icalrecur code doc

Author: minichma

src/libical/icalrecur.c

@@ -15,8 +15,8 @@
   How this code works:
 
   Processing starts when the caller generates a new recurrence
-  iterator via icalrecur_iterator_new(). This routine copies the
-  recurrence rule into the iterator and extracts things like start and
+  iterator via icalrecur_iterator_new(). This routine stores a
+  reference to the recurrence rule and extracts things like start and
   end dates. Then, it checks if the rule is legal, using some logic
   from RFC5545 and some logic that probably should be in RFC5545.
 
@@ -25,12 +25,14 @@
   and configures ICU4C to convert occurrences to/from non-Gregorian dates.
 
   Then, icalrecur_iterator_new() re-writes some of the BY*
-  arrays. This involves ( via a call to setup_defaults() ) :
+  arrays (this happens within the iterator, the rule itselfs is
+  treated immutable). This involves ( via a call to setup_defaults() ) :
 
   1) For BY rule parts with no data ( ie BYSECOND was not specified )
-  copy the corresponding time part from DTSTART into the BY array. (
-  So impl->by_ptrs[ICAL_BY_SECOND] will then have one element if is
-  originally had none ) This only happens if the BY* rule part data
+  set up the corresponding time part from DTSTART in the corresponding
+  impl->bydata. So impl->bydata[ICAL_BY_SECOND].by will then have one
+  element if is originally had none ).
+  This only happens if the BY* rule part data
   would expand the number of occurrences in the occurrence set. This
   lets the code ignore DTSTART later on and still use it to get the
   time parts that were not specified in any other way.
@@ -1171,7 +1173,7 @@ static void recur_iterator_set_static_single_by_value(icalrecur_iterator *impl,
     by->by.size = 1;
     by->by.data = &by->buffer_value;
     by->by.data[0] = value;
-    }
+}
 
 static void setup_defaults(icalrecur_iterator *impl,
                            icalrecurrencetype_byrule byrule, int deftime)
@@ -2143,15 +2145,15 @@ icalrecur_iterator *icalrecur_iterator_new(struct icalrecurrencetype *rule,
     for (byrule = 0; byrule < ICAL_BY_NUM_PARTS; byrule++) {
         impl->bydata[byrule].by = impl->rule->by[byrule];
 
-    /* Note which by rules had data in them when the iterator was
-       created. We can't use the actual by_x arrays, because the
-       empty ones will be given default values later in this
-       routine. The orig_data array will be used later in has_by_data */
+        /* Note which by rules had data in them when the iterator was
+        created. We can't use the actual by_x arrays, because the
+        empty ones will be given default values later in this
+        routine. The orig_data array will be used later in has_by_data */
 
-    impl->bydata[byrule].orig_data =
-        (short)(impl->rule->by[byrule].size > 0);
+        impl->bydata[byrule].orig_data =
+            (short)(impl->rule->by[byrule].size > 0);
 
-    /* Check if the recurrence rule is legal */
+        /* Check if the recurrence rule is legal */
         if (expand_map[freq].map[byrule] == ILLEGAL &&
             has_by_data(impl, byrule)) {
             ical_invalid_rrule_handling rruleHandlingSetting =
@@ -2258,7 +2260,7 @@ static void increment_month(icalrecur_iterator *impl, int inc)
         struct icaltimetype this = occurrence_as_icaltime(impl, 0);
 
         while (this.year < 20000) {
-icalrecurrence_iterator_by_data *bydata = &impl->bydata[ICAL_BY_MONTH];
+            icalrecurrence_iterator_by_data *bydata = &impl->bydata[ICAL_BY_MONTH];
             for (bydata->index = 0;
                  bydata->index < bydata->by.size; bydata->index++) {
                 if (this.month == bydata->by.data[bydata->index])
@@ -2387,7 +2389,7 @@ static int prev_unit(icalrecur_iterator *impl,
                      void (*increment_unit)(icalrecur_iterator *, int),
                      void (*increment_super_unit)(icalrecur_iterator *, int))
 {
-icalrecurrence_iterator_by_data *bydata = &impl->bydata[by_unit];
+    icalrecurrence_iterator_by_data *bydata = &impl->bydata[by_unit];
     int has_by_unit = (by_unit > ICAL_BYRULE_NO_CONTRACTION) &&
                       (bydata->by.size > 0);
     int this_frequency = (impl->rule->freq == frequency);