--- nfo/perl/libs/Data/Transfer/Sync/Core.pm	2003/01/20 17:01:14	1.3
+++ nfo/perl/libs/Data/Transfer/Sync/Core.pm	2004/06/19 01:45:08	1.12
@@ -1,11 +1,44 @@
-##    $Id: Core.pm,v 1.3 2003/01/20 17:01:14 joko Exp $
+## -------------------------------------------------------------------------
+##
+##    $Id: Core.pm,v 1.12 2004/06/19 01:45:08 joko Exp $
 ##
 ##    Copyright (c) 2002  Andreas Motl <andreas.motl@ilo.de>
 ##
 ##    See COPYRIGHT section in pod text below for usage and distribution rights.
 ##
-##    ----------------------------------------------------------------------------------------
+## -------------------------------------------------------------------------
 ##    $Log: Core.pm,v $
+##    Revision 1.12  2004/06/19 01:45:08  joko
+##    introduced "local checksum"-mechanism
+##    moved _dumpCompact to ::Compare::Checksum
+##
+##    Revision 1.11  2004/05/11 20:03:48  jonen
+##    bugfix[joko] related to Attribute Map
+##
+##    Revision 1.10  2003/06/25 23:03:57  joko
+##    no debugging
+##
+##    Revision 1.9  2003/05/13 08:17:52  joko
+##    buildAttributeMap now propagates error
+##
+##    Revision 1.8  2003/03/27 15:31:15  joko
+##    fixes to modules regarding new namespace(s) below Data::Mungle::*
+##
+##    Revision 1.7  2003/02/21 08:01:11  joko
+##    debugging, logging
+##    renamed module
+##
+##    Revision 1.6  2003/02/14 14:03:49  joko
+##    + logging, debugging
+##    - refactored code to sister module
+##
+##    Revision 1.5  2003/02/11 05:30:47  joko
+##    + minor fixes and some debugging mud
+##
+##    Revision 1.4  2003/02/09 05:01:10  joko
+##    + major structure changes
+##    - refactored code to sister modules
+##
 ##    Revision 1.3  2003/01/20 17:01:14  joko
 ##    + cosmetics and debugging
 ##    + probably refactored code to new plugin-modules 'Metadata.pm' and/or 'StorageInterface.pm' (guess it was the last one...)
@@ -48,7 +81,7 @@
 ##    + minor cosmetics for logging
 ##
 ##    Revision 1.2  2002/12/01 04:43:25  joko
-##    + mapping deatil entries may now be either an ARRAY or a HASH
+##    + mapping detail entries may now be either an ARRAY or a HASH
 ##    + erase flag is used now (for export-operations)
 ##    + expressions to refer to values inside deep nested structures
 ##    - removed old mappingV2-code
@@ -60,7 +93,7 @@
 ##
 ##    Revision 1.1  2002/10/10 03:44:21  cvsjoko
 ##    + new
-##    ----------------------------------------------------------------------------------------
+## -------------------------------------------------------------------------
 
 
 package Data::Transfer::Sync::Core;
@@ -75,13 +108,13 @@
 
 use Data::Dumper;
 
-use misc::HashExt;
-use libp qw( md5_base64 );
-use libdb qw( quotesql hash2Sql );
-use Data::Transform::Deep qw( hash2object refexpr2perlref );
-use Data::Compare::Struct qw( getDifference isEmpty );
+#use misc::HashExt;
+use Hash::Serializer;
+use Data::Mungle::Compare::Struct qw( getDifference isEmpty );
+use Data::Mungle::Transform::Deep qw( deep_copy expand );
 use Data::Storage::Container;
 use DesignPattern::Object;
+use shortcuts::database qw( quotesql );
 
 # get logger instance
 my $logger = Log::Dispatch::Config->instance;
@@ -112,12 +145,18 @@
     $self->{container}->addStorage($_, $self->{storages}->{$_});
   }
   
+  # trace
+    #print Dumper($self);
+    #exit;
+
   return 1;
   
 }
 
 sub _initV1 {
   my $self = shift;
+  $logger->debug( __PACKAGE__ . "->_initV1" );
+  die("this should not be reached!");
   # tag storages with id-authority and checksum-provider information
   # TODO: better store tag inside metadata to hold bits together!
   map { $self->{container}->{storage}->{$_}->{isIdentAuthority} = 1 } @{$self->{id_authorities}};
@@ -127,11 +166,17 @@
 
 
 # TODO: abstract the hardwired use of "source" and "target" in here somehow - hmmmm.......  /(="§/%???
-sub _syncNodes {
+sub _run {
 
   my $self = shift;
   
-  my $tc = OneLineDumpHash->new( {} );
+  #print "verbose: ", $self->{verbose}, "\n";
+  $self->{verbose} = 1;
+  
+  $logger->debug( __PACKAGE__ . "->_run" );
+
+  # for statistics
+  my $tc = Hash::Serializer->new( {} );
   my $results;
   
   # set of objects is already in $self->{args}
@@ -150,30 +195,49 @@
 
   # checkpoint: do we actually have a list to iterate through?
   if (!$results || !@{$results}) {
-    $logger->notice( __PACKAGE__ . "->syncNodes: No nodes to synchronize." );
+    $logger->notice( __PACKAGE__ . "->_run: No nodes to synchronize." );
     return;
   }
+
+  #print Dumper(@$results);
+  #exit;
+
+  # check if we actually *have* a synchronization method
+  if (!$self->{options}->{metadata}->{syncMethod}) {
+    $logger->critical( __PACKAGE__ . "->_run: No synchronization method (checksum|timestamp) specified" );
+    return;
+  }
+    
   
   # dereference
   my @results = @{$results};
+  #print Dumper(@results);
 
   # iterate through set
   foreach my $source_node_real (@results) {
 
+    print ":" if $self->{verbose};
+
+    #print Dumper($source_node_real);
+
     $tc->{total}++;
 
-#print "========================  iter", "\n";
+    #print "=" x 80, "\n";
 
     # clone object (in case we have to modify it here)
     # TODO:
     #   - is a "deep_copy" needed here if occouring modifications take place?
     #   - puuhhhh, i guess a deep_copy would destroy tangram mechanisms?
     #   - after all, just take care for now that this object doesn't get updated!
+    #   - so, just use its reference for now - if some cloning is needed in future, do this here!
     my $source_node = $source_node_real;
+    #my $source_node = expand($source_node_real);
 
     # modify entry - handle new style callbacks (the readers)
-#print Dumper($source_node);
-#exit;
+
+    # trace
+    #print Dumper($source_node);
+    #exit;
 
     my $descent = 'source';
 
@@ -181,13 +245,22 @@
     my $map_callbacks = {};
     if (my $callbacks = $self->{meta}->{$descent}->{Callback}) {
 
+      # trace
+        #print Dumper($callbacks);
+        #exit;
+
       my $error = 0;
 
       foreach my $node (keys %{$callbacks->{read}}) {
         
+        #print "cb_node: $node", "\n";
+        
         my $object = $source_node;
         my $value; # = $source_node->{$node};
 
+      # trace
+        #print Dumper($self->{options});
+
         # ------------  half-redundant: make $self->callCallback($object, $value, $opts)
         #my $perl_callback = $self->{meta}->{$descent}->{node} . '::' . $node . '_read';
         my $perl_callback = $self->{meta}->{$descent}->{nodeType} . '::' . $node . '_read';
@@ -195,9 +268,9 @@
         #print $evalstring, "\n"; exit;
         my $cb_result = eval($evalstring);
         if ($@) {
-          die $@;
           $error = 1;
-          print $@, "\n";
+          $logger->error( __PACKAGE__ . "->_run: $@" );
+          next;
         }
         # ------------  half-redundant: make $self->callCallback($object, $value, $opts)
         
@@ -207,7 +280,8 @@
 
     }
 
-#print Dumper($source_node);
+    # trace
+      #print Dumper($source_node);
 
     # exclude defined fields  (simply delete from object)
     map { delete $source_node->{$_} } @{$self->{meta}->{source}->{subnodes_exclude}};
@@ -216,17 +290,20 @@
     $self->{node} = {};
     $self->{node}->{source}->{payload} = $source_node;
 
-#print "res - ident", "\n";
+    # trace
+      #print Dumper($self->{node});
+      #exit;
 
     # determine ident of entry
     my $identOK = $self->_resolveNodeIdent('source');
     #if (!$identOK && lc $self->{args}->{direction} ne 'import') {
     if (!$identOK) {
       #print Dumper($self->{meta}->{source});
-      $logger->critical( __PACKAGE__ . "->syncNodes: No ident found in source node ( nodeName='$self->{meta}->{source}->{nodeName}', nodeType='$self->{meta}->{source}->{nodeType}') try to \"prepare\" this node first?" );
+      $logger->critical( __PACKAGE__ . "->_run: No ident found in source node ( nodeName='$self->{meta}->{source}->{nodeName}', nodeType='$self->{meta}->{source}->{nodeType}') try to \"prepare\" this node first?" );
       return;
     }
 
+    #print "l" if $self->{verbose};
     my $statOK = $self->_statloadNode('target', $self->{node}->{source}->{ident});
 
     # mark node as new either if there's no ident or if stat/load failed
@@ -235,32 +312,27 @@
       print "n" if $self->{verbose};
     }
 
-#print "checksum", "\n";
-    
     # determine status of entry by synchronization method
-    if ( (lc $self->{args}->{method} eq 'checksum') ) {
+    if ( lc $self->{options}->{metadata}->{syncMethod} eq 'checksum' ) {
     #if ( $statOK && (lc $self->{args}->{method} eq 'checksum') ) {
     #if ( !$self->{node}->{status}->{new} && (lc $self->{args}->{method} eq 'checksum') ) {
       
-      # TODO:
-      # is this really worth a "critical"???
-      # no - it should just be a debug appendix i believe
-
-#print "readcs", "\n";
-      
-      # calculate checksum of source node
+    # calculate local checksum of source node
+    $self->handleLocalChecksum('source');
+    
+    # calculate checksum of source node
       #$self->_calcChecksum('source');
-      if (!$self->_readChecksum('source')) {
-        $logger->critical( __PACKAGE__ . "->_readChecksum: Could not find \"source\" entry with ident=\"$self->{node}->{source}->{ident}\"" );
+      if (!$self->readChecksum('source')) {
+        $logger->warning( __PACKAGE__ . "->_run: Could not find \"source\" entry with ident=\"$self->{node}->{source}->{ident}\"" );
         $tc->{skip}++;
         print "s" if $self->{verbose};
         next;
       }
       
       # get checksum from synchronization target
-      $self->_readChecksum('target');
-      #if (!$self->_readChecksum('target')) {
-      #  $logger->critical( __PACKAGE__ . "->_readChecksum: Could not find \"target\" entry with ident=\"$self->{node}->{source}->{ident}\"" );
+      $self->readChecksum('target');
+      #if (!$self->readChecksum('target')) {
+      #  $logger->critical( __PACKAGE__ . "->readChecksum: Could not find \"target\" entry with ident=\"$self->{node}->{source}->{ident}\"" );
       #  next;
       #}
   
@@ -273,6 +345,14 @@
       # determine if entry is "new" or "dirty"
       # after all, this seems to be the point where the hammer falls.....
       print "c" if $self->{verbose};
+
+      # trace
+        #print Dumper($self->{node});
+        #exit;
+        #print "LOCAL: ", $self->{node}->{source}->{checksum_local_storage}, " <-> ", $self->{node}->{source}->{checksum_local_calculated}, "\n";
+        #print "REMOTE: ", $self->{node}->{source}->{checksum}, " <-> ", $self->{node}->{target}->{checksum}, "\n";
+
+      # calculate new/dirty status
       $self->{node}->{status}->{new} = !$self->{node}->{target}->{checksum};
       if (!$self->{node}->{status}->{new}) {
         $self->{node}->{status}->{dirty} = 
@@ -282,6 +362,24 @@
           $self->{args}->{force};
       }
 
+      # new 2004-06-17: also check if local checksum is inconsistent
+      if ($self->{node}->{source}->{checksum_local_storage} ne $self->{node}->{source}->{checksum_local_calculated}) {
+        $self->{node}->{status}->{dirty_local} = 1;
+        $self->{node}->{status}->{dirty} = 1;
+      }
+
+    } else {
+      $logger->warning( __PACKAGE__ . "->_run: Synchronization method '$self->{options}->{metadata}->{syncMethod}' is not implemented" );
+      $tc->{skip}++;
+      print "s" if $self->{verbose};
+      next;
+    }
+
+    # new 2004-06-17: also update local checksum
+    if ($self->{node}->{status}->{dirty_local}) {
+      $tc->{locally_modified}++;
+      print "[lm]" if $self->{verbose};
+      $self->_doModify_LocalChecksum('source');
     }
 
     # first reaction on entry-status: continue with next entry if the current is already "in sync"
@@ -290,25 +388,37 @@
       next;
     }
 
-    # build map to actually transfer the data from source to target
-    $self->_buildMap();
-
+    #print Dumper($self->{node}->{source});
 
-#print Dumper($self->{node}); exit;
+    # build map to actually transfer the data from source to target
+    if (!$self->buildAttributeMap()) {
+      #$logger->warning( __PACKAGE__ . "->_run: Attribute Map could not be created. Will not insert or modify node.");
+      push( @{$tc->{error_per_row}}, "Attribute Map could not be created. Will not insert or modify node $self->{node}->{source}->{ident}.");
+      #push( @{$tc->{error_per_row}}, "Attribute Map could not be created. Will not insert or modify node " . Dumper($self->{node}->{source}) . ".");
+      $tc->{error}++;
+      print "e" if $self->{verbose};
+      next;
+    }
 
-#print "attempt", "\n";
+    # trace
+      #print Dumper($self->{node}); exit;
+      #print "attempt", "\n";
 
     # additional (new) checks for feature "write-protection"
     if ($self->{meta}->{target}->{storage}->{isWriteProtected}) {
       $tc->{attempt_transfer}++;
       print "\n" if $self->{verbose};
-      $logger->notice( __PACKAGE__ . "->syncNodes: Target is write-protected. Will not insert or modify node. " .
+      $logger->notice( __PACKAGE__ . "->_run: Target is write-protected. Will not insert or modify node. " .
           "(Ident: $self->{node}->{source}->{ident} " . "Dump:\n" . Dumper($self->{node}->{source}->{payload}) . ")" );
       print "\n" if $self->{verbose};
       $tc->{skip}++;
       next;
     }
 
+    # trace
+      #print Dumper($self);
+      #exit;
+
     # transfer contents of map to target
     if ($self->{node}->{status}->{new}) {
       $tc->{attempt_new}++;
@@ -316,14 +426,14 @@
       # asymmetry: refetch node from target to re-calculate new ident and checksum (TODO: is IdentAuthority of relevance here?)
       #print Dumper($self->{node});
       $self->_statloadNode('target', $self->{node}->{target}->{ident}, 1);
-      $self->_readChecksum('target');
+      $self->readChecksum('target');
 
     } elsif ($self->{node}->{status}->{dirty}) {
       $tc->{attempt_modify}++;
       # asymmetry: get ident before updating (TODO: is IdentAuthority of relevance here?)
       $self->{node}->{target}->{ident} = $self->{node}->{map}->{$self->{meta}->{target}->{IdentProvider}->{arg}};
       $self->_doTransferToTarget('update');
-      $self->_readChecksum('target');
+      $self->readChecksum('target');
     }
 
     if ($self->{node}->{status}->{ok}) {
@@ -337,17 +447,23 @@
       print "e" if $self->{verbose};
     }
     
+    # trace
+      #print Dumper($self);
+      #exit;
+    
     # change ident in source (take from target), if transfer was ok and target is an IdentAuthority
     # this is (for now) called a "retransmit" indicated by a "r"-character when verbosing
-    if ($self->{node}->{status}->{ok} && $self->{meta}->{target}->{storage}->{isIdentAuthority}) {
+    #if ($self->{node}->{status}->{ok} && $self->{options}->{target}->{storage}->{idAuthority}) {
+    if ($self->{node}->{status}->{ok} && $self->{meta}->{target}->{isIdentAuthority}) {
       print "r" if $self->{verbose};
       #print Dumper($self->{meta});
       #print Dumper($self->{node});
       #exit;
       $self->_doModifySource_IdentChecksum($self->{node}->{target}->{ident});
     }
-
-    print ":" if $self->{verbose};
+    
+    #print "UNLOAD", "\n";
+    #$self->{meta}->{source}->{storage}->unload( $self->{node}->{source}->{payload} );
 
   }
 
@@ -364,452 +480,27 @@
     
     # todo!!!
     #sysevent( { usermsg => $msg, level => $level }, $taskEvent );
-    $logger->info( __PACKAGE__ . "->syncNodes: $msg" );
+    #$logger->info( __PACKAGE__ . "->_run: $msg" );
+    $logger->info($msg . "\n");
 
   return $tc;
 
 }
 
 
-# refactor this as some core-function to do a generic dump resolving data-encapsulations of e.g. Set::Object
-sub _dumpCompact {
-  my $self = shift;
-
-  #my $vars = \@_;
-  my @data = ();
-
-  my $count = 0;
-  foreach (@_) {
-    my $item = {};
-    foreach my $key (keys %$_) {
-      my $val = $_->{$key};
-
-#print Dumper($val);
-
-      if (ref $val eq 'Set::Object') {
-        #print "========================= SET", "\n";
-#print Dumper($val);
-        #print Dumper($val->members());
-        #$val = $val->members();
-        #$vars->[$count]->{$key} = $val->members() if $val->can("members");
-        #$item->{$key} = $val->members() if $val->can("members");
-        $item->{$key} = $val->members();
-        #print Dumper($vars->[$count]->{$key});
-
-      } else {
-        $item->{$key} = $val;
-      }
-
-    }
-    push @data, $item;
-    $count++;
-  }
-
-#print "Dump:", Dumper(@data), "\n";
-
-  $Data::Dumper::Indent = 0;
-  my $result = Dumper(@data);
-  $Data::Dumper::Indent = 2;
-  return $result;
-  
-}
-
-
-sub _calcChecksum {
-
-  my $self = shift;
-  my $descent = shift;
-  my $specifier = shift;
-
-  # calculate checksum for current object
-    my $ident = $self->{node}->{$descent}->{ident};
-  
-  # build dump of this node
-    my $payload = $self->{node}->{$descent}->{payload};
-    #my $dump = $ident . "\n" . $item->quickdump();
-    #my $dump = $ident . "\n" . Dumper($item);
-    my $dump = $ident . "\n" . $self->_dumpCompact($payload);
-  
-  # TODO: $logger->dump( ... );
-    #$logger->debug( __PACKAGE__ . ": " . $dump );
-    #$logger->dump( __PACKAGE__ . ": " . $dump );
-  
-  # calculate checksum from dump
-    # note: the 32-bit integer hash from DBI seems 
-    # to generate duplicates with small payloads already in ranges of hundreds of items/rows!!!
-    # try to avoid to use it or try to use it only for payloads greater than, hmmm, let's say 30 chars?
-    # (we had about 15 chars average per item (row))
-
-    # md5-based fingerprint, base64 encoded (from Digest::MD5)
-      $self->{node}->{$descent}->{checksum} = md5_base64($dump) . '==';
-    # 32-bit integer "hash" value (maybe faster?) (from DBI)
-      #$self->{node}->{$descent}->{checksum} = DBI::hash($dump, 1);
-
-  # signal good
-  return 1;
-
-}
-
-
-sub _readChecksum {
-  my $self = shift;
-
-  my $descent = shift;
-
-  #print "getcheck:", "\n"; print Dumper($self->{node}->{$descent});
-  
-  if (!$self->{node}->{$descent}) {
-    # signal checksum bad
-    return;
-  }
-
-  # get checksum for current entry
-  # TODO: don't have the checksum column/property hardcoded as "cs" here, make this configurable somehow
-
-  if ($self->{meta}->{$descent}->{storage}->{isChecksumAuthority}) {
-    #$self->{node}->{$descent}->{checksum} = $entry->{cs};
-    #$self->{node}->{$descent}->{checksum} = $self->_calcChecksum($descent); # $entry->{cs};
-    #print "descent: $descent", "\n";
-    $self->_calcChecksum($descent);
-    #print "checksum: ", $self->{node}->{$descent}->{checksum}, "\n";
-  } else {
-
-    #$self->{node}->{$descent}->{checksum} = $entry->{cs};
-    $self->{node}->{$descent}->{checksum} = $self->{node}->{$descent}->{payload}->{cs};
-  }
-
-  # signal checksum good
-  return 1;
-
-}
-
-
-sub _buildMap {
-
- my $self = shift;
-
-  # field-structure for building sql
-  # mapping of sql-fieldnames to object-attributes
-    $self->{node}->{map} = {};
-
-    # manually set ...
-      # ... object-id
-      $self->{node}->{map}->{$self->{meta}->{target}->{IdentProvider}->{arg}} = $self->{node}->{source}->{ident};
-      # ... checksum
-      $self->{node}->{map}->{cs} = $self->{node}->{source}->{checksum};
-
-#print "sqlmap: ", Dumper($self->{node}->{map}), "\n";
-
-    # for transferring flat structures via simple (1:1) mapping
-    # TODO: diff per property / property value
-
-    if ($self->{args}->{mapping}) {
-      # apply mapping from $self->{args}->{mapping} to $self->{node}->{map}
-      #foreach my $key (@{$self->{meta}->{source}->{childnodes}}) {
-      my @childnodes = @{$self->{meta}->{source}->{childnodes}};
-      for (my $mapidx = 0; $mapidx <= $#childnodes; $mapidx++) {
-        #my $map_right = $self->{args}->{mapping}->{$key};
-        
-        $self->{node}->{source}->{propcache} = {};
-        $self->{node}->{target}->{propcache} = {};
-        
-        # get property name
-        $self->{node}->{source}->{propcache}->{property} = $self->{meta}->{source}->{childnodes}->[$mapidx];
-        $self->{node}->{target}->{propcache}->{property} = $self->{meta}->{target}->{childnodes}->[$mapidx];
-        #print "map: $map_right", "\n";
-
-        # get property value
-        my $value;
-        
-        # detect for callback - old style - (maybe the better???)
-        if (ref($self->{node}->{target}->{map}) eq 'CODE') {
-          #$value = &$map_right($objClone);
-        } else {
-          # plain (scalar?) value
-          #$value = $objClone->{$map_right};
-          $self->{node}->{source}->{propcache}->{value} = $self->{node}->{source}->{payload}->{$self->{node}->{source}->{propcache}->{property}};
-        }
-        #$self->{node}->{map}->{$key} = $value;
-        
-        # detect expression
-        # for transferring deeply nested structures described by expressions
-        #print "val: $self->{node}->{source}->{propcache}->{value}", "\n";
-        if ($self->{node}->{source}->{propcache}->{property} =~ s/^expr://) {
-          
-          # create an anonymous sub to act as callback target dispatcher
-            my $cb_dispatcher = sub {
-              #print "===============  CALLBACK DISPATCHER", "\n";
-              #print "ident: ", $self->{node}->{source}->{ident}, "\n";
-              #return $self->{node}->{source}->{ident};
-              
-            };
-          
-
-#print Dumper($self->{node});
-          
-          # build callback map for helper function
-          #my $cbmap = { $self->{meta}->{source}->{IdentProvider}->{arg} => $cb_dispatcher };
-          my $cbmap = {};
-          my $value = refexpr2perlref($self->{node}->{source}->{payload}, $self->{node}->{source}->{propcache}->{property}, $cbmap);
-          $self->{node}->{source}->{propcache}->{value} = $value;
-        }
-
-        # encode values dependent on type of underlying storage here - expand cases...
-        my $storage_type = $self->{meta}->{target}->{storage}->{locator}->{type};
-        if ($storage_type eq 'DBI') {
-          # ...for sql
-          $self->{node}->{source}->{propcache}->{value} = quotesql($self->{node}->{source}->{propcache}->{value});
-        }
-         elsif ($storage_type eq 'Tangram') {
-          # iso? utf8 already possible?
-        
-        } elsif ($storage_type eq 'LDAP') {
-          # TODO: encode utf8 here?
-        }
-
-        # store value to transfer map
-        $self->{node}->{map}->{$self->{node}->{target}->{propcache}->{property}} = $self->{node}->{source}->{propcache}->{value};
-
-      }
-    }
-
-    
-  # TODO: $logger->dump( ... );
-  #$logger->debug( "sqlmap:" . "\n" . Dumper($self->{node}->{map}) );
-#print "sqlmap: ", Dumper($self->{node}->{map}), "\n";
-#print "entrystatus: ", Dumper($self->{node}), "\n";
-
-}
-
-
-
-sub _modifyNode {
+sub _doTransferToTarget {
   my $self = shift;
-  my $descent = shift;
   my $action = shift;
-  my $map = shift;
-  my $crit = shift;
-
-  # map for new style callbacks
-  my $map_callbacks = {};
-
-  # checks go first!
-  
-    # TODO: this should be reviewed first - before extending  ;-)
-    # TODO: this should be extended:
-    # count this cases inside the caller to this sub and provide a better overall message
-    # if this counts still zero in the end:
-    #     "No nodes have been touched for modify: Do you have column-headers in your csv file?"
-    if (not defined $self->{node}) {
-      #$logger->critical( __PACKAGE__ . "->_modifyNode failed: \"$descent\" node is empty." );
-      #return;
-    }
-
-  # transfer callback nodes from value map to callback map - handle them afterwards! - (new style callbacks)
-  if (my $callbacks = $self->{meta}->{$descent}->{Callback}) {
-    foreach my $callback (keys %{$callbacks->{write}}) {
-      $map_callbacks->{write}->{$callback} = $map->{$callback};
-      delete $map->{$callback};
-    }
-  }
-  
-  
-  #print Dumper($self->{meta});
-
-  # DBI speaks SQL
-  if ($self->{meta}->{$descent}->{storage}->{locator}->{type} eq 'DBI') {
-
-#print Dumper($self->{node});
-    my $sql_main;
-    # translate map to sql
-    #print $action, "\n"; exit;
-    #print $self->{meta}->{$descent}->{node}, "\n"; exit;
-    #print "action:";
-    #print $action, "\n";
-#$action = "anc";
-#print "yai", "\n";
-
-#print Dumper($map);
-#delete $map->{cs};
-
-    if (lc($action) eq 'insert') {
-      $sql_main = hash2Sql($self->{meta}->{$descent}->{node}, $map, 'SQL_INSERT');
-    } elsif (lc $action eq 'update') {
-      $crit ||= "$self->{meta}->{$descent}->{IdentProvider}->{arg}='$self->{node}->{$descent}->{ident}'";
-      $sql_main = hash2Sql($self->{meta}->{$descent}->{node}, $map, 'SQL_UPDATE', $crit);
-    }
-
-#$sql_main = "UPDATE currencies_csv SET oid='abcdef' WHERE text='Australian Dollar' AND key='AUD';";
-#$sql_main = "UPDATE currencies_csv SET oid='huhu2' WHERE ekey='AUD'";
-
-#print "sql: ", $sql_main, "\n";
-#exit;
-
-    # transfer data
-    my $sqlHandle = $self->{meta}->{$descent}->{storage}->sendCommand($sql_main);
-
-#exit;
-
-    # handle errors
-    if ($sqlHandle->err) {
-      #if ($self->{args}->{debug}) { print "sql-error with statement: $sql_main", "\n"; }
-      $self->{node}->{status}->{error} = {
-        statement => $sql_main,
-        state => $sqlHandle->state, 
-        err => $sqlHandle->err, 
-        errstr => $sqlHandle->errstr, 
-      };
-    } else {
-      $self->{node}->{status}->{ok} = 1;
-    }
-
-  # Tangram does it the oo-way (naturally)
-  } elsif ($self->{meta}->{$descent}->{storage}->{locator}->{type} eq 'Tangram') {
-    my $sql_main;
-    my $object;
-
-    # determine classname
-    my $classname = $self->{meta}->{$descent}->{node};
-    
-    # properties to exclude
-    my @exclude = @{$self->{meta}->{$descent}->{subnodes_exclude}};
-
-
-    if (my $identProvider = $self->{meta}->{$descent}->{IdentProvider}) {
-      push @exclude, $identProvider->{arg};
-    }
-
-    # new feature:
-    #     - check TypeProvider metadata property from other side
-    #     - use argument (arg) inside as a classname for object creation on this side
-    #my $otherSide = $self->_otherSide($descent);
-    if (my $typeProvider = $self->{meta}->{$descent}->{TypeProvider}) {
-      #print Dumper($map);
-      $classname = $map->{$typeProvider->{arg}};
-      # remove nodes from map also (push nodes to "subnodes_exclude" list)
-      push @exclude, $typeProvider->{arg};
-    }
     
-    # exclude banned properties (remove from map)
-    #map { delete $self->{node}->{map}->{$_} } @{$self->{args}->{exclude}};
-    map { delete $map->{$_} } @exclude;
-
-    # list of properties
-    my @props = keys %{$map};
+  # trace
+    #print Dumper($self->{meta});
+    #print Dumper($self->{node});
+    #exit;
     
-    # transfer data
-    if (lc $action eq 'insert') {
-
-      # build array to initialize object
-      #my @initarray = ();
-      #map { push @initarray, $_, undef; } @props;
-
-      # make the object persistent in four steps:
-      #   - raw create (perl / class tangram scope)
-      #   - engine insert (tangram scope)   ... this establishes inheritance - don't try to fill in inherited properties before!
-      #   - raw fill-in from hash (perl scope)
-      #   - engine update (tangram scope)  ... this updates all properties just filled in
-      
-      # create new object ... 
-      #my $object = $classname->new( @initarray );
-      $object = $classname->new();
-      
-      # ... pass to orm ...
-      $self->{meta}->{$descent}->{storage}->insert($object);
-
-      # ... and initialize with empty (undef'd) properties.
-      #print Dumper(@props);
-      map { $object->{$_} = undef; } @props;
-
-      # mix in values ...
-      hash2object($object, $map);
-
-      # ... and re-update@orm.
-#print Dumper($object);
-      $self->{meta}->{$descent}->{storage}->update($object);
-
-      # asymmetry: get ident after insert
-      # TODO:
-      #   - just do this if it is an IdentAuthority
-      #   - use IdentProvider metadata here
-#print Dumper($self->{meta}->{$descent});
-      my $oid = $self->{meta}->{$descent}->{storage}->id($object);
-#print "oid: $oid", "\n";
-      $self->{node}->{$descent}->{ident} = $oid;
-
-
-    } elsif (lc $action eq 'update') {
-      
-      # get fresh object from orm first
-      $object = $self->{meta}->{$descent}->{storage}->load($self->{node}->{$descent}->{ident});
-
-#print Dumper($self->{node});
-      
-      # mix in values
-      #print Dumper($object);
-      hash2object($object, $map);
-      #print Dumper($object);
-      #exit;
-      $self->{meta}->{$descent}->{storage}->update($object);
-    }
-
-    my $error = 0;
-
-    # handle new style callbacks - this is a HACK - do this without an eval!
-    #print Dumper($map);
-    #print "cb: ", Dumper($self->{meta}->{$descent}->{Callback});
-    #print Dumper($map_callbacks);
-    foreach my $node (keys %{$map_callbacks->{write}}) {
-      #print Dumper($node);
-      my $perl_callback = $self->{meta}->{$descent}->{node} . '::' . $node . '_write';
-      my $evalstring = $perl_callback . '( { object => $object, value => $map_callbacks->{write}->{$node}, storage => $self->{meta}->{$descent}->{storage} } );';
-      #print $evalstring, "\n"; exit;
-      eval($evalstring);
-      if ($@) {
-        $error = 1;
-        print $@, "\n";
-      }
-      
-      #print "after eval", "\n";
-      
-      if (!$error) {
-        # re-update@orm
-        $self->{meta}->{$descent}->{storage}->update($object);
-      }
-    }
-  
-    # handle errors
-    if ($error) {
-      #print "error", "\n";
-=pod
-      my $sqlHandle;
-      #if ($self->{args}->{debug}) { print "sql-error with statement: $sql_main", "\n"; }
-      $self->{node}->{status}->{error} = {
-        statement => $sql_main,
-        state => $sqlHandle->state, 
-        err => $sqlHandle->err, 
-        errstr => $sqlHandle->errstr, 
-      };
-=cut
-      # rollback....
-      #print "rollback", "\n";
-      $self->{meta}->{$descent}->{storage}->erase($object);
-      #print "after rollback", "\n";
-    } else {
-      $self->{node}->{status}->{ok} = 1;
-    }
-
-
-  }
-
-}
-
-sub _doTransferToTarget {
-  my $self = shift;
-  my $action = shift;
   $self->_modifyNode('target', $action, $self->{node}->{map});
 }
 
+
 sub _doModifySource_IdentChecksum {
   my $self = shift;
   my $ident_new = shift;
@@ -829,7 +520,14 @@
   $self->_modifyNode('source', 'update', $map);
 }
 
-
+sub _doModify_LocalChecksum {
+  my $self = shift;
+  my $descent = shift;
+  my $map = {
+    cs_local => $self->{node}->{$descent}->{checksum_local_calculated},
+  };
+  $self->_modifyNode($descent, 'update', $map);
+}
 
 sub _prepareNode_MetaProperties {
   my $self = shift;
@@ -865,10 +563,12 @@
 
 }
 
+# TODO: load column-metadata from reversed mapping-metadata
 sub _prepareNode_DummyIdent {
   my $self = shift;
   my $descent = shift;
 
+  #print Dumper($self->{options});
   $logger->info( __PACKAGE__ . "->_prepareNode_DummyIdent( descent $descent )" );
 
   my $list = $self->_getNodeList($descent);
@@ -882,6 +582,7 @@
     my $map = {
       $self->{meta}->{$descent}->{IdentProvider}->{arg} => $ident_dummy,
       cs => undef,
+      cs_local => undef,
     };
     
     # diff lists and ...
@@ -923,12 +624,6 @@
   return '';
 }
 
-sub _erase_all {
-  my $self = shift;
-  my $descent = shift;
-  #my $node = shift;
-  my $node = $self->{meta}->{$descent}->{node};
-  $self->{meta}->{$descent}->{storage}->eraseAll($node);
-}
 
 1;
+__END__