[Checkins] SVN: gocept.zeoraid/trunk/src/gocept/zeoraid/recovery.py added pseudo code for online recovery

[Thomas Lotze]

Log message for revision 83338:
  added pseudo code for online recovery

Changed:
  A   gocept.zeoraid/trunk/src/gocept/zeoraid/recovery.py

-=-
Added: gocept.zeoraid/trunk/src/gocept/zeoraid/recovery.py
===================================================================
--- gocept.zeoraid/trunk/src/gocept/zeoraid/recovery.py	                        (rev 0)
+++ gocept.zeoraid/trunk/src/gocept/zeoraid/recovery.py	2008-01-31 16:29:18 UTC (rev 83338)
@@ -0,0 +1,59 @@
+# vim:fileencoding=utf-8
+# Copyright (c) 2007 gocept gmbh & co. kg
+# See also LICENSE.txt
+# $Id$
+"""ZEORaid online recovery implementation."""
+
+
+class Recovery(object):
+    """ZEORaid online recovery implementation.
+    """
+
+    _current = 0
+    raid_transaction_count = 0
+    target_transaction_count = 0
+
+    def __init__(self, raid_storage, target_name):
+        self.raid_storage = raid_storage
+        self.target_name = target_name
+        self.target = raid_storage.storages[target_name]
+        self.target_transaction_count = ...
+        # initialize counting up self.raid_transaction_count
+
+    def get_raid_transaction_info(self, n):
+        """Retrieves the n-th transaction info from the RAID, counting from
+        the beginning of the storage's history.
+        """
+
+    def get_target_transaction_info(self, n):
+        """Retrieves the n-th transaction info from the target storage,
+        counting from the beginning of the storage's history.
+        """
+
+    def __call__(self):
+        """Performs recovery."""
+        # Verify old transactions that may already be stored in the target
+        # storage.
+        for self._current in xrange(self.target_transaction_count):
+            if (self.get_raid_transaction_info(self._current) !=
+                self.get_target_transaction_info(self._current)):
+                raise XXX
+
+        # Recover all transaction from that point on until self._current
+        # equals self.raid_transaction_count.
+        # self._current now points to the first transaction to be copied.
+        # We need to do a "while True" loop in order to be able to check on
+        # our progress and finalize recovery atomically.
+        while True:
+            lock
+            try:
+                if self._current == self.raid_transaction_count:
+                    no longer degraded
+                    break
+            finally:
+                unlock
+
+            # Recover transaction self._current.
+            foo
+
+            self._current += 1


Property changes on: gocept.zeoraid/trunk/src/gocept/zeoraid/recovery.py
___________________________________________________________________
Name: svn:keywords
   + Id Rev Date
Name: svn:eol-style
   + native