vtysh: Speed up output of configuration across daemons

With a config that contains a large number of prefix-lists a 'show run' command
was an expensive operation:

sharpd@eva ~/frr_internal2 ((cl4.1.0))> time vtysh -c "show run" | grep ACTIVE | wc -l
32397
________________________________________________________
Executed in   14.53 secs   fish           external
   usr time   14.45 secs  591.00 micros   14.45 secs
   sys time    0.03 secs  189.00 micros    0.03 secs
sharpd@eva ~/frr_internal2 ((cl4.1.0))>

Effectively we are keeping a linked list of data to store the configuration.
When we received a new item we would look in the list to see if it already
does, by doing a string search across each element in the list.

Add to the master configuration a hash of items for O(1) lookup.
Keep the list for order so we don't mangle that up.

New time:
sharpd@eva ~/frr_internal1 (dev)> time vtysh -c "show run" | grep ACTIVE | wc -l
32397
________________________________________________________
Executed in  277.94 millis    fish           external
   usr time  237.46 millis   20.53 millis  216.93 millis
   sys time   14.31 millis    0.00 millis   14.31 millis

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

diff --git a/vtysh/vtysh_config.c b/vtysh/vtysh_config.c
index 61bcf3b658d06fe870701129ac73e3b9d1e514d0..85221b8b4522f62c98d33fa90e9242831efba69d 100644 (file)
--- a/vtysh/vtysh_config.c
+++ b/vtysh/vtysh_config.c
@@ -35,6 +35,7 @@ DEFINE_MTYPE_STATIC(MVTYSH, VTYSH_CONFIG_LINE, "Vtysh configuration line")
 vector configvec;
 
 PREDECL_LIST(config_master);
+PREDECL_HASH(config_master_hash);
 
 struct config {
        /* Configuration node name. */
@@ -51,6 +52,7 @@ struct config {
 
        /* Node entry for the typed Red-black tree */
        struct config_master_item rbt_item;
+       struct config_master_hash_item hash_item;
 };
 
 struct list *config_top;
@@ -79,29 +81,49 @@ static void config_del(struct config *config)
        XFREE(MTYPE_VTYSH_CONFIG, config);
 }
 
+static int config_cmp(const struct config *c1, const struct config *c2)
+{
+       return strcmp(c1->name, c2->name);
+}
+
+static uint32_t config_hash(const struct config *c)
+{
+       return string_hash_make(c->name);
+}
+
 DECLARE_LIST(config_master, struct config, rbt_item)
+DECLARE_HASH(config_master_hash, struct config, hash_item, config_cmp,
+            config_hash)
+
+/*
+ * The config_master_head is a list for order of receipt
+ * The hash is for quick lookup under this NODE
+ */
+struct configuration {
+       struct config_master_head master;
+       struct config_master_hash_head hash_master;
+};
 
 static struct config *config_get(int index, const char *line)
 {
        struct config *config, *config_loop;
-       struct config_master_head *master;
+       struct configuration *configuration;
+       struct config lookup;
 
        config = config_loop = NULL;
 
-       master = vector_lookup_ensure(configvec, index);
+       configuration = vector_lookup_ensure(configvec, index);
 
-       if (!master) {
-               master = XMALLOC(MTYPE_VTYSH_CONFIG, sizeof(struct config_master_head));
-               config_master_init(master);
-               vector_set_index(configvec, index, master);
+       if (!configuration) {
+               configuration = XMALLOC(MTYPE_VTYSH_CONFIG,
+                                       sizeof(struct configuration));
+               config_master_init(&configuration->master);
+               config_master_hash_init(&configuration->hash_master);
+               vector_set_index(configvec, index, configuration);
        }
 
-       frr_each (config_master, master, config_loop) {
-               if (strcmp(config_loop->name, line) == 0) {
-                       config = config_loop;
-                       break;
-               }
-       }
+       lookup.name = (char *)line;
+       config = config_master_hash_find(&configuration->hash_master, &lookup);
 
        if (!config) {
                config = config_new();
@@ -110,7 +132,8 @@ static struct config *config_get(int index, const char *line)
                config->line->cmp = (int (*)(void *, void *))line_cmp;
                config->name = XSTRDUP(MTYPE_VTYSH_CONFIG_LINE, line);
                config->index = index;
-               config_master_add_tail(master, config);
+               config_master_add_tail(&configuration->master, config);
+               config_master_hash_add(&configuration->hash_master, config);
        }
        return config;
 }
@@ -438,7 +461,7 @@ void vtysh_config_dump(void)
        struct listnode *node, *nnode;
        struct listnode *mnode, *mnnode;
        struct config *config;
-       struct config_master_head *master;
+       struct configuration *configuration;
        char *line;
        unsigned int i;
 
@@ -448,8 +471,11 @@ void vtysh_config_dump(void)
        vty_out(vty, "!\n");
 
        for (i = 0; i < vector_active(configvec); i++)
-               if ((master = vector_slot(configvec, i)) != NULL) {
-                       while ((config = config_master_pop(master))) {
+               if ((configuration = vector_slot(configvec, i)) != NULL) {
+                       while ((config = config_master_pop(
+                                       &configuration->master))) {
+                               config_master_hash_del(
+                                       &configuration->hash_master, config);
                                /* Don't print empty sections for interface.
                                 * Route maps on the
                                 * other hand could have a legitimate empty
@@ -477,9 +503,10 @@ void vtysh_config_dump(void)
                }
 
        for (i = 0; i < vector_active(configvec); i++)
-               if ((master = vector_slot(configvec, i)) != NULL) {
-                       config_master_fini(master);
-                       XFREE(MTYPE_VTYSH_CONFIG, master);
+               if ((configuration = vector_slot(configvec, i)) != NULL) {
+                       config_master_fini(&configuration->master);
+                       config_master_hash_fini(&configuration->hash_master);
+                       XFREE(MTYPE_VTYSH_CONFIG, configuration);
                        vector_slot(configvec, i) = NULL;
                }
        list_delete_all_node(config_top);