode of the uploaded
file) when the operation completes."""
- def delete(name):
+ def delete(name, must_exist=True, must_be_directory=False, must_be_file=False):
"""I remove the child at the specific name. I return a Deferred that
fires when the operation finishes. The child name must be a unicode
- string. I raise NoSuchChildError if I do not have a child by that
- name."""
-
- def create_empty_directory(name, overwrite=True):
- """I create and attach an empty directory at the given name. The
- child name must be a unicode string. I return a Deferred that fires
- when the operation finishes."""
+ string. If must_exist is True and I do not have a child by that name,
+ I raise NoSuchChildError. If must_be_directory is True and the child
+ is a file, or if must_be_file is True and the child is a directory,
+ I raise ChildOfWrongTypeError."""
+
+ def create_subdirectory(name, initial_children={}, overwrite=True, metadata=None):
+ """I create and attach a directory at the given name. The new
+ directory can be empty, or it can be populated with children
+ according to 'initial_children', which takes a dictionary in the same
+ format as set_nodes (i.e. mapping unicode child name to (childnode,
+ metadata) tuples). The child name must be a unicode string. I return
+ a Deferred that fires (with the new directory node) when the
+ operation finishes."""
def move_child_to(current_child_name, new_parent, new_child_name=None,
overwrite=True):
encode(), unless of course it already happens to be an even multiple
of required_shares in length.)
- ALSO: the requirement to break up your data into 'required_shares'
- chunks before calling encode() feels a bit surprising, at least from
- the point of view of a user who doesn't know how FEC works. It feels
- like an implementation detail that has leaked outside the
- abstraction barrier. Can you imagine a use case in which the data to
- be encoded might already be available in pre-segmented chunks, such
- that it is faster or less work to make encode() take a list rather
- than splitting a single string?
-
- ALSO ALSO: I think 'inshares' is a misleading term, since encode()
- is supposed to *produce* shares, so what it *accepts* should be
- something other than shares. Other places in this interface use the
- word 'data' for that-which-is-not-shares.. maybe we should use that
- term?
+ Note: the requirement to break up your data into
+ 'required_shares' chunks of exactly the right length before
+ calling encode() is surprising from point of view of a user
+ who doesn't know how FEC works. It feels like an
+ implementation detail that has leaked outside the abstraction
+ barrier. Is there a use case in which the data to be encoded
+ might already be available in pre-segmented chunks, such that
+ it is faster or less work to make encode() take a list rather
+ than splitting a single string?
+
+ Yes, there is: suppose you are uploading a file with K=64,
+ N=128, segsize=262,144. Then each in-share will be of size
+ 4096. If you use this .encode() API then your code could first
+ read each successive 4096-byte chunk from the file and store
+ each one in a Python string and store each such Python string
+ in a Python list. Then you could call .encode(), passing that
+ list as "inshares". The encoder would generate the other 64
+ "secondary shares" and return to you a new list containing
+ references to the same 64 Python strings that you passed in
+ (as the primary shares) plus references to the new 64 Python
+ strings.
+
+ (You could even imagine that your code could use readv() so
+ that the operating system can arrange to get all of those
+ bytes copied from the file into the Python list of Python
+ strings as efficiently as possible instead of having a loop
+ written in C or in Python to copy the next part of the file
+ into the next string.)
+
+ On the other hand if you instead use the .encode_proposal()
+ API (above), then your code can first read in all of the
+ 262,144 bytes of the segment from the file into a Python
+ string, then call .encode_proposal() passing the segment data
+ as the "data" argument. The encoder would basically first
+ split the "data" argument into a list of 64 in-shares of 4096
+ byte each, and then do the same thing that .encode() does. So
+ this would result in a little bit more copying of data and a
+ little bit higher of a "maximum memory usage" during the
+ process, although it might or might not make a practical
+ difference for our current use cases.
+
+ Note that "inshares" is a strange name for the parameter if
+ you think of the parameter as being just for feeding in data
+ to the codec. It makes more sense if you think of the result
+ of this encoding as being the set of shares from inshares plus
+ an extra set of "secondary shares" (or "check shares"). It is
+ a surprising name! If the API is going to be surprising then
+ the name should be surprising. If we switch to
+ encode_proposal() above then we should also switch to an
+ unsurprising name.
'desired_share_ids', if provided, is required to be a sequence of
ints, each of which is required to be >= 0 and < max_shares. If not
class ICodecDecoder(Interface):
def set_params(data_size, required_shares, max_shares):
- """Set the params. They have to be exactly the same ones that were used for encoding. """
+ """Set the params. They have to be exactly the same ones that were
+ used for encoding."""
def get_needed_shares():
"""Return the number of shares needed to reconstruct the data.
def set_params(params):
"""Override the default encoding parameters. 'params' is a tuple of
(k,d,n), where 'k' is the number of required shares, 'd' is the
- shares_of_happiness, and 'n' is the total number of shares that will
+ servers_of_happiness, and 'n' is the total number of shares that will
be created.
Encoding parameters can be set in three ways. 1: The Encoder class
pushed.
'share_counts': return a tuple describing how many shares are used:
- (needed_shares, shares_of_happiness, total_shares)
+ (needed_shares, servers_of_happiness, total_shares)
'num_segments': return an int with the number of segments that
will be encoded.
Once this is called, set_size() and set_params() may not be called.
"""
- def set_shareholders(shareholders):
+ def set_shareholders(shareholders, servermap):
"""Tell the encoder where to put the encoded shares. 'shareholders'
must be a dictionary that maps share number (an integer ranging from
- 0 to n-1) to an instance that provides IStorageBucketWriter. This
- must be performed before start() can be called."""
+ 0 to n-1) to an instance that provides IStorageBucketWriter.
+ 'servermap' is a dictionary that maps share number (as defined above)
+ to a set of peerids. This must be performed before start() can be
+ called."""
def start():
"""Begin the encode/upload process. This involves reading encrypted
set_encrypted_uploadable() and set_shareholders() must be called
before this can be invoked.
- This returns a Deferred that fires with a verify cap when the upload process is
- complete. The verifycap, plus the encryption key, is sufficient to construct the read
- cap.
+ This returns a Deferred that fires with a verify cap when the upload
+ process is complete. The verifycap, plus the encryption key, is
+ sufficient to construct the read cap.
"""
class IDecoder(Interface):
called. Whatever it returns will be returned to the invoker of
Downloader.download.
"""
- # The following methods are just because that 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(storageindex):
- """ Set the storage index. """
- def set_encodingparams(encodingparams):
- """ Set the encoding parameters. """
class IDownloader(Interface):
def download(uri, target):
plaintext hashes, but don't need the redundant encrypted data)."""
def get_plaintext_hashtree_leaves(first, last, num_segments):
- """OBSOLETE; Get the leaf nodes of a merkle hash tree over the plaintext
- segments, i.e. get the tagged hashes of the given segments. The
- segment size is expected to be generated by the IEncryptedUploadable
- before any plaintext is read or ciphertext produced, so that the
- segment hashes can be generated with only a single pass.
+ """OBSOLETE; Get the leaf nodes of a merkle hash tree over the
+ plaintext segments, i.e. get the tagged hashes of the given segments.
+ The segment size is expected to be generated by the
+ IEncryptedUploadable before any plaintext is read or ciphertext
+ produced, so that the segment hashes can be generated with only a
+ single pass.
This returns a Deferred which fires with a sequence of hashes, using:
If the data must be acquired through multiple internal read
operations, returning a list instead of a single string may help to
- reduce string copies.
+ reduce string copies. However, the length of the concatenated strings
+ must equal the amount of data requested, unless EOF is encountered.
+ Long reads, or short reads without EOF, are not allowed. read()
+ should return the same amount of data as a local disk file read, just
+ in a different shape and asynchronously.
'length' will typically be equal to (min(get_size(),1MB)/req_shares),
so a 10kB file means length=3kB, 100kB file means length=30kB,
"""The upload is finished, and whatever filehandle was in use may be
closed."""
+
+class IMutableUploadable(Interface):
+ """
+ I represent content that is due to be uploaded to a mutable filecap.
+ """
+ # This is somewhat simpler than the IUploadable interface above
+ # because mutable files do not need to be concerned with possibly
+ # generating a CHK, nor with per-file keys. It is a subset of the
+ # methods in IUploadable, though, so we could just as well implement
+ # the mutable uploadables as IUploadables that don't happen to use
+ # those methods (with the understanding that the unused methods will
+ # never be called on such objects)
+ def get_size():
+ """
+ Returns a Deferred that fires with the size of the content held
+ by the uploadable.
+ """
+
+ def read(length):
+ """
+ Returns a list of strings which, when concatenated, are the next
+ length bytes of the file, or fewer if there are fewer bytes
+ between the current location and the end of the file.
+ """
+
+ def close():
+ """
+ The process that used the Uploadable is finished using it, so
+ the uploadable may be closed.
+ """
+
class IUploadResults(Interface):
"""I am returned by upload() methods. I contain a number of public
attributes which can be read to determine the results of the upload. Some
.file_size : the size of the file, in bytes
.servers_used : set of server peerids that were used during download
.server_problems : dict mapping server peerid to a problem string. Only
- servers that had problems (bad hashes, disconnects) are
- listed here.
+ servers that had problems (bad hashes, disconnects)
+ are listed here.
.servermap : dict mapping server peerid to a set of share numbers. Only
servers that had any shares are listed here.
.timings : dict of timing information, mapping name to seconds (float)
class IUploader(Interface):
def upload(uploadable):
"""Upload the file. 'uploadable' must impement IUploadable. This
- returns a Deferred which fires with an UploadResults instance, from
+ returns a Deferred which fires with an IUploadResults instance, from
which the URI of the file can be obtained as results.uri ."""
def upload_ssk(write_capability, new_version, uploadable):
class ICheckable(Interface):
def check(monitor, verify=False, add_lease=False):
- """Check upon my health, optionally repairing any problems.
+ """Check up on my health, optionally repairing any problems.
This returns a Deferred that fires with an instance that provides
ICheckResults, or None if the object is non-distributed (i.e. LIT
def get_data():
- """Return a dictionary that describes the state of the file/dir. LIT
- files always return an empty dictionary. Normal files and directories return a
- dictionary with the following keys (note that these use binary strings rather than
- base32-encoded ones) (also note that for mutable files, these counts are for the 'best'
- version):
+ """Return a dictionary that describes the state of the file/dir. LIT
+ files always return an empty dictionary. Normal files and directories
+ return a dictionary with the following keys (note that these use
+ binary strings rather than base32-encoded ones) (also note that for
+ mutable files, these counts are for the 'best' version):
count-shares-good: the number of distinct good shares that were found
count-shares-needed: 'k', the number of shares required for recovery
that was found to be corrupt. Each share
locator is a list of (serverid, storage_index,
sharenum).
- count-incompatible-shares: the number of shares which are of a share format unknown to
- this checker
- list-incompatible-shares: a list of 'share locators', one for each share that was found
- to be of an unknown format. Each share locator is a list of
- (serverid, storage_index, sharenum).
+ count-incompatible-shares: the number of shares which are of a share
+ format unknown to this checker
+ list-incompatible-shares: a list of 'share locators', one for each
+ share that was found to be of an unknown
+ format. Each share locator is a list of
+ (serverid, storage_index, sharenum).
servers-responding: list of (binary) storage server identifiers,
one for each server which responded to the share
- query (even if they said they didn't have shares,
- and even if they said they did have shares but then
- didn't send them when asked, or dropped the
- connection, or returned a Failure, and even if they
- said they did have shares and sent incorrect ones
- when asked)
+ query (even if they said they didn't have
+ shares, and even if they said they did have
+ shares but then didn't send them when asked, or
+ dropped the connection, or returned a Failure,
+ and even if they said they did have shares and
+ sent incorrect ones when asked)
sharemap: dict mapping share identifier to list of serverids
(binary strings). This indicates which servers are holding
which shares. For immutable files, the shareid is an
def get_storage_index_string():
"""Return a string with the (printable) abbreviated storage index."""
def get_repair_attempted():
- """Return a boolean, True if a repair was attempted."""
+ """Return a boolean, True if a repair was attempted. We might not
+ attempt to repair the file because it was healthy, or healthy enough
+ (i.e. some shares were missing but not enough to exceed some
+ threshold), or because we don't know how to repair this object."""
def get_repair_successful():
"""Return a boolean, True if repair was attempted and the file/dir
was fully healthy afterwards. False if no repair was attempted or if
class IRepairResults(Interface):
"""I contain the results of a repair operation."""
+ def get_successful(self):
+ """Returns a boolean: True if the repair made the file healthy, False
+ if not. Repair failure generally indicates a file that has been
+ damaged beyond repair."""
class IClient(Interface):
"""
def create_mutable_file(contents=""):
- """Create a new mutable file with contents, get back the URI string.
- @param contents: the initial contents to place in the file.
- @return: a Deferred that fires with tne (string) SSK URI for the new
- file.
+ """Create a new mutable file (with initial) contents, get back the
+ new node instance.
+
+ @param contents: (bytestring, callable, or None): this provides the
+ initial contents of the mutable file. If 'contents' is a bytestring,
+ it will be used as-is. If 'contents' is a callable, it will be
+ invoked with the new MutableFileNode instance and is expected to
+ return a bytestring with the initial contents of the file (the
+ callable can use node.get_writekey() to decide how to encrypt the
+ initial contents, e.g. for a brand new dirnode with initial
+ children). contents=None is equivalent to an empty string. Using
+ content_maker= is more efficient than creating a mutable file and
+ setting its contents in two separate operations.
+
+ @return: a Deferred that fires with an IMutableFileNode instance.
"""
- def create_empty_dirnode():
- """Create a new dirnode, empty and unattached.
+ def create_dirnode(initial_children={}):
+ """Create a new unattached dirnode, possibly with initial children.
+
+ @param initial_children: dict with keys that are unicode child names,
+ and values that are (childnode, metadata) tuples.
+
@return: a Deferred that fires with the new IDirectoryNode instance.
"""
- def create_node_from_uri(uri):
+ def create_node_from_uri(uri, rouri):
"""Create a new IFilesystemNode instance from the uri, synchronously.
- @param uri: a string or IURI-providing instance. This could be for a
- LiteralFileNode, a CHK file node, a mutable file node, or
- a directory node
- @return: an instance that provides IFilesystemNode (or more usefully one
- of its subclasses). File-specifying URIs will result in
- IFileNode or IMutableFileNode -providing instances, like
- FileNode, LiteralFileNode, or MutableFileNode.
- Directory-specifying URIs will result in
- IDirectoryNode-providing instances, like NewDirectoryNode.
- """
+ @param uri: a string or IURI-providing instance, or None. This could
+ be for a LiteralFileNode, a CHK file node, a mutable file
+ node, or a directory node
+ @param rouri: a string or IURI-providing instance, or None. If the
+ main uri is None, I will use the rouri instead. If I
+ recognize the format of the main uri, I will ignore the
+ rouri (because it can be derived from the writecap).
+
+ @return: an instance that provides IFilesystemNode (or more usefully
+ one of its subclasses). File-specifying URIs will result in
+ IFileNode-providing instances, like ImmutableFileNode,
+ LiteralFileNode, or MutableFileNode. Directory-specifying
+ URIs will result in IDirectoryNode-providing instances, like
+ DirectoryNode.
+ """
+
+class INodeMaker(Interface):
+ """The NodeMaker is used to create IFilesystemNode instances. It can
+ accept a filecap/dircap string and return the node right away. It can
+ also create new nodes (i.e. upload a file, or create a mutable file)
+ asynchronously. Once you have one of these nodes, you can use other
+ methods to determine whether it is a file or directory, and to download
+ or modify its contents.
+
+ The NodeMaker encapsulates all the authorities that these
+ IFilesystemNodes require (like references to the StorageFarmBroker). Each
+ Tahoe process will typically have a single NodeMaker, but unit tests may
+ create simplified/mocked forms for testing purposes.
+ """
+ def create_from_cap(writecap, readcap=None, **kwargs):
+ """I create an IFilesystemNode from the given writecap/readcap. I can
+ only provide nodes for existing file/directory objects: use my other
+ methods to create new objects. I return synchronously."""
+
+ def create_mutable_file(contents=None, keysize=None):
+ """I create a new mutable file, and return a Deferred which will fire
+ with the IMutableFileNode instance when it is ready. If contents= is
+ provided (a bytestring), it will be used as the initial contents of
+ the new file, otherwise the file will contain zero bytes. keysize= is
+ for use by unit tests, to create mutable files that are smaller than
+ usual."""
+
+ def create_new_mutable_directory(initial_children={}):
+ """I create a new mutable directory, and return a Deferred which will
+ fire with the IDirectoryNode instance when it is ready. If
+ initial_children= is provided (a dict mapping unicode child name to
+ (childnode, metadata_dict) tuples), the directory will be populated
+ with those children, otherwise it will be empty."""
class IClientStatus(Interface):
def list_all_uploads():
storage servers.
"""
- def upload_from_file_to_uri(filename=str, convergence=ChoiceOf(None, StringConstraint(2**20))):
+ def upload_from_file_to_uri(filename=str,
+ convergence=ChoiceOf(None,
+ StringConstraint(2**20))):
"""Upload a file to the grid. This accepts a filename (which must be
absolute) that points to a file on the node's local disk. The node will
read the contents of this file, upload it to the grid, then return the
@return: a dictionary mapping peerid to a float (RTT time in seconds)
"""
- return DictOf(Nodeid, float)
+ return DictOf(str, float)
UploadResults = Any() #DictOf(str, str)
def get_stats():
"""
- returns a dictionary containing 'counters' and 'stats', each a dictionary
- with string counter/stat name keys, and numeric values. counters are
- monotonically increasing measures of work done, and stats are instantaneous
- measures (potentially time averaged internally)
+ returns a dictionary containing 'counters' and 'stats', each a
+ dictionary with string counter/stat name keys, and numeric or None values.
+ counters are monotonically increasing measures of work done, and
+ stats are instantaneous measures (potentially time averaged
+ internally)
"""
- return DictOf(str, DictOf(str, ChoiceOf(float, int, long)))
+ return DictOf(str, DictOf(str, ChoiceOf(float, int, long, None)))
class RIStatsGatherer(RemoteInterface):
__remote_name__ = "RIStatsGatherer.tahoe.allmydata.com"
class IValidatedThingProxy(Interface):
def start():
- """ Acquire a thing and validate it. Return a deferred which is eventually fired with
- self if the thing is valid or errbacked if it can't be acquired or validated. """
+ """ Acquire a thing and validate it. Return a deferred which is
+ eventually fired with self if the thing is valid or errbacked if it
+ can't be acquired or validated."""
class InsufficientVersionError(Exception):
def __init__(self, needed, got):
def __repr__(self):
return "InsufficientVersionError(need '%s', got %s)" % (self.needed,
self.got)
+
+class EmptyPathnameComponentError(Exception):
+ """The webapi disallows empty pathname components."""
projects / tahoe-lafs / tahoe-lafs.git / blobdiff