def cloneByPickle(obj, ignore_list=()):
    """Makes a copy of a ZODB object, loading ghosts as needed.

    Ignores specified objects along the way, replacing them with None
    in the copy.
    """
    ignore_dict = {}
    for o in ignore_list:
        ignore_dict[id(o)] = o

    def persistent_id(ob, ignore_dict=ignore_dict):
        if id(ob) in ignore_dict:
            return 'ignored'
        if getattr(ob, '_p_changed', 0) is None:
            ob._p_changed = 0
        return None

    def persistent_load(ref):
        assert ref == 'ignored'
        # Return a placeholder object that will be replaced by
        # removeNonVersionedData().
        placeholder = SimpleItem()
        placeholder.id = "ignored_subobject"
        return placeholder

    stream = BytesIO()
    p = Pickler(stream, 1)
    p.persistent_id = persistent_id
    p.dump(obj)
    stream.seek(0)
    u = Unpickler(stream)
    u.persistent_load = persistent_load
    return u.load()
Exemplo n.º 2
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    def testDeepCopyCanInvalidate(self):
        """
        Tests regression for invalidation problems related to missing
        readers and writers values in cloned objects (see
        http://mail.zope.org/pipermail/zodb-dev/2008-August/012054.html)
        """
        import ZODB.MappingStorage
        database = DB(ZODB.blob.BlobStorage(
            'blobs', ZODB.MappingStorage.MappingStorage()))
        connection = database.open()
        root = connection.root()
        transaction.begin()
        root['blob'] = Blob()
        transaction.commit()

        stream = BytesIO()
        p = Pickler(stream, _protocol)
        p.dump(root['blob'])
        u = Unpickler(stream)
        stream.seek(0)
        clone = u.load()
        clone._p_invalidate()

        # it should also be possible to open the cloned blob
        # (even though it won't contain the original data)
        clone.open().close()

        # tearDown
        database.close()
Exemplo n.º 3
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    def testDeepCopyCanInvalidate(self):
        """
        Tests regression for invalidation problems related to missing
        readers and writers values in cloned objects (see
        http://mail.zope.org/pipermail/zodb-dev/2008-August/012054.html)
        """
        import ZODB.MappingStorage
        database = DB(ZODB.blob.BlobStorage(
            'blobs', ZODB.MappingStorage.MappingStorage()))
        connection = database.open()
        root = connection.root()
        transaction.begin()
        root['blob'] = Blob()
        transaction.commit()

        stream = BytesIO()
        p = Pickler(stream, _protocol)
        p.dump(root['blob'])
        u = Unpickler(stream)
        stream.seek(0)
        clone = u.load()
        clone._p_invalidate()

        # it should also be possible to open the cloned blob
        # (even though it won't contain the original data)
        clone.open().close()

        # tearDown
        database.close()
def cloneByPickle(obj, ignore_list=()):
    """Makes a copy of a ZODB object, loading ghosts as needed.

    Ignores specified objects along the way, replacing them with None
    in the copy.
    """
    ignore_dict = {}
    for o in ignore_list:
        ignore_dict[id(o)] = o

    def persistent_id(ob, ignore_dict=ignore_dict):
        if id(ob) in ignore_dict:
            return 'ignored'
        if getattr(ob, '_p_changed', 0) is None:
            ob._p_changed = 0
        return None

    def persistent_load(ref):
        assert ref == 'ignored'
        # Return a placeholder object that will be replaced by
        # removeNonVersionedData().
        placeholder = SimpleItem()
        placeholder.id = "ignored_subobject"
        return placeholder

    stream = BytesIO()
    p = Pickler(stream, 1)
    p.persistent_id = persistent_id
    p.dump(obj)
    stream.seek(0)
    u = Unpickler(stream)
    u.persistent_load = persistent_load
    return u.load()
Exemplo n.º 5
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 def save(self, pos, fname):
     with open(fname, 'wb') as f:
         pickler = Pickler(f, _protocol)
         pickler.fast = True
         pickler.dump(pos)
         for k, v in six.iteritems(self._data):
             pickler.dump((k, v.toString()))
         pickler.dump(None)
 def __init__(self, obj=None):
     self._file = BytesIO()
     self._p = Pickler(self._file, _protocol)
     if sys.version_info[0] < 3:
         self._p.inst_persistent_id = self.persistent_id
     else:
         self._p.persistent_id = self.persistent_id
     self._stack = []
     if obj is not None:
         self._stack.append(obj)
         jar = obj._p_jar
         assert myhasattr(jar, "new_oid")
         self._jar = jar
Exemplo n.º 7
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 def _initroot(self):
     try:
         load_current(self._storage, ZERO)
     except KeyError:
         from ZODB.Connection import TransactionMetaData
         file = BytesIO()
         p = Pickler(file, _protocol)
         p.dump((PersistentMapping, None))
         p.dump({'_container': {}})
         t = TransactionMetaData()
         t.description = u'initial database creation'
         self._storage.tpc_begin(t)
         self._storage.store(ZERO, None, file.getvalue(), '', t)
         self._storage.tpc_vote(t)
         self._storage.tpc_finish(t)
Exemplo n.º 8
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 def __init__(self, obj=None):
     self._file = BytesIO()
     self._p = Pickler(self._file, _protocol)
     if sys.version_info[0] < 3:
         self._p.inst_persistent_id = self.persistent_id
         # PyPy uses a python implementation of cPickle in both Python 2
         # and Python 3. We can't really detect inst_persistent_id as its
         # a magic attribute that's not readable, but it doesn't hurt to
         # simply always assign to persistent_id also
         self._p.persistent_id = self.persistent_id
     else:
         self._p.persistent_id = self.persistent_id
     self._stack = []
     if obj is not None:
         self._stack.append(obj)
         jar = obj._p_jar
         assert myhasattr(jar, "new_oid")
         self._jar = jar
 def __init__(self, obj=None):
     self._file = BytesIO()
     self._p = Pickler(self._file, _protocol)
     if sys.version_info[0] < 3:
         self._p.inst_persistent_id = self.persistent_id
     else:
         self._p.persistent_id = self.persistent_id
     self._stack = []
     if obj is not None:
         self._stack.append(obj)
         jar = obj._p_jar
         assert myhasattr(jar, "new_oid")
         self._jar = jar
Exemplo n.º 10
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def dumps(obj):
    def getpersid(obj):
        if hasattr(obj, 'getoid'):
            return obj.getoid()
        return None

    s = BytesIO()
    p = Pickler(s, _protocol)
    if sys.version_info[0] < 3:
        p.inst_persistent_id = getpersid
    else:
        p.persistent_id = getpersid
    p.dump(obj)
    p.dump(None)
    return s.getvalue()
Exemplo n.º 11
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def dumps(obj):
    def getpersid(obj):
        if hasattr(obj, 'getoid'):
            return obj.getoid()
        return None
    s = BytesIO()
    p = Pickler(s, _protocol)
    if sys.version_info[0] < 3:
        p.inst_persistent_id = getpersid
    else:
        p.persistent_id = getpersid
    p.dump(obj)
    p.dump(None)
    return s.getvalue()
Exemplo n.º 12
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 def __init__(self, obj=None):
     self._file = BytesIO()
     self._p = Pickler(self._file, _protocol)
     if sys.version_info[0] < 3:
         self._p.inst_persistent_id = self.persistent_id
         # PyPy uses a python implementation of cPickle in both Python 2
         # and Python 3. We can't really detect inst_persistent_id as its
         # a magic attribute that's not readable, but it doesn't hurt to
         # simply always assign to persistent_id also
         self._p.persistent_id = self.persistent_id
     else:
         self._p.persistent_id = self.persistent_id
     self._stack = []
     if obj is not None:
         self._stack.append(obj)
         jar = obj._p_jar
         assert myhasattr(jar, "new_oid")
         self._jar = jar
Exemplo n.º 13
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def zodb_pickle(obj):
    """Create a pickle in the format expected by ZODB."""
    f = BytesIO()
    p = Pickler(f, _protocol)
    if sys.version_info[0] < 3:
        p.inst_persistent_id = _persistent_id
    else:
        p.persistent_id = _persistent_id
    klass = obj.__class__
    assert not hasattr(obj, '__getinitargs__'), "not ready for constructors"
    args = None

    mod = getattr(klass, '__module__', None)
    if mod is not None:
        klass = mod, klass.__name__

    state = obj.__getstate__()

    p.dump((klass, args))
    p.dump(state)
    return f.getvalue()
Exemplo n.º 14
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 def _initroot(self):
     try:
         self._storage.load(ZERO, '')
     except KeyError:
         from transaction import Transaction
         file = BytesIO()
         p = Pickler(file, _protocol)
         p.dump((PersistentMapping, None))
         p.dump({'_container': {}})
         t = Transaction()
         t.description = 'initial database creation'
         self._storage.tpc_begin(t)
         self._storage.store(ZERO, None, file.getvalue(), '', t)
         self._storage.tpc_vote(t)
         self._storage.tpc_finish(t)
Exemplo n.º 15
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def zodb_pickle(obj):
    """Create a pickle in the format expected by ZODB."""
    f = BytesIO()
    p = Pickler(f, _protocol)
    if sys.version_info[0] < 3:
        p.inst_persistent_id = _persistent_id
    else:
        p.persistent_id = _persistent_id
    klass = obj.__class__
    assert not hasattr(obj, '__getinitargs__'), "not ready for constructors"
    args = None

    mod = getattr(klass, '__module__', None)
    if mod is not None:
        klass = mod, klass.__name__

    state = obj.__getstate__()

    p.dump((klass, args))
    p.dump(state)
    return f.getvalue()
Exemplo n.º 16
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def make_pickle(ob):
    sio = BytesIO()
    p = Pickler(sio, _protocol)
    p.dump(ob)
    return sio.getvalue()
Exemplo n.º 17
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def pdumps(obj):
    s = BytesIO()
    p = Pickler(s, _protocol)
    p.dump(obj)
    p.dump(None)
    return s.getvalue()
Exemplo n.º 18
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    def _importDuringCommit(self, transaction, f, return_oid_list):
        """Import data during two-phase commit.

        Invoked by the transaction manager mid commit.
        Appends one item, the OID of the first object created,
        to return_oid_list.
        """
        oids = {}

        # IMPORTANT: This code should be consistent with the code in
        # serialize.py. It is currently out of date and doesn't handle
        # weak references.

        def persistent_load(ooid):
            """Remap a persistent id to a new ID and create a ghost for it."""

            klass = None
            if isinstance(ooid, tuple):
                ooid, klass = ooid

            if not isinstance(ooid, bytes):
                assert isinstance(ooid, str)
                # this happens on Python 3 when all bytes in the oid are < 0x80
                ooid = ooid.encode('ascii')

            if ooid in oids:
                oid = oids[ooid]
            else:
                if klass is None:
                    oid = self._storage.new_oid()
                else:
                    oid = self._storage.new_oid(), klass
                oids[ooid] = oid

            return Ghost(oid)

        while 1:
            header = f.read(16)
            if header == export_end_marker:
                break
            if len(header) != 16:
                raise ExportError("Truncated export file")

            # Extract header information
            ooid = header[:8]
            length = u64(header[8:16])
            data = f.read(length)

            if len(data) != length:
                raise ExportError("Truncated export file")

            if oids:
                oid = oids[ooid]
                if isinstance(oid, tuple):
                    oid = oid[0]
            else:
                oids[ooid] = oid = self._storage.new_oid()
                return_oid_list.append(oid)

            # Blob support
            blob_begin = f.read(len(blob_begin_marker))
            if blob_begin == blob_begin_marker:
                # Copy the blob data to a temporary file
                # and remember the name
                blob_len = u64(f.read(8))
                blob_filename = mktemp()
                blob_file = open(blob_filename, "wb")
                cp(f, blob_file, blob_len)
                blob_file.close()
            else:
                f.seek(-len(blob_begin_marker),1)
                blob_filename = None

            pfile = BytesIO(data)
            unpickler = Unpickler(pfile)
            unpickler.persistent_load = persistent_load

            newp = BytesIO()
            pickler = Pickler(newp, _protocol)
            if sys.version_info[0] < 3:
                pickler.inst_persistent_id = persistent_id
            else:
                pickler.persistent_id = persistent_id

            pickler.dump(unpickler.load())
            pickler.dump(unpickler.load())
            data = newp.getvalue()

            if blob_filename is not None:
                self._storage.storeBlob(oid, None, data, blob_filename,
                                        '', transaction)
            else:
                self._storage.store(oid, None, data, '', transaction)
Exemplo n.º 19
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class ObjectWriter:
    """Serializes objects for storage in the database.

    The ObjectWriter creates object pickles in the ZODB format.  It
    also detects new persistent objects reachable from the current
    object.
    """

    _jar = None

    def __init__(self, obj=None):
        self._file = BytesIO()
        self._p = Pickler(self._file, _protocol)
        if sys.version_info[0] < 3:
            self._p.inst_persistent_id = self.persistent_id
            # PyPy uses a python implementation of cPickle in both Python 2
            # and Python 3. We can't really detect inst_persistent_id as its
            # a magic attribute that's not readable, but it doesn't hurt to
            # simply always assign to persistent_id also
            self._p.persistent_id = self.persistent_id
        else:
            self._p.persistent_id = self.persistent_id
        self._stack = []
        if obj is not None:
            self._stack.append(obj)
            jar = obj._p_jar
            assert myhasattr(jar, "new_oid")
            self._jar = jar

    def persistent_id(self, obj):
        """Return the persistent id for obj.

        >>> from ZODB.tests.util import P
        >>> class DummyJar:
        ...     xrefs = True
        ...     def new_oid(self):
        ...         return 42
        ...     def db(self):
        ...         return self
        ...     databases = {}

        >>> jar = DummyJar()
        >>> class O:
        ...     _p_jar = jar
        >>> writer = ObjectWriter(O)

        Normally, object references include the oid and a cached named
        reference to the class.  Having the class information
        available allows fast creation of the ghost, avoiding
        requiring an additional database lookup.

        >>> bob = P('bob')
        >>> oid, cls = writer.persistent_id(bob)
        >>> oid
        42
        >>> cls is P
        True

        If a persistent object does not already have an oid and jar,
        these will be assigned by persistent_id():

        >>> bob._p_oid
        42
        >>> bob._p_jar is jar
        True

        If the object already has a persistent id, the id is not changed:

        >>> bob._p_oid = 24
        >>> oid, cls = writer.persistent_id(bob)
        >>> oid
        24
        >>> cls is P
        True

        If the jar doesn't match that of the writer, an error is raised:

        >>> bob._p_jar = DummyJar()
        >>> writer.persistent_id(bob)
        ... # doctest: +NORMALIZE_WHITESPACE +ELLIPSIS
        Traceback (most recent call last):
          ...
        InvalidObjectReference:
        ('Attempt to store an object from a foreign database connection',
        <ZODB.serialize.DummyJar ...>, P(bob))

        Constructor arguments used by __new__(), as returned by
        __getnewargs__(), can affect memory allocation, but may also
        change over the life of the object.  This makes it useless to
        cache even the object's class.

        >>> class PNewArgs(P):
        ...     def __getnewargs__(self):
        ...         return ()

        >>> sam = PNewArgs('sam')
        >>> writer.persistent_id(sam)
        42
        >>> sam._p_oid
        42
        >>> sam._p_jar is jar
        True

        Check that simple objects don't get accused of persistence:

        >>> writer.persistent_id(42)
        >>> writer.persistent_id(object())

        Check that a classic class doesn't get identified improperly:

        >>> class ClassicClara:
        ...    pass
        >>> clara = ClassicClara()

        >>> writer.persistent_id(clara)
        """

        # Most objects are not persistent. The following cheap test
        # identifies most of them.  For these, we return None,
        # signalling that the object should be pickled normally.
        if not isinstance(obj, (Persistent, type, WeakRef)):
            # Not persistent, pickle normally
            return None

        # Any persistent object must have an oid:
        try:
            oid = obj._p_oid
        except AttributeError:
            # Not persistent, pickle normally
            return None

        if not (oid is None or isinstance(oid, bytes)):
            # Deserves a closer look:

            # Make sure it's not a descriptor
            if hasattr(oid, "__get__"):
                # The oid is a descriptor.  That means obj is a non-persistent
                # class whose instances are persistent, so ...
                # Not persistent, pickle normally
                return None

            if oid is WeakRefMarker:
                # we have a weakref, see weakref.py

                oid = obj.oid
                if oid is None:
                    target = obj()  # get the referenced object
                    oid = target._p_oid
                    if oid is None:
                        # Here we are causing the object to be saved in
                        # the database. One could argue that we shouldn't
                        # do this, because a weakref should not cause an object
                        # to be added.  We'll be optimistic, though, and
                        # assume that the object will be added eventually.

                        oid = self._jar.new_oid()
                        target._p_jar = self._jar
                        target._p_oid = oid
                        self._stack.append(target)
                    obj.oid = oid
                    obj.dm = target._p_jar
                    obj.database_name = obj.dm.db().database_name
                if obj.dm is self._jar:
                    return ["w", (oid,)]
                else:
                    return ["w", (oid, obj.database_name)]

        # Since we have an oid, we have either a persistent instance
        # (an instance of Persistent), or a persistent class.

        # NOTE! Persistent classes don't (and can't) subclass persistent.

        database_name = None

        if oid is None:
            oid = obj._p_oid = self._jar.new_oid()
            obj._p_jar = self._jar
            self._stack.append(obj)

        elif obj._p_jar is not self._jar:
            if not self._jar.db().xrefs:
                raise InvalidObjectReference(
                    "Database %r doesn't allow implicit cross-database " "references" % self._jar.db().database_name,
                    self._jar,
                    obj,
                )

            try:
                otherdb = obj._p_jar.db()
                database_name = otherdb.database_name
            except AttributeError:
                otherdb = self

            if self._jar.db().databases.get(database_name) is not otherdb:
                raise InvalidObjectReference(
                    "Attempt to store an object from a foreign " "database connection", self._jar, obj
                )

            if self._jar.get_connection(database_name) is not obj._p_jar:
                raise InvalidObjectReference(
                    "Attempt to store a reference to an object from "
                    "a separate connection to the same database or "
                    "multidatabase",
                    self._jar,
                    obj,
                )

            # OK, we have an object from another database.
            # Lets make sure the object ws not *just* loaded.

            if obj._p_jar._implicitlyAdding(oid):
                raise InvalidObjectReference(
                    "A new object is reachable from multiple databases. " "Won't try to guess which one was correct!",
                    self._jar,
                    obj,
                )

        klass = type(obj)
        if hasattr(klass, "__getnewargs__"):
            # We don't want to save newargs in object refs.
            # It's possible that __getnewargs__ is degenerate and
            # returns (), but we don't want to have to deghostify
            # the object to find out.

            # Note that this has the odd effect that, if the class has
            # __getnewargs__ of its own, we'll lose the optimization
            # of caching the class info.

            if database_name is not None:
                return ["n", (database_name, oid)]

            return oid

        # Note that we never get here for persistent classes.
        # We'll use direct refs for normal classes.

        if database_name is not None:
            return ["m", (database_name, oid, klass)]

        return oid, klass

    def serialize(self, obj):
        # We don't use __class__ here, because obj could be a persistent proxy.
        # We don't want to be fooled by proxies.
        klass = type(obj)

        # We want to serialize persistent classes by name if they have
        # a non-None non-empty module so as not to have a direct
        # ref. This is important when copying.  We probably want to
        # revisit this in the future.
        newargs = getattr(obj, "__getnewargs__", None)
        if isinstance(getattr(klass, "_p_oid", 0), _oidtypes) and klass.__module__:
            # This is a persistent class with a non-empty module.  This
            # uses pickle format #3 or #7.
            klass = klass.__module__, klass.__name__
            if newargs is None:
                meta = klass, None
            else:
                meta = klass, newargs()
        elif newargs is None:
            # Pickle format #1.
            meta = klass
        else:
            # Pickle format #2.
            meta = klass, newargs()

        return self._dump(meta, obj.__getstate__())

    def _dump(self, classmeta, state):
        # To reuse the existing BytesIO object, we must reset
        # the file position to 0 and truncate the file after the
        # new pickle is written.
        self._file.seek(0)
        self._p.clear_memo()
        self._p.dump(classmeta)
        self._p.dump(state)
        self._file.truncate()
        return self._file.getvalue()

    def __iter__(self):
        return NewObjectIterator(self._stack)
Exemplo n.º 20
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def tryToResolveConflict(self, oid, committedSerial, oldSerial, newpickle,
                         committedData=b''):
    # class_tuple, old, committed, newstate = ('',''), 0, 0, 0
    try:
        prfactory = PersistentReferenceFactory()
        newpickle = self._crs_untransform_record_data(newpickle)
        file = BytesIO(newpickle)
        unpickler = Unpickler(file)
        unpickler.find_global = find_global
        unpickler.persistent_load = prfactory.persistent_load
        meta = unpickler.load()
        if isinstance(meta, tuple):
            klass = meta[0]
            newargs = meta[1] or ()
            if isinstance(klass, tuple):
                klass = find_global(*klass)
        else:
            klass = meta
            newargs = ()

        if klass in _unresolvable:
            raise ConflictError

        inst = klass.__new__(klass, *newargs)

        try:
            resolve = inst._p_resolveConflict
        except AttributeError:
            _unresolvable[klass] = 1
            raise ConflictError


        oldData = self.loadSerial(oid, oldSerial)
        if not committedData:
            committedData  = self.loadSerial(oid, committedSerial)

        if newpickle == oldData:
            # old -> new diff is empty, so merge is trivial
            return committedData
        if committedData == oldData:
            # old -> committed diff is empty, so merge is trivial
            return newpickle

        newstate = unpickler.load()
        old       = state(self, oid, oldSerial, prfactory, oldData)
        committed = state(self, oid, committedSerial, prfactory, committedData)

        resolved = resolve(old, committed, newstate)

        file = BytesIO()
        pickler = Pickler(file, _protocol)
        if sys.version_info[0] < 3:
            pickler.inst_persistent_id = persistent_id
        else:
            pickler.persistent_id = persistent_id
        pickler.dump(meta)
        pickler.dump(resolved)
        return self._crs_transform_record_data(file.getvalue())
    except (ConflictError, BadClassName):
        pass
    except:
        # If anything else went wrong, catch it here and avoid passing an
        # arbitrary exception back to the client.  The error here will mask
        # the original ConflictError.  A client can recover from a
        # ConflictError, but not necessarily from other errors.  But log
        # the error so that any problems can be fixed.
        logger.error("Unexpected error", exc_info=True)

    raise ConflictError(oid=oid, serials=(committedSerial, oldSerial),
                        data=newpickle)
class ObjectWriter:
    """Serializes objects for storage in the database.

    The ObjectWriter creates object pickles in the ZODB format.  It
    also detects new persistent objects reachable from the current
    object.
    """

    _jar = None

    def __init__(self, obj=None):
        self._file = BytesIO()
        self._p = Pickler(self._file, _protocol)
        if sys.version_info[0] < 3:
            self._p.inst_persistent_id = self.persistent_id
        else:
            self._p.persistent_id = self.persistent_id
        self._stack = []
        if obj is not None:
            self._stack.append(obj)
            jar = obj._p_jar
            assert myhasattr(jar, "new_oid")
            self._jar = jar

    def persistent_id(self, obj):
        """Return the persistent id for obj.

        >>> from ZODB.tests.util import P
        >>> class DummyJar:
        ...     xrefs = True
        ...     def new_oid(self):
        ...         return 42
        ...     def db(self):
        ...         return self
        ...     databases = {}

        >>> jar = DummyJar()
        >>> class O:
        ...     _p_jar = jar
        >>> writer = ObjectWriter(O)

        Normally, object references include the oid and a cached named
        reference to the class.  Having the class information
        available allows fast creation of the ghost, avoiding
        requiring an additional database lookup.

        >>> bob = P('bob')
        >>> oid, cls = writer.persistent_id(bob)
        >>> oid
        42
        >>> cls is P
        True

        If a persistent object does not already have an oid and jar,
        these will be assigned by persistent_id():

        >>> bob._p_oid
        42
        >>> bob._p_jar is jar
        True

        If the object already has a persistent id, the id is not changed:

        >>> bob._p_oid = 24
        >>> oid, cls = writer.persistent_id(bob)
        >>> oid
        24
        >>> cls is P
        True

        If the jar doesn't match that of the writer, an error is raised:

        >>> bob._p_jar = DummyJar()
        >>> writer.persistent_id(bob)
        ... # doctest: +NORMALIZE_WHITESPACE +ELLIPSIS
        Traceback (most recent call last):
          ...
        InvalidObjectReference:
        ('Attempt to store an object from a foreign database connection',
        <ZODB.serialize.DummyJar ...>, P(bob))

        Constructor arguments used by __new__(), as returned by
        __getnewargs__(), can affect memory allocation, but may also
        change over the life of the object.  This makes it useless to
        cache even the object's class.

        >>> class PNewArgs(P):
        ...     def __getnewargs__(self):
        ...         return ()

        >>> sam = PNewArgs('sam')
        >>> writer.persistent_id(sam)
        42
        >>> sam._p_oid
        42
        >>> sam._p_jar is jar
        True

        Check that simple objects don't get accused of persistence:

        >>> writer.persistent_id(42)
        >>> writer.persistent_id(object())

        Check that a classic class doesn't get identified improperly:

        >>> class ClassicClara:
        ...    pass
        >>> clara = ClassicClara()

        >>> writer.persistent_id(clara)
        """

        # Most objects are not persistent. The following cheap test
        # identifies most of them.  For these, we return None,
        # signalling that the object should be pickled normally.
        if not isinstance(obj, (Persistent, type, WeakRef)):
            # Not persistent, pickle normally
            return None

        # Any persistent object must have an oid:
        try:
            oid = obj._p_oid
        except AttributeError:
            # Not persistent, pickle normally
            return None

        if not (oid is None or isinstance(oid, bytes)):
            # Deserves a closer look:

            # Make sure it's not a descriptor
            if hasattr(oid, '__get__'):
                # The oid is a descriptor.  That means obj is a non-persistent
                # class whose instances are persistent, so ...
                # Not persistent, pickle normally
                return None

            if oid is WeakRefMarker:
                # we have a weakref, see weakref.py

                oid = obj.oid
                if oid is None:
                    target = obj()  # get the referenced object
                    oid = target._p_oid
                    if oid is None:
                        # Here we are causing the object to be saved in
                        # the database. One could argue that we shouldn't
                        # do this, because a weakref should not cause an object
                        # to be added.  We'll be optimistic, though, and
                        # assume that the object will be added eventually.

                        oid = self._jar.new_oid()
                        target._p_jar = self._jar
                        target._p_oid = oid
                        self._stack.append(target)
                    obj.oid = oid
                    obj.dm = target._p_jar
                    obj.database_name = obj.dm.db().database_name
                if obj.dm is self._jar:
                    return ['w', (oid, )]
                else:
                    return ['w', (oid, obj.database_name)]

        # Since we have an oid, we have either a persistent instance
        # (an instance of Persistent), or a persistent class.

        # NOTE! Persistent classes don't (and can't) subclass persistent.

        database_name = None

        if oid is None:
            oid = obj._p_oid = self._jar.new_oid()
            obj._p_jar = self._jar
            self._stack.append(obj)

        elif obj._p_jar is not self._jar:
            if not self._jar.db().xrefs:
                raise InvalidObjectReference(
                    "Database %r doesn't allow implicit cross-database "
                    "references" % self._jar.db().database_name, self._jar,
                    obj)

            try:
                otherdb = obj._p_jar.db()
                database_name = otherdb.database_name
            except AttributeError:
                otherdb = self

            if self._jar.db().databases.get(database_name) is not otherdb:
                raise InvalidObjectReference(
                    "Attempt to store an object from a foreign "
                    "database connection",
                    self._jar,
                    obj,
                )

            if self._jar.get_connection(database_name) is not obj._p_jar:
                raise InvalidObjectReference(
                    "Attempt to store a reference to an object from "
                    "a separate connection to the same database or "
                    "multidatabase",
                    self._jar,
                    obj,
                )

            # OK, we have an object from another database.
            # Lets make sure the object ws not *just* loaded.

            if obj._p_jar._implicitlyAdding(oid):
                raise InvalidObjectReference(
                    "A new object is reachable from multiple databases. "
                    "Won't try to guess which one was correct!",
                    self._jar,
                    obj,
                )

        klass = type(obj)
        if hasattr(klass, '__getnewargs__'):
            # We don't want to save newargs in object refs.
            # It's possible that __getnewargs__ is degenerate and
            # returns (), but we don't want to have to deghostify
            # the object to find out.

            # Note that this has the odd effect that, if the class has
            # __getnewargs__ of its own, we'll lose the optimization
            # of caching the class info.

            if database_name is not None:
                return ['n', (database_name, oid)]

            return oid

        # Note that we never get here for persistent classes.
        # We'll use direct refs for normal classes.

        if database_name is not None:
            return ['m', (database_name, oid, klass)]

        return oid, klass

    def serialize(self, obj):
        # We don't use __class__ here, because obj could be a persistent proxy.
        # We don't want to be fooled by proxies.
        klass = type(obj)

        # We want to serialize persistent classes by name if they have
        # a non-None non-empty module so as not to have a direct
        # ref. This is important when copying.  We probably want to
        # revisit this in the future.
        newargs = getattr(obj, "__getnewargs__", None)
        if (isinstance(getattr(klass, '_p_oid', 0), _oidtypes)
                and klass.__module__):
            # This is a persistent class with a non-empty module.  This
            # uses pickle format #3 or #7.
            klass = klass.__module__, klass.__name__
            if newargs is None:
                meta = klass, None
            else:
                meta = klass, newargs()
        elif newargs is None:
            # Pickle format #1.
            meta = klass
        else:
            # Pickle format #2.
            meta = klass, newargs()

        return self._dump(meta, obj.__getstate__())

    def _dump(self, classmeta, state):
        # To reuse the existing BytesIO object, we must reset
        # the file position to 0 and truncate the file after the
        # new pickle is written.
        self._file.seek(0)
        self._p.clear_memo()
        self._p.dump(classmeta)
        self._p.dump(state)
        self._file.truncate()
        return self._file.getvalue()

    def __iter__(self):
        return NewObjectIterator(self._stack)
Exemplo n.º 22
0
    def _importDuringCommit(self, transaction, f, return_oid_list):
        """Import data during two-phase commit.

        Invoked by the transaction manager mid commit.
        Appends one item, the OID of the first object created,
        to return_oid_list.
        """
        oids = {}

        # IMPORTANT: This code should be consistent with the code in
        # serialize.py. It is currently out of date and doesn't handle
        # weak references.

        def persistent_load(ooid):
            """Remap a persistent id to a new ID and create a ghost for it."""

            klass = None
            if isinstance(ooid, tuple):
                ooid, klass = ooid

            if not isinstance(ooid, bytes):
                assert isinstance(ooid, str)
                # this happens on Python 3 when all bytes in the oid are < 0x80
                ooid = ooid.encode('ascii')

            if ooid in oids:
                oid = oids[ooid]
            else:
                if klass is None:
                    oid = self._storage.new_oid()
                else:
                    oid = self._storage.new_oid(), klass
                oids[ooid] = oid

            return Ghost(oid)

        while 1:
            header = f.read(16)
            if header == export_end_marker:
                break
            if len(header) != 16:
                raise ExportError("Truncated export file")

            # Extract header information
            ooid = header[:8]
            length = u64(header[8:16])
            data = f.read(length)

            if len(data) != length:
                raise ExportError("Truncated export file")

            if oids:
                oid = oids[ooid]
                if isinstance(oid, tuple):
                    oid = oid[0]
            else:
                oids[ooid] = oid = self._storage.new_oid()
                return_oid_list.append(oid)

            # Blob support
            blob_begin = f.read(len(blob_begin_marker))
            if blob_begin == blob_begin_marker:
                # Copy the blob data to a temporary file
                # and remember the name
                blob_len = u64(f.read(8))
                blob_filename = mktemp()
                blob_file = open(blob_filename, "wb")
                cp(f, blob_file, blob_len)
                blob_file.close()
            else:
                f.seek(-len(blob_begin_marker), 1)
                blob_filename = None

            pfile = BytesIO(data)
            unpickler = Unpickler(pfile)
            unpickler.persistent_load = persistent_load

            newp = BytesIO()
            pickler = Pickler(newp, _protocol)
            if sys.version_info[0] < 3:
                pickler.inst_persistent_id = persistent_id
            else:
                pickler.persistent_id = persistent_id

            pickler.dump(unpickler.load())
            pickler.dump(unpickler.load())
            data = newp.getvalue()

            if blob_filename is not None:
                self._storage.storeBlob(oid, None, data, blob_filename, '',
                                        transaction)
            else:
                self._storage.store(oid, None, data, '', transaction)
Exemplo n.º 23
0
Arquivo: DB.py Projeto: axiros/ZODB
    def __init__(self, storage,
                 pool_size=7,
                 pool_timeout=1<<31,
                 cache_size=400,
                 cache_size_bytes=0,
                 historical_pool_size=3,
                 historical_cache_size=1000,
                 historical_cache_size_bytes=0,
                 historical_timeout=300,
                 database_name='unnamed',
                 databases=None,
                 xrefs=True,
                 large_record_size=1<<24,
                 **storage_args):
        """Create an object database.

        :Parameters:
          - `storage`: the storage used by the database, e.g. FileStorage
          - `pool_size`: expected maximum number of open connections
          - `cache_size`: target size of Connection object cache
          - `cache_size_bytes`: target size measured in total estimated size
               of objects in the Connection object cache.
               "0" means unlimited.
          - `historical_pool_size`: expected maximum number of total
            historical connections
          - `historical_cache_size`: target size of Connection object cache for
            historical (`at` or `before`) connections
          - `historical_cache_size_bytes` -- similar to `cache_size_bytes` for
            the historical connection.
          - `historical_timeout`: minimum number of seconds that
            an unused historical connection will be kept, or None.
          - `xrefs` - Boolian flag indicating whether implicit cross-database
            references are allowed
        """
        if isinstance(storage, six.string_types):
            from ZODB import FileStorage
            storage = ZODB.FileStorage.FileStorage(storage, **storage_args)
        elif storage is None:
            from ZODB import MappingStorage
            storage = ZODB.MappingStorage.MappingStorage(**storage_args)

        # Allocate lock.
        x = threading.RLock()
        self._a = x.acquire
        self._r = x.release

        # pools and cache sizes
        self.pool = ConnectionPool(pool_size, pool_timeout)
        self.historical_pool = KeyedConnectionPool(historical_pool_size,
                                                   historical_timeout)
        self._cache_size = cache_size
        self._cache_size_bytes = cache_size_bytes
        self._historical_cache_size = historical_cache_size
        self._historical_cache_size_bytes = historical_cache_size_bytes

        # Setup storage
        self.storage = storage
        self.references = ZODB.serialize.referencesf
        try:
            storage.registerDB(self)
        except TypeError:
            storage.registerDB(self, None) # Backward compat

        if (not hasattr(storage, 'tpc_vote')) and not storage.isReadOnly():
            warnings.warn(
                "Storage doesn't have a tpc_vote and this violates "
                "the storage API. Violently monkeypatching in a do-nothing "
                "tpc_vote.",
                DeprecationWarning, 2)
            storage.tpc_vote = lambda *args: None

        if IMVCCStorage.providedBy(storage):
            temp_storage = storage.new_instance()
        else:
            temp_storage = storage
        try:
            try:
                temp_storage.load(z64, '')
            except KeyError:
                # Create the database's root in the storage if it doesn't exist
                from persistent.mapping import PersistentMapping
                root = PersistentMapping()
                # Manually create a pickle for the root to put in the storage.
                # The pickle must be in the special ZODB format.
                file = BytesIO()
                p = Pickler(file, _protocol)
                p.dump((root.__class__, None))
                p.dump(root.__getstate__())
                t = transaction.Transaction()
                t.description = 'initial database creation'
                temp_storage.tpc_begin(t)
                temp_storage.store(z64, None, file.getvalue(), '', t)
                temp_storage.tpc_vote(t)
                temp_storage.tpc_finish(t)
        finally:
            if IMVCCStorage.providedBy(temp_storage):
                temp_storage.release()

        # Multi-database setup.
        if databases is None:
            databases = {}
        self.databases = databases
        self.database_name = database_name
        if database_name in databases:
            raise ValueError("database_name %r already in databases" %
                             database_name)
        databases[database_name] = self
        self.xrefs = xrefs

        self.large_record_size = large_record_size
Exemplo n.º 24
0
def pdumps(obj):
    s = BytesIO()
    p = Pickler(s, _protocol)
    p.dump(obj)
    p.dump(None)
    return s.getvalue()
Exemplo n.º 25
0
def make_pickle(ob):
    sio = BytesIO()
    p = Pickler(sio, _protocol)
    p.dump(ob)
    return sio.getvalue()
Exemplo n.º 26
0
    def __init__(self,
                 storage,
                 pool_size=7,
                 pool_timeout=1 << 31,
                 cache_size=400,
                 cache_size_bytes=0,
                 historical_pool_size=3,
                 historical_cache_size=1000,
                 historical_cache_size_bytes=0,
                 historical_timeout=300,
                 database_name='unnamed',
                 databases=None,
                 xrefs=True,
                 large_record_size=1 << 24,
                 **storage_args):
        """Create an object database.

        :Parameters:
          - `storage`: the storage used by the database, e.g. FileStorage
          - `pool_size`: expected maximum number of open connections
          - `cache_size`: target size of Connection object cache
          - `cache_size_bytes`: target size measured in total estimated size
               of objects in the Connection object cache.
               "0" means unlimited.
          - `historical_pool_size`: expected maximum number of total
            historical connections
          - `historical_cache_size`: target size of Connection object cache for
            historical (`at` or `before`) connections
          - `historical_cache_size_bytes` -- similar to `cache_size_bytes` for
            the historical connection.
          - `historical_timeout`: minimum number of seconds that
            an unused historical connection will be kept, or None.
          - `xrefs` - Boolian flag indicating whether implicit cross-database
            references are allowed
        """
        if isinstance(storage, six.string_types):
            from ZODB import FileStorage
            storage = ZODB.FileStorage.FileStorage(storage, **storage_args)
        elif storage is None:
            from ZODB import MappingStorage
            storage = ZODB.MappingStorage.MappingStorage(**storage_args)

        # Allocate lock.
        x = threading.RLock()
        self._a = x.acquire
        self._r = x.release

        # pools and cache sizes
        self.pool = ConnectionPool(pool_size, pool_timeout)
        self.historical_pool = KeyedConnectionPool(historical_pool_size,
                                                   historical_timeout)
        self._cache_size = cache_size
        self._cache_size_bytes = cache_size_bytes
        self._historical_cache_size = historical_cache_size
        self._historical_cache_size_bytes = historical_cache_size_bytes

        # Setup storage
        self.storage = storage
        self.references = ZODB.serialize.referencesf
        try:
            storage.registerDB(self)
        except TypeError:
            storage.registerDB(self, None)  # Backward compat

        if (not hasattr(storage, 'tpc_vote')) and not storage.isReadOnly():
            warnings.warn(
                "Storage doesn't have a tpc_vote and this violates "
                "the storage API. Violently monkeypatching in a do-nothing "
                "tpc_vote.", DeprecationWarning, 2)
            storage.tpc_vote = lambda *args: None

        if IMVCCStorage.providedBy(storage):
            temp_storage = storage.new_instance()
        else:
            temp_storage = storage
        try:
            try:
                temp_storage.load(z64, '')
            except KeyError:
                # Create the database's root in the storage if it doesn't exist
                from persistent.mapping import PersistentMapping
                root = PersistentMapping()
                # Manually create a pickle for the root to put in the storage.
                # The pickle must be in the special ZODB format.
                file = BytesIO()
                p = Pickler(file, _protocol)
                p.dump((root.__class__, None))
                p.dump(root.__getstate__())
                t = transaction.Transaction()
                t.description = 'initial database creation'
                temp_storage.tpc_begin(t)
                temp_storage.store(z64, None, file.getvalue(), '', t)
                temp_storage.tpc_vote(t)
                temp_storage.tpc_finish(t)
        finally:
            if IMVCCStorage.providedBy(temp_storage):
                temp_storage.release()

        # Multi-database setup.
        if databases is None:
            databases = {}
        self.databases = databases
        self.database_name = database_name
        if database_name in databases:
            raise ValueError("database_name %r already in databases" %
                             database_name)
        databases[database_name] = self
        self.xrefs = xrefs

        self.large_record_size = large_record_size