replication: use MD5 hash instead of XOR

git-svn-id: https://svn.erp5.org/repos/neo/trunk@2804 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/lib/protocol.py

@@ -481,13 +481,6 @@ class PNumber(PStructItem):
     def __init__(self, name):
         PStructItem.__init__(self, name, '!L')
 
-class PChecksum(PStructItem):
-    """
-        A checksum
-    """
-    def __init__(self, name):
-        PStructItem.__init__(self, name, '!Q')
-
 class PIndex(PStructItem):
     """
         A big integer to defined indexes in a huge list.
@@ -563,6 +556,7 @@ class PTID(PItem):
 
 # same definition, for now
 POID = PTID
+PChecksum = PUUID # (md5 is same length as uuid)
 
 # common definitions
 

neo/lib/python.py

@@ -39,6 +39,11 @@ if sys.version_info < (2, 5):
       return False
     __builtin__.any = any
 
+    import md5, sha
+    sys.modules['hashlib'] = hashlib = imp.new_module('hashlib')
+    hashlib.md5 = md5.new
+    hashlib.sha1 = sha.new
+
     import struct
 
     class Struct(object):

neo/storage/database/btree.py

@@ -22,9 +22,10 @@ Not persistent ! (no data retained after process exit)
 
 from BTrees.OOBTree import OOBTree as _OOBTree
 import neo.lib
+from hashlib import md5
 
 from neo.storage.database import DatabaseManager
-from neo.lib.protocol import CellStates
+from neo.lib.protocol import CellStates, ZERO_OID, ZERO_TID
 from neo.lib import util
 
 # The only purpose of this value (and code using it) is to avoid creating
@@ -672,50 +673,51 @@ class BTreeDatabaseManager(DatabaseManager):
         batchDelete(self._obj, obj_callback, recycle_subtrees=True)
 
     def checkTIDRange(self, min_tid, max_tid, length, num_partitions, partition):
-        # XXX: XOR is a lame checksum
-        count = 0
-        tid_checksum = 0
-        tid = 0
-        upper_bound = util.u64(max_tid)
-        max_tid = 0
+        if length:
+            tid_list = []
             for tid in safeIter(self._trans.keys, min=util.u64(min_tid),
-                max=upper_bound):
+                                                  max=util.u64(max_tid)):
                 if tid % num_partitions == partition:
-                if count >= length:
+                    tid_list.append(tid)
+                    if len(tid_list) >= length:
                         break
-                max_tid = tid
-                tid_checksum ^= tid
-                count += 1
-        return count, tid_checksum, util.p64(max_tid)
+            if tid_list:
+                return (len(tid_list),
+                        md5(','.join(map(str, tid_list))).digest(),
+                        util.p64(tid_list[-1]))
+        return 0, None, ZERO_TID
 
     def checkSerialRange(self, min_oid, min_serial, max_tid, length,
             num_partitions, partition):
-        # XXX: XOR is a lame checksum
+        if length:
             u64 = util.u64
-        p64 = util.p64
             min_oid = u64(min_oid)
-        count = 0
-        oid_checksum = serial_checksum = 0
-        max_oid = oid = max_serial = serial = 0
+            max_tid = u64(max_tid)
+            oid_list = []
+            serial_list = []
             for oid, tserial in safeIter(self._obj.items, min=min_oid):
                 if oid % num_partitions == partition:
-                if oid == min_oid:
                     try:
-                        serial_iter = tserial.keys(min=u64(min_serial),
-                            max=u64(max_tid))
+                        if oid == min_oid:
+                            tserial = tserial.keys(min=u64(min_serial),
+                                                   max=max_tid)
+                        else:
+                            tserial = tserial.keys(max=max_tid)
                     except ValueError:
                         continue
-                else:
-                    serial_iter = tserial.keys()
-                for serial in serial_iter:
-                    if count >= length:
+                    for serial in tserial:
+                        oid_list.append(oid)
+                        serial_list.append(serial)
+                        if len(oid_list) >= length:
                             break
-                    oid_checksum ^= oid
-                    serial_checksum ^= serial
-                    max_serial = serial
-                    max_oid = oid
-                    count += 1
-                if count >= length:
+                    else:
+                        continue
                     break
-        return count, oid_checksum, p64(max_oid), serial_checksum, p64(max_serial)
-
+            if oid_list:
+                p64 = util.p64
+                return (len(oid_list),
+                        md5(','.join(map(str, oid_list))).digest(),
+                        p64(oid_list[-1]),
+                        md5(','.join(map(str, serial_list))).digest(),
+                        p64(serial_list[-1]))
+        return 0, None, ZERO_OID, None, ZERO_TID

neo/storage/database/mysqldb.py

@@ -15,6 +15,7 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 
+from binascii import a2b_hex
 import MySQLdb
 from MySQLdb import OperationalError
 from MySQLdb.constants.CR import SERVER_GONE_ERROR, SERVER_LOST
@@ -811,9 +812,8 @@ class MySQLDatabaseManager(DatabaseManager):
         self.commit()
 
     def checkTIDRange(self, min_tid, max_tid, length, num_partitions, partition):
-        # XXX: XOR is a lame checksum
         count, tid_checksum, max_tid = self.query('SELECT COUNT(*), '
-            'BIT_XOR(tid), MAX(tid) FROM ('
+            'MD5(GROUP_CONCAT(tid SEPARATOR ",")), MAX(tid) FROM ('
               'SELECT tid FROM trans '
               'WHERE partition = %(partition)s '
               'AND tid >= %(min_tid)d '
@@ -826,39 +826,37 @@ class MySQLDatabaseManager(DatabaseManager):
                 'length': length,
         })[0]
         if count == 0:
-            tid_checksum = 0
             max_tid = ZERO_TID
         else:
+            tid_checksum = a2b_hex(tid_checksum)
             max_tid = util.p64(max_tid)
         return count, tid_checksum, max_tid
 
     def checkSerialRange(self, min_oid, min_serial, max_tid, length,
             num_partitions, partition):
-        # XXX: XOR is a lame checksum
         u64 = util.u64
-        p64 = util.p64
-        r = self.query('SELECT oid, serial FROM obj_short WHERE '
-            'partition = %(partition)s AND '
-            'serial <= %(max_tid)d AND '
-            '(oid > %(min_oid)d OR '
-            '(oid = %(min_oid)d AND serial >= %(min_serial)d)) '
-            'ORDER BY oid ASC, serial ASC LIMIT %(length)d' % {
+        count, oid_checksum, max_oid, serial_checksum, max_serial = self.query(
+            """SELECT COUNT(*), MD5(GROUP_CONCAT(oid SEPARATOR ",")), MAX(oid),
+                      MD5(GROUP_CONCAT(serial SEPARATOR ",")), MAX(serial)
+               FROM obj_short
+               WHERE partition = %(partition)s
+                 AND serial <= %(max_tid)d
+                 AND (oid > %(min_oid)d OR
+                      oid = %(min_oid)d AND serial >= %(min_serial)d)
+               ORDER BY oid ASC, serial ASC LIMIT %(length)d""" % {
                 'min_oid': u64(min_oid),
                 'min_serial': u64(min_serial),
                 'max_tid': u64(max_tid),
                 'length': length,
                 'partition': partition,
-        })
-        count = len(r)
-        oid_checksum = serial_checksum = 0
-        if count == 0:
+        })[0]
+        if count:
+            oid_checksum = a2b_hex(oid_checksum)
+            serial_checksum = a2b_hex(serial_checksum)
+            max_oid = util.p64(max_oid)
+            max_serial = util.p64(max_serial)
+        else:
             max_oid = ZERO_OID
             max_serial = ZERO_TID
-        else:
-            for max_oid, max_serial in r:
-                oid_checksum ^= max_oid
-                serial_checksum ^= max_serial
-            max_oid = p64(max_oid)
-            max_serial = p64(max_serial)
         return count, oid_checksum, max_oid, serial_checksum, max_serial
 

neo/tests/storage/testStorageHandler.py

@@ -149,7 +149,7 @@ class StorageStorageHandlerTests(NeoUnitTestBase):
 
     def test_askCheckTIDRange(self):
         count = 1
-        tid_checksum = 2
+        tid_checksum = self.getNewUUID()
         min_tid = self.getNextTID()
         num_partitions = 4
         length = 5
@@ -173,12 +173,12 @@ class StorageStorageHandlerTests(NeoUnitTestBase):
 
     def test_askCheckSerialRange(self):
         count = 1
-        oid_checksum = 2
+        oid_checksum = self.getNewUUID()
         min_oid = self.getOID(1)
         num_partitions = 4
         length = 5
         partition = 6
-        serial_checksum = 7
+        serial_checksum = self.getNewUUID()
         min_serial = self.getNextTID()
         max_serial = self.getNextTID()
         max_oid = self.getOID(2)

neo/tests/testProtocol.py

@@ -686,7 +686,7 @@ class ProtocolTests(NeoUnitTestBase):
         min_tid = self.getNextTID()
         length = 2
         count = 1
-        tid_checksum = 42
+        tid_checksum = self.getNewUUID()
         max_tid = self.getNextTID()
         p = Packets.AnswerCheckTIDRange(min_tid, length, count, tid_checksum,
             max_tid)
@@ -717,9 +717,9 @@ class ProtocolTests(NeoUnitTestBase):
         min_serial = self.getNextTID()
         length = 2
         count = 1
-        oid_checksum = 24
+        oid_checksum = self.getNewUUID()
         max_oid = self.getOID(5)
-        tid_checksum = 42
+        tid_checksum = self.getNewUUID()
         max_serial = self.getNextTID()
         p = Packets.AnswerCheckSerialRange(min_oid, min_serial, length, count,
             oid_checksum, max_oid, tid_checksum, max_serial)