[core] Allow disabling of stat cache through stat_cache.ttl 0;

src/main/plugin_core.c

@@ -201,7 +201,7 @@ static liHandlerResult core_handle_docroot(liVRequest *vr, gpointer param, gpoin
 	for (; i < arr->len; i++) {
 		struct stat st;
 		gint err;
-		
+
 
 		g_string_truncate(vr->physical.doc_root, 0);
 		li_pattern_eval(vr, vr->physical.doc_root, g_array_index(arr, liPattern*, i), core_docroot_nth_cb, vr->request.uri.host, li_pattern_regex_cb, match_info);
@@ -483,7 +483,7 @@ static void core_index_free(liServer *srv, gpointer param) {
 
 	UNUSED(srv);
 
-	for (i = 0; i < files->len; i++) 
+	for (i = 0; i < files->len; i++)
 		li_value_free(g_array_index(files, liValue*, i));
 
 	g_array_free(files, TRUE);
@@ -599,7 +599,7 @@ static liHandlerResult core_handle_static(liVRequest *vr, gpointer param, gpoint
 		if (CORE_OPTION(LI_CORE_OPTION_DEBUG_REQUEST_HANDLING).boolean) {
 			VR_DEBUG(vr, "not a regular file: '%s'", vr->physical.path->str);
 		}
-		
+
 		if (fd != -1)
 			close(fd);
 
@@ -979,7 +979,7 @@ static gboolean core_io_timeout(liServer *srv, liPlugin* p, liValue *val, gpoint
 static gboolean core_stat_cache_ttl(liServer *srv, liPlugin* p, liValue *val, gpointer userdata) {
 	UNUSED(p); UNUSED(userdata);
 
-	if (!val || val->type != LI_VALUE_NUMBER || val->data.number < 1) {
+	if (!val || val->type != LI_VALUE_NUMBER || val->data.number < 0) {
 		ERROR(srv, "%s", "stat_cache.ttl expects a positive number as parameter");
 		return FALSE;
 	}

src/main/server.c

@@ -178,6 +178,7 @@ liServer* li_server_new(const gchar *module_dir, gboolean module_resident) {
 
 	srv->io_timeout = 300; /* default I/O timeout */
 	srv->keep_alive_queue_timeout = 5;
+	srv->stat_cache_ttl = 10.0; /* default stat cache ttl */
 
 #ifdef LIGHTY_OS_LINUX
 	/* sched_getaffinity is only available on linux */

src/main/stat_cache.c

@@ -12,9 +12,13 @@ void li_stat_cache_new(liWorker *wrk, gdouble ttl) {
 	liStatCache *sc;
 	GError *err;
 
-	/* ttl default 10s */
-	if (ttl < 1)
+	if (ttl < 0) {
+		/* fall back to default if not sane */
 		ttl = 10.0;
+	} else if (ttl == 0) {
+		/* ttl means disabled stat cache */
+		return;
+	}
 
 	sc = g_slice_new0(liStatCache);
 	sc->ttl = ttl;
@@ -43,6 +47,10 @@ void li_stat_cache_free(liStatCache *sc) {
 	liStatCacheEntry *sce;
 	liWaitQueueElem *wqe;
 
+	/* check if stat cache was enabled */
+	if (!sc)
+		return;
+
 	/* wake up thread */
 	sce = g_slice_new0(liStatCacheEntry);
 	g_async_queue_push(sc->job_queue_out, sce);
@@ -296,43 +304,40 @@ static liHandlerResult stat_cache_get(liVRequest *vr, GString *path, struct stat
 	liStatCacheEntry *sce;
 	guint i;
 
-	if (NULL == vr) goto callstat;
-
-	sc = vr->wrk->stat_cache;
-	sce = g_hash_table_lookup(sc->entries, path);
+	/* force blocking call if we are not in a vrequest context or stat cache is disabled */
+	if (!vr || !(sc = vr->wrk->stat_cache))
+		async = FALSE;
 
-	if (sce) {
-		/* cache hit, check state */
-		if (g_atomic_int_get(&sce->state) == STAT_CACHE_ENTRY_WAITING) {
-			if (async) {
-				sce = NULL;
-				goto callstat;
-			}
+	if (async) {
+		sce = g_hash_table_lookup(sc->entries, path);
 
-			/* already waiting for it? */
-			for (i = 0; i < vr->stat_cache_entries->len; i++) {
-				if (g_ptr_array_index(vr->stat_cache_entries, i) == sce) {
-					return LI_HANDLER_WAIT_FOR_EVENT;
+		if (sce) {
+			/* cache hit, check state */
+			if (g_atomic_int_get(&sce->state) == STAT_CACHE_ENTRY_WAITING) {
+				/* already waiting for it? */
+				for (i = 0; i < vr->stat_cache_entries->len; i++) {
+					if (g_ptr_array_index(vr->stat_cache_entries, i) == sce) {
+						return LI_HANDLER_WAIT_FOR_EVENT;
+					}
 				}
+				li_stat_cache_entry_acquire(vr, sce);
+				return LI_HANDLER_WAIT_FOR_EVENT;
 			}
+
+			sc->hits++;
+		} else {
+			/* cache miss, allocate new entry */
+			sce = stat_cache_entry_new(path);
+			sce->type = STAT_CACHE_ENTRY_SINGLE;
 			li_stat_cache_entry_acquire(vr, sce);
+			li_waitqueue_push(&sc->delete_queue, &sce->queue_elem);
+			g_hash_table_insert(sc->entries, sce->data.path, sce);
+			g_async_queue_push(sc->job_queue_out, sce);
+			sc->misses++;
 			return LI_HANDLER_WAIT_FOR_EVENT;
 		}
-
-		sc->hits++;
-	} else if (async) {
-		/* cache miss, allocate new entry */
-		sce = stat_cache_entry_new(path);
-		sce->type = STAT_CACHE_ENTRY_SINGLE;
-		li_stat_cache_entry_acquire(vr, sce);
-		li_waitqueue_push(&sc->delete_queue, &sce->queue_elem);
-		g_hash_table_insert(sc->entries, sce->data.path, sce);
-		g_async_queue_push(sc->job_queue_out, sce);
-		sc->misses++;
-		return LI_HANDLER_WAIT_FOR_EVENT;
 	}
 
-callstat:
 	if (fd) {
 		/* open + fstat */
 		while (-1 == (*fd = open(path->str, O_RDONLY))) {

src/main/worker.c

@@ -455,8 +455,6 @@ liWorker* li_worker_new(liServer *srv, struct ev_loop *loop) {
 	ev_async_start(wrk->loop, &wrk->job_async_queue_watcher);
 	ev_unref(wrk->loop); /* this watcher shouldn't keep the loop alive */
 
-	li_stat_cache_new(wrk, srv->stat_cache_ttl);
-
 	wrk->network_read_buf = g_byte_array_sized_new(0);
 
 	return wrk;
@@ -558,6 +556,10 @@ void li_worker_run(liWorker *wrk) {
 		}
 	}
 
+	/* setup stat cache if necessary */
+	if (wrk->srv->stat_cache_ttl && !wrk->stat_cache)
+		li_stat_cache_new(wrk, wrk->srv->stat_cache_ttl);
+
 	ev_loop(wrk->loop, 0);
 }
 
@@ -572,7 +574,8 @@ void li_worker_stop(liWorker *context, liWorker *wrk) {
 		ev_async_stop(wrk->loop, &wrk->new_con_watcher);
 		li_waitqueue_stop(&wrk->io_timeout_queue);
 		li_waitqueue_stop(&wrk->throttle_queue);
-		li_waitqueue_stop(&wrk->stat_cache->delete_queue);
+		if (wrk->stat_cache)
+			li_waitqueue_stop(&wrk->stat_cache->delete_queue);
 		li_worker_new_con_cb(wrk->loop, &wrk->new_con_watcher, 0); /* handle remaining new connections */
 
 		/* close keep alive connections */
@@ -656,7 +659,7 @@ void li_worker_con_put(liConnection *con) {
 	guint threshold;
 	liWorker *wrk = con->wrk;
 	ev_tstamp now = CUR_TS(wrk);
-	
+
 	if (con->state == LI_CON_STATE_DEAD)
 		/* already disconnected */
 		return;