From b75718ea9fe4d6c90f1794e517a0712729553c0c Mon Sep 17 00:00:00 2001
From: Sebastian Harl <sh@tokkee.org>
Date: Thu, 24 Sep 2015 20:49:55 +0200
Subject: [PATCH] store, plugin: Let the plugin module determine an objects
 backends.

The store writer plugins are only expected to record the provided backend
(after merging it with existing entries).
---
 src/core/plugin.c        | 33 +++++++++++++++++++++++
 src/core/store.c         | 58 +++++++++++++++++++++++++---------------
 src/include/core/store.h |  8 +++---
 3 files changed, 74 insertions(+), 25 deletions(-)

diff --git a/src/core/plugin.c b/src/core/plugin.c
index 2cb852e..83ef6ea 100644
--- a/src/core/plugin.c
+++ b/src/core/plugin.c
@@ -661,6 +661,21 @@ plugin_add_callback(sdb_llist_t **list, const char *type,
 	return 0;
 } /* plugin_add_callback */
 
+static void
+get_backend(const char **backends, size_t *backends_num)
+{
+	const sdb_plugin_info_t *info;
+
+	info = sdb_plugin_current();
+	if ((! info) || (! info->plugin_name) || (! *info->plugin_name)) {
+		*backends_num = 0;
+		return;
+	}
+
+	backends[0] = info->plugin_name;
+	*backends_num = 1;
+} /* get_backend */
+
 /*
  * public API
  */
@@ -1470,6 +1485,7 @@ int
 sdb_plugin_store_host(const char *name, sdb_time_t last_update)
 {
 	sdb_store_host_t host = { 0 };
+	const char *backends[1];
 	char *cname;
 
 	sdb_llist_iter_t *iter;
@@ -1492,6 +1508,8 @@ sdb_plugin_store_host(const char *name, sdb_time_t last_update)
 
 	host.name = cname;
 	host.last_update = last_update;
+	host.backends = backends;
+	get_backend(host.backends, &host.backends_num);
 
 	iter = sdb_llist_get_iter(writer_list);
 	while (sdb_llist_iter_has_next(iter)) {
@@ -1512,6 +1530,7 @@ sdb_plugin_store_service(const char *hostname, const char *name,
 		sdb_time_t last_update)
 {
 	sdb_store_service_t service = { 0 };
+	const char *backends[1];
 	char *cname;
 
 	sdb_llist_iter_t *iter;
@@ -1537,6 +1556,8 @@ sdb_plugin_store_service(const char *hostname, const char *name,
 	service.hostname = cname;
 	service.name = name;
 	service.last_update = last_update;
+	service.backends = backends;
+	get_backend(service.backends, &service.backends_num);
 
 	iter = sdb_llist_get_iter(writer_list);
 	while (sdb_llist_iter_has_next(iter)) {
@@ -1567,6 +1588,7 @@ sdb_plugin_store_metric(const char *hostname, const char *name,
 		sdb_metric_store_t *store, sdb_time_t last_update)
 {
 	sdb_store_metric_t metric = { 0 };
+	const char *backends[1];
 	char *cname;
 
 	sdb_llist_iter_t *iter;
@@ -1599,6 +1621,8 @@ sdb_plugin_store_metric(const char *hostname, const char *name,
 		metric.store.id = store->id;
 	}
 	metric.last_update = last_update;
+	metric.backends = backends;
+	get_backend(metric.backends, &metric.backends_num);
 
 	iter = sdb_llist_get_iter(writer_list);
 	while (sdb_llist_iter_has_next(iter)) {
@@ -1629,6 +1653,7 @@ sdb_plugin_store_attribute(const char *hostname, const char *key,
 		const sdb_data_t *value, sdb_time_t last_update)
 {
 	sdb_store_attribute_t attr = { 0 };
+	const char *backends[1];
 	char *cname;
 
 	sdb_llist_iter_t *iter;
@@ -1654,6 +1679,8 @@ sdb_plugin_store_attribute(const char *hostname, const char *key,
 	attr.key = key;
 	attr.value = *value;
 	attr.last_update = last_update;
+	attr.backends = backends;
+	get_backend(attr.backends, &attr.backends_num);
 
 	iter = sdb_llist_get_iter(writer_list);
 	while (sdb_llist_iter_has_next(iter)) {
@@ -1674,6 +1701,7 @@ sdb_plugin_store_service_attribute(const char *hostname, const char *service,
 		const char *key, const sdb_data_t *value, sdb_time_t last_update)
 {
 	sdb_store_attribute_t attr = { 0 };
+	const char *backends[1];
 	char *cname;
 
 	sdb_llist_iter_t *iter;
@@ -1700,6 +1728,8 @@ sdb_plugin_store_service_attribute(const char *hostname, const char *service,
 	attr.key = key;
 	attr.value = *value;
 	attr.last_update = last_update;
+	attr.backends = backends;
+	get_backend(attr.backends, &attr.backends_num);
 
 	iter = sdb_llist_get_iter(writer_list);
 	while (sdb_llist_iter_has_next(iter)) {
@@ -1720,6 +1750,7 @@ sdb_plugin_store_metric_attribute(const char *hostname, const char *metric,
 		const char *key, const sdb_data_t *value, sdb_time_t last_update)
 {
 	sdb_store_attribute_t attr = { 0 };
+	const char *backends[1];
 	char *cname;
 
 	sdb_llist_iter_t *iter;
@@ -1746,6 +1777,8 @@ sdb_plugin_store_metric_attribute(const char *hostname, const char *metric,
 	attr.key = key;
 	attr.value = *value;
 	attr.last_update = last_update;
+	attr.backends = backends;
+	get_backend(attr.backends, &attr.backends_num);
 
 	iter = sdb_llist_get_iter(writer_list);
 	while (sdb_llist_iter_has_next(iter)) {
diff --git a/src/core/store.c b/src/core/store.c
index 9c83218..c6e22df 100644
--- a/src/core/store.c
+++ b/src/core/store.c
@@ -66,8 +66,10 @@ typedef struct {
 	int type;
 	const char *name;
 	sdb_time_t last_update;
+	const char **backends;
+	size_t backends_num;
 } store_obj_t;
-#define STORE_OBJ_INIT { NULL, NULL, 0, NULL, 0 }
+#define STORE_OBJ_INIT { NULL, NULL, 0, NULL, 0, NULL, 0 }
 
 static sdb_type_t host_type;
 static sdb_type_t service_type;
@@ -304,33 +306,39 @@ static sdb_type_t attribute_type = {
  */
 
 static int
-record_backend(sdb_store_obj_t *obj)
+record_backends(sdb_store_obj_t *obj,
+		const char **backends, size_t backends_num)
 {
-	const sdb_plugin_info_t *info;
 	char **tmp;
 	size_t i;
 
-	info = sdb_plugin_current();
-	if (! info)
-		return 0;
+	for (i = 0; i < backends_num; i++) {
+		bool found = 0;
+		size_t j;
 
-	for (i = 0; i < obj->backends_num; ++i)
-		if (!strcasecmp(obj->backends[i], info->plugin_name))
-			return 0;
+		for (j = 0; j < obj->backends_num; ++j) {
+			if (!strcasecmp(obj->backends[j], backends[i])) {
+				found = 1;
+				break;
+			}
+		}
+		if (found)
+			continue;
 
-	tmp = realloc(obj->backends,
-			(obj->backends_num + 1) * sizeof(*obj->backends));
-	if (! tmp)
-		return -1;
+		tmp = realloc(obj->backends,
+				(obj->backends_num + 1) * sizeof(*obj->backends));
+		if (! tmp)
+			return -1;
 
-	obj->backends = tmp;
-	obj->backends[obj->backends_num] = strdup(info->plugin_name);
-	if (! obj->backends[obj->backends_num])
-		return -1;
+		obj->backends = tmp;
+		obj->backends[obj->backends_num] = strdup(backends[i]);
+		if (! obj->backends[obj->backends_num])
+			return -1;
 
-	++obj->backends_num;
+		++obj->backends_num;
+	}
 	return 0;
-} /* record_backend */
+} /* record_backends */
 
 static int
 store_obj(store_obj_t *obj, sdb_store_obj_t **updated_obj)
@@ -421,7 +429,7 @@ store_obj(store_obj_t *obj, sdb_store_obj_t **updated_obj)
 	if (updated_obj)
 		*updated_obj = new;
 
-	if (record_backend(new))
+	if (record_backends(new, obj->backends, obj->backends_num))
 		return -1;
 	return status;
 } /* store_obj */
@@ -599,6 +607,8 @@ store_attribute(sdb_store_attribute_t *attr, sdb_object_t *user_data)
 	obj.type = SDB_ATTRIBUTE;
 	obj.name = attr->key;
 	obj.last_update = attr->last_update;
+	obj.backends = attr->backends;
+	obj.backends_num = attr->backends_num;
 	if (! status)
 		status = store_obj(&obj, &new);
 
@@ -622,7 +632,7 @@ static int
 store_host(sdb_store_host_t *host, sdb_object_t *user_data)
 {
 	sdb_store_t *st = SDB_STORE(user_data);
-	store_obj_t obj = { NULL, st->hosts, SDB_HOST, NULL, 0 };
+	store_obj_t obj = { NULL, st->hosts, SDB_HOST, NULL, 0, NULL, 0 };
 	int status = 0;
 
 	if ((! host) || (! host->name))
@@ -630,6 +640,8 @@ store_host(sdb_store_host_t *host, sdb_object_t *user_data)
 
 	obj.name = host->name;
 	obj.last_update = host->last_update;
+	obj.backends = host->backends;
+	obj.backends_num = host->backends_num;
 	pthread_rwlock_wrlock(&st->host_lock);
 	status = store_obj(&obj, NULL);
 	pthread_rwlock_unlock(&st->host_lock);
@@ -662,6 +674,8 @@ store_service(sdb_store_service_t *service, sdb_object_t *user_data)
 
 	obj.name = service->name;
 	obj.last_update = service->last_update;
+	obj.backends = service->backends;
+	obj.backends_num = service->backends_num;
 	if (! status)
 		status = store_obj(&obj, NULL);
 
@@ -699,6 +713,8 @@ store_metric(sdb_store_metric_t *metric, sdb_object_t *user_data)
 
 	obj.name = metric->name;
 	obj.last_update = metric->last_update;
+	obj.backends = metric->backends;
+	obj.backends_num = metric->backends_num;
 	if (! status)
 		status = store_obj(&obj, &new);
 	sdb_object_deref(SDB_OBJ(host));
diff --git a/src/include/core/store.h b/src/include/core/store.h
index a1e5e17..bccb792 100644
--- a/src/include/core/store.h
+++ b/src/include/core/store.h
@@ -118,7 +118,7 @@ typedef struct {
 
 	sdb_time_t last_update;
 	sdb_time_t interval;
-	char **backends;
+	const char **backends;
 	size_t backends_num;
 } sdb_store_host_t;
 
@@ -131,7 +131,7 @@ typedef struct {
 
 	sdb_time_t last_update;
 	sdb_time_t interval;
-	char **backends;
+	const char **backends;
 	size_t backends_num;
 } sdb_store_service_t;
 
@@ -156,7 +156,7 @@ typedef struct {
 
 	sdb_time_t last_update;
 	sdb_time_t interval;
-	char **backends;
+	const char **backends;
 	size_t backends_num;
 } sdb_store_metric_t;
 
@@ -172,7 +172,7 @@ typedef struct {
 
 	sdb_time_t last_update;
 	sdb_time_t interval;
-	char **backends;
+	const char **backends;
 	size_t backends_num;
 } sdb_store_attribute_t;
 
-- 
2.30.2