Implement iterator() on the Storage.

git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@1014 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/client/Storage.py

@@ -125,7 +125,7 @@ class Storage(BaseStorage.BaseStorage,
             raise POSException.POSKeyError (oid, tid)
 
     def iterator(self, start=None, stop=None):
-        raise NotImplementedError
+        return self.app.iterator(start, stop)
 
     # undo
     def undo(self, transaction_id, txn):

neo/client/app.py

+#
 # Copyright (C) 2006-2009  Nexedi SA
 # 
 # This program is free software; you can redistribute it and/or
@@ -22,26 +23,29 @@ from Queue import Queue, Empty
 from random import shuffle
 from time import sleep
 
-from neo.client.mq import MQ
-from neo.node import NodeManager, MasterNode, StorageNode
-from neo.connection import MTClientConnection
+from ZODB.POSException import UndoError, StorageTransactionError, ConflictError
+
 from neo import protocol
-from neo.client.handlers import storage, master
-from neo.client.exception import NEOStorageError, NEOStorageConflictError, \
-     NEOStorageNotFoundError
-from neo.exception import NeoException
+from neo.event import EventManager
 from neo.util import makeChecksum, dump
+from neo.locking import RLock, Lock
+from neo.connection import MTClientConnection
+from neo.node import NodeManager, MasterNode, StorageNode
 from neo.connector import getConnectorHandler
+from neo.client.exception import NEOStorageError, NEOStorageConflictError
+from neo.client.exception import NEOStorageNotFoundError
+from neo.exception import NeoException
+from neo.client.handlers import storage, master
 from neo.client.dispatcher import Dispatcher
 from neo.client.poll import ThreadedPoll
-from neo.event import EventManager
-from neo.locking import RLock, Lock
+from neo.client.iterator import Iterator
+from neo.client.mq import MQ
 
-from ZODB.POSException import UndoError, StorageTransactionError, ConflictError
 
 class ConnectionClosed(Exception): 
     pass
 
+
 class ConnectionPool(object):
     """This class manages a pool of connections to storage nodes."""
 
@@ -942,7 +946,9 @@ class Application(object):
                                     'be found' % (tid, )
 
             if filter is None or filter(self.local_var.txn_info):
-                self.local_var.txn_info.pop("oids")
+                # XXX: oids entry is not needed by undoLog but required for the
+                # iterator, this code should be splited then specialized
+                #self.local_var.txn_info.pop("oids")
                 append(self.local_var.txn_info)
                 if len(undo_info) >= last - first:
                     break
@@ -1018,6 +1024,9 @@ class Application(object):
 
         return history_list
 
+    def iterator(self, start=None, stop=None):
+        return Iterator(self, start, stop)
+
     def __del__(self):
         """Clear all connection."""
         # Due to bug in ZODB, close is not always called when shutting

neo/client/iterator.py

+#
+# Copyright (C) 2006-2009  Nexedi SA
+# 
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+from ZODB import BaseStorage
+from neo import util import
+
+
+class Record(BaseStorage.DataRecord):
+    """ TBaseStorageransaction record yielded by the Transaction object """
+
+    def __init__(self, oid, tid, version, data, prev):
+        self.oid = oid
+        self.tid = tid
+        self.version = version
+        self.data = data
+        self.data_txn = prev
+
+    def __str__(self):
+        oid = util.u64(self.oid)
+        tid = util.u64(self.tid)
+        args = (oid, tid, len(self.data), self.data_txn)
+        return 'Record %s:%s: %s (%s)' % args
+
+
+class Transaction(BaseStorage.TransactionRecord):
+    """ Transaction object yielded by the NEO iterator """
+
+    def __init__(self, app, tid, status, user, desc, ext, oid_list):
+        self.app = app
+        self.tid = tid
+        self.status = status
+        self.user = user
+        self.description = desc
+        self._extension = ext
+        self.oid_list = oid_list
+        self.history = []
+
+    def __iter__(self):
+        return self
+
+    def next(self):
+        """ Iterate over the transaction records """
+        app = self.app
+        if not self.oid_list:
+            # no more records for this transaction
+            raise StopIteration
+        oid = self.oid_list.pop()
+        # load an object
+        result = app._load(oid, serial=self.tid)
+        data, start_serial, end_serial = result
+        record = Record(oid, self.tid, '', data, end_serial)
+        return record
+
+    def __str__(self):
+        tid = util.u64(self.tid)
+        args = (tid, self.user, self.status)
+        return 'Transaction #%s: %s %s' % args
+
+
+class Iterator(object):
+    """ An iterator for the NEO storage """
+
+    def __init__(self, app, start, stop):
+        if start is not None or stop is not None:
+            raise NotImplementedError('partial scan not implemented yet')
+        self.app = app
+        self.txn_list = []
+        self.index = 0
+
+    def __iter__(self):
+        return self
+
+    def next(self):
+        """ Return an iterator for the next transaction"""
+        app = self.app
+        if not self.txn_list:
+            # ask some transactions
+            self.txn_list = app.undoLog(self.index, self.index + 100)
+            if not self.txn_list:
+                # scan finished
+                raise StopIteration
+            self.index += len(self.txn_list)
+        txn = self.txn_list.pop()
+        tid = txn['id']
+        user = txn['user_name']
+        desc = txn['description']
+        oid_list = txn['oids']
+        txn = Transaction(self.app, tid, ' ', user, desc, None, oid_list)
+        return txn
+
+    def __str__(self):
+        return 'NEO transactions iteratpr'
+