# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1439330034 -7200
# Node ID f8b21bbd82bfee1c42f9b9c67a2a91ee1f4e6011
# Parent  806c54989b5672a344b061713474505bf0ab1736
Added initial support for lists of objects providing recurrences after a given
point in time, thus offering a selective, more efficient approach to computing
and updating the recurrence periods when expanding a window of availability to
cover a later period.
Fixed the table retrieval method to not strip tabs (and thus blank columns) from
the ends of lines.

diff -r 806c54989b56 -r f8b21bbd82bf imip_store.py
--- a/imip_store.py	Sun Aug 09 23:24:29 2015 +0200
+++ b/imip_store.py	Tue Aug 11 23:53:54 2015 +0200
@@ -22,7 +22,7 @@
 from datetime import datetime
 from imiptools.config import STORE_DIR, PUBLISH_DIR
 from imiptools.data import make_calendar, parse_object, to_stream
-from imiptools.dates import format_datetime
+from imiptools.dates import format_datetime, get_datetime
 from imiptools.filesys import fix_permissions, FileBase
 from imiptools.period import FreeBusyPeriod
 from os.path import exists, isfile, join
@@ -70,7 +70,7 @@
             try:
                 l = []
                 for line in f.readlines():
-                    t = line.strip().split("\t")
+                    t = line.strip(" \r\n").split("\t")
                     if empty_defaults:
                         t = self._set_defaults(t, empty_defaults)
                     l.append(tuple(t))
@@ -341,6 +341,40 @@
 
         return True
 
+    # Free/busy period providers, upon extension of the free/busy records.
+
+    def get_freebusy_providers(self, user, dt=None):
+
+        """
+        Return a set of uncancelled events of the form (uid, recurrenceid)
+        providing free/busy details beyond the given datetime 'dt'.
+        """
+
+        filename = self.get_object_in_store(user, "freebusy-providers")
+        if not filename or not exists(filename):
+            return None
+        else:
+            # Attempt to read providers, with a declaration of the datetime
+            # from which such providers are considered as still being active.
+
+            t = self._get_table(user, filename, [(1, None)])
+            try:
+                dt_string = t[0][0]
+            except IndexError:
+                return None
+
+            # If the requested datetime is earlier than the stated datetime, the
+            # providers will need to be recomputed.
+
+            if dt:
+                providers_dt = get_datetime(dt_string)
+                if not providers_dt or providers_dt > dt:
+                    return None
+
+            # Otherwise, return the providers.
+
+            return t[1:]
+
     # Free/busy period access.
 
     def get_freebusy(self, user):
diff -r 806c54989b56 -r f8b21bbd82bf tools/make_freebusy.py
--- a/tools/make_freebusy.py	Sun Aug 09 23:24:29 2015 +0200
+++ b/tools/make_freebusy.py	Tue Aug 11 23:53:54 2015 +0200
@@ -21,6 +21,7 @@
 this program.  If not, see <http://www.gnu.org/licenses/>.
 """
 
+from bisect import bisect_left
 from codecs import getwriter
 from imiptools.data import get_window_end, Object
 from imiptools.dates import get_default_timezone
@@ -62,9 +63,23 @@
     store = FileStore()
     publisher = FilePublisher()
 
-    # Get identifiers for uncancelled events.
+    # Get identifiers for uncancelled events either from a list of events
+    # providing free/busy periods at the end of the given time window, or from
+    # a list of all events.
+
+    all_events = store.get_freebusy_providers(user, window_end)
 
-    all_events = store.get_active_events(user)
+    if not all_events:
+        all_events = store.get_active_events(user)
+        fb = []
+
+    # With providers of additional periods, append to the existing collection.
+
+    else:
+        if user == participant:
+            fb = store.get_freebusy(user)
+        else:
+            fb = store.get_freebusy_for_other(user, participant)
 
     # Obtain event objects.
 
@@ -78,16 +93,18 @@
 
     # Build a free/busy collection for the given user.
 
-    fb = []
     for obj in objs:
         partstat = obj.get_participation_status(participant)
         recurrenceids = not obj.get_recurrenceid() and store.get_recurrences(user, obj.get_uid())
 
         if obj.get_participation(partstat, include_needs_action):
             for p in obj.get_active_periods(recurrenceids, tzid, window_end):
-                fb.append(obj.get_freebusy_period(p, partstat == "ORG"))
-
-    fb.sort()
+                fbp = obj.get_freebusy_period(p, partstat == "ORG")
+                i = bisect_left(fb, fbp)
+                if i == len(fb):
+                    fb.append(fbp)
+                elif fb[i] != fbp:
+                    fb.insert(i, fbp)
 
     # Store and publish the free/busy collection.