##############################################################################
#
# Copyright (c) 2001, 2002 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""More recovery and iterator tests."""

import transaction
from transaction import Transaction
from ZODB.tests.IteratorStorage import IteratorDeepCompare
from ZODB.tests.StorageTestBase import MinPO, zodb_unpickle, snooze
from ZODB import DB
from ZODB.serialize import referencesf

import time


class RecoveryStorage(IteratorDeepCompare):

    # Requires a setUp() that creates a self._dst destination storage
    def checkSimpleRecovery(self):
        oid = self._storage.new_oid()
        revid = self._dostore(oid, data=11)
        revid = self._dostore(oid, revid=revid, data=12)
        revid = self._dostore(oid, revid=revid, data=13)
        self._dst.copyTransactionsFrom(self._storage)
        self.compare(self._storage, self._dst)

    def checkRestoreAcrossPack(self):
        db = DB(self._storage)
        c = db.open()
        r = c.root()
        obj = r["obj1"] = MinPO(1)
        transaction.commit()
        obj = r["obj2"] = MinPO(1)
        transaction.commit()

        self._dst.copyTransactionsFrom(self._storage)
        self._dst.pack(time.time(), referencesf)

        self._undo(self._storage.undoInfo()[0]['id'])

        # copy the final transaction manually.  even though there
        # was a pack, the restore() ought to succeed.
        it = self._storage.iterator()
        # Get the last transaction and its record iterator. Record iterators
        # can't be accessed out-of-order, so we need to do this in a bit
        # complicated way:
        for final  in it:
            records = list(final)

        self._dst.tpc_begin(final, final.tid, final.status)
        for r in records:
            self._dst.restore(r.oid, r.tid, r.data, '', r.data_txn,
                              final)
        self._dst.tpc_vote(final)
        self._dst.tpc_finish(final)

    def checkPackWithGCOnDestinationAfterRestore(self):
        raises = self.assertRaises
        db = DB(self._storage)
        conn = db.open()
        root = conn.root()
        root.obj = obj1 = MinPO(1)
        txn = transaction.get()
        txn.note('root -> obj')
        txn.commit()
        root.obj.obj = obj2 = MinPO(2)
        txn = transaction.get()
        txn.note('root -> obj -> obj')
        txn.commit()
        del root.obj
        txn = transaction.get()
        txn.note('root -X->')
        txn.commit()
        # Now copy the transactions to the destination
        self._dst.copyTransactionsFrom(self._storage)
        # Now pack the destination.
        snooze()
        self._dst.pack(time.time(),  referencesf)
        # And check to see that the root object exists, but not the other
        # objects.
        data, serial = self._dst.load(root._p_oid, '')
        raises(KeyError, self._dst.load, obj1._p_oid, '')
        raises(KeyError, self._dst.load, obj2._p_oid, '')

    def checkRestoreWithMultipleObjectsInUndoRedo(self):
        from ZODB.FileStorage import FileStorage

        # Undo creates backpointers in (at least) FileStorage.  ZODB 3.2.1
        # FileStorage._data_find() had an off-by-8 error, neglecting to
        # account for the size of the backpointer when searching a
        # transaction with multiple data records.  The results were
        # unpredictable.  For example, it could raise a Python exception
        # due to passing a negative offset to file.seek(), or could
        # claim that a transaction didn't have data for an oid despite
        # that it actually did.
        #
        # The former failure mode was seen in real life, in a ZRS secondary
        # doing recovery.  On my box today, the second failure mode is
        # what happens in this test (with an unpatched _data_find, of
        # course).  Note that the error can only "bite" if more than one
        # data record is in a transaction, and the oid we're looking for
        # follows at least one data record with a backpointer.
        #
        # Unfortunately, _data_find() is a low-level implementation detail,
        # and this test does some horrid white-box abuse to test it.

        is_filestorage = isinstance(self._storage, FileStorage)

        db = DB(self._storage)
        c = db.open()
        r = c.root()

        # Create some objects.
        r["obj1"] = MinPO(1)
        r["obj2"] = MinPO(1)
        transaction.commit()

        # Add x attributes to them.
        r["obj1"].x = 'x1'
        r["obj2"].x = 'x2'
        transaction.commit()

        r = db.open().root()
        self.assertEquals(r["obj1"].x, 'x1')
        self.assertEquals(r["obj2"].x, 'x2')

        # Dirty tricks.
        if is_filestorage:
            obj1_oid = r["obj1"]._p_oid
            obj2_oid = r["obj2"]._p_oid
            # This will be the offset of the next transaction, which
            # will contain two backpointers.
            pos = self._storage.getSize()

        # Undo the attribute creation.
        info = self._storage.undoInfo()
        tid = info[0]['id']
        t = Transaction()
        self._storage.tpc_begin(t)
        oids = self._storage.undo(tid, t)
        self._storage.tpc_vote(t)
        self._storage.tpc_finish(t)

        r = db.open().root()
        self.assertRaises(AttributeError, getattr, r["obj1"], 'x')
        self.assertRaises(AttributeError, getattr, r["obj2"], 'x')

        if is_filestorage:
            # _data_find should find data records for both objects in that
            # transaction.  Without the patch, the second assert failed
            # (it claimed it couldn't find a data record for obj2) on my
            # box, but other failure modes were possible.
            self.assert_(self._storage._data_find(pos, obj1_oid, '') > 0)
            self.assert_(self._storage._data_find(pos, obj2_oid, '') > 0)

            # The offset of the next ("redo") transaction.
            pos = self._storage.getSize()

        # Undo the undo (restore the attributes).
        info = self._storage.undoInfo()
        tid = info[0]['id']
        t = Transaction()
        self._storage.tpc_begin(t)
        oids = self._storage.undo(tid, t)
        self._storage.tpc_vote(t)
        self._storage.tpc_finish(t)

        r = db.open().root()
        self.assertEquals(r["obj1"].x, 'x1')
        self.assertEquals(r["obj2"].x, 'x2')

        if is_filestorage:
            # Again _data_find should find both objects in this txn, and
            # again the second assert failed on my box.
            self.assert_(self._storage._data_find(pos, obj1_oid, '') > 0)
            self.assert_(self._storage._data_find(pos, obj2_oid, '') > 0)

        # Indirectly provoke .restore().  .restore in turn indirectly
        # provokes _data_find too, but not usefully for the purposes of
        # the specific bug this test aims at:  copyTransactionsFrom() uses
        # storage iterators that chase backpointers themselves, and
        # return the data they point at instead.  The result is that
        # _data_find didn't actually see anything dangerous in this
        # part of the test.
        self._dst.copyTransactionsFrom(self._storage)
        self.compare(self._storage, self._dst)
