added function ldap.filter.time_span_filter()

CHANGES

@@ -11,6 +11,7 @@ Lib/
   LDAPObject._l to completely invalidate C wrapper object
 * LDAPObject.unbind_ext() now flushes trace file
 * added functions ldap.strf_secs() and ldap.strp_secs()
+* added function ldap.filter.time_span_filter()
 * Refactored ldif.LDIFParser
   * ldif.LDIFParser.version ís now Integer
   * ignore multiple empty lines between records
@@ -1266,4 +1267,4 @@ Released 2.0.0pre02 2002-02-01
 ----------------------------------------------------------------
 Released 1.10alpha3 2000-09-19
 
-$Id: CHANGES,v 1.382 2016/07/17 19:46:49 stroeder Exp $
+$Id: CHANGES,v 1.383 2016/07/24 15:14:56 stroeder Exp $

Lib/ldap/filter.py

@@ -3,14 +3,18 @@
 
 See http://www.python-ldap.org/ for details.
 
-\$Id: filter.py,v 1.10 2015/06/06 09:21:37 stroeder Exp $
+\$Id: filter.py,v 1.11 2016/07/24 15:14:56 stroeder Exp $
 
 Compability:
 - Tested with Python 2.0+
 """
 
 from ldap import __version__
 
+from ldap.functions import strf_secs
+
+import time
+
 
 def escape_filter_chars(assertion_value,escape_mode=0):
   """
@@ -53,3 +57,35 @@ def filter_format(filter_template,assertion_values):
         count of %s in filter_template.
   """
   return filter_template % (tuple(map(escape_filter_chars,assertion_values)))
+
+
+def time_span_filter(
+        filterstr='',
+        from_timestamp=0,
+        until_timestamp=None,
+        delta_attr='modifyTimestamp',
+    ):
+    """
+    If last_run_timestr is non-zero filterstr will be extended
+    """
+    if until_timestamp is None:
+        until_timestamp = time.time()
+        if from_timestamp < 0:
+            from_timestamp = until_timestamp + from_timestamp
+    if from_timestamp > until_timestamp:
+        raise ValueError('from_timestamp %r must not be greater than until_timestamp %r' % (
+            from_timestamp, until_timestamp
+        ))
+    return (
+        '(&'
+        '{filterstr}'
+        '({delta_attr}>={from_timestr})'
+        '(!({delta_attr}>={until_timestr}))'
+        ')'
+    ).format(
+        filterstr=filterstr,
+        delta_attr=delta_attr,
+        from_timestr=strf_secs(from_timestamp),
+        until_timestr=strf_secs(until_timestamp),
+    )
+    # end of time_span_filter()