--- /dev/null
+#include <string.h>
+
+#include "util.h"
+#include "cache.h"
+
+static void remove_entry(AvahiCache *c, AvahiCacheEntry *e) {
+ AvahiCacheEntry *t;
+
+ g_assert(c);
+ g_assert(e);
+
+/* g_message("removing from cache: %p %p", c, e); */
+
+ /* Remove from hash table */
+ t = g_hash_table_lookup(c->hash_table, e->record->key);
+ AVAHI_LLIST_REMOVE(AvahiCacheEntry, by_key, t, e);
+ if (t)
+ g_hash_table_replace(c->hash_table, t->record->key, t);
+ else
+ g_hash_table_remove(c->hash_table, e->record->key);
+
+ /* Remove from linked list */
+ AVAHI_LLIST_REMOVE(AvahiCacheEntry, entry, c->entries, e);
+
+ if (e->time_event)
+ avahi_time_event_queue_remove(c->server->time_event_queue, e->time_event);
+
+ avahi_subscription_notify(c->server, c->interface, e->record, AVAHI_SUBSCRIPTION_REMOVE);
+
+ avahi_record_unref(e->record);
+
+ g_free(e);
+}
+
+AvahiCache *avahi_cache_new(AvahiServer *server, AvahiInterface *iface) {
+ AvahiCache *c;
+ g_assert(server);
+
+ c = g_new(AvahiCache, 1);
+ c->server = server;
+ c->interface = iface;
+ c->hash_table = g_hash_table_new((GHashFunc) avahi_key_hash, (GEqualFunc) avahi_key_equal);
+
+ AVAHI_LLIST_HEAD_INIT(AvahiCacheEntry, c->entries);
+
+ return c;
+}
+
+void avahi_cache_free(AvahiCache *c) {
+ g_assert(c);
+
+ while (c->entries)
+ remove_entry(c, c->entries);
+
+ g_hash_table_destroy(c->hash_table);
+
+ g_free(c);
+}
+
+AvahiCacheEntry *avahi_cache_lookup_key(AvahiCache *c, AvahiKey *k) {
+ g_assert(c);
+ g_assert(k);
+
+ g_assert(!avahi_key_is_pattern(k));
+
+ return g_hash_table_lookup(c->hash_table, k);
+}
+
+gpointer avahi_cache_walk(AvahiCache *c, AvahiKey *pattern, AvahiCacheWalkCallback cb, gpointer userdata) {
+ gpointer ret;
+
+ g_assert(c);
+ g_assert(pattern);
+ g_assert(cb);
+
+ if (avahi_key_is_pattern(pattern)) {
+ AvahiCacheEntry *e, *n;
+
+ for (e = c->entries; e; e = n) {
+ n = e->entry_next;
+
+ if (avahi_key_pattern_match(pattern, e->record->key))
+ if ((ret = cb(c, pattern, e, userdata)))
+ return ret;
+ }
+
+ } else {
+ AvahiCacheEntry *e, *n;
+
+ for (e = avahi_cache_lookup_key(c, pattern); e; e = n) {
+ n = e->by_key_next;
+
+ if ((ret = cb(c, pattern, e, userdata)))
+ return ret;
+ }
+ }
+
+ return NULL;
+}
+
+static gpointer lookup_record_callback(AvahiCache *c, AvahiKey *pattern, AvahiCacheEntry *e, void *userdata) {
+ g_assert(c);
+ g_assert(pattern);
+ g_assert(e);
+
+ if (avahi_record_equal_no_ttl(e->record, userdata))
+ return e;
+
+ return NULL;
+}
+
+AvahiCacheEntry *avahi_cache_lookup_record(AvahiCache *c, AvahiRecord *r) {
+ AvahiCacheEntry *e;
+
+ g_assert(c);
+ g_assert(r);
+
+ return avahi_cache_walk(c, r->key, lookup_record_callback, r);
+}
+
+static void next_expiry(AvahiCache *c, AvahiCacheEntry *e, guint percent);
+
+static void elapse_func(AvahiTimeEvent *t, void *userdata) {
+ AvahiCacheEntry *e = userdata;
+
+ g_assert(t);
+ g_assert(e);
+
+ if (e->state == AVAHI_CACHE_FINAL) {
+ remove_entry(e->cache, e);
+ g_message("Removing entry from cache due to expiration");
+ } else {
+ guint percent = 0;
+
+ switch (e->state) {
+ case AVAHI_CACHE_VALID:
+ e->state = AVAHI_CACHE_EXPIRY1;
+ percent = 85;
+ break;
+
+ case AVAHI_CACHE_EXPIRY1:
+ e->state = AVAHI_CACHE_EXPIRY2;
+ percent = 90;
+ break;
+ case AVAHI_CACHE_EXPIRY2:
+ e->state = AVAHI_CACHE_EXPIRY3;
+ percent = 95;
+ break;
+
+ case AVAHI_CACHE_EXPIRY3:
+ e->state = AVAHI_CACHE_FINAL;
+ percent = 100;
+ break;
+
+ default:
+ ;
+ }
+
+ g_assert(percent > 0);
+
+ g_message("Requesting cache entry update at %i%%.", percent);
+
+ /* Request a cache update, if we are subscribed to this entry */
+ if (avahi_is_subscribed(e->cache->server, e->record->key))
+ avahi_interface_post_query(e->cache->interface, e->record->key, TRUE);
+
+ /* Check again later */
+ next_expiry(e->cache, e, percent);
+ }
+}
+
+static void update_time_event(AvahiCache *c, AvahiCacheEntry *e) {
+ g_assert(c);
+ g_assert(e);
+
+ if (e->time_event)
+ avahi_time_event_queue_update(c->server->time_event_queue, e->time_event, &e->expiry);
+ else
+ e->time_event = avahi_time_event_queue_add(c->server->time_event_queue, &e->expiry, elapse_func, e);
+}
+
+static void next_expiry(AvahiCache *c, AvahiCacheEntry *e, guint percent) {
+ gulong usec;
+
+ g_assert(c);
+ g_assert(e);
+ g_assert(percent > 0 && percent <= 100);
+
+ e->expiry = e->timestamp;
+
+ usec = e->record->ttl * 10000;
+
+ /* 2% jitter */
+ usec = g_random_int_range(usec*percent, usec*(percent+2));
+
+ g_time_val_add(&e->expiry, usec);
+ update_time_event(c, e);
+}
+
+void avahi_cache_update(AvahiCache *c, AvahiRecord *r, gboolean unique, const AvahiAddress *a) {
+ AvahiCacheEntry *e, *t;
+ gchar *txt;
+
+ g_assert(c);
+ g_assert(r && r->ref >= 1);
+
+ g_message("cache update: %s", (txt = avahi_record_to_string(r)));
+ g_free(txt);
+
+ if (r->ttl == 0) {
+
+ /* This is a goodbye request */
+
+ if ((e = avahi_cache_lookup_record(c, r))) {
+
+ e->state = AVAHI_CACHE_FINAL;
+ g_get_current_time(&e->timestamp);
+ e->expiry = e->timestamp;
+ g_time_val_add(&e->expiry, 1000000); /* 1s */
+ update_time_event(c, e);
+ }
+
+ } else {
+
+ /* This is an update request */
+
+ if ((t = e = avahi_cache_lookup_key(c, r->key))) {
+
+ if (unique) {
+
+ /* For unique records, remove all entries but one */
+ while (e->by_key_next)
+ remove_entry(c, e->by_key_next);
+
+ } else {
+
+ /* For non-unique record, look for exactly the same entry */
+ for (; e; e = e->by_key_next)
+ if (avahi_record_equal_no_ttl(e->record, r))
+ break;
+ }
+ }
+
+ if (e) {
+
+/* g_message("found matching cache entry"); */
+
+ /* We are the first in the linked list so let's replace the hash table key with the new one */
+ if (e->by_key_prev == NULL)
+ g_hash_table_replace(c->hash_table, r->key, e);
+
+ /* Notify subscribers */
+ if (!avahi_record_equal_no_ttl(e->record, r))
+ avahi_subscription_notify(c->server, c->interface, r, AVAHI_SUBSCRIPTION_CHANGE);
+
+ /* Update the record */
+ avahi_record_unref(e->record);
+ e->record = avahi_record_ref(r);
+
+ } else {
+ /* No entry found, therefore we create a new one */
+
+/* g_message("couldn't find matching cache entry"); */
+
+ e = g_new(AvahiCacheEntry, 1);
+ e->cache = c;
+ e->time_event = NULL;
+ e->record = avahi_record_ref(r);
+
+ /* Append to hash table */
+ AVAHI_LLIST_PREPEND(AvahiCacheEntry, by_key, t, e);
+ g_hash_table_replace(c->hash_table, e->record->key, t);
+
+ /* Append to linked list */
+ AVAHI_LLIST_PREPEND(AvahiCacheEntry, entry, c->entries, e);
+
+ /* Notify subscribers */
+ avahi_subscription_notify(c->server, c->interface, e->record, AVAHI_SUBSCRIPTION_NEW);
+ }
+
+ e->origin = *a;
+ g_get_current_time(&e->timestamp);
+ next_expiry(c, e, 80);
+ e->state = AVAHI_CACHE_VALID;
+ }
+}
+
+static gpointer drop_key_callback(AvahiCache *c, AvahiKey *pattern, AvahiCacheEntry *e, gpointer userdata) {
+ g_assert(c);
+ g_assert(pattern);
+ g_assert(e);
+
+ remove_entry(c, e);
+ return NULL;
+}
+
+void avahi_cache_drop_key(AvahiCache *c, AvahiKey *k) {
+ g_assert(c);
+ g_assert(k);
+
+ avahi_cache_walk(c, k, drop_key_callback, NULL);
+}
+
+void avahi_cache_drop_record(AvahiCache *c, AvahiRecord *r) {
+ AvahiCacheEntry *e;
+
+ g_assert(c);
+ g_assert(r);
+
+ if ((e = avahi_cache_lookup_record(c, r)))
+ remove_entry(c, e);
+}
+
+static void func(gpointer key, gpointer data, gpointer userdata) {
+ AvahiCacheEntry *e = data;
+ AvahiKey *k = key;
+ gchar *t;
+
+ t = avahi_record_to_string(e->record);
+ fprintf((FILE*) userdata, "%s\n", t);
+ g_free(t);
+}
+
+void avahi_cache_dump(AvahiCache *c, FILE *f) {
+ g_assert(c);
+ g_assert(f);
+
+ fprintf(f, ";;; CACHE DUMP FOLLOWS ;;;\n");
+ g_hash_table_foreach(c->hash_table, func, f);
+}
+
+gboolean avahi_cache_entry_half_ttl(AvahiCache *c, AvahiCacheEntry *e) {
+ GTimeVal now;
+ guint age;
+
+ g_assert(c);
+ g_assert(e);
+
+ g_get_current_time(&now);
+
+ age = avahi_timeval_diff(&now, &e->timestamp)/1000000;
+
+ g_message("age: %u, ttl/2: %u", age, e->record->ttl);
+
+ return age >= e->record->ttl/2;
+}
projects / catta / blobdiff