/**
* Pickup a cache randomly from the known set. If there's no URL used that
* has not been used recently, NULL will be returned. The timestamp for
* the picked URL is updated automatically.
*
* Try to avoid using default bootstrapping URLs if we have more than the
* minimum set of caches in stock...
*
* @return a GWebCache URL or NULL on failure.
*/
static const char *
gwc_pick(void)
{
int count = hset_count(gwc_known_url);
int idx, i;
const char *url = NULL;
time_t now = tm_time();
if (0 == count)
return NULL;
g_assert(count > 0);
g_assert(count <= MAX_GWC_URLS);
g_assert(count == MAX_GWC_URLS || gwc_url_slot < count);
idx = random_value(count - 1);
for (i = 0; i < count; i++) {
time_t stamp = gwc_url[idx].stamp;
if (0 == stamp || delta_time(now, stamp) > 3900) {
url = gwc_url[idx].url;
gwc_url[idx].stamp = now;
break;
}
}
if (GNET_PROPERTY(bootstrap_debug) && url)
g_message("GWC picked webcache \"%s\"", url);
return url;
}
/**
* Clear all results from search.
*/
void
search_gui_clear_search(search_t *search)
{
g_assert(search);
g_assert(search->dups);
search_gui_clear_tree(search);
search_gui_clear_queue(search);
g_assert(0 == hset_count(search->dups));
g_assert(0 == htable_count(search->parents));
}
/**
* Initialize web cache.
*/
void
gwc_init(void)
{
uint i;
gwc_known_url = hset_create(HASH_KEY_STRING, 0);
gwc_failed_url = hset_create(HASH_KEY_STRING, 0);
gwc_retrieve();
if (0 == hset_count(gwc_known_url)) {
for (i = 0; i < N_ITEMS(boot_url) && boot_url[i]; i++)
gwc_add(boot_url[i]);
}
}
/**
* Removes the URL from the set of known URL, but do not free its memory
* and keeps it in the set of failed URLs for the session.
*/
static void
gwc_forget_url(const char *url)
{
struct gwc url_tmp[MAX_GWC_URLS]; /* Temporary copy */
int count = hset_count(gwc_known_url);
int i;
int j = 0;
g_assert(count > 0);
g_assert(count <= MAX_GWC_URLS);
g_assert(count == MAX_GWC_URLS || gwc_url_slot < count);
g_assert(gwc_url_slot >= 0);
STATIC_ASSERT(sizeof(url_tmp) == sizeof(gwc_url));
if (GNET_PROPERTY(bootstrap_debug))
g_warning("forgetting GWC URL \"%s\"", url);
/*
* It is possible that the URL we're trying to forget was
* already removed from the cache if it was at a slot overridden
* in the round-robin buffer, should we have got new GWC URL since
* it was selected.
*/
if (hset_contains(gwc_known_url, url))
hset_remove(gwc_known_url, url);
else {
if (GNET_PROPERTY(bootstrap_debug))
g_warning("URL was already gone from GWC");
return;
}
hset_insert(gwc_failed_url, url);
/*
* Because we have a round-robin buffer, removing something in the
* middle of the buffer is not straightforward. The `gwc_url_slot'
* variable points to the last filled value in the buffer.
*
* We're going to build a copy in url_tmp[], filled from 0 to "count - 1",
* and we'll move back that copy into the regular gwc_url[] cache.
* The reason is that since there will be less entries in the cache
* than the maximum amount, the round-robin buffer must be linearily
* filled from 0 and upwards.
*/
memset(url_tmp, 0, sizeof(url_tmp));
if (count == MAX_GWC_URLS) { /* Buffer was full */
for (i = gwc_url_slot;;) {
if (gwc_url[i].url != url) /* Atoms: we can compare addresses */
url_tmp[j++] = gwc_url[i];
i++;
if (i == MAX_GWC_URLS)
i = 0;
if (i == gwc_url_slot) /* Back to where we started */
break;
}
} else { /* Buffer was partially filled */
for (i = 0; i <= gwc_url_slot; i++) {
if (gwc_url[i].url != url) /* Atoms: we can compare addresses */
url_tmp[j++] = gwc_url[i];
}
}
count--; /* New amount of data in cache */
gwc_url_slot = j - 1; /* Last position we filled */
gwc_url_slot = MAX(0, gwc_url_slot); /* If we removed ALL entries */
g_assert(gwc_url_slot == MAX(0, count - 1));
memcpy(gwc_url, url_tmp, sizeof(gwc_url));
g_assert(gwc_url_slot >= 0 && gwc_url_slot < MAX_GWC_URLS);
gwc_file_dirty = TRUE;
}
