Add dbiIndexSetFilter and dbiIndexSetFilterSet methods

They will be used to resolve "with" rich dependencies.

lib/backend/dbiset.c

@@ -152,6 +152,39 @@ int dbiIndexSetPruneSet(dbiIndexSet set, dbiIndexSet oset, int sortset)
     return dbiIndexSetPrune(set, oset->recs, oset->count, sortset);
 }
 
+int dbiIndexSetFilter(dbiIndexSet set, dbiIndexItem recs,
+                        unsigned int nrecs, int sorted)
+{
+    unsigned int from;
+    unsigned int to = 0;
+    unsigned int num = set->count;
+    unsigned int numCopied = 0;
+    size_t recsize = sizeof(*recs);
+
+    if (num == 0 || nrecs == 0) {
+	set->count = 0;
+	return num ? 0 : 1;
+    }
+    if (nrecs > 1 && !sorted)
+	qsort(recs, nrecs, recsize, hdrNumCmp);
+    for (from = 0; from < num; from++) {
+	if (!bsearch(&set->recs[from], recs, nrecs, recsize, hdrNumCmp)) {
+	    set->count--;
+	    continue;
+	}
+	if (from != to)
+	    set->recs[to] = set->recs[from]; /* structure assignment */
+	to++;
+	numCopied++;
+    }
+    return (numCopied == num);
+}
+
+int dbiIndexSetFilterSet(dbiIndexSet set, dbiIndexSet oset, int sorted)
+{
+    return dbiIndexSetFilter(set, oset->recs, oset->count, sorted);
+}
+
 unsigned int dbiIndexSetCount(dbiIndexSet set)
 {
     return (set != NULL) ? set->count : 0;

lib/backend/dbiset.h

@@ -86,6 +86,28 @@ int dbiIndexSetPrune(dbiIndexSet set, dbiIndexItem recs,
 RPM_GNUC_INTERNAL
 int dbiIndexSetPruneSet(dbiIndexSet set, dbiIndexSet oset, int sorted);
 
+/**
+ * Filter element(s) from set of index database items.
+ * @param set          set of index database items
+ * @param recs         array of items to remove from set
+ * @param nrecs                number of items
+ * @param sorted       recs array is already sorted?
+ * @return             0 success, 1 failure (no items removed)
+ */
+RPM_GNUC_INTERNAL
+int dbiIndexSetFilter(dbiIndexSet set, dbiIndexItem recs,
+		      unsigned int nrecs, int sorted);
+
+/**
+ * Filter (intersect) an index set with another.
+ * @param set          set of index database items
+ * @param oset         set of entries that should be intersected
+ * @param sorted       oset is already sorted?
+ * @return             0 success, 1 failure (no items removed)
+ */
+RPM_GNUC_INTERNAL
+int dbiIndexSetFilterSet(dbiIndexSet set, dbiIndexSet oset, int sorted);
+
 /* Count items in index database set. */
 RPM_GNUC_INTERNAL
 unsigned int dbiIndexSetCount(dbiIndexSet set);