svn commit: samba r16492 - in branches/SOC/mkhl: .

[mkhl at samba.org]

Author: mkhl
Date: 2006-06-24 14:10:46 +0000 (Sat, 24 Jun 2006)
New Revision: 16492

WebSVN: http://websvn.samba.org/cgi-bin/viewcvs.cgi?view=rev&root=samba&rev=16492

Log:
Reflection on denoting the relation between a local and remote
(i.e. mapped) record.
Improvement of request pseudo-code.

Martin

Modified:
   branches/SOC/mkhl/map.txt


Changeset:
Modified: branches/SOC/mkhl/map.txt
===================================================================
--- branches/SOC/mkhl/map.txt	2006-06-24 12:33:45 UTC (rev 16491)
+++ branches/SOC/mkhl/map.txt	2006-06-24 14:10:46 UTC (rev 16492)
@@ -35,13 +35,9 @@
 
 *** Internal attribute "isMapped"
 The local part of each mapped record includes an internal attribute
-"isMapped", the value of which might denote the DN of the remote part.
-It is not present in the local part of a record that is not
-mapped. (Or maybe it is but with a distinguished/empty value).
+"isMapped", the value of which is irrelevant.  It is not present in
+the local part of a record that is not mapped.
 
-The attribute is not visible from the outside(?) and cannot be
-modified directly.
-
 *** Local != Fallback
 Each attribute must either be mapped or ignored; the local part should
 be reserved for ignored data and not serve as fallback storage for
@@ -76,6 +72,39 @@
 of the map instance.
 
 
+** Alternatives to local "isMapped"
+
+*** Local "isMappedTo"
+Instead of setting a local attribute to just denote whether a record
+is mapped or not, the attribute could contain the DN of the remote
+part if the records data.  When looking for the attribute, its
+contents could be extracted and instantly reused to access remote
+data.
+
+*** Remote "isMappedFrom"
+Instead of the local part pointing to the remote part, the latter
+could be assigned an attribute containing the DN of the local part of
+the data.  Finding the remote part of a record with a local DN would
+then consist of searching for a record that claims to be mapped from
+that local DN.
+
+*** More GUIDs
+Use GUIDs instead of DNs to identify related records.
+
+*** Another "masterGUID=%" RDN
+The idea from local_password could be reused.  This would also save us
+from mapping DNs back and forth all over the place.
+
+
+** Problems with these alternatives
+The obvious problem is the use of a local/remote schema which might
+prevent our use of arbitrary internal attributes for mapped data.
+Another is mapping the directory structure in the remote backend,
+which the third alternative would prevent.
+We would also need to be in samdb to get to use GUIDs for all I
+understand.
+
+
 ** Mappings
 
 *** Abstractly
@@ -124,14 +153,14 @@
 ** Requests
 
 *** Delete
-look for "isMapped" on local self
-if set:
-  delete remote DN
-delete local DN
+look for remote record
+if found:
+  delete remote record
+delete local record
 
 *** Rename
-look for "isMapped" on local self
-if set:
+look for remote record
+if found:
   rename remote record
 rename local record
 
@@ -152,14 +181,25 @@
 otherwise:
   add local record w/o "isMapped"
 
+This doesn't make sense: we're trying to *add* the remote record, so
+we can't possibly query it before adding it!
+Our only choices are to either find out immediately which mappings
+cannot be performed due to missing context data or to split the remote
+message into an immediate and a postponed part, the immediate one
+being run *right now* and the postponed, well, postponed until after
+that; the postponed message would then have to be split up again and
+again until either the immediate part is empty (i.e. some data cannot
+be added) or the postponed part is empty (i.e. we're done and can go
+home now).
+
 *** Modify
 if no requested changes are remote:
   just run local request
-look for "isMapped" on local self
-if not set:
-  turn request into "add"
+look for remote record
+if not found:
+  turn remote request into "add"
   add remote record (with context)
-  modify local record with "isMapped"
+  register relation between local and remote record
 otherwise:
   modify remote record (with context)
   modify local record