X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=src%2Fcore%2Fstore.c;h=8cb30efaea88a250284cb569db2ae07b05d7fa12;hb=ef3e099a424694e6247252a40c7b3be343f3cebd;hp=49aaeb259eb3f0a3b74841e3b88617e9a153a47a;hpb=f922c934ade661b38047d405cb2b065152d6a526;p=sysdb.git

diff --git a/src/core/store.c b/src/core/store.c
index 49aaeb2..8cb30ef 100644
--- a/src/core/store.c
+++ b/src/core/store.c
@@ -32,8 +32,8 @@
 #include "sysdb.h"
 #include "core/store-private.h"
 #include "core/plugin.h"
+#include "utils/avltree.h"
 #include "utils/error.h"
-#include "utils/llist.h"
 
 #include <assert.h>
 
@@ -49,7 +49,7 @@
  * private variables
  */
 
-static sdb_llist_t *host_list = NULL;
+static sdb_avltree_t *hosts = NULL;
 static pthread_rwlock_t host_lock = PTHREAD_RWLOCK_INITIALIZER;
 
 /*
@@ -58,6 +58,7 @@ static pthread_rwlock_t host_lock = PTHREAD_RWLOCK_INITIALIZER;
 
 static sdb_type_t sdb_host_type;
 static sdb_type_t sdb_service_type;
+static sdb_type_t sdb_metric_type;
 static sdb_type_t sdb_attribute_type;
 
 static int
@@ -102,10 +103,13 @@ sdb_host_init(sdb_object_t *obj, va_list ap)
 	if (ret)
 		return ret;
 
-	sobj->services = sdb_llist_create();
+	sobj->services = sdb_avltree_create();
 	if (! sobj->services)
 		return -1;
-	sobj->attributes = sdb_llist_create();
+	sobj->metrics = sdb_avltree_create();
+	if (! sobj->metrics)
+		return -1;
+	sobj->attributes = sdb_avltree_create();
 	if (! sobj->attributes)
 		return -1;
 	return 0;
@@ -120,9 +124,11 @@ sdb_host_destroy(sdb_object_t *obj)
 	store_obj_destroy(obj);
 
 	if (sobj->services)
-		sdb_llist_destroy(sobj->services);
+		sdb_avltree_destroy(sobj->services);
+	if (sobj->metrics)
+		sdb_avltree_destroy(sobj->metrics);
 	if (sobj->attributes)
-		sdb_llist_destroy(sobj->attributes);
+		sdb_avltree_destroy(sobj->attributes);
 } /* sdb_host_destroy */
 
 static int
@@ -136,7 +142,7 @@ sdb_service_init(sdb_object_t *obj, va_list ap)
 	if (ret)
 		return ret;
 
-	sobj->attributes = sdb_llist_create();
+	sobj->attributes = sdb_avltree_create();
 	if (! sobj->attributes)
 		return -1;
 	return 0;
@@ -151,9 +157,45 @@ sdb_service_destroy(sdb_object_t *obj)
 	store_obj_destroy(obj);
 
 	if (sobj->attributes)
-		sdb_llist_destroy(sobj->attributes);
+		sdb_avltree_destroy(sobj->attributes);
 } /* sdb_service_destroy */
 
+static int
+sdb_metric_init(sdb_object_t *obj, va_list ap)
+{
+	sdb_metric_t *sobj = METRIC(obj);
+	int ret;
+
+	/* this will consume the first argument (type) of ap */
+	ret = store_obj_init(obj, ap);
+	if (ret)
+		return ret;
+
+	sobj->attributes = sdb_avltree_create();
+	if (! sobj->attributes)
+		return -1;
+
+	sobj->store.type = sobj->store.id = NULL;
+	return 0;
+} /* sdb_metric_init */
+
+static void
+sdb_metric_destroy(sdb_object_t *obj)
+{
+	sdb_metric_t *sobj = METRIC(obj);
+	assert(obj);
+
+	store_obj_destroy(obj);
+
+	if (sobj->attributes)
+		sdb_avltree_destroy(sobj->attributes);
+
+	if (sobj->store.type)
+		free(sobj->store.type);
+	if (sobj->store.id)
+		free(sobj->store.id);
+} /* sdb_metric_destroy */
+
 static int
 sdb_attr_init(sdb_object_t *obj, va_list ap)
 {
@@ -194,6 +236,12 @@ static sdb_type_t sdb_service_type = {
 	sdb_service_destroy
 };
 
+static sdb_type_t sdb_metric_type = {
+	sizeof(sdb_metric_t),
+	sdb_metric_init,
+	sdb_metric_destroy
+};
+
 static sdb_type_t sdb_attribute_type = {
 	sizeof(sdb_attribute_t),
 	sdb_attr_init,
@@ -207,7 +255,7 @@ static sdb_type_t sdb_attribute_type = {
 static sdb_host_t *
 lookup_host(const char *name)
 {
-	return HOST(sdb_llist_search_by_name(host_list, name));
+	return HOST(sdb_avltree_lookup(hosts, name));
 } /* lookup_host */
 
 static int
@@ -240,22 +288,22 @@ record_backend(sdb_store_obj_t *obj)
 } /* record_backend */
 
 static int
-store_obj(sdb_llist_t *parent_list, int type, const char *name,
+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;
 
-	assert(parent_list);
+	assert(parent_tree);
 
 	if (last_update <= 0)
 		last_update = sdb_gettime();
 
-	old = STORE_OBJ(sdb_llist_search_by_name(parent_list, name));
+	old = STORE_OBJ(sdb_avltree_lookup(parent_tree, name));
 	if (old) {
 		if (old->last_update > last_update) {
 			sdb_log(SDB_LOG_DEBUG, "store: Cannot update %s '%s' - "
-					"value too old (%"PRIscTIME" < %"PRIscTIME")",
+					"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
@@ -280,6 +328,7 @@ store_obj(sdb_llist_t *parent_list, int type, const char *name,
 		}
 
 		new = old;
+		sdb_object_deref(SDB_OBJ(old));
 	}
 	else {
 		if (type == SDB_ATTRIBUTE) {
@@ -289,15 +338,18 @@ store_obj(sdb_llist_t *parent_list, int type, const char *name,
 		}
 		else {
 			sdb_type_t t;
-			t = type == SDB_HOST ? sdb_host_type : sdb_service_type;
+			t = type == SDB_HOST
+				? sdb_host_type
+				: type == SDB_SERVICE
+					? sdb_service_type
+					: sdb_metric_type;
 			new = STORE_OBJ(sdb_object_create(name, t, type, last_update));
 		}
 
 		if (new) {
-			status = sdb_llist_insert_sorted(parent_list, SDB_OBJ(new),
-					sdb_object_cmp_by_name);
+			status = sdb_avltree_insert(parent_tree, SDB_OBJ(new));
 
-			/* pass control to the list or destroy in case of an error */
+			/* pass control to the tree or destroy in case of an error */
 			sdb_object_deref(SDB_OBJ(new));
 		}
 		else {
@@ -322,7 +374,7 @@ store_obj(sdb_llist_t *parent_list, int type, const char *name,
 } /* store_obj */
 
 static int
-store_attr(sdb_llist_t *attributes, const char *key, const sdb_data_t *value,
+store_attr(sdb_avltree_t *attributes, const char *key, const sdb_data_t *value,
 		sdb_time_t last_update)
 {
 	sdb_store_obj_t *attr = NULL;
@@ -343,16 +395,17 @@ store_attr(sdb_llist_t *attributes, const char *key, const sdb_data_t *value,
 } /* store_attr */
 
 /* The host_lock has to be acquired before calling this function. */
-static sdb_llist_t *
+static sdb_avltree_t *
 get_host_children(const char *hostname, int type)
 {
 	char *cname = NULL;
 	sdb_host_t *host;
 
 	assert(hostname);
-	assert((type == SDB_SERVICE) || (type == SDB_ATTRIBUTE));
+	assert((type == SDB_SERVICE) || (type == SDB_METRIC)
+			|| (type == SDB_ATTRIBUTE));
 
-	if (! host_list)
+	if (! hosts)
 		return NULL;
 
 	cname = sdb_plugin_cname(strdup(hostname));
@@ -366,8 +419,11 @@ get_host_children(const char *hostname, int type)
 	if (! host)
 		return NULL;
 
+	sdb_object_deref(SDB_OBJ(host));
 	if (type == SDB_ATTRIBUTE)
 		return host->attributes;
+	else if (type == SDB_METRIC)
+		return host->metrics;
 	else
 		return host->services;
 } /* get_host_children */
@@ -385,6 +441,7 @@ store_common_tojson(sdb_store_obj_t *obj, sdb_strbuf_t *buf)
 	char interval_str[64];
 	size_t i;
 
+	/* TODO: make time and interval formats configurable */
 	if (! sdb_strftime(time_str, sizeof(time_str),
 				"%F %T %z", obj->last_update))
 		snprintf(time_str, sizeof(time_str), "<error>");
@@ -408,20 +465,23 @@ store_common_tojson(sdb_store_obj_t *obj, sdb_strbuf_t *buf)
 } /* store_common_tojson */
 
 /*
- * store_obj_tojson serializes attribute / service objects to JSON.
+ * store_obj_tojson serializes attribute / metric / 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_llist_t *list, int type, sdb_strbuf_t *buf, int flags)
+store_obj_tojson(sdb_avltree_t *tree, int type, sdb_strbuf_t *buf,
+		sdb_store_matcher_t *filter, int flags)
 {
-	sdb_llist_iter_t *iter;
+	sdb_avltree_iter_t *iter;
 
-	assert((type == SDB_ATTRIBUTE) || (type == SDB_SERVICE));
+	assert((type == SDB_ATTRIBUTE)
+			|| (type == SDB_METRIC)
+			|| (type == SDB_SERVICE));
 
 	sdb_strbuf_append(buf, "[");
-	iter = sdb_llist_get_iter(list);
+	iter = sdb_avltree_get_iter(tree);
 	if (! iter) {
 		char errbuf[1024];
 		sdb_log(SDB_LOG_ERR, "store: Failed to retrieve %ss: %s\n",
@@ -432,11 +492,14 @@ store_obj_tojson(sdb_llist_t *list, int type, sdb_strbuf_t *buf, int flags)
 	}
 
 	/* has_next returns false if the iterator is NULL */
-	while (sdb_llist_iter_has_next(iter)) {
-		sdb_store_obj_t *sobj = STORE_OBJ(sdb_llist_iter_get_next(iter));
+	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 (filter && (! sdb_store_matcher_matches(filter, sobj, NULL)))
+			continue;
+
 		sdb_strbuf_append(buf, "{\"name\": \"%s\", ", SDB_OBJ(sobj)->name);
 		if (sobj->type == SDB_ATTRIBUTE) {
 			char tmp[sdb_data_strlen(&ATTR(sobj)->value) + 1];
@@ -450,18 +513,78 @@ store_obj_tojson(sdb_llist_t *list, int type, sdb_strbuf_t *buf, int flags)
 				&& (! (flags & SDB_SKIP_ATTRIBUTES))) {
 			sdb_strbuf_append(buf, ", \"attributes\": ");
 			store_obj_tojson(SVC(sobj)->attributes, SDB_ATTRIBUTE,
-					buf, flags);
+					buf, filter, flags);
+		}
+		else if ((sobj->type == SDB_METRIC)
+				&& (! (flags & SDB_SKIP_ATTRIBUTES))) {
+			sdb_strbuf_append(buf, ", \"attributes\": ");
+			store_obj_tojson(METRIC(sobj)->attributes, SDB_ATTRIBUTE,
+					buf, filter, flags);
 		}
 		sdb_strbuf_append(buf, "}");
 
-		if (sdb_llist_iter_has_next(iter))
+		if (sdb_avltree_iter_has_next(iter))
 			sdb_strbuf_append(buf, ",");
 	}
 
-	sdb_llist_iter_destroy(iter);
+	sdb_avltree_iter_destroy(iter);
 	sdb_strbuf_append(buf, "]");
 } /* store_obj_tojson */
 
+/*
+ * ts_tojson serializes a time-series to JSON.
+ *
+ * The function never returns an error. Rather, an error message will be part
+ * of the serialized data.
+ */
+static void
+ts_tojson(sdb_timeseries_t *ts, sdb_strbuf_t *buf)
+{
+	char start_str[64];
+	char end_str[64];
+
+	size_t i;
+
+	/* TODO: make time format configurable */
+	if (! sdb_strftime(start_str, sizeof(start_str),
+				"%F %T %z", ts->start))
+		snprintf(start_str, sizeof(start_str), "<error>");
+	start_str[sizeof(start_str) - 1] = '\0';
+	if (! sdb_strftime(end_str, sizeof(end_str),
+				"%F %T %z", ts->end))
+		snprintf(end_str, sizeof(end_str), "<error>");
+	end_str[sizeof(end_str) - 1] = '\0';
+
+	sdb_strbuf_append(buf, "{\"start\": \"%s\", \"end\": \"%s\", \"data\": {",
+			start_str, end_str);
+
+	for (i = 0; i < ts->data_names_len; ++i) {
+		size_t j;
+		sdb_strbuf_append(buf, "\"%s\": [", ts->data_names[i]);
+
+		for (j = 0; j < ts->data_len; ++j) {
+			char time_str[64];
+
+			if (! sdb_strftime(time_str, sizeof(time_str),
+						"%F %T %z", ts->data[i][j].timestamp))
+				snprintf(time_str, sizeof(time_str), "<error>");
+			time_str[sizeof(time_str) - 1] = '\0';
+
+			sdb_strbuf_append(buf, "{\"timestamp\": \"%s\", "
+					"\"value\": \"%f\"}", time_str, ts->data[i][j].value);
+
+			if (j < ts->data_len - 1)
+				sdb_strbuf_append(buf, ",");
+		}
+
+		if (i < ts->data_names_len - 1)
+			sdb_strbuf_append(buf, "],");
+		else
+			sdb_strbuf_append(buf, "]");
+	}
+	sdb_strbuf_append(buf, "}}");
+} /* ts_tojson */
+
 /*
  * public API
  */
@@ -469,8 +592,8 @@ store_obj_tojson(sdb_llist_t *list, int type, sdb_strbuf_t *buf, int flags)
 void
 sdb_store_clear(void)
 {
-	sdb_llist_destroy(host_list);
-	host_list = NULL;
+	sdb_avltree_destroy(hosts);
+	hosts = NULL;
 } /* sdb_store_clear */
 
 int
@@ -489,12 +612,12 @@ sdb_store_host(const char *name, sdb_time_t last_update)
 	}
 
 	pthread_rwlock_wrlock(&host_lock);
-	if (! host_list)
-		if (! (host_list = sdb_llist_create()))
+	if (! hosts)
+		if (! (hosts = sdb_avltree_create()))
 			status = -1;
 
 	if (! status)
-		status = store_obj(host_list, SDB_HOST, cname, last_update, NULL);
+		status = store_obj(hosts, SDB_HOST, cname, last_update, NULL);
 	pthread_rwlock_unlock(&host_lock);
 
 	free(cname);
@@ -525,7 +648,6 @@ sdb_store_get_host(const char *name)
 	if (! host)
 		return NULL;
 
-	sdb_object_ref(SDB_OBJ(host));
 	return STORE_OBJ(host);
 } /* sdb_store_get_host */
 
@@ -534,7 +656,7 @@ sdb_store_attribute(const char *hostname,
 		const char *key, const sdb_data_t *value,
 		sdb_time_t last_update)
 {
-	sdb_llist_t *attrs;
+	sdb_avltree_t *attrs;
 	int status = 0;
 
 	if ((! hostname) || (! key))
@@ -559,7 +681,7 @@ int
 sdb_store_service(const char *hostname, const char *name,
 		sdb_time_t last_update)
 {
-	sdb_llist_t *services;
+	sdb_avltree_t *services;
 
 	int status = 0;
 
@@ -584,7 +706,7 @@ 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_llist_t *services;
+	sdb_avltree_t *services;
 	sdb_service_t *svc;
 	int status = 0;
 
@@ -601,7 +723,7 @@ sdb_store_service_attr(const char *hostname, const char *service,
 		return -1;
 	}
 
-	svc = SVC(sdb_llist_search_by_name(services, service));
+	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);
@@ -611,69 +733,300 @@ sdb_store_service_attr(const char *hostname, const char *service,
 	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_attr */
 
 int
-sdb_store_host_tojson(sdb_store_obj_t *h, sdb_strbuf_t *buf, int flags)
+sdb_store_metric(const char *hostname, const char *name,
+		sdb_metric_store_t *store, sdb_time_t last_update)
 {
-	sdb_host_t *host;
+	sdb_store_obj_t *obj = NULL;
+	sdb_metric_t *metric;
+
+	sdb_avltree_t *metrics;
+
+	int status = 0;
+
+	if ((! hostname) || (! name))
+		return -1;
+	if (store && ((! store->type) || (! store->id)))
+		return -1;
+
+	pthread_rwlock_wrlock(&host_lock);
+	metrics = get_host_children(hostname, SDB_METRIC);
+	if (! metrics) {
+		sdb_log(SDB_LOG_ERR, "store: Failed to store metric '%s' - "
+				"host '%s' not found", name, hostname);
+		status = -1;
+	}
+
+	if (! status)
+		status = store_obj(metrics, SDB_METRIC, name, last_update, &obj);
+
+	if (status || (! store)) {
+		pthread_rwlock_unlock(&host_lock);
+		return status;
+	}
+
+	assert(obj);
+	metric = METRIC(obj);
+
+	if ((! metric->store.type) || strcasecmp(metric->store.type, store->type)) {
+		if (metric->store.type)
+			free(metric->store.type);
+		metric->store.type = strdup(store->type);
+	}
+	if ((! metric->store.id) || strcasecmp(metric->store.id, store->id)) {
+		if (metric->store.id)
+			free(metric->store.id);
+		metric->store.id = strdup(store->id);
+	}
+
+	if ((! metric->store.type) || (! metric->store.id)) {
+		if (metric->store.type)
+			free(metric->store.type);
+		if (metric->store.id)
+			free(metric->store.id);
+		metric->store.type = metric->store.id = NULL;
+		status = -1;
+	}
+	pthread_rwlock_unlock(&host_lock);
+	return status;
+} /* sdb_store_metric */
+
+int
+sdb_store_metric_attr(const char *hostname, const char *metric,
+		const char *key, const sdb_data_t *value, sdb_time_t last_update)
+{
+	sdb_avltree_t *metrics;
+	sdb_metric_t *m;
+	int status = 0;
+
+	if ((! hostname) || (! metric) || (! key))
+		return -1;
+
+	pthread_rwlock_wrlock(&host_lock);
+	metrics = get_host_children(hostname, SDB_METRIC);
+	if (! metrics) {
+		sdb_log(SDB_LOG_ERR, "store: Failed to store attribute '%s' "
+				"for metric '%s' - host '%s' not found",
+				key, metric, hostname);
+		pthread_rwlock_unlock(&host_lock);
+		return -1;
+	}
+
+	m = METRIC(sdb_avltree_lookup(metrics, metric));
+	if (! m) {
+		sdb_log(SDB_LOG_ERR, "store: Failed to store attribute '%s' - "
+				"metric '%s/%s' not found", key, hostname, metric);
+		status = -1;
+	}
+
+	if (! status)
+		status = store_attr(m->attributes, key, value, last_update);
+
+	sdb_object_deref(SDB_OBJ(m));
+	pthread_rwlock_unlock(&host_lock);
+	return status;
+} /* sdb_store_metric_attr */
+
+int
+sdb_store_fetch_timeseries(const char *hostname, const char *metric,
+		sdb_timeseries_opts_t *opts, sdb_strbuf_t *buf)
+{
+	sdb_avltree_t *metrics;
+	sdb_metric_t *m;
+
+	sdb_timeseries_t *ts;
+
+	if ((! hostname) || (! metric) || (! opts) || (! buf))
+		return -1;
+
+	pthread_rwlock_rdlock(&host_lock);
+	metrics = get_host_children(hostname, SDB_METRIC);
+	if (! metrics) {
+		sdb_log(SDB_LOG_ERR, "store: Failed to fetch time-series '%s/%s' "
+				"- host '%s' not found", hostname, metric, hostname);
+		pthread_rwlock_unlock(&host_lock);
+		return -1;
+	}
+
+	m = METRIC(sdb_avltree_lookup(metrics, metric));
+	if (! m) {
+		sdb_log(SDB_LOG_ERR, "store: Failed to fetch time-series '%s/%s' "
+				"- metric '%s' not found", hostname, metric, metric);
+		pthread_rwlock_unlock(&host_lock);
+		return -1;
+	}
+
+	if ((! m->store.type) || (! m->store.id)) {
+		sdb_log(SDB_LOG_ERR, "store: Failed to fetch time-series '%s/%s' "
+				"- no data-store configured for the stored metric",
+				hostname, metric);
+		pthread_rwlock_unlock(&host_lock);
+		return -1;
+	}
+
+	{
+		char type[strlen(m->store.type) + 1];
+		char id[strlen(m->store.id) + 1];
+
+		strncpy(type, m->store.type, sizeof(type));
+		strncpy(id, m->store.id, sizeof(id));
+		pthread_rwlock_unlock(&host_lock);
+
+		ts = sdb_plugin_fetch_timeseries(type, id, opts);
+		if (! ts) {
+			sdb_log(SDB_LOG_ERR, "store: Failed to fetch time-series '%s/%s' "
+					"- %s fetcher callback returned no data for '%s'",
+					hostname, metric, type, id);
+			return -1;
+		}
+	}
+
+	ts_tojson(ts, buf);
+	sdb_timeseries_destroy(ts);
+	return 0;
+} /* sdb_store_fetch_timeseries */
+
+int
+sdb_store_get_field(sdb_store_obj_t *obj, int field, sdb_data_t *res)
+{
+	if ((! obj) || (! res))
+		return -1;
+
+	switch (field) {
+		case SDB_FIELD_LAST_UPDATE:
+			res->type = SDB_TYPE_DATETIME;
+			res->data.datetime = obj->last_update;
+			break;
+		case SDB_FIELD_AGE:
+			res->type = SDB_TYPE_DATETIME;
+			res->data.datetime = sdb_gettime() - obj->last_update;
+			break;
+		case SDB_FIELD_INTERVAL:
+			res->type = SDB_TYPE_DATETIME;
+			res->data.datetime = obj->interval;
+			break;
+		case SDB_FIELD_BACKEND:
+			/* TODO: add support for storing array values in a data object
+			 * for now, fall thru to the error case */
+		default:
+			return -1;
+	}
+	return 0;
+} /* sdb_store_get_field */
+
+int
+sdb_store_host_tojson(sdb_store_obj_t *h, sdb_strbuf_t *buf,
+		sdb_store_matcher_t *filter, int flags)
+{
+	sdb_host_t *host = HOST(h);
 
 	if ((! h) || (h->type != SDB_HOST) || (! buf))
 		return -1;
 
-	host = HOST(h);
+	/* This function ignores SKIP_EMPTY flags given that the current
+	 * implementation sucks and it's nut currently used when calling this
+	 * function directly. */
 
 	sdb_strbuf_append(buf, "{\"name\": \"%s\", ", SDB_OBJ(host)->name);
 	store_common_tojson(h, buf);
 
 	if (! (flags & SDB_SKIP_ATTRIBUTES)) {
 		sdb_strbuf_append(buf, ", \"attributes\": ");
-		store_obj_tojson(host->attributes, SDB_ATTRIBUTE, buf, flags);
+		store_obj_tojson(host->attributes, SDB_ATTRIBUTE, buf, filter, flags);
+	}
+
+	if (! (flags & SDB_SKIP_METRICS)) {
+		sdb_strbuf_append(buf, ", \"metrics\": ");
+		store_obj_tojson(host->metrics, SDB_METRIC, buf, filter, flags);
 	}
 
 	if (! (flags & SDB_SKIP_SERVICES)) {
 		sdb_strbuf_append(buf, ", \"services\": ");
-		store_obj_tojson(host->services, SDB_SERVICE, buf, flags);
+		store_obj_tojson(host->services, SDB_SERVICE, buf, filter, flags);
 	}
 
 	sdb_strbuf_append(buf, "}");
 	return 0;
 } /* sdb_store_host_tojson */
 
+static _Bool
+has_children(sdb_avltree_t *tree, sdb_store_matcher_t *filter)
+{
+	sdb_avltree_iter_t *iter;
+
+	if (! filter)
+		return sdb_avltree_size(tree) > 0;
+
+	iter = sdb_avltree_get_iter(tree);
+	while (sdb_avltree_iter_has_next(iter)) {
+		sdb_store_obj_t *sobj = STORE_OBJ(sdb_avltree_iter_get_next(iter));
+		if (sdb_store_matcher_matches(filter, sobj, NULL)) {
+			sdb_avltree_iter_destroy(iter);
+			return 1;
+		}
+	}
+	sdb_avltree_iter_destroy(iter);
+	return 0;
+} /* has_children */
+
 int
-sdb_store_tojson(sdb_strbuf_t *buf, int flags)
+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 (! 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;
 	}
 
-	sdb_strbuf_append(buf, "{\"hosts\":[");
+	sdb_strbuf_append(buf, "[");
 
-	while (sdb_llist_iter_has_next(host_iter)) {
-		sdb_store_obj_t *host = STORE_OBJ(sdb_llist_iter_get_next(host_iter));
-		assert(host);
+	len = sdb_strbuf_len(buf);
+	while (sdb_avltree_iter_has_next(host_iter)) {
+		sdb_store_obj_t *host;
 
-		if (sdb_store_host_tojson(host, buf, flags))
-			return -1;
+		host = STORE_OBJ(sdb_avltree_iter_get_next(host_iter));
+		assert(host);
 
-		if (sdb_llist_iter_has_next(host_iter))
+		if (filter && (! sdb_store_matcher_matches(filter, host, NULL)))
+			continue;
+
+		/*
+		 * XXX: This approach sucks but it's the best we can do at the moment.
+		 * In the future, all store lookups should be split into multiple
+		 * steps instead: first, retrieve all relevant objects and apply all
+		 * pre-processing operations and then format it for the wire.
+		 */
+		if ((flags & SDB_SKIP_EMPTY_SERVICES)
+				&& (! has_children(HOST(host)->services, filter)))
+			continue;
+		if ((flags & SDB_SKIP_EMPTY_METRICS)
+				&& (! has_children(HOST(host)->metrics, filter)))
+			continue;
+
+		if (sdb_strbuf_len(buf) > len)
 			sdb_strbuf_append(buf, ",");
+		len = sdb_strbuf_len(buf);
+
+		if (sdb_store_host_tojson(host, buf, filter, flags))
+			return -1;
 	}
 
-	sdb_strbuf_append(buf, "]}");
+	sdb_strbuf_append(buf, "]");
 
-	sdb_llist_iter_destroy(host_iter);
+	sdb_avltree_iter_destroy(host_iter);
 	pthread_rwlock_unlock(&host_lock);
 	return 0;
 } /* sdb_store_tojson */
@@ -682,18 +1035,20 @@ sdb_store_tojson(sdb_strbuf_t *buf, int flags)
 int
 sdb_store_iterate(sdb_store_iter_cb cb, void *user_data)
 {
-	sdb_llist_iter_t *host_iter;
+	sdb_avltree_iter_t *host_iter;
 	int status = 0;
 
 	pthread_rwlock_rdlock(&host_lock);
 
-	host_iter = sdb_llist_get_iter(host_list);
+	host_iter = sdb_avltree_get_iter(hosts);
 	if (! host_iter)
 		status = -1;
 
 	/* has_next returns false if the iterator is NULL */
-	while (sdb_llist_iter_has_next(host_iter)) {
-		sdb_store_obj_t *host = STORE_OBJ(sdb_llist_iter_get_next(host_iter));
+	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 (cb(host, user_data)) {
@@ -702,7 +1057,7 @@ sdb_store_iterate(sdb_store_iter_cb cb, void *user_data)
 		}
 	}
 
-	sdb_llist_iter_destroy(host_iter);
+	sdb_avltree_iter_destroy(host_iter);
 	pthread_rwlock_unlock(&host_lock);
 	return status;
 } /* sdb_store_iterate */