database: Allocate subnets list only once

This is a performance improvement when exporting networks flattened. For
the subnet search, we allocate an empty list many times which is often
not required.

This patch changes this behaviour that (if needed) the lists will be
allocated and will stay around and cleared if necessary.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

diff --git a/src/database.c b/src/database.c
index 8835507e7be4bdb3c9e7b654d84d8d63f70227d0..1b3484592e3c08c484c80f8d01db0217d616c1e9 100644 (file)
--- a/src/database.c
+++ b/src/database.c
@@ -125,6 +125,7 @@ struct loc_database_enumerator {
 
        // For subnet search and bogons
        struct loc_network_list* stack;
+       struct loc_network_list* subnets;
 
        // For bogons
        struct in6_addr gap6_start;
@@ -984,6 +985,9 @@ static void loc_database_enumerator_free(struct loc_database_enumerator* enumera
        if (enumerator->stack)
                loc_network_list_unref(enumerator->stack);
 
+       if (enumerator->subnets)
+               loc_network_list_unref(enumerator->subnets);
+
        free(enumerator);
 }
 
@@ -1301,12 +1305,13 @@ static int __loc_database_enumerator_next_network_flattened(
                return 0;
 
        struct loc_network* subnet = NULL;
-       struct loc_network_list* subnets;
 
        // Create a list with all subnets
-       r = loc_network_list_new(enumerator->ctx, &subnets);
-       if (r)
-               return r;
+       if (!enumerator->subnets) {
+               r = loc_network_list_new(enumerator->ctx, &enumerator->subnets);
+               if (r)
+                       return r;
+       }
 
        // Search all subnets from the database
        while (1) {
@@ -1314,7 +1319,7 @@ static int __loc_database_enumerator_next_network_flattened(
                r = __loc_database_enumerator_next_network(enumerator, &subnet, 0);
                if (r) {
                        loc_network_unref(subnet);
-                       loc_network_list_unref(subnets);
+                       loc_network_list_clear(enumerator->subnets);
 
                        return r;
                }
@@ -1325,10 +1330,10 @@ static int __loc_database_enumerator_next_network_flattened(
 
                // Collect all subnets in a list
                if (loc_network_is_subnet(*network, subnet)) {
-                       r = loc_network_list_push(subnets, subnet);
+                       r = loc_network_list_push(enumerator->subnets, subnet);
                        if (r) {
                                loc_network_unref(subnet);
-                               loc_network_list_unref(subnets);
+                               loc_network_list_clear(enumerator->subnets);
 
                                return r;
                        }
@@ -1341,7 +1346,7 @@ static int __loc_database_enumerator_next_network_flattened(
                r = loc_network_list_push(enumerator->stack, subnet);
                if (r) {
                        loc_network_unref(subnet);
-                       loc_network_list_unref(subnets);
+                       loc_network_list_clear(enumerator->subnets);
 
                        return r;
                }
@@ -1350,27 +1355,28 @@ static int __loc_database_enumerator_next_network_flattened(
                break;
        }
 
-       DEBUG(enumerator->ctx, "Found %zu subnet(s)\n", loc_network_list_size(subnets));
+       DEBUG(enumerator->ctx, "Found %zu subnet(s)\n",
+               loc_network_list_size(enumerator->subnets));
 
        // We can abort here if the network has no subnets
-       if (loc_network_list_empty(subnets)) {
-               loc_network_list_unref(subnets);
+       if (loc_network_list_empty(enumerator->subnets)) {
+               loc_network_list_clear(enumerator->subnets);
 
                return 0;
        }
 
        // If the network has any subnets, we will break it into smaller parts
        // without the subnets.
-       struct loc_network_list* excluded = loc_network_exclude_list(*network, subnets);
+       struct loc_network_list* excluded = loc_network_exclude_list(*network, enumerator->subnets);
        if (!excluded) {
-               loc_network_list_unref(subnets);
+               loc_network_list_clear(enumerator->subnets);
                return -1;
        }
 
        // Merge subnets onto the stack
-       r = loc_network_list_merge(enumerator->stack, subnets);
+       r = loc_network_list_merge(enumerator->stack, enumerator->subnets);
        if (r) {
-               loc_network_list_unref(subnets);
+               loc_network_list_clear(enumerator->subnets);
                loc_network_list_unref(excluded);
 
                return r;
@@ -1379,13 +1385,13 @@ static int __loc_database_enumerator_next_network_flattened(
        // Push excluded list onto the stack
        r = loc_network_list_merge(enumerator->stack, excluded);
        if (r) {
-               loc_network_list_unref(subnets);
+               loc_network_list_clear(enumerator->subnets);
                loc_network_list_unref(excluded);
 
                return r;
        }
 
-       loc_network_list_unref(subnets);
+       loc_network_list_clear(enumerator->subnets);
        loc_network_list_unref(excluded);
 
        // Drop the network and restart the whole process again to pick the next network