X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=src%2Fcore%2Fstore.c;h=ee861d33eedafbbce9906b183bf06df3ffc11cfa;hb=1b899f6e899047a521d473d00492bcf699f44ede;hp=cbd5f0c05595ccdca54ce2dba48b02d386fed972;hpb=7ff716de0679a2bfab0086e575c4a3c1b1642ff4;p=sysdb.git

diff --git a/src/core/store.c b/src/core/store.c
index cbd5f0c..ee861d3 100644
--- a/src/core/store.c
+++ b/src/core/store.c
@@ -1,6 +1,6 @@
 /*
  * SysDB - src/core/store.c
- * Copyright (C) 2012 Sebastian 'tokkee' Harl <sh@tokkee.org>
+ * Copyright (C) 2012-2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -25,10 +25,15 @@
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#if HAVE_CONFIG_H
+#	include "config.h"
+#endif /* HAVE_CONFIG_H */
+
 #include "sysdb.h"
-#include "core/store.h"
-#include "utils/llist.h"
-#include "utils/string.h"
+#include "core/store-private.h"
+#include "core/plugin.h"
+#include "utils/avltree.h"
+#include "utils/error.h"
 
 #include <assert.h>
 
@@ -40,65 +45,68 @@
 
 #include <pthread.h>
 
-/*
- * private data types
- */
-
-/* type used for looking up named objects */
-typedef struct {
-	sdb_object_t parent;
-	const char *obj_name;
-} sdb_store_lookup_obj_t;
-#define SDB_STORE_LOOKUP_OBJ_INIT { SDB_OBJECT_INIT, NULL }
-
 /*
  * private variables
  */
 
-static sdb_llist_t *host_list = NULL;
+static sdb_avltree_t *hosts = NULL;
 static pthread_rwlock_t host_lock = PTHREAD_RWLOCK_INITIALIZER;
 
 /*
- * private helper functions
+ * private types
  */
 
+static sdb_type_t sdb_host_type;
+static sdb_type_t sdb_service_type;
+static sdb_type_t sdb_attribute_type;
+
 static int
-sdb_store_obj_cmp_by_name(const sdb_object_t *a, const sdb_object_t *b)
+store_obj_init(sdb_object_t *obj, va_list ap)
 {
-	const sdb_store_obj_t *h1 = (const sdb_store_obj_t *)a;
-	const sdb_store_obj_t *h2 = (const sdb_store_obj_t *)b;
+	sdb_store_obj_t *sobj = STORE_OBJ(obj);
 
-	assert(h1 && h2);
-	return strcasecmp(h1->name, h2->name);
-} /* sdb_store_obj_cmp_by_name */
+	sobj->type = va_arg(ap, int);
 
-static int
-sdb_cmp_store_obj_with_name(const sdb_object_t *a, const sdb_object_t *b)
+	sobj->last_update = va_arg(ap, sdb_time_t);
+	sobj->interval = 0;
+	sobj->backends = NULL;
+	sobj->backends_num = 0;
+	sobj->parent = NULL;
+	return 0;
+} /* store_obj_init */
+
+static void
+store_obj_destroy(sdb_object_t *obj)
 {
-	const sdb_store_obj_t *obj = (const sdb_store_obj_t *)a;
-	const sdb_store_lookup_obj_t *lookup = (const sdb_store_lookup_obj_t *)b;
+	sdb_store_obj_t *sobj = STORE_OBJ(obj);
+	size_t i;
+
+	for (i = 0; i < sobj->backends_num; ++i)
+		free(sobj->backends[i]);
+	free(sobj->backends);
+	sobj->backends = NULL;
+	sobj->backends_num = 0;
 
-	assert(obj && lookup);
-	return strcasecmp(obj->name, lookup->obj_name);
-} /* sdb_cmp_store_obj_with_name */
+	if (sobj->parent)
+		sdb_object_deref(SDB_OBJ(sobj->parent));
+} /* store_obj_destroy */
 
 static int
 sdb_host_init(sdb_object_t *obj, va_list ap)
 {
-	const char *name = va_arg(ap, const char *);
+	sdb_host_t *sobj = HOST(obj);
+	int ret;
 
-	SDB_HOST(obj)->host_name = strdup(name);
-	if (! SDB_HOST(obj)->host_name)
-		return -1;
-
-	SDB_HOST(obj)->host_last_update = sdb_gettime();
-	/* ignore errors -> last_update will be updated later */
+	/* this will consume the first argument (type) of ap */
+	ret = store_obj_init(obj, ap);
+	if (ret)
+		return ret;
 
-	SDB_HOST(obj)->attributes = sdb_llist_create();
-	if (! SDB_HOST(obj)->attributes)
+	sobj->services = sdb_avltree_create();
+	if (! sobj->services)
 		return -1;
-	SDB_HOST(obj)->services = sdb_llist_create();
-	if (! SDB_HOST(obj)->services)
+	sobj->attributes = sdb_avltree_create();
+	if (! sobj->attributes)
 		return -1;
 	return 0;
 } /* sdb_host_init */
@@ -106,533 +114,612 @@ sdb_host_init(sdb_object_t *obj, va_list ap)
 static void
 sdb_host_destroy(sdb_object_t *obj)
 {
+	sdb_host_t *sobj = HOST(obj);
 	assert(obj);
 
-	if (SDB_HOST(obj)->host_name)
-		free(SDB_HOST(obj)->host_name);
+	store_obj_destroy(obj);
 
-	if (SDB_HOST(obj)->attributes)
-		sdb_llist_destroy(SDB_HOST(obj)->attributes);
-	if (SDB_HOST(obj)->services)
-		sdb_llist_destroy(SDB_HOST(obj)->services);
+	if (sobj->services)
+		sdb_avltree_destroy(sobj->services);
+	if (sobj->attributes)
+		sdb_avltree_destroy(sobj->attributes);
 } /* sdb_host_destroy */
 
 static int
-sdb_attr_init(sdb_object_t *obj, va_list ap)
+sdb_service_init(sdb_object_t *obj, va_list ap)
 {
-	const char *hostname = va_arg(ap, const char *);
-	const char *name = va_arg(ap, const char *);
-	const char *value = va_arg(ap, const char *);
-
-	SDB_ATTR(obj)->hostname = strdup(hostname);
-	SDB_ATTR(obj)->attr_name = strdup(name);
-	SDB_ATTR(obj)->attr_value = strdup(value);
-	if ((! SDB_ATTR(obj)->hostname)
-			|| (! SDB_ATTR(obj)->attr_name) || (! SDB_ATTR(obj)->attr_value))
-		return -1;
+	sdb_service_t *sobj = SVC(obj);
+	int ret;
+
+	/* this will consume the first argument (type) of ap */
+	ret = store_obj_init(obj, ap);
+	if (ret)
+		return ret;
 
-	SDB_ATTR(obj)->attr_last_update = sdb_gettime();
+	sobj->attributes = sdb_avltree_create();
+	if (! sobj->attributes)
+		return -1;
 	return 0;
-} /* sdb_attr_init */
+} /* sdb_service_init */
 
 static void
-sdb_attr_destroy(sdb_object_t *obj)
+sdb_service_destroy(sdb_object_t *obj)
 {
+	sdb_service_t *sobj = SVC(obj);
 	assert(obj);
 
-	if (SDB_ATTR(obj)->hostname)
-		free(SDB_ATTR(obj)->hostname);
-	if (SDB_ATTR(obj)->attr_name)
-		free(SDB_ATTR(obj)->attr_name);
-	if (SDB_ATTR(obj)->attr_value)
-		free(SDB_ATTR(obj)->attr_value);
-} /* sdb_attr_destroy */
+	store_obj_destroy(obj);
+
+	if (sobj->attributes)
+		sdb_avltree_destroy(sobj->attributes);
+} /* sdb_service_destroy */
 
 static int
-sdb_svc_init(sdb_object_t *obj, va_list ap)
+sdb_attr_init(sdb_object_t *obj, va_list ap)
 {
-	const char *hostname = va_arg(ap, const char *);
-	const char *name = va_arg(ap, const char *);
-
-	SDB_SVC(obj)->hostname = strdup(hostname);
-	SDB_SVC(obj)->svc_name = strdup(name);
-	if ((! SDB_SVC(obj)->hostname) || (! SDB_SVC(obj)->svc_name))
-		return -1;
-
-	SDB_SVC(obj)->svc_last_update = sdb_gettime();
-	/* ignore errors -> last_update will be updated later */
+	const sdb_data_t *value;
+	int ret;
+
+	/* this will consume the first two arguments
+	 * (type and last_update) of ap */
+	ret = store_obj_init(obj, ap);
+	if (ret)
+		return ret;
+	value = va_arg(ap, const sdb_data_t *);
+
+	if (value)
+		if (sdb_data_copy(&ATTR(obj)->value, value))
+			return -1;
 	return 0;
-} /* sdb_svc_init */
+} /* sdb_attr_init */
 
 static void
-sdb_svc_destroy(sdb_object_t *obj)
+sdb_attr_destroy(sdb_object_t *obj)
 {
 	assert(obj);
 
-	if (SDB_SVC(obj)->hostname)
-		free(SDB_SVC(obj)->hostname);
-	if (SDB_SVC(obj)->svc_name)
-		free(SDB_SVC(obj)->svc_name);
-} /* sdb_svc_destroy */
+	store_obj_destroy(obj);
+	sdb_data_free_datum(&ATTR(obj)->value);
+} /* sdb_attr_destroy */
+
+static sdb_type_t sdb_host_type = {
+	sizeof(sdb_host_t),
+	sdb_host_init,
+	sdb_host_destroy
+};
+
+static sdb_type_t sdb_service_type = {
+	sizeof(sdb_service_t),
+	sdb_service_init,
+	sdb_service_destroy
+};
+
+static sdb_type_t sdb_attribute_type = {
+	sizeof(sdb_attribute_t),
+	sdb_attr_init,
+	sdb_attr_destroy
+};
 
 /*
- * public API
+ * private helper functions
  */
 
-sdb_host_t *
-sdb_host_create(const char *name)
+static sdb_host_t *
+lookup_host(const char *name)
 {
-	sdb_object_t *obj;
-
-	if (! name)
-		return NULL;
+	return HOST(sdb_avltree_lookup(hosts, name));
+} /* lookup_host */
 
-	obj = sdb_object_create(sizeof(sdb_host_t), sdb_host_init,
-			sdb_host_destroy, name);
-	if (! obj)
-		return NULL;
-	return SDB_HOST(obj);
-} /* sdb_host_create */
-
-sdb_host_t *
-sdb_host_clone(const sdb_host_t *host)
+static int
+record_backend(sdb_store_obj_t *obj)
 {
-	sdb_host_t *new;
+	const sdb_plugin_info_t *info;
+	char **tmp;
+	size_t i;
 
-	new = sdb_host_create(host->host_name);
-	if (! new)
-		return NULL;
+	info = sdb_plugin_current();
+	if (! info)
+		return 0;
 
-	/* make sure these are initialized; else sdb_object_deref() might access
-	 * arbitrary memory in case of an error */
-	new->services = new->attributes = NULL;
+	for (i = 0; i < obj->backends_num; ++i)
+		if (!strcasecmp(obj->backends[i], info->plugin_name))
+			return 0;
 
-	if (host->attributes) {
-		new->attributes = sdb_llist_clone(host->attributes);
-		if (! new->attributes) {
-			sdb_object_deref(SDB_OBJ(new));
-			return NULL;
-		}
-	}
+	tmp = realloc(obj->backends,
+			(obj->backends_num + 1) * sizeof(*obj->backends));
+	if (! tmp)
+		return -1;
 
-	new->host_last_update = host->host_last_update;
-	if (host->services) {
-		new->services = sdb_llist_clone(host->services);
-		if (! new->services) {
-			sdb_object_deref(SDB_OBJ(new));
-			return NULL;
-		}
-	}
-	return new;
-} /* sdb_host_clone */
+	obj->backends = tmp;
+	obj->backends[obj->backends_num] = strdup(info->plugin_name);
+	if (! obj->backends[obj->backends_num])
+		return -1;
 
-int
-sdb_store_host(const sdb_host_t *host)
-{
-	sdb_store_lookup_obj_t lookup = SDB_STORE_LOOKUP_OBJ_INIT;
-	sdb_time_t last_update;
+	++obj->backends_num;
+	return 0;
+} /* record_backend */
 
-	sdb_host_t *old;
+static int
+store_obj(sdb_avltree_t *parent_tree, int type, const char *name,
+		sdb_time_t last_update, sdb_store_obj_t **updated_obj)
+{
+	sdb_store_obj_t *old, *new;
 	int status = 0;
 
-	if ((! host) || (! host->host_name))
-		return -1;
+	assert(parent_tree);
 
-	last_update = host->host_last_update;
 	if (last_update <= 0)
 		last_update = sdb_gettime();
 
-	pthread_rwlock_wrlock(&host_lock);
-
-	if (! host_list) {
-		if (! (host_list = sdb_llist_create())) {
-			pthread_rwlock_unlock(&host_lock);
-			return -1;
-		}
-	}
-
-	lookup.obj_name = host->host_name;
-	old = SDB_HOST(sdb_llist_search(host_list, (const sdb_object_t *)&lookup,
-				sdb_cmp_store_obj_with_name));
-
+	old = STORE_OBJ(sdb_avltree_lookup(parent_tree, name));
 	if (old) {
-		if (old->host_last_update > last_update) {
-			fprintf(stderr, "store: Cannot update host '%s' - "
-					"value too old (%"PRIscTIME" < %"PRIscTIME")\n",
-					host->host_name, last_update, old->host_last_update);
-			/* don't report an error; the host may be updated by multiple
+		if (old->last_update > last_update) {
+			sdb_log(SDB_LOG_DEBUG, "store: Cannot update %s '%s' - "
+					"value too old (%"PRIsdbTIME" < %"PRIsdbTIME")",
+					SDB_STORE_TYPE_TO_NAME(type), name,
+					last_update, old->last_update);
+			/* don't report an error; the object may be updated by multiple
 			 * backends */
 			status = 1;
 		}
+		else if (old->last_update == last_update) {
+			/* don't report an error and also don't even log this to avoid
+			 * excessive noise on high sampling frequencies */
+			status = 1;
+		}
 		else {
-			old->host_last_update = last_update;
+			sdb_time_t interval = last_update - old->last_update;
+			old->last_update = last_update;
+			if (interval) {
+				if (old->interval)
+					old->interval = (sdb_time_t)((0.9 * (double)old->interval)
+							+ (0.1 * (double)interval));
+				else
+					old->interval = interval;
+			}
 		}
+
+		new = old;
+		sdb_object_deref(SDB_OBJ(old));
 	}
 	else {
-		sdb_host_t *new = sdb_host_clone(host);
-		if (! new) {
-			char errbuf[1024];
-			fprintf(stderr, "store: Failed to clone host object: %s\n",
-					sdb_strerror(errno, errbuf, sizeof(errbuf)));
-			pthread_rwlock_unlock(&host_lock);
-			return -1;
+		if (type == SDB_ATTRIBUTE) {
+			/* the value will be updated by the caller */
+			new = STORE_OBJ(sdb_object_create(name, sdb_attribute_type,
+						type, last_update, NULL));
 		}
-
-		if (! new->attributes) {
-			if (! (new->attributes = sdb_llist_create())) {
-				char errbuf[1024];
-				fprintf(stderr, "store: Failed to initialize "
-						"host object '%s': %s\n", host->host_name,
-						sdb_strerror(errno, errbuf, sizeof(errbuf)));
-				sdb_object_deref(SDB_OBJ(new));
-				pthread_rwlock_unlock(&host_lock);
-				return -1;
-			}
+		else {
+			sdb_type_t t;
+			t = type == SDB_HOST ? sdb_host_type : sdb_service_type;
+			new = STORE_OBJ(sdb_object_create(name, t, type, last_update));
 		}
 
-		if (! new->services) {
-			if (! (new->services = sdb_llist_create())) {
-				char errbuf[1024];
-				fprintf(stderr, "store: Failed to initialize "
-						"host object '%s': %s\n", host->host_name,
-						sdb_strerror(errno, errbuf, sizeof(errbuf)));
-				sdb_object_deref(SDB_OBJ(new));
-				pthread_rwlock_unlock(&host_lock);
-				return -1;
-			}
+		if (new) {
+			status = sdb_avltree_insert(parent_tree, SDB_OBJ(new));
+
+			/* pass control to the tree or destroy in case of an error */
+			sdb_object_deref(SDB_OBJ(new));
+		}
+		else {
+			char errbuf[1024];
+			sdb_log(SDB_LOG_ERR, "store: Failed to create %s '%s': %s",
+					SDB_STORE_TYPE_TO_NAME(type), name,
+					sdb_strerror(errno, errbuf, sizeof(errbuf)));
+			status = -1;
 		}
+	}
 
-		status = sdb_llist_insert_sorted(host_list, SDB_OBJ(new),
-				sdb_store_obj_cmp_by_name);
+	if (status < 0)
+		return status;
+	assert(new);
 
-		/* pass control to the list or destroy in case of an error */
-		sdb_object_deref(SDB_OBJ(new));
-	}
+	if (updated_obj)
+		*updated_obj = new;
 
-	pthread_rwlock_unlock(&host_lock);
+	if (record_backend(new))
+		return -1;
 	return status;
-} /* sdb_store_host */
+} /* store_obj */
 
-const sdb_host_t *
-sdb_store_get_host(const char *name)
+static int
+store_attr(sdb_avltree_t *attributes, const char *key, const sdb_data_t *value,
+		sdb_time_t last_update)
 {
-	sdb_store_lookup_obj_t lookup = SDB_STORE_LOOKUP_OBJ_INIT;
-	sdb_host_t *host;
+	sdb_store_obj_t *attr = NULL;
+	int status;
 
-	if (! name)
-		return NULL;
+	status = store_obj(attributes, SDB_ATTRIBUTE, key, last_update, &attr);
+	if (status)
+		return status;
 
-	lookup.obj_name = name;
-	host = SDB_HOST(sdb_llist_search(host_list, (const sdb_object_t *)&lookup,
-				sdb_cmp_store_obj_with_name));
+	/* don't update unchanged values */
+	if (! sdb_data_cmp(&ATTR(attr)->value, value))
+		return status;
 
-	if (! host)
-		return NULL;
-	return host;
-} /* sdb_store_get_host */
+	assert(attr);
+	if (sdb_data_copy(&ATTR(attr)->value, value))
+		return -1;
+	return status;
+} /* store_attr */
 
-sdb_attribute_t *
-sdb_attribute_create(const char *hostname,
-		const char *name, const char *value)
+/* The host_lock has to be acquired before calling this function. */
+static sdb_avltree_t *
+get_host_children(const char *hostname, int type)
 {
-	sdb_object_t *obj;
+	char *cname = NULL;
+	sdb_host_t *host;
 
-	if ((! hostname) || (! name) || (! value))
-		return NULL;
+	assert(hostname);
+	assert((type == SDB_SERVICE) || (type == SDB_ATTRIBUTE));
 
-	obj = sdb_object_create(sizeof(sdb_attribute_t), sdb_attr_init,
-			sdb_attr_destroy, hostname, name, value);
-	if (! obj)
+	if (! hosts)
 		return NULL;
-	return SDB_ATTR(obj);
-} /* sdb_attribute_create */
 
-sdb_attribute_t *
-sdb_attribute_clone(const sdb_attribute_t *attr)
-{
-	sdb_attribute_t *new;
+	cname = sdb_plugin_cname(strdup(hostname));
+	if (! cname) {
+		sdb_log(SDB_LOG_ERR, "store: strdup failed");
+		return NULL;
+	}
 
-	new = sdb_attribute_create(attr->hostname,
-			attr->attr_name, attr->attr_value);
-	if (! new)
+	host = lookup_host(cname);
+	free(cname);
+	if (! host)
 		return NULL;
 
-	new->attr_last_update = attr->attr_last_update;
-	return new;
-} /* sdb_attribute_clone */
+	sdb_object_deref(SDB_OBJ(host));
+	if (type == SDB_ATTRIBUTE)
+		return host->attributes;
+	else
+		return host->services;
+} /* get_host_children */
 
-int
-sdb_store_attribute(const sdb_attribute_t *attr)
+/*
+ * store_common_tojson serializes common object attributes to JSON.
+ *
+ * The function never returns an error. Rather, an error message will be part
+ * of the serialized data.
+ */
+static void
+store_common_tojson(sdb_store_obj_t *obj, sdb_strbuf_t *buf)
 {
-	sdb_store_lookup_obj_t lookup = SDB_STORE_LOOKUP_OBJ_INIT;
-	sdb_host_t *host;
-
-	sdb_attribute_t *old;
+	char time_str[64];
+	char interval_str[64];
+	size_t i;
+
+	if (! sdb_strftime(time_str, sizeof(time_str),
+				"%F %T %z", obj->last_update))
+		snprintf(time_str, sizeof(time_str), "<error>");
+	time_str[sizeof(time_str) - 1] = '\0';
+
+	if (! sdb_strfinterval(interval_str, sizeof(interval_str),
+				obj->interval))
+		snprintf(interval_str, sizeof(interval_str), "<error>");
+	interval_str[sizeof(interval_str) - 1] = '\0';
+
+	sdb_strbuf_append(buf, "\"last_update\": \"%s\", "
+			"\"update_interval\": \"%s\", \"backends\": [",
+			time_str, interval_str);
+
+	for (i = 0; i < obj->backends_num; ++i) {
+		sdb_strbuf_append(buf, "\"%s\"", obj->backends[i]);
+		if (i < obj->backends_num - 1)
+			sdb_strbuf_append(buf, ",");
+	}
+	sdb_strbuf_append(buf, "]");
+} /* store_common_tojson */
 
-	sdb_time_t last_update;
+/*
+ * store_obj_tojson serializes attribute / service objects to JSON.
+ *
+ * The function never returns an error. Rather, an error message will be part
+ * of the serialized data.
+ */
+static void
+store_obj_tojson(sdb_avltree_t *tree, int type, sdb_strbuf_t *buf,
+		sdb_store_matcher_t *filter, int flags)
+{
+	sdb_avltree_iter_t *iter;
+
+	assert((type == SDB_ATTRIBUTE) || (type == SDB_SERVICE));
+
+	sdb_strbuf_append(buf, "[");
+	iter = sdb_avltree_get_iter(tree);
+	if (! iter) {
+		char errbuf[1024];
+		sdb_log(SDB_LOG_ERR, "store: Failed to retrieve %ss: %s\n",
+				SDB_STORE_TYPE_TO_NAME(type),
+				sdb_strerror(errno, errbuf, sizeof(errbuf)));
+		sdb_strbuf_append(buf, "{\"error\": \"failed to retrieve %ss: %s\"}",
+				SDB_STORE_TYPE_TO_NAME(type), errbuf);
+	}
 
-	int status = 0;
+	/* has_next returns false if the iterator is NULL */
+	while (sdb_avltree_iter_has_next(iter)) {
+		sdb_store_obj_t *sobj = STORE_OBJ(sdb_avltree_iter_get_next(iter));
+		assert(sobj);
+		assert(sobj->type == type);
 
-	if (! attr)
-		return -1;
+		if (filter && (! sdb_store_matcher_matches(filter, sobj, NULL)))
+			continue;
 
-	last_update = attr->attr_last_update;
-	if (last_update <= 0)
-		last_update = sdb_gettime();
+		sdb_strbuf_append(buf, "{\"name\": \"%s\", ", SDB_OBJ(sobj)->name);
+		if (sobj->type == SDB_ATTRIBUTE) {
+			char tmp[sdb_data_strlen(&ATTR(sobj)->value) + 1];
+			sdb_data_format(&ATTR(sobj)->value, tmp, sizeof(tmp),
+					SDB_DOUBLE_QUOTED);
+			sdb_strbuf_append(buf, "\"value\": %s, ", tmp);
+		}
+		store_common_tojson(sobj, buf);
 
-	if (! host_list)
-		return -1;
+		if ((sobj->type == SDB_SERVICE)
+				&& (! (flags & SDB_SKIP_ATTRIBUTES))) {
+			sdb_strbuf_append(buf, ", \"attributes\": ");
+			store_obj_tojson(SVC(sobj)->attributes, SDB_ATTRIBUTE,
+					buf, filter, flags);
+		}
+		sdb_strbuf_append(buf, "}");
 
-	pthread_rwlock_wrlock(&host_lock);
+		if (sdb_avltree_iter_has_next(iter))
+			sdb_strbuf_append(buf, ",");
+	}
 
-	lookup.obj_name = attr->hostname;
-	host = SDB_HOST(sdb_llist_search(host_list, (const sdb_object_t *)&lookup,
-				sdb_cmp_store_obj_with_name));
+	sdb_avltree_iter_destroy(iter);
+	sdb_strbuf_append(buf, "]");
+} /* store_obj_tojson */
 
-	if (! host) {
-		pthread_rwlock_unlock(&host_lock);
-		return -1;
-	}
+/*
+ * public API
+ */
 
-	lookup.obj_name = attr->attr_name;
-	old = SDB_ATTR(sdb_llist_search(host->attributes,
-				(const sdb_object_t *)&lookup,
-				sdb_cmp_store_obj_with_name));
+void
+sdb_store_clear(void)
+{
+	sdb_avltree_destroy(hosts);
+	hosts = NULL;
+} /* sdb_store_clear */
 
-	if (old) {
-		if (old->host_last_update > last_update) {
-			fprintf(stderr, "store: Cannot update attribute '%s/%s' - "
-					"value too old (%"PRIscTIME" < %"PRIscTIME")\n",
-					attr->hostname, attr->attr_name, last_update,
-					old->host_last_update);
-			status = 1;
-		}
-		else {
-			old->attr_last_update = last_update;
-		}
-	}
-	else {
-		sdb_attribute_t *new = sdb_attribute_clone(attr);
-		if (! new) {
-			char errbuf[1024];
-			fprintf(stderr, "store: Failed to clone attribute object: %s\n",
-					sdb_strerror(errno, errbuf, sizeof(errbuf)));
-			pthread_rwlock_unlock(&host_lock);
-			return -1;
-		}
+int
+sdb_store_host(const char *name, sdb_time_t last_update)
+{
+	char *cname = NULL;
+	int status = 0;
 
-		status = sdb_llist_insert_sorted(host->attributes, SDB_OBJ(new),
-				sdb_store_obj_cmp_by_name);
+	if (! name)
+		return -1;
 
-		/* pass control to the list or destroy in case of an error */
-		sdb_object_deref(SDB_OBJ(new));
+	cname = sdb_plugin_cname(strdup(name));
+	if (! cname) {
+		sdb_log(SDB_LOG_ERR, "store: strdup failed");
+		return -1;
 	}
 
+	pthread_rwlock_wrlock(&host_lock);
+	if (! hosts)
+		if (! (hosts = sdb_avltree_create()))
+			status = -1;
+
+	if (! status)
+		status = store_obj(hosts, SDB_HOST, cname, last_update, NULL);
 	pthread_rwlock_unlock(&host_lock);
+
+	free(cname);
 	return status;
-} /* sdb_store_attribute */
+} /* sdb_store_host */
 
-sdb_service_t *
-sdb_service_create(const char *hostname, const char *name)
+_Bool
+sdb_store_has_host(const char *name)
 {
-	sdb_object_t *obj;
+	sdb_host_t *host;
 
-	if ((! hostname) || (! name))
+	if (! name)
 		return NULL;
 
-	obj = sdb_object_create(sizeof(sdb_service_t), sdb_svc_init,
-			sdb_svc_destroy, hostname, name);
-	if (! obj)
-		return NULL;
-	return SDB_SVC(obj);
-} /* sdb_service_create */
+	host = lookup_host(name);
+	return host != NULL;
+} /* sdb_store_has_host */
 
-sdb_service_t *
-sdb_service_clone(const sdb_service_t *svc)
+sdb_store_obj_t *
+sdb_store_get_host(const char *name)
 {
-	sdb_service_t *new;
+	sdb_host_t *host;
 
-	new = sdb_service_create(svc->hostname, svc->svc_name);
-	if (! new)
+	if (! name)
 		return NULL;
 
-	new->svc_last_update = svc->svc_last_update;
-	return new;
-} /* sdb_service_clone */
+	host = lookup_host(name);
+	if (! host)
+		return NULL;
+
+	return STORE_OBJ(host);
+} /* sdb_store_get_host */
 
 int
-sdb_store_service(const sdb_service_t *svc)
+sdb_store_attribute(const char *hostname,
+		const char *key, const sdb_data_t *value,
+		sdb_time_t last_update)
 {
-	sdb_store_lookup_obj_t lookup = SDB_STORE_LOOKUP_OBJ_INIT;
-	sdb_host_t *host;
+	sdb_avltree_t *attrs;
+	int status = 0;
 
-	sdb_service_t *old;
+	if ((! hostname) || (! key))
+		return -1;
 
-	sdb_time_t last_update;
+	pthread_rwlock_wrlock(&host_lock);
+	attrs = get_host_children(hostname, SDB_ATTRIBUTE);
+	if (! attrs) {
+		sdb_log(SDB_LOG_ERR, "store: Failed to store attribute '%s' - "
+				"host '%s' not found", key, hostname);
+		status = -1;
+	}
 
-	int status = 0;
+	if (! status)
+		status = store_attr(attrs, key, value, last_update);
 
-	if (! svc)
-		return -1;
+	pthread_rwlock_unlock(&host_lock);
+	return status;
+} /* sdb_store_attribute */
 
-	last_update = svc->svc_last_update;
-	if (last_update <= 0)
-		last_update = sdb_gettime();
+int
+sdb_store_service(const char *hostname, const char *name,
+		sdb_time_t last_update)
+{
+	sdb_avltree_t *services;
+
+	int status = 0;
 
-	if (! host_list)
+	if ((! hostname) || (! name))
 		return -1;
 
 	pthread_rwlock_wrlock(&host_lock);
+	services = get_host_children(hostname, SDB_SERVICE);
+	if (! services) {
+		sdb_log(SDB_LOG_ERR, "store: Failed to store service '%s' - "
+				"host '%s' not found", name, hostname);
+		status = -1;
+	}
 
-	lookup.obj_name = svc->hostname;
-	host = SDB_HOST(sdb_llist_search(host_list, (const sdb_object_t *)&lookup,
-				sdb_cmp_store_obj_with_name));
+	if (! status)
+		status = store_obj(services, SDB_SERVICE, name, last_update, NULL);
+	pthread_rwlock_unlock(&host_lock);
+	return status;
+} /* sdb_store_service */
 
-	if (! host) {
+int
+sdb_store_service_attr(const char *hostname, const char *service,
+		const char *key, const sdb_data_t *value, sdb_time_t last_update)
+{
+	sdb_avltree_t *services;
+	sdb_service_t *svc;
+	int status = 0;
+
+	if ((! hostname) || (! service) || (! key))
+		return -1;
+
+	pthread_rwlock_wrlock(&host_lock);
+	services = get_host_children(hostname, SDB_SERVICE);
+	if (! services) {
+		sdb_log(SDB_LOG_ERR, "store: Failed to store attribute '%s' "
+				"for service '%s' - host '%ss' not found",
+				key, service, hostname);
 		pthread_rwlock_unlock(&host_lock);
 		return -1;
 	}
 
-	lookup.obj_name = svc->svc_name;
-	old = SDB_SVC(sdb_llist_search(host->services, (const sdb_object_t *)&lookup,
-				sdb_cmp_store_obj_with_name));
-
-	if (old) {
-		if (old->host_last_update > last_update) {
-			fprintf(stderr, "store: Cannot update service '%s/%s' - "
-					"value too old (%"PRIscTIME" < %"PRIscTIME")\n",
-					svc->hostname, svc->svc_name, last_update,
-					old->host_last_update);
-			status = 1;
-		}
-		else {
-			old->svc_last_update = last_update;
-		}
+	svc = SVC(sdb_avltree_lookup(services, service));
+	if (! svc) {
+		sdb_log(SDB_LOG_ERR, "store: Failed to store attribute '%s' - "
+				"service '%s/%s' not found", key, hostname, service);
+		status = -1;
 	}
-	else {
-		sdb_service_t *new = sdb_service_clone(svc);
-		if (! new) {
-			char errbuf[1024];
-			fprintf(stderr, "store: Failed to clone service object: %s\n",
-					sdb_strerror(errno, errbuf, sizeof(errbuf)));
-			pthread_rwlock_unlock(&host_lock);
-			return -1;
-		}
 
-		status = sdb_llist_insert_sorted(host->services, SDB_OBJ(new),
-				sdb_store_obj_cmp_by_name);
-
-		/* pass control to the list or destroy in case of an error */
-		sdb_object_deref(SDB_OBJ(new));
-	}
+	if (! status)
+		status = store_attr(svc->attributes, key, value, last_update);
 
+	sdb_object_deref(SDB_OBJ(svc));
 	pthread_rwlock_unlock(&host_lock);
 	return status;
-} /* sdb_store_service */
+} /* sdb_store_service_attr */
 
-const sdb_service_t *
-sdb_store_get_service(const sdb_host_t *host, const char *name)
+int
+sdb_store_host_tojson(sdb_store_obj_t *h, sdb_strbuf_t *buf,
+		sdb_store_matcher_t *filter, int flags)
 {
-	sdb_store_lookup_obj_t lookup = SDB_STORE_LOOKUP_OBJ_INIT;
-	sdb_service_t *svc;
+	sdb_host_t *host = HOST(h);
 
-	if ((! host) || (! name))
-		return NULL;
+	if ((! h) || (h->type != SDB_HOST) || (! buf))
+		return -1;
 
-	lookup.obj_name = name;
-	svc = SDB_SVC(sdb_llist_search(host->services,
-				(const sdb_object_t *)&lookup,
-				sdb_cmp_store_obj_with_name));
+	sdb_strbuf_append(buf, "{\"name\": \"%s\", ", SDB_OBJ(host)->name);
+	store_common_tojson(h, buf);
 
-	if (! svc)
-		return NULL;
-	return svc;
-} /* sdb_store_get_service */
+	if (! (flags & SDB_SKIP_ATTRIBUTES)) {
+		sdb_strbuf_append(buf, ", \"attributes\": ");
+		store_obj_tojson(host->attributes, SDB_ATTRIBUTE, buf, filter, flags);
+	}
+
+	if (! (flags & SDB_SKIP_SERVICES)) {
+		sdb_strbuf_append(buf, ", \"services\": ");
+		store_obj_tojson(host->services, SDB_SERVICE, buf, filter, flags);
+	}
+
+	sdb_strbuf_append(buf, "}");
+	return 0;
+} /* sdb_store_host_tojson */
 
 int
-sdb_store_dump(FILE *fh)
+sdb_store_tojson(sdb_strbuf_t *buf, sdb_store_matcher_t *filter, int flags)
 {
-	sdb_llist_iter_t *host_iter;
+	sdb_avltree_iter_t *host_iter;
+	size_t len;
 
-	if (! fh)
+	if (! buf)
 		return -1;
 
 	pthread_rwlock_rdlock(&host_lock);
 
-	host_iter = sdb_llist_get_iter(host_list);
+	host_iter = sdb_avltree_get_iter(hosts);
 	if (! host_iter) {
 		pthread_rwlock_unlock(&host_lock);
 		return -1;
 	}
 
-	while (sdb_llist_iter_has_next(host_iter)) {
-		sdb_host_t *host = SDB_HOST(sdb_llist_iter_get_next(host_iter));
-		sdb_llist_iter_t *svc_iter;
-		sdb_llist_iter_t *attr_iter;
+	sdb_strbuf_append(buf, "{\"hosts\":[");
 
-		char time_str[64];
+	len = sdb_strbuf_len(buf);
+	while (sdb_avltree_iter_has_next(host_iter)) {
+		sdb_store_obj_t *host;
 
+		host = STORE_OBJ(sdb_avltree_iter_get_next(host_iter));
 		assert(host);
 
-		if (! sdb_strftime(time_str, sizeof(time_str),
-					"%F %T %z", host->host_last_update))
-			snprintf(time_str, sizeof(time_str), "<error>");
-		time_str[sizeof(time_str) - 1] = '\0';
+		if (filter && (! sdb_store_matcher_matches(filter, host, NULL)))
+			continue;
 
-		fprintf(fh, "Host '%s' (last updated: %s):\n",
-				host->host_name, time_str);
+		if (sdb_strbuf_len(buf) > len)
+			sdb_strbuf_append(buf, ",");
+		len = sdb_strbuf_len(buf);
 
-		attr_iter = sdb_llist_get_iter(host->attributes);
-		if (! attr_iter) {
-			char errbuf[1024];
-			fprintf(fh, "Failed to retrieve attributes: %s\n",
-					sdb_strerror(errno, errbuf, sizeof(errbuf)));
-			continue;
-		}
+		if (sdb_store_host_tojson(host, buf, filter, flags))
+			return -1;
+	}
 
-		while (sdb_llist_iter_has_next(attr_iter)) {
-			sdb_attribute_t *attr = SDB_ATTR(sdb_llist_iter_get_next(attr_iter));
-			assert(attr);
+	sdb_strbuf_append(buf, "]}");
 
-			if (! sdb_strftime(time_str, sizeof(time_str),
-						"%F %T %z", attr->attr_last_update))
-				snprintf(time_str, sizeof(time_str), "<error>");
-			time_str[sizeof(time_str) - 1] = '\0';
+	sdb_avltree_iter_destroy(host_iter);
+	pthread_rwlock_unlock(&host_lock);
+	return 0;
+} /* sdb_store_tojson */
 
-			fprintf(fh, "\tAttribute '%s' -> '%s' (last updated: %s)\n",
-					attr->attr_name, attr->attr_value, time_str);
-		}
+/* TODO: actually support hierarchical data */
+int
+sdb_store_iterate(sdb_store_iter_cb cb, void *user_data)
+{
+	sdb_avltree_iter_t *host_iter;
+	int status = 0;
 
-		sdb_llist_iter_destroy(attr_iter);
+	pthread_rwlock_rdlock(&host_lock);
 
-		svc_iter = sdb_llist_get_iter(host->services);
-		if (! svc_iter) {
-			char errbuf[1024];
-			fprintf(fh, "Failed to retrieve services: %s\n",
-					sdb_strerror(errno, errbuf, sizeof(errbuf)));
-			continue;
-		}
+	host_iter = sdb_avltree_get_iter(hosts);
+	if (! host_iter)
+		status = -1;
 
-		while (sdb_llist_iter_has_next(svc_iter)) {
-			sdb_service_t *svc = SDB_SVC(sdb_llist_iter_get_next(svc_iter));
-			assert(svc);
+	/* has_next returns false if the iterator is NULL */
+	while (sdb_avltree_iter_has_next(host_iter)) {
+		sdb_store_obj_t *host;
 
-			if (! sdb_strftime(time_str, sizeof(time_str),
-						"%F %T %z", svc->svc_last_update))
-				snprintf(time_str, sizeof(time_str), "<error>");
-			time_str[sizeof(time_str) - 1] = '\0';
+		host = STORE_OBJ(sdb_avltree_iter_get_next(host_iter));
+		assert(host);
 
-			fprintf(fh, "\tService '%s' (last updated: %s)\n",
-					svc->svc_name, time_str);
+		if (cb(host, user_data)) {
+			status = -1;
+			break;
 		}
-
-		sdb_llist_iter_destroy(svc_iter);
 	}
 
-	sdb_llist_iter_destroy(host_iter);
+	sdb_avltree_iter_destroy(host_iter);
 	pthread_rwlock_unlock(&host_lock);
-	return 0;
-} /* sdb_store_dump */
+	return status;
+} /* sdb_store_iterate */
 
 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */