Add range_add_value and range_remove_value.

These APIs can insert or remove a single value into a range structure.
Adding a value may extend an existing range or create a new one.
Removing a value may remove a range item.

Change-Id: Ia6995ecf7760aca1fb7fd9b4c53972298a57675f
Reviewed-on: https://code.wireshark.org/review/17836
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>

debian/libwireshark0.symbols

@@ -1158,6 +1158,8 @@ libwireshark.so.0 libwireshark0 #MINVER#
  range_copy@Base 1.9.1
  range_empty@Base 1.9.1
  range_foreach@Base 1.9.1
+ range_add_value@Base 2.3.0
+ range_remove_value@Base 2.3.0
  ranges_are_equal@Base 1.9.1
  read_disabled_heur_dissector_list@Base 1.99.8
  read_disabled_protos_list@Base 1.12.0~rc1

epan/range.c

@@ -280,6 +280,99 @@ value_is_in_range(range_t *range, guint32 val)
    return(FALSE);
 }
 
+/* This function returns TRUE if val has successfully been added to
+ * a range.  This may extend an existing range or create a new one
+ */
+gboolean
+range_add_value(range_t **range, guint32 val)
+{
+   guint i;
+
+   if ((range) && (*range)) {
+      for (i=0; i < (*range)->nranges; i++) {
+         if (val >= (*range)->ranges[i].low && val <= (*range)->ranges[i].high)
+            return TRUE;
+
+         if (val == (*range)->ranges[i].low-1)
+         {
+             /* Sink to a new low */
+             (*range)->ranges[i].low = val;
+             return TRUE;
+         }
+
+         if (val == (*range)->ranges[i].high+1)
+         {
+             /* Reach a new high */
+             (*range)->ranges[i].high = val;
+             return TRUE;
+         }
+      }
+
+      (*range) = (range_t *)g_realloc((*range), RANGE_HDR_SIZE +
+                                ((*range)->nranges+1)*sizeof (range_admin_t));
+      (*range)->nranges++;
+      (*range)->ranges[i].low = (*range)->ranges[i].high = val;
+      return TRUE;
+   }
+   return(FALSE);
+}
+
+/* This function returns TRUE if val has successfully been removed from
+ * a range.  This may delete an existing range
+ */
+gboolean
+range_remove_value(range_t **range, guint32 val)
+{
+   guint i, j, new_j;
+   range_t *new_range;
+
+   if ((range) && (*range)) {
+      for (i=0; i < (*range)->nranges; i++) {
+
+          /* value is in the middle of the range, so it can't really be removed */
+         if (val > (*range)->ranges[i].low && val < (*range)->ranges[i].high)
+            return TRUE;
+
+         if ((val ==  (*range)->ranges[i].low) && (val == (*range)->ranges[i].high))
+         {
+             /* Remove the range item entirely */
+             new_range = (range_t*)g_malloc(RANGE_HDR_SIZE + ((*range)->nranges-1)*sizeof (range_admin_t));
+             new_range->nranges = (*range)->nranges-1;
+             for (j=0, new_j = 0; j < (*range)->nranges; j++) {
+
+                 /* Skip the current range */
+                 if (j == i)
+                     continue;
+
+                 new_range->ranges[new_j].low = (*range)->ranges[j].low;
+                 new_range->ranges[new_j].high = (*range)->ranges[j].high;
+                 new_j++;
+             }
+
+             g_free(*range);
+             *range = new_range;
+             return TRUE;
+         }
+
+         if (val == (*range)->ranges[i].low)
+         {
+             /* Raise low */
+             (*range)->ranges[i].low++;
+             return TRUE;
+         }
+
+         if (val == (*range)->ranges[i].high)
+         {
+             /* Reach a new high */
+             (*range)->ranges[i].high--;
+             return TRUE;
+         }
+      }
+      return TRUE;
+   }
+   return(FALSE);
+}
+
 /* This function returns TRUE if the two given range_t's are equal.
  */
 gboolean

epan/range.h

@@ -103,6 +103,22 @@ convert_ret_t range_convert_str_work(range_t **range, const gchar *es,
  */
 WS_DLL_PUBLIC gboolean value_is_in_range(range_t *range, guint32 val);
 
+/** This function returns TRUE if val has successfully been added to
+ * a range.  This may extend an existing range or create a new one
+ * @param range to add value
+ * @param val value to add to range
+ * @return TRUE if the value is successsfully added to range
+ */
+WS_DLL_PUBLIC gboolean range_add_value(range_t **range, guint32 val);
+
+/** This function returns TRUE if val has successfully been removed from
+ * a range.  This may remove an existing range.
+ * @param range to remove value
+ * @param val value to remove within range
+ * @return TRUE if the value is successsfully removed to range
+ */
+WS_DLL_PUBLIC gboolean range_remove_value(range_t **range, guint32 val);
+
 /** This function returns TRUE if the two given range_t's are equal.
  * @param a first range
  * @param b second range