Exposed database storages using the public "storage" attribute.

(The storage is also available as "_storage" for backward
compatibility, mainly for test code.)

src/ZEO/tests/invalidations_while_connecting.test

@@ -73,10 +73,10 @@ This tests tries to provoke this bug by:
     ...    _ = lock.acquire()
     ...    try:
     ...      time.sleep(.1)
-    ...      assert (db._storage.lastTransaction()
-    ...              == db._storage._server.lastTransaction()), (
-    ...                  db._storage.lastTransaction(),
-    ...                  db._storage._server.lastTransactiion())
+    ...      assert (db.storage.lastTransaction()
+    ...              == db.storage._server.lastTransaction()), (
+    ...                  db.storage.lastTransaction(),
+    ...                  db.storage._server.lastTransactiion())
     ...      conn = db.open()
     ...      for i in range(1000):
     ...        if conn.root()[i].value != conn2.root()[i].value:

src/ZODB/Connection.py

@@ -93,8 +93,8 @@ class Connection(ExportImport, object):
         # Multi-database support
         self.connections = {self._db.database_name: self}
 
-        self._normal_storage = self._storage = db._storage
-        self.new_oid = db._storage.new_oid
+        self._normal_storage = self._storage = db.storage
+        self.new_oid = db.storage.new_oid
         self._savepoint_storage = None
 
         # Do we need to join a txn manager?

src/ZODB/DB.py

@@ -407,7 +407,7 @@ class DB(object):
         self._historical_cache_size_bytes = historical_cache_size_bytes
 
         # Setup storage
-        self._storage = storage
+        self.storage = storage
         self.references = ZODB.serialize.referencesf
         try:
             storage.registerDB(self)
@@ -455,7 +455,7 @@ class DB(object):
         self.history = storage.history
 
     def _setupUndoMethods(self):
-        storage = self._storage
+        storage = self.storage
         try:
             self.supportsUndo = storage.supportsUndo
         except AttributeError:
@@ -471,6 +471,10 @@ class DB(object):
                 raise NotImplementedError
             self.undo = undo
 
+    @property
+    def _storage(self):      # Backward compatibility
+        return self.storage
+
     # This is called by Connection.close().
     def _returnToPool(self, connection):
         """Return a connection to the pool.
@@ -614,7 +618,7 @@ class DB(object):
         is closed, so they stop behaving usefully.  Perhaps close()
         should also close all the Connections.
         """
-        self._storage.close()
+        self.storage.close()
 
     def getCacheSize(self):
         return self._cache_size
@@ -623,16 +627,16 @@ class DB(object):
         return self._cache_size_bytes
 
     def lastTransaction(self):
-        return self._storage.lastTransaction()
+        return self.storage.lastTransaction()
 
     def getName(self):
-        return self._storage.getName()
+        return self.storage.getName()
 
     def getPoolSize(self):
         return self.pool.size
 
     def getSize(self):
-        return self._storage.getSize()
+        return self.storage.getSize()
 
     def getHistoricalCacheSize(self):
         return self._historical_cache_size
@@ -668,7 +672,7 @@ class DB(object):
         self._connectionMap(lambda c: c.invalidateCache())
 
     def objectCount(self):
-        return len(self._storage)
+        return len(self.storage)
 
     def open(self, transaction_manager=None, at=None, before=None):
         """Return a database Connection for use by application code.
@@ -782,7 +786,7 @@ class DB(object):
             t = time()
         t -= days * 86400
         try:
-            self._storage.pack(t, self.references)
+            self.storage.pack(t, self.references)
         except:
             logger.error("packing", exc_info=True)
             raise
@@ -891,9 +895,9 @@ class ResourceManager(object):
     def __init__(self, db):
         self._db = db
         # Delegate the actual 2PC methods to the storage
-        self.tpc_vote = self._db._storage.tpc_vote
-        self.tpc_finish = self._db._storage.tpc_finish
-        self.tpc_abort = self._db._storage.tpc_abort
+        self.tpc_vote = self._db.storage.tpc_vote
+        self.tpc_finish = self._db.storage.tpc_finish
+        self.tpc_abort = self._db.storage.tpc_abort
 
         # Get a number from a simple thread-safe counter, then
         # increment it, for the purpose of sorting ResourceManagers by
@@ -908,12 +912,12 @@ class ResourceManager(object):
             resource_counter_lock.release()
 
     def sortKey(self):
-        return "%s:%016x" % (self._db._storage.sortKey(), self._count)
+        return "%s:%016x" % (self._db.storage.sortKey(), self._count)
 
     def tpc_begin(self, txn, sub=False):
         if sub:
             raise ValueError("doesn't support sub-transactions")
-        self._db._storage.tpc_begin(txn)
+        self._db.storage.tpc_begin(txn)
 
     # The object registers itself with the txn manager, so the ob
     # argument to the methods below is self.
@@ -932,5 +936,5 @@ class TransactionalUndo(ResourceManager):
 
     def commit(self, ob, t):
         # XXX see XXX in ResourceManager
-        tid, oids = self._db._storage.undo(self._tid, t)
+        tid, oids = self._db.storage.undo(self._tid, t)
         self._db.invalidate(tid, dict.fromkeys(oids, 1))

src/ZODB/interfaces.py

@@ -355,6 +355,15 @@ class IDatabase(IStorageDB):
         entry.
         """)
 
+    storage = Attribute(
+        """The object that provides storage for the database
+
+        This attribute is useful primarily for tests.  Normal
+        application code should rarely, if ever, have a need to use
+        this attribute.
+        """)
+    
+
     def open(transaction_manager=None, serial=''):
         """Return an IConnection object for use by application code.
 

src/ZODB/tests/testConfig.py

@@ -26,7 +26,7 @@ class ConfigTestBase(ZODB.tests.util.TestCase):
 
     def _test(self, s):
         db = self._opendb(s)
-        self.storage = db._storage
+        self.storage = db.storage
         # Do something with the database to make sure it works
         cn = db.open()
         rt = cn.root()

src/ZODB/tests/testConnection.py

@@ -96,7 +96,7 @@ class ConnectionDotAdd(ZODB.tests.util.TestCase):
         self.assert_(obj._p_oid is None)
         self.assert_(obj._p_jar is None)
         self.assertRaises(KeyError, self.datamgr.get, oid)
-        self.assertEquals(self.db._storage._stored, [oid])
+        self.assertEquals(self.db.storage._stored, [oid])
 
     def checkCommit(self):
         obj = StubObject()
@@ -111,8 +111,8 @@ class ConnectionDotAdd(ZODB.tests.util.TestCase):
         # This next assert_ is covered by an assert in tpc_finish.
         ##self.assert_(not self.datamgr._added)
 
-        self.assertEquals(self.db._storage._stored, [oid])
-        self.assertEquals(self.db._storage._finished, [oid])
+        self.assertEquals(self.db.storage._stored, [oid])
+        self.assertEquals(self.db.storage._finished, [oid])
 
     def checkModifyOnGetstate(self):
         member = StubObject()
@@ -123,7 +123,7 @@ class ConnectionDotAdd(ZODB.tests.util.TestCase):
         self.datamgr.tpc_begin(self.transaction)
         self.datamgr.commit(self.transaction)
         self.datamgr.tpc_finish(self.transaction)
-        storage = self.db._storage
+        storage = self.db.storage
         self.assert_(obj._p_oid in storage._stored, "object was not stored")
         self.assert_(subobj._p_oid in storage._stored,
                 "subobject was not stored")
@@ -352,7 +352,7 @@ class UserMethodTests(unittest.TestCase):
 
         An expedient way to create a read-only storage:
 
-        >>> db._storage.isReadOnly = lambda: True
+        >>> db.storage.isReadOnly = lambda: True
         >>> cn = db.open()
         >>> cn.isReadOnly()
         True
@@ -753,7 +753,7 @@ class TestConnectionInterface(unittest.TestCase):
 class StubDatabase:
 
     def __init__(self):
-        self._storage = StubStorage()
+        self.storage = StubStorage()
 
     classFactory = None
     database_name = 'stubdatabase'

src/ZODB/tests/testmvcc.py

@@ -135,7 +135,7 @@ True
 We can confirm that we have a non-current revision by asking the
 storage.
 
->>> db._storage.isCurrent(r2["a"]._p_oid, r2["a"]._p_serial)
+>>> db.storage.isCurrent(r2["a"]._p_oid, r2["a"]._p_serial)
 False
 
 It's possible to modify "a", but we get a conflict error when we