X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=src%2Fplugin.c;h=6272581f7bc5ef476c4b424decd8753230bca38f;hb=bc7992ed0693313a2b1fe282a5bf23f1cc9f8e42;hp=e991c78dfa2704c6908ccbb03abddf48ad096c64;hpb=4ff510ffa41e47f31c695c83f045fd79efecf5f4;p=collectd.git

diff --git a/src/plugin.c b/src/plugin.c
index e991c78d..cd7b1083 100644
--- a/src/plugin.c
+++ b/src/plugin.c
@@ -1,11 +1,10 @@
 /**
  * collectd - src/plugin.c
- * Copyright (C) 2005  Florian octo Forster
+ * Copyright (C) 2005-2009  Florian octo Forster
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2 of the License, or (at your
- * option) any later version.
+ * Free Software Foundation; only version 2 of the License is applicable.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -18,32 +17,68 @@
  *
  * Authors:
  *   Florian octo Forster <octo at verplant.org>
+ *   Sebastian Harl <sh at tokkee.org>
  **/
 
 #include "collectd.h"
+#include "utils_complain.h"
 
 #include <ltdl.h>
 
+#if HAVE_PTHREAD_H
+# include <pthread.h>
+#endif
+
+#include "common.h"
 #include "plugin.h"
-#include "network.h"
-#include "utils_debug.h"
+#include "configfile.h"
+#include "utils_avltree.h"
+#include "utils_llist.h"
+#include "utils_cache.h"
+#include "utils_threshold.h"
+#include "filter_chain.h"
 
-typedef struct plugin
+/*
+ * Private structures
+ */
+struct read_func_s
 {
-	char *type;
-	void (*init) (void);
-	void (*read) (void);
-	void (*write) (char *host, char *inst, char *val);
-	struct plugin *next;
-} plugin_t;
+	int wait_time;
+	int wait_left;
+	int (*callback) (void);
+	enum { DONE = 0, TODO = 1, ACTIVE = 2 } needs_read;
+};
+typedef struct read_func_s read_func_t;
+
+/*
+ * Private variables
+ */
+static llist_t *list_init;
+static llist_t *list_read;
+static llist_t *list_write;
+static llist_t *list_filter;
+static llist_t *list_flush;
+static llist_t *list_shutdown;
+static llist_t *list_log;
+static llist_t *list_notification;
 
-static plugin_t *first_plugin = NULL;
+static fc_chain_t *pre_cache_chain = NULL;
+static fc_chain_t *post_cache_chain = NULL;
 
-extern int operating_mode;
+static c_avl_tree_t *data_sets;
 
 static char *plugindir = NULL;
 
-char *plugin_get_dir (void)
+static int             read_loop = 1;
+static pthread_mutex_t read_lock = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t  read_cond = PTHREAD_COND_INITIALIZER;
+static pthread_t      *read_threads = NULL;
+static int             read_threads_num = 0;
+
+/*
+ * Static functions
+ */
+static const char *plugin_get_dir (void)
 {
 	if (plugindir == NULL)
 		return (PLUGINDIR);
@@ -51,71 +86,66 @@ char *plugin_get_dir (void)
 		return (plugindir);
 }
 
-void plugin_set_dir (const char *dir)
+static int register_callback (llist_t **list, const char *name, void *callback)
 {
-	if (plugindir != NULL)
-		free (plugindir);
+	llentry_t *le;
+	char *key;
 
-	if (dir == NULL)
-		plugindir = NULL;
-	else if ((plugindir = strdup (dir)) == NULL)
-		syslog (LOG_ERR, "strdup: %s", strerror (errno));
-}
+	if ((*list == NULL)
+			&& ((*list = llist_create ()) == NULL))
+		return (-1);
 
-/*
- * Returns the number of plugins registered
- */
-int plugin_count (void)
-{
-	int i;
-	plugin_t *p;
+	le = llist_search (*list, name);
+	if (le == NULL)
+	{
+		key = strdup (name);
+		if (key == NULL)
+			return (-1);
 
-	for (i = 0, p = first_plugin; p != NULL; p = p->next)
-		i++;
+		le = llentry_create (key, callback);
+		if (le == NULL)
+		{
+			free (key);
+			return (-1);
+		}
 
-	return (i);
-}
+		llist_append (*list, le);
+	}
+	else
+	{
+		le->value = callback;
+	}
 
-/*
- * Returns the plugins with the type `type' or NULL if it's not found.
- */
-plugin_t *plugin_search (const char *type)
+	return (0);
+} /* int register_callback */
+
+static int plugin_unregister (llist_t *list, const char *name)
 {
-	plugin_t *ret;
+	llentry_t *e;
 
-	if (type == NULL)
-		return (NULL);
+	e = llist_search (list, name);
 
-	for (ret = first_plugin; ret != NULL; ret = ret->next)
-		if (strcmp (ret->type, type) == 0)
-			break;
+	if (e == NULL)
+		return (-1);
 
-	return (ret);
-}
+	llist_remove (list, e);
+	free (e->key);
+	llentry_destroy (e);
 
-/*
- * Returns true if the plugin is loaded (i.e. `exists') and false otherwise.
- * This is used in `configfile.c' to skip sections that are not needed..
- */
-int plugin_exists (char *type)
-{
-	if (plugin_search (type) == NULL)
-		return (0);
-	else
-		return (1);
-}
+	return (0);
+} /* int plugin_unregister */
 
 /*
  * (Try to) load the shared object `file'. Won't complain if it isn't a shared
  * object, but it will bitch about a shared object not having a
  * ``module_register'' symbol..
  */
-int plugin_load_file (char *file)
+static int plugin_load_file (char *file)
 {
 	lt_dlhandle dlh;
 	void (*reg_handle) (void);
 
-	DBG ("file = %s", file);
+	DEBUG ("file = %s", file);
 
 	lt_dlinit ();
 	lt_dlerror (); /* clear errors */
@@ -124,14 +154,14 @@ int plugin_load_file (char *file)
 	{
 		const char *error = lt_dlerror ();
 
-		syslog (LOG_ERR, "lt_dlopen failed: %s", error);
-		DBG ("lt_dlopen failed: %s", error);
+		ERROR ("lt_dlopen (%s) failed: %s", file, error);
+		fprintf (stderr, "lt_dlopen (%s) failed: %s\n", file, error);
 		return (1);
 	}
 
-	if ((reg_handle = lt_dlsym (dlh, "module_register")) == NULL)
+	if ((reg_handle = (void (*) (void)) lt_dlsym (dlh, "module_register")) == NULL)
 	{
-		syslog (LOG_WARNING, "Couldn't find symbol ``module_register'' in ``%s'': %s\n",
+		WARNING ("Couldn't find symbol `module_register' in `%s': %s\n",
 				file, lt_dlerror ());
 		lt_dlclose (dlh);
 		return (-1);
@@ -142,39 +172,184 @@ int plugin_load_file (char *file)
 	return (0);
 }
 
+static void *plugin_read_thread (void *args)
+{
+	llentry_t   *le;
+	read_func_t *rf;
+	int          status;
+	int          done;
+
+	pthread_mutex_lock (&read_lock);
+
+	while (read_loop != 0)
+	{
+		le = llist_head (list_read);
+		done = 0;
+
+		while ((read_loop != 0) && (le != NULL))
+		{
+			rf = (read_func_t *) le->value;
+
+			if (rf->needs_read != TODO)
+			{
+				le = le->next;
+				continue;
+			}
+
+			/* We will do this read function */
+			rf->needs_read = ACTIVE;
+
+			DEBUG ("[thread #%5lu] plugin: plugin_read_thread: Handling %s",
+					(unsigned long int) pthread_self (), le->key);
+			pthread_mutex_unlock (&read_lock);
+
+			status = rf->callback ();
+			done++;
+
+			if (status != 0)
+			{
+				if (rf->wait_time < interval_g)
+					rf->wait_time = interval_g;
+				rf->wait_left = rf->wait_time;
+				rf->wait_time = rf->wait_time * 2;
+				if (rf->wait_time > 86400)
+					rf->wait_time = 86400;
+
+				NOTICE ("read-function of plugin `%s' "
+						"failed. Will suspend it for %i "
+						"seconds.", le->key, rf->wait_left);
+			}
+			else
+			{
+				rf->wait_left = 0;
+				rf->wait_time = interval_g;
+			}
+
+			pthread_mutex_lock (&read_lock);
+
+			rf->needs_read = DONE;
+			le = le->next;
+		} /* while (le != NULL) */
+
+		if ((read_loop != 0) && (done == 0))
+		{
+			DEBUG ("[thread #%5lu] plugin: plugin_read_thread: Waiting on read_cond.",
+					(unsigned long int) pthread_self ());
+			pthread_cond_wait (&read_cond, &read_lock);
+		}
+	} /* while (read_loop) */
+
+	pthread_mutex_unlock (&read_lock);
+
+	pthread_exit (NULL);
+	return ((void *) 0);
+} /* void *plugin_read_thread */
+
+static void start_threads (int num)
+{
+	int i;
+
+	if (read_threads != NULL)
+		return;
+
+	read_threads = (pthread_t *) calloc (num, sizeof (pthread_t));
+	if (read_threads == NULL)
+	{
+		ERROR ("plugin: start_threads: calloc failed.");
+		return;
+	}
+
+	read_threads_num = 0;
+	for (i = 0; i < num; i++)
+	{
+		if (pthread_create (read_threads + read_threads_num, NULL,
+					plugin_read_thread, NULL) == 0)
+		{
+			read_threads_num++;
+		}
+		else
+		{
+			ERROR ("plugin: start_threads: pthread_create failed.");
+			return;
+		}
+	} /* for (i) */
+} /* void start_threads */
+
+static void stop_threads (void)
+{
+	int i;
+
+	if (read_threads == NULL)
+		return;
+
+	pthread_mutex_lock (&read_lock);
+	read_loop = 0;
+	DEBUG ("plugin: stop_threads: Signalling `read_cond'");
+	pthread_cond_broadcast (&read_cond);
+	pthread_mutex_unlock (&read_lock);
+
+	for (i = 0; i < read_threads_num; i++)
+	{
+		if (pthread_join (read_threads[i], NULL) != 0)
+		{
+			ERROR ("plugin: stop_threads: pthread_join failed.");
+		}
+		read_threads[i] = (pthread_t) 0;
+	}
+	sfree (read_threads);
+	read_threads_num = 0;
+} /* void stop_threads */
+
+/*
+ * Public functions
+ */
+void plugin_set_dir (const char *dir)
+{
+	if (plugindir != NULL)
+		free (plugindir);
+
+	if (dir == NULL)
+		plugindir = NULL;
+	else if ((plugindir = strdup (dir)) == NULL)
+	{
+		char errbuf[1024];
+		ERROR ("strdup failed: %s",
+				sstrerror (errno, errbuf, sizeof (errbuf)));
+	}
+}
+
 #define BUFSIZE 512
 int plugin_load (const char *type)
 {
 	DIR  *dh;
-	char *dir;
-	char  filename[BUFSIZE];
+	const char *dir;
+	char  filename[BUFSIZE] = "";
 	char  typename[BUFSIZE];
 	int   typename_len;
 	int   ret;
 	struct stat    statbuf;
 	struct dirent *de;
 
-	DBG ("type = %s", type);
+	DEBUG ("type = %s", type);
 
 	dir = plugin_get_dir ();
 	ret = 1;
 
-	/* don't load twice */
-	if (plugin_search (type) != NULL)
-		return (0);
-
 	/* `cpu' should not match `cpufreq'. To solve this we add `.so' to the
 	 * type when matching the filename */
-	if (snprintf (typename, BUFSIZE, "%s.so", type) >= BUFSIZE)
+	if (ssnprintf (typename, sizeof (typename),
+			"%s.so", type) >= sizeof (typename))
 	{
-		syslog (LOG_WARNING, "snprintf: truncated: `%s.so'", type);
+		WARNING ("snprintf: truncated: `%s.so'", type);
 		return (-1);
 	}
 	typename_len = strlen (typename);
 
 	if ((dh = opendir (dir)) == NULL)
 	{
-		syslog (LOG_ERR, "opendir (%s): %s", dir, strerror (errno));
+		char errbuf[1024];
+		ERROR ("opendir (%s): %s", dir,
+				sstrerror (errno, errbuf, sizeof (errbuf)));
 		return (-1);
 	}
 
@@ -183,15 +358,18 @@ int plugin_load (const char *type)
 		if (strncasecmp (de->d_name, typename, typename_len))
 			continue;
 
-		if (snprintf (filename, BUFSIZE, "%s/%s", dir, de->d_name) >= BUFSIZE)
+		if (ssnprintf (filename, sizeof (filename),
+				"%s/%s", dir, de->d_name) >= sizeof (filename))
 		{
-			syslog (LOG_WARNING, "snprintf: truncated: `%s/%s'", dir, de->d_name);
+			WARNING ("snprintf: truncated: `%s/%s'", dir, de->d_name);
 			continue;
 		}
 
 		if (lstat (filename, &statbuf) == -1)
 		{
-			syslog (LOG_WARNING, "stat %s: %s", filename, strerror (errno));
+			char errbuf[1024];
+			WARNING ("stat %s: %s", filename,
+					sstrerror (errno, errbuf, sizeof (errbuf)));
 			continue;
 		}
 		else if (!S_ISREG (statbuf.st_mode))
@@ -206,147 +384,812 @@ int plugin_load (const char *type)
 			ret = 0;
 			break;
 		}
+		else
+		{
+			fprintf (stderr, "Unable to load plugin %s.\n", type);
+		}
 	}
 
 	closedir (dh);
 
+	if (filename[0] == '\0')
+		fprintf (stderr, "Could not find plugin %s.\n", type);
+
 	return (ret);
 }
 
 /*
- * (Try to) load all plugins in `dir'. Returns the number of loaded plugins..
+ * The `register_*' functions follow
  */
-int plugin_load_all (char *dir)
+int plugin_register_config (const char *name,
+		int (*callback) (const char *key, const char *val),
+		const char **keys, int keys_num)
 {
-	DIR *dh;
-	struct dirent *de;
-	char filename[BUFSIZE];
-	struct stat statbuf;
+	cf_register (name, callback, keys, keys_num);
+	return (0);
+} /* int plugin_register_config */
 
-	if (dir == NULL)
-		dir = plugin_get_dir ();
-	else
-		plugin_set_dir (dir);
+int plugin_register_complex_config (const char *type,
+		int (*callback) (oconfig_item_t *))
+{
+	return (cf_register_complex (type, callback));
+} /* int plugin_register_complex_config */
 
-	if ((dh = opendir (dir)) == NULL)
+int plugin_register_init (const char *name,
+		int (*callback) (void))
+{
+	return (register_callback (&list_init, name, (void *) callback));
+} /* plugin_register_init */
+
+int plugin_register_read (const char *name,
+		int (*callback) (void))
+{
+	read_func_t *rf;
+
+	rf = (read_func_t *) malloc (sizeof (read_func_t));
+	if (rf == NULL)
 	{
-		syslog (LOG_ERR, "opendir (%s): %s", dir, strerror (errno));
-		return (0);
+		char errbuf[1024];
+		ERROR ("plugin_register_read: malloc failed: %s",
+				sstrerror (errno, errbuf, sizeof (errbuf)));
+		return (-1);
 	}
 
-	while ((de = readdir (dh)) != NULL)
+	memset (rf, '\0', sizeof (read_func_t));
+	rf->wait_time = interval_g;
+	rf->wait_left = 0;
+	rf->callback = callback;
+	rf->needs_read = DONE;
+
+	return (register_callback (&list_read, name, (void *) rf));
+} /* int plugin_register_read */
+
+int plugin_register_write (const char *name,
+		int (*callback) (const data_set_t *ds, const value_list_t *vl))
+{
+	return (register_callback (&list_write, name, (void *) callback));
+} /* int plugin_register_write */
+
+int plugin_register_filter (const char *name,
+		int (*callback) (const data_set_t *ds, value_list_t *vl))
+{
+	return (register_callback (&list_filter, name, (void *) callback));
+} /* int plugin_register_filter */
+
+int plugin_register_flush (const char *name,
+		int (*callback) (const int timeout, const char *identifier))
+{
+	return (register_callback (&list_flush, name, (void *) callback));
+} /* int plugin_register_flush */
+
+int plugin_register_shutdown (char *name,
+		int (*callback) (void))
+{
+	return (register_callback (&list_shutdown, name, (void *) callback));
+} /* int plugin_register_shutdown */
+
+int plugin_register_data_set (const data_set_t *ds)
+{
+	data_set_t *ds_copy;
+	int i;
+
+	if ((data_sets != NULL)
+			&& (c_avl_get (data_sets, ds->type, NULL) == 0))
 	{
-		if (snprintf (filename, BUFSIZE, "%s/%s", dir, de->d_name) >= BUFSIZE)
+		NOTICE ("Replacing DS `%s' with another version.", ds->type);
+		plugin_unregister_data_set (ds->type);
+	}
+	else if (data_sets == NULL)
+	{
+		data_sets = c_avl_create ((int (*) (const void *, const void *)) strcmp);
+		if (data_sets == NULL)
+			return (-1);
+	}
+
+	ds_copy = (data_set_t *) malloc (sizeof (data_set_t));
+	if (ds_copy == NULL)
+		return (-1);
+	memcpy(ds_copy, ds, sizeof (data_set_t));
+
+	ds_copy->ds = (data_source_t *) malloc (sizeof (data_source_t)
+			* ds->ds_num);
+	if (ds_copy->ds == NULL)
+	{
+		free (ds_copy);
+		return (-1);
+	}
+
+	for (i = 0; i < ds->ds_num; i++)
+		memcpy (ds_copy->ds + i, ds->ds + i, sizeof (data_source_t));
+
+	return (c_avl_insert (data_sets, (void *) ds_copy->type, (void *) ds_copy));
+} /* int plugin_register_data_set */
+
+int plugin_register_log (char *name,
+		void (*callback) (int priority, const char *msg))
+{
+	return (register_callback (&list_log, name, (void *) callback));
+} /* int plugin_register_log */
+
+int plugin_register_notification (const char *name,
+		int (*callback) (const notification_t *notif))
+{
+	return (register_callback (&list_notification, name, (void *) callback));
+} /* int plugin_register_log */
+
+int plugin_unregister_config (const char *name)
+{
+	cf_unregister (name);
+	return (0);
+} /* int plugin_unregister_config */
+
+int plugin_unregister_complex_config (const char *name)
+{
+	cf_unregister_complex (name);
+	return (0);
+} /* int plugin_unregister_complex_config */
+
+int plugin_unregister_init (const char *name)
+{
+	return (plugin_unregister (list_init, name));
+}
+
+int plugin_unregister_read (const char *name)
+{
+	llentry_t *e;
+
+	e = llist_search (list_read, name);
+
+	if (e == NULL)
+		return (-1);
+
+	llist_remove (list_read, e);
+	free (e->value);
+	free (e->key);
+	llentry_destroy (e);
+
+	return (0);
+}
+
+int plugin_unregister_write (const char *name)
+{
+	return (plugin_unregister (list_write, name));
+}
+
+int plugin_unregister_filter (const char *name)
+{
+	return (plugin_unregister (list_filter, name));
+}
+
+int plugin_unregister_flush (const char *name)
+{
+	return (plugin_unregister (list_flush, name));
+}
+
+int plugin_unregister_shutdown (const char *name)
+{
+	return (plugin_unregister (list_shutdown, name));
+}
+
+int plugin_unregister_data_set (const char *name)
+{
+	data_set_t *ds;
+
+	if (data_sets == NULL)
+		return (-1);
+
+	if (c_avl_remove (data_sets, name, NULL, (void *) &ds) != 0)
+		return (-1);
+
+	sfree (ds->ds);
+	sfree (ds);
+
+	return (0);
+} /* int plugin_unregister_data_set */
+
+int plugin_unregister_log (const char *name)
+{
+	return (plugin_unregister (list_log, name));
+}
+
+int plugin_unregister_notification (const char *name)
+{
+	return (plugin_unregister (list_notification, name));
+}
+
+void plugin_init_all (void)
+{
+	const char *chain_name;
+	int (*callback) (void);
+	llentry_t *le;
+	int status;
+
+	/* Init the value cache */
+	uc_init ();
+
+	chain_name = global_option_get ("PreCacheChain");
+	pre_cache_chain = fc_chain_get_by_name (chain_name);
+
+	chain_name = global_option_get ("PostCacheChain");
+	post_cache_chain = fc_chain_get_by_name (chain_name);
+
+
+	if ((list_init == NULL) && (list_read == NULL))
+		return;
+
+	/* Calling all init callbacks before checking if read callbacks
+	 * are available allows the init callbacks to register the read
+	 * callback. */
+	le = llist_head (list_init);
+	while (le != NULL)
+	{
+		callback = (int (*) (void)) le->value;
+		status = (*callback) ();
+
+		if (status != 0)
 		{
-			syslog (LOG_WARNING, "snprintf: truncated: %s/%s", dir, de->d_name);
-			continue;
+			ERROR ("Initialization of plugin `%s' "
+					"failed with status %i. "
+					"Plugin will be unloaded.",
+					le->key, status);
+			/* Plugins that register read callbacks from the init
+			 * callback should take care of appropriate error
+			 * handling themselves. */
+			/* FIXME: Unload _all_ functions */
+			plugin_unregister_read (le->key);
 		}
 
-		if (lstat (filename, &statbuf) == -1)
+		le = le->next;
+	}
+
+	/* Start read-threads */
+	if (list_read != NULL)
+	{
+		const char *rt;
+		int num;
+		rt = global_option_get ("ReadThreads");
+		num = atoi (rt);
+		if (num != -1)
+			start_threads ((num > 0) ? num : 5);
+	}
+} /* void plugin_init_all */
+
+void plugin_read_all (void)
+{
+	llentry_t   *le;
+	read_func_t *rf;
+
+	uc_check_timeout ();
+
+	if (list_read == NULL)
+		return;
+
+	pthread_mutex_lock (&read_lock);
+
+	le = llist_head (list_read);
+	while (le != NULL)
+	{
+		rf = (read_func_t *) le->value;
+
+		if (rf->needs_read != DONE)
 		{
-			syslog (LOG_WARNING, "stat %s: %s", filename, strerror (errno));
+			le = le->next;
 			continue;
 		}
-		else if (!S_ISREG (statbuf.st_mode))
+
+		if (rf->wait_left > 0)
+			rf->wait_left -= interval_g;
+
+		if (rf->wait_left <= 0)
 		{
-			continue;
+			rf->needs_read = TODO;
 		}
 
-		plugin_load_file (filename);
+		le = le->next;
 	}
 
-	closedir (dh);
+	DEBUG ("plugin: plugin_read_all: Signalling `read_cond'");
+	pthread_cond_broadcast (&read_cond);
+	pthread_mutex_unlock (&read_lock);
+} /* void plugin_read_all */
 
-	return (plugin_count ());
-}
-#undef BUFSIZE
+/* Read function called when the `-T' command line argument is given. */
+int plugin_read_all_once (void)
+{
+	llentry_t   *le;
+	read_func_t *rf;
+	int status;
+	int return_status = 0;
 
-/*
- * Call `init' on all plugins (if given)
- */
-void plugin_init_all (void)
+	if (list_read == NULL)
+	{
+		NOTICE ("No read-functions are registered.");
+		return (0);
+	}
+
+	for (le = llist_head (list_read);
+	     le != NULL;
+	     le = le->next)
+	{
+		rf = (read_func_t *) le->value;
+		status = rf->callback ();
+		if (status != 0)
+		{
+			NOTICE ("read-function of plugin `%s' failed.",
+				le->key);
+			return_status = -1;
+		}
+	}
+
+	return (return_status);
+} /* int plugin_read_all_once */
+
+int plugin_write (const char *plugin, /* {{{ */
+		const data_set_t *ds, const value_list_t *vl)
 {
-	plugin_t *p;
+  int (*callback) (const data_set_t *ds, const value_list_t *vl);
+  llentry_t *le;
+  int status;
 
-	for (p = first_plugin; p != NULL; p = p->next)
-		if (p->init != NULL)
-			(*p->init) ();
-}
+  if (vl == NULL)
+    return (EINVAL);
 
-/*
- * Call `read' on all plugins (if given)
- */
-void plugin_read_all (void)
+  if (list_write == NULL)
+    return (ENOENT);
+
+  if (ds == NULL)
+  {
+    ds = plugin_get_ds (vl->type);
+    if (ds == NULL)
+    {
+      ERROR ("plugin_write: Unable to lookup type `%s'.", vl->type);
+      return (ENOENT);
+    }
+  }
+
+  if (plugin == NULL)
+  {
+    int success = 0;
+    int failure = 0;
+
+    le = llist_head (list_write);
+    while (le != NULL)
+    {
+      callback = le->value;
+      status = (*callback) (ds, vl);
+      if (status != 0)
+        failure++;
+      else
+        success++;
+
+      le = le->next;
+    }
+
+    if ((success == 0) && (failure != 0))
+      status = -1;
+    else
+      status = 0;
+  }
+  else /* plugin != NULL */
+  {
+    le = llist_head (list_write);
+    while (le != NULL)
+    {
+      if (strcasecmp (plugin, le->key) == 0)
+        break;
+
+      le = le->next;
+    }
+
+    if (le == NULL)
+      return (ENOENT);
+
+    callback = le->value;
+    status = (*callback) (ds, vl);
+  }
+
+  return (status);
+} /* }}} int plugin_write */
+
+int plugin_flush (const char *plugin, int timeout, const char *identifier)
 {
-	plugin_t *p;
+  int (*callback) (int timeout, const char *identifier);
+  llentry_t *le;
 
-	for (p = first_plugin; p != NULL; p = p->next)
-		if (p->read != NULL)
-			(*p->read) ();
-}
+  if (list_flush == NULL)
+    return (0);
 
-/*
- * Add plugin to the linked list of registered plugins.
- */
-void plugin_register (char *type,
-		void (*init) (void),
-		void (*read) (void),
-		void (*write) (char *, char *, char *))
+  le = llist_head (list_flush);
+  while (le != NULL)
+  {
+    if ((plugin != NULL)
+        && (strcmp (plugin, le->key) != 0))
+    {
+      le = le->next;
+      continue;
+    }
+
+    callback = (int (*) (int, const char *)) le->value;
+    (*callback) (timeout, identifier);
+
+    le = le->next;
+  }
+  return (0);
+} /* int plugin_flush */
+
+void plugin_shutdown_all (void)
 {
-	plugin_t *p;
+	int (*callback) (void);
+	llentry_t *le;
+
+	stop_threads ();
 
-	if (plugin_search (type) != NULL)
+	if (list_shutdown == NULL)
 		return;
 
-#ifdef HAVE_LIBRRD
-	if (operating_mode != MODE_SERVER)
+	le = llist_head (list_shutdown);
+	while (le != NULL)
+	{
+		callback = (int (*) (void)) le->value;
+
+		/* Advance the pointer before calling the callback allows
+		 * shutdown functions to unregister themselves. If done the
+		 * other way around the memory `le' points to will be freed
+		 * after callback returns. */
+		le = le->next;
+
+		(*callback) ();
+	}
+} /* void plugin_shutdown_all */
+
+int plugin_dispatch_values (value_list_t *vl)
+{
+	int status;
+	static c_complain_t no_write_complaint = C_COMPLAIN_INIT_STATIC;
+
+	data_set_t *ds;
+
+	if ((vl == NULL) || (*vl->type == '\0')) {
+		ERROR ("plugin_dispatch_values: Invalid value list.");
+		return (-1);
+	}
+
+	if (list_write == NULL)
+		c_complain_once (LOG_WARNING, &no_write_complaint,
+				"plugin_dispatch_values: No write callback has been "
+				"registered. Please load at least one output plugin, "
+				"if you want the collected data to be stored.");
+
+	if (data_sets == NULL)
+	{
+		ERROR ("plugin_dispatch_values: No data sets registered. "
+				"Could the types database be read? Check "
+				"your `TypesDB' setting!");
+		return (-1);
+	}
+
+	if (c_avl_get (data_sets, vl->type, (void *) &ds) != 0)
+	{
+		INFO ("plugin_dispatch_values: Dataset not found: %s", vl->type);
+		return (-1);
+	}
+
+	if (vl->time == 0)
+		vl->time = time (NULL);
+
+	DEBUG ("plugin_dispatch_values: time = %u; interval = %i; "
+			"host = %s; "
+			"plugin = %s; plugin_instance = %s; "
+			"type = %s; type_instance = %s;",
+			(unsigned int) vl->time, vl->interval,
+			vl->host,
+			vl->plugin, vl->plugin_instance,
+			vl->type, vl->type_instance);
+
+#if COLLECT_DEBUG
+	assert (0 == strcmp (ds->type, vl->type));
+#else
+	if (0 != strcmp (ds->type, vl->type))
+		WARNING ("plugin_dispatch_values: (ds->type = %s) != (vl->type = %s)",
+				ds->type, vl->type);
 #endif
-		if ((init != NULL) && (read == NULL))
-			syslog (LOG_NOTICE, "Plugin `%s' doesn't provide a read function.", type);
 
-	if ((p = (plugin_t *) malloc (sizeof (plugin_t))) == NULL)
-		return;
+#if COLLECT_DEBUG
+	assert (ds->ds_num == vl->values_len);
+#else
+	if (ds->ds_num != vl->values_len)
+	{
+		ERROR ("plugin_dispatch_values: ds->type = %s: "
+				"(ds->ds_num = %i) != "
+				"(vl->values_len = %i)",
+				ds->type, ds->ds_num, vl->values_len);
+		return (-1);
+	}
+#endif
 
-	if ((p->type = strdup (type)) == NULL)
+	escape_slashes (vl->host, sizeof (vl->host));
+	escape_slashes (vl->plugin, sizeof (vl->plugin));
+	escape_slashes (vl->plugin_instance, sizeof (vl->plugin_instance));
+	escape_slashes (vl->type, sizeof (vl->type));
+	escape_slashes (vl->type_instance, sizeof (vl->type_instance));
+
+	if (pre_cache_chain != NULL)
 	{
-		free (p);
-		return;
+		status = fc_process_chain (ds, vl, pre_cache_chain);
+		if (status < 0)
+		{
+			WARNING ("plugin_dispatch_values: Running the "
+					"pre-cache chain failed with "
+					"status %i (%#x).",
+					status, status);
+		}
+		else if (status == FC_TARGET_STOP)
+			return (0);
 	}
 
-	p->init  = init;
-	p->read  = read;
-	p->write = write;
+	/* Update the value cache */
+	uc_update (ds, vl);
 
-	p->next = first_plugin;
-	first_plugin = p;
-}
+	if (post_cache_chain != NULL)
+	{
+		status = fc_process_chain (ds, vl, post_cache_chain);
+		if (status < 0)
+		{
+			WARNING ("plugin_dispatch_values: Running the "
+					"post-cache chain failed with "
+					"status %i (%#x).",
+					status, status);
+		}
+	}
+	else
+		fc_default_action (ds, vl);
 
-/*
- * Send received data back to the plugin/module which will append DS
- * definitions and pass it on to ``rrd_update_file''.
- */
-void plugin_write (char *host, char *type, char *inst, char *val)
+	return (0);
+} /* int plugin_dispatch_values */
+
+int plugin_dispatch_notification (const notification_t *notif)
 {
-	plugin_t *p;
+	int (*callback) (const notification_t *);
+	llentry_t *le;
+	/* Possible TODO: Add flap detection here */
+
+	DEBUG ("plugin_dispatch_notification: severity = %i; message = %s; "
+			"time = %u; host = %s;",
+			notif->severity, notif->message,
+			(unsigned int) notif->time, notif->host);
+
+	/* Nobody cares for notifications */
+	if (list_notification == NULL)
+		return (-1);
 
-	if ((p = plugin_search (type)) == NULL)
+	le = llist_head (list_notification);
+	while (le != NULL)
+	{
+		callback = (int (*) (const notification_t *)) le->value;
+		(*callback) (notif);
+
+		le = le->next;
+	}
+
+	return (0);
+} /* int plugin_dispatch_notification */
+
+void plugin_log (int level, const char *format, ...)
+{
+	char msg[1024];
+	va_list ap;
+
+	void (*callback) (int, const char *);
+	llentry_t *le;
+
+	if (list_log == NULL)
 		return;
 
-	if (p->write == NULL)
+#if !COLLECT_DEBUG
+	if (level >= LOG_DEBUG)
 		return;
+#endif
+
+	va_start (ap, format);
+	vsnprintf (msg, sizeof (msg), format, ap);
+	msg[sizeof (msg) - 1] = '\0';
+	va_end (ap);
 
-	(*p->write) (host, inst, val);
+	le = llist_head (list_log);
+	while (le != NULL)
+	{
+		callback = (void (*) (int, const char *)) le->value;
+		(*callback) (level, msg);
+
+		le = le->next;
+	}
+} /* void plugin_log */
+
+const data_set_t *plugin_get_ds (const char *name)
+{
+	data_set_t *ds;
+
+	if (c_avl_get (data_sets, name, (void *) &ds) != 0)
+	{
+		DEBUG ("No such dataset registered: %s", name);
+		return (NULL);
+	}
+
+	return (ds);
+} /* data_set_t *plugin_get_ds */
+
+static int plugin_notification_meta_add (notification_t *n,
+    const char *name,
+    enum notification_meta_type_e type,
+    const void *value)
+{
+  notification_meta_t *meta;
+  notification_meta_t *tail;
+
+  if ((n == NULL) || (name == NULL) || (value == NULL))
+  {
+    ERROR ("plugin_notification_meta_add: A pointer is NULL!");
+    return (-1);
+  }
+
+  meta = (notification_meta_t *) malloc (sizeof (notification_meta_t));
+  if (meta == NULL)
+  {
+    ERROR ("plugin_notification_meta_add: malloc failed.");
+    return (-1);
+  }
+  memset (meta, 0, sizeof (notification_meta_t));
+
+  sstrncpy (meta->name, name, sizeof (meta->name));
+  meta->type = type;
+
+  switch (type)
+  {
+    case NM_TYPE_STRING:
+    {
+      meta->nm_value.nm_string = strdup ((const char *) value);
+      if (meta->nm_value.nm_string == NULL)
+      {
+        ERROR ("plugin_notification_meta_add: strdup failed.");
+        sfree (meta);
+        return (-1);
+      }
+      break;
+    }
+    case NM_TYPE_SIGNED_INT:
+    {
+      meta->nm_value.nm_signed_int = *((int64_t *) value);
+      break;
+    }
+    case NM_TYPE_UNSIGNED_INT:
+    {
+      meta->nm_value.nm_unsigned_int = *((uint64_t *) value);
+      break;
+    }
+    case NM_TYPE_DOUBLE:
+    {
+      meta->nm_value.nm_double = *((double *) value);
+      break;
+    }
+    case NM_TYPE_BOOLEAN:
+    {
+      meta->nm_value.nm_boolean = *((bool *) value);
+      break;
+    }
+    default:
+    {
+      ERROR ("plugin_notification_meta_add: Unknown type: %i", type);
+      sfree (meta);
+      return (-1);
+    }
+  } /* switch (type) */
+
+  meta->next = NULL;
+  tail = n->meta;
+  while ((tail != NULL) && (tail->next != NULL))
+    tail = tail->next;
+
+  if (tail == NULL)
+    n->meta = meta;
+  else
+    tail->next = meta;
+
+  return (0);
+} /* int plugin_notification_meta_add */
+
+int plugin_notification_meta_add_string (notification_t *n,
+    const char *name,
+    const char *value)
+{
+  return (plugin_notification_meta_add (n, name, NM_TYPE_STRING, value));
 }
 
-/*
- * Receive data from the plugin/module and get it somehow to ``plugin_write'':
- * Either using ``network_send'' (when in network/client mode) or call it
- * directly (in local mode).
- */
-void plugin_submit (char *type, char *inst, char *val)
+int plugin_notification_meta_add_signed_int (notification_t *n,
+    const char *name,
+    int64_t value)
 {
-        if (operating_mode == MODE_CLIENT)
-		network_send (type, inst, val);
-	else
-		plugin_write (NULL, type, inst, val);
+  return (plugin_notification_meta_add (n, name, NM_TYPE_SIGNED_INT, &value));
+}
+
+int plugin_notification_meta_add_unsigned_int (notification_t *n,
+    const char *name,
+    uint64_t value)
+{
+  return (plugin_notification_meta_add (n, name, NM_TYPE_UNSIGNED_INT, &value));
 }
+
+int plugin_notification_meta_add_double (notification_t *n,
+    const char *name,
+    double value)
+{
+  return (plugin_notification_meta_add (n, name, NM_TYPE_DOUBLE, &value));
+}
+
+int plugin_notification_meta_add_boolean (notification_t *n,
+    const char *name,
+    bool value)
+{
+  return (plugin_notification_meta_add (n, name, NM_TYPE_BOOLEAN, &value));
+}
+
+int plugin_notification_meta_copy (notification_t *dst,
+    const notification_t *src)
+{
+  notification_meta_t *meta;
+
+  assert (dst != NULL);
+  assert (src != NULL);
+  assert (dst != src);
+  assert ((src->meta == NULL) || (src->meta != dst->meta));
+
+  for (meta = src->meta; meta != NULL; meta = meta->next)
+  {
+    if (meta->type == NM_TYPE_STRING)
+      plugin_notification_meta_add_string (dst, meta->name,
+          meta->nm_value.nm_string);
+    else if (meta->type == NM_TYPE_SIGNED_INT)
+      plugin_notification_meta_add_signed_int (dst, meta->name,
+          meta->nm_value.nm_signed_int);
+    else if (meta->type == NM_TYPE_UNSIGNED_INT)
+      plugin_notification_meta_add_unsigned_int (dst, meta->name,
+          meta->nm_value.nm_unsigned_int);
+    else if (meta->type == NM_TYPE_DOUBLE)
+      plugin_notification_meta_add_double (dst, meta->name,
+          meta->nm_value.nm_double);
+    else if (meta->type == NM_TYPE_BOOLEAN)
+      plugin_notification_meta_add_boolean (dst, meta->name,
+          meta->nm_value.nm_boolean);
+  }
+
+  return (0);
+} /* int plugin_notification_meta_copy */
+
+int plugin_notification_meta_free (notification_t *n)
+{
+  notification_meta_t *this;
+  notification_meta_t *next;
+
+  if (n == NULL)
+  {
+    ERROR ("plugin_notification_meta_free: n == NULL!");
+    return (-1);
+  }
+
+  this = n->meta;
+  n->meta = NULL;
+  while (this != NULL)
+  {
+    next = this->next;
+
+    if (this->type == NM_TYPE_STRING)
+    {
+      free ((char *)this->nm_value.nm_string);
+      this->nm_value.nm_string = NULL;
+    }
+    sfree (this);
+
+    this = next;
+  }
+
+  return (0);
+} /* int plugin_notification_meta_free */