segtree: refactor decomposition of closed intervals

Move the code in `interval_map_decompose` which adds a new closed
interval to the set into a separate function.  In addition to the moving
of the code, there is one other change: `compound_expr_add` is called
once, after the main conditional, instead of being called in each
branch.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Florian Westphal <fw@strlen.de>

diff --git a/src/segtree.c b/src/segtree.c
index c36497ce62533616ba8368a3cf0b07a999cf73cb..d15c39f31f3a4c776bd12ab98bb43305dc79c192 100644 (file)
--- a/src/segtree.c
+++ b/src/segtree.c
@@ -493,12 +493,48 @@ static struct expr *interval_to_range(struct expr *low, struct expr *i, mpz_t ra
        return __expr_to_set_elem(low, tmp);
 }
 
+static void
+add_interval(struct expr *set, struct expr *low, struct expr *i)
+{
+       struct expr *expr;
+       mpz_t range, p;
+
+       mpz_init(range);
+       mpz_init(p);
+
+       mpz_sub(range, expr_value(i)->value, expr_value(low)->value);
+       mpz_sub_ui(range, range, 1);
+
+       mpz_and(p, expr_value(low)->value, range);
+
+       if (!mpz_cmp_ui(range, 0)) {
+               if (expr_basetype(low)->type == TYPE_STRING)
+                       mpz_switch_byteorder(expr_value(low)->value,
+                                            expr_value(low)->len / BITS_PER_BYTE);
+               low->flags |= EXPR_F_KERNEL;
+               expr = expr_get(low);
+       } else if (range_is_prefix(range) && !mpz_cmp_ui(p, 0)) {
+
+               if (i->dtype->flags & DTYPE_F_PREFIX)
+                       expr = interval_to_prefix(low, i, range);
+               else if (expr_basetype(i)->type == TYPE_STRING)
+                       expr = interval_to_string(low, i, range);
+               else
+                       expr = interval_to_range(low, i, range);
+       } else
+               expr = interval_to_range(low, i, range);
+
+       compound_expr_add(set, expr);
+
+       mpz_clear(range);
+       mpz_clear(p);
+}
+
 void interval_map_decompose(struct expr *set)
 {
        struct expr *i, *next, *low = NULL, *end, *catchall = NULL, *key;
        struct expr **elements, **ranges;
        unsigned int n, m, size;
-       mpz_t range, p;
        bool interval;
 
        if (set->size == 0)
@@ -507,9 +543,6 @@ void interval_map_decompose(struct expr *set)
        elements = xmalloc_array(set->size, sizeof(struct expr *));
        ranges = xmalloc_array(set->size * 2, sizeof(struct expr *));
 
-       mpz_init(range);
-       mpz_init(p);
-
        /* Sort elements */
        n = 0;
        list_for_each_entry_safe(i, next, &set->expressions, list) {
@@ -568,32 +601,7 @@ void interval_map_decompose(struct expr *set)
                        }
                }
 
-               mpz_sub(range, expr_value(i)->value, expr_value(low)->value);
-               mpz_sub_ui(range, range, 1);
-
-               mpz_and(p, expr_value(low)->value, range);
-
-               if (!mpz_cmp_ui(range, 0)) {
-                       if (expr_basetype(low)->type == TYPE_STRING)
-                               mpz_switch_byteorder(expr_value(low)->value, expr_value(low)->len / BITS_PER_BYTE);
-                       low->flags |= EXPR_F_KERNEL;
-                       compound_expr_add(set, expr_get(low));
-               } else if (range_is_prefix(range) && !mpz_cmp_ui(p, 0)) {
-                       struct expr *expr;
-
-                       if (i->dtype->flags & DTYPE_F_PREFIX)
-                               expr = interval_to_prefix(low, i, range);
-                       else if (expr_basetype(i)->type == TYPE_STRING)
-                               expr = interval_to_string(low, i, range);
-                       else
-                               expr = interval_to_range(low, i, range);
-
-                       compound_expr_add(set, expr);
-               } else {
-                       struct expr *expr = interval_to_range(low, i, range);
-
-                       compound_expr_add(set, expr);
-               }
+               add_interval(set, low, i);
 
                if (i->flags & EXPR_F_INTERVAL_END) {
                        expr_free(low);
@@ -633,9 +641,6 @@ out:
        if (catchall)
                compound_expr_add(set, catchall);
 
-       mpz_clear(range);
-       mpz_clear(p);
-
        xfree(ranges);
        xfree(elements);
 }