X-Git-Url: https://git.tokkee.org/?p=sysdb.git;a=blobdiff_plain;f=src%2Fcore%2Fmemstore.c;fp=src%2Fcore%2Fmemstore.c;h=244982777cfb38fc82b5b99e8e8cf1c645e56b91;hp=0000000000000000000000000000000000000000;hb=25bba5d07cafb9f1169d687bffb742dae6f77a8e;hpb=78ea02850cbffccb0df63d77cd4e42238137e63f

diff --git a/src/core/memstore.c b/src/core/memstore.c
new file mode 100644
index 0000000..2449827
--- /dev/null
+++ b/src/core/memstore.c
@@ -0,0 +1,1085 @@
+/*
+ * SysDB - src/core/memstore.c
+ * Copyright (C) 2012-2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#if HAVE_CONFIG_H
+#	include "config.h"
+#endif /* HAVE_CONFIG_H */
+
+#include "sysdb.h"
+#include "core/memstore-private.h"
+#include "core/plugin.h"
+#include "utils/avltree.h"
+#include "utils/error.h"
+
+#include <assert.h>
+
+#include <errno.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <pthread.h>
+
+/*
+ * private types
+ */
+
+struct sdb_memstore {
+	sdb_object_t super;
+
+	/* hosts are the top-level entries and
+	 * reference everything else */
+	sdb_avltree_t *hosts;
+	pthread_rwlock_t host_lock;
+};
+
+/* internal representation of a to-be-stored object */
+typedef struct {
+	sdb_memstore_obj_t *parent;
+	sdb_avltree_t *parent_tree;
+	int type;
+	const char *name;
+	sdb_time_t last_update;
+	sdb_time_t interval;
+	const char * const *backends;
+	size_t backends_num;
+} store_obj_t;
+#define STORE_OBJ_INIT { NULL, NULL, 0, NULL, 0, 0, NULL, 0 }
+
+static sdb_type_t host_type;
+static sdb_type_t service_type;
+static sdb_type_t metric_type;
+static sdb_type_t attribute_type;
+
+static int
+store_init(sdb_object_t *obj, va_list __attribute__((unused)) ap)
+{
+	int err;
+	if (! (SDB_MEMSTORE(obj)->hosts = sdb_avltree_create()))
+		return -1;
+	if ((err = pthread_rwlock_init(&SDB_MEMSTORE(obj)->host_lock,
+					/* attr = */ NULL))) {
+		char errbuf[128];
+		sdb_log(SDB_LOG_ERR, "memstore: Failed to initialize lock: %s",
+				sdb_strerror(err, errbuf, sizeof(errbuf)));
+		return -1;
+	}
+	return 0;
+} /* store_init */
+
+static void
+store_destroy(sdb_object_t *obj)
+{
+	int err;
+	if ((err = pthread_rwlock_destroy(&SDB_MEMSTORE(obj)->host_lock))) {
+		char errbuf[128];
+		sdb_log(SDB_LOG_ERR, "memstore: Failed to destroy lock: %s",
+				sdb_strerror(err, errbuf, sizeof(errbuf)));
+		return;
+	}
+	sdb_avltree_destroy(SDB_MEMSTORE(obj)->hosts);
+	SDB_MEMSTORE(obj)->hosts = NULL;
+} /* store_destroy */
+
+static int
+store_obj_init(sdb_object_t *obj, va_list ap)
+{
+	sdb_memstore_obj_t *sobj = STORE_OBJ(obj);
+	sobj->type = va_arg(ap, int);
+	return 0;
+} /* store_obj_init */
+
+static void
+store_obj_destroy(sdb_object_t *obj)
+{
+	sdb_memstore_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;
+
+	// We don't currently keep an extra reference for parent objects to
+	// avoid circular self-references which are not handled correctly by
+	// the ref-count base management layer.
+	//sdb_object_deref(SDB_OBJ(sobj->parent));
+} /* store_obj_destroy */
+
+static int
+host_init(sdb_object_t *obj, va_list ap)
+{
+	host_t *sobj = HOST(obj);
+	int ret;
+
+	/* this will consume the first argument (type) of ap */
+	ret = store_obj_init(obj, ap);
+	if (ret)
+		return ret;
+
+	sobj->services = sdb_avltree_create();
+	if (! sobj->services)
+		return -1;
+	sobj->metrics = sdb_avltree_create();
+	if (! sobj->metrics)
+		return -1;
+	sobj->attributes = sdb_avltree_create();
+	if (! sobj->attributes)
+		return -1;
+	return 0;
+} /* host_init */
+
+static void
+host_destroy(sdb_object_t *obj)
+{
+	host_t *sobj = HOST(obj);
+	assert(obj);
+
+	store_obj_destroy(obj);
+
+	if (sobj->services)
+		sdb_avltree_destroy(sobj->services);
+	if (sobj->metrics)
+		sdb_avltree_destroy(sobj->metrics);
+	if (sobj->attributes)
+		sdb_avltree_destroy(sobj->attributes);
+} /* host_destroy */
+
+static int
+service_init(sdb_object_t *obj, va_list ap)
+{
+	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;
+
+	sobj->attributes = sdb_avltree_create();
+	if (! sobj->attributes)
+		return -1;
+	return 0;
+} /* service_init */
+
+static void
+service_destroy(sdb_object_t *obj)
+{
+	service_t *sobj = SVC(obj);
+	assert(obj);
+
+	store_obj_destroy(obj);
+
+	if (sobj->attributes)
+		sdb_avltree_destroy(sobj->attributes);
+} /* service_destroy */
+
+static int
+metric_init(sdb_object_t *obj, va_list ap)
+{
+	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;
+} /* metric_init */
+
+static void
+metric_destroy(sdb_object_t *obj)
+{
+	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);
+} /* metric_destroy */
+
+static int
+attr_init(sdb_object_t *obj, va_list ap)
+{
+	const sdb_data_t *value;
+	int ret;
+
+	/* this will consume the first argument (type) 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;
+} /* attr_init */
+
+static void
+attr_destroy(sdb_object_t *obj)
+{
+	assert(obj);
+
+	store_obj_destroy(obj);
+	sdb_data_free_datum(&ATTR(obj)->value);
+} /* attr_destroy */
+
+static sdb_type_t store_type = {
+	/* size = */ sizeof(sdb_memstore_t),
+	/* init = */ store_init,
+	/* destroy = */ store_destroy,
+};
+
+static sdb_type_t host_type = {
+	/* size = */ sizeof(host_t),
+	/* init = */ host_init,
+	/* destroy = */ host_destroy
+};
+
+static sdb_type_t service_type = {
+	/* size = */ sizeof(service_t),
+	/* init = */ service_init,
+	/* destroy = */ service_destroy
+};
+
+static sdb_type_t metric_type = {
+	/* size = */ sizeof(metric_t),
+	/* init = */ metric_init,
+	/* destroy = */ metric_destroy
+};
+
+static sdb_type_t attribute_type = {
+	/* size = */ sizeof(attr_t),
+	/* init = */ attr_init,
+	/* destroy = */ attr_destroy
+};
+
+/*
+ * private helper functions
+ */
+
+static int
+record_backends(sdb_memstore_obj_t *obj,
+		const char * const *backends, size_t backends_num)
+{
+	char **tmp;
+	size_t i;
+
+	for (i = 0; i < backends_num; i++) {
+		bool found = 0;
+		size_t j;
+
+		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;
+
+		obj->backends = tmp;
+		obj->backends[obj->backends_num] = strdup(backends[i]);
+		if (! obj->backends[obj->backends_num])
+			return -1;
+
+		++obj->backends_num;
+	}
+	return 0;
+} /* record_backends */
+
+static int
+store_obj(store_obj_t *obj, sdb_memstore_obj_t **updated_obj)
+{
+	sdb_memstore_obj_t *old, *new;
+	int status = 0;
+
+	assert(obj->parent_tree);
+
+	old = STORE_OBJ(sdb_avltree_lookup(obj->parent_tree, obj->name));
+	if (old) {
+		new = old;
+		sdb_object_deref(SDB_OBJ(old));
+	}
+	else {
+		if (obj->type == SDB_ATTRIBUTE) {
+			/* the value will be updated by the caller */
+			new = STORE_OBJ(sdb_object_create(obj->name, attribute_type,
+						obj->type, NULL));
+		}
+		else {
+			sdb_type_t t;
+			t = obj->type == SDB_HOST
+				? host_type
+				: obj->type == SDB_SERVICE
+					? service_type
+					: metric_type;
+			new = STORE_OBJ(sdb_object_create(obj->name, t, obj->type));
+		}
+
+		if (new) {
+			status = sdb_avltree_insert(obj->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, "memstore: Failed to create %s '%s': %s",
+					SDB_STORE_TYPE_TO_NAME(obj->type), obj->name,
+					sdb_strerror(errno, errbuf, sizeof(errbuf)));
+			status = -1;
+		}
+	}
+
+	if (status < 0)
+		return status;
+	assert(new);
+
+	new->last_update = obj->last_update;
+	new->interval = obj->interval;
+
+	if (new->parent != obj->parent) {
+		// Avoid circular self-references which are not handled
+		// correctly by the ref-count based management layer.
+		//sdb_object_deref(SDB_OBJ(new->parent));
+		//sdb_object_ref(SDB_OBJ(obj->parent));
+		new->parent = obj->parent;
+	}
+
+	if (updated_obj)
+		*updated_obj = new;
+
+	if (record_backends(new, obj->backends, obj->backends_num))
+		return -1;
+	return status;
+} /* store_obj */
+
+static int
+store_metric_store(metric_t *metric, sdb_store_metric_t *m)
+{
+	char *type = metric->store.type;
+	char *id = metric->store.id;
+
+	if ((! metric->store.type) || strcasecmp(metric->store.type, m->store.type)) {
+		if (! (type = strdup(m->store.type)))
+			return -1;
+	}
+	if ((! metric->store.id) || strcasecmp(metric->store.id, m->store.id)) {
+		if (! (id = strdup(m->store.id))) {
+			if (type != metric->store.type)
+				free(type);
+			return -1;
+		}
+	}
+
+	if (type != metric->store.type) {
+		if (metric->store.type)
+			free(metric->store.type);
+		metric->store.type = type;
+	}
+	if (id != metric->store.id) {
+		if (metric->store.id)
+			free(metric->store.id);
+		metric->store.id = id;
+	}
+	return 0;
+} /* store_metric_store */
+
+/* The store's host_lock has to be acquired before calling this function. */
+static sdb_avltree_t *
+get_host_children(host_t *host, int type)
+{
+	if ((type != SDB_SERVICE) && (type != SDB_METRIC)
+			&& (type != SDB_ATTRIBUTE))
+		return NULL;
+
+	if (! host)
+		return NULL;
+
+	if (type == SDB_ATTRIBUTE)
+		return host->attributes;
+	else if (type == SDB_METRIC)
+		return host->metrics;
+	else
+		return host->services;
+} /* get_host_children */
+
+static sdb_avltree_t *
+get_obj_attrs(sdb_memstore_obj_t *obj)
+{
+	if (obj->type == SDB_HOST)
+		return HOST(obj)->attributes;
+	else if (obj->type == SDB_SERVICE)
+		return SVC(obj)->attributes;
+	else if (obj->type == SDB_METRIC)
+		return METRIC(obj)->attributes;
+	return NULL;
+} /* get_obj_attrs */
+
+/*
+ * store writer API
+ */
+
+static int
+store_attribute(sdb_store_attribute_t *attr, sdb_object_t *user_data)
+{
+	sdb_memstore_t *st = SDB_MEMSTORE(user_data);
+	store_obj_t obj = STORE_OBJ_INIT;
+	sdb_memstore_obj_t *new = NULL;
+	const char *hostname;
+	host_t *host;
+
+	sdb_avltree_t *children = NULL;
+	int status = 0;
+
+	if ((! attr) || (! attr->parent) || (! attr->key))
+		return -1;
+
+	hostname = attr->hostname;
+	if (attr->parent_type == SDB_HOST)
+		hostname = attr->parent;
+	if (! hostname)
+		return -1;
+
+	pthread_rwlock_wrlock(&st->host_lock);
+	host = HOST(sdb_avltree_lookup(st->hosts, hostname));
+	if (! host) {
+		sdb_log(SDB_LOG_ERR, "memstore: Failed to store attribute '%s' - "
+				"host '%s' not found", attr->key, hostname);
+		status = -1;
+	}
+
+	switch (attr->parent_type) {
+	case SDB_HOST:
+		obj.parent = STORE_OBJ(host);
+		obj.parent_tree = get_host_children(host, SDB_ATTRIBUTE);
+		break;
+	case SDB_SERVICE:
+	case SDB_METRIC:
+		children = get_host_children(host, attr->parent_type);
+		break;
+	default:
+		status = -1;
+		break;
+	}
+
+	if (children) {
+		obj.parent = STORE_OBJ(sdb_avltree_lookup(children, attr->parent));
+		if (! obj.parent) {
+			sdb_log(SDB_LOG_ERR, "memstore: Failed to store attribute '%s' - "
+					"%s '%s/%s' not found", attr->key,
+					SDB_STORE_TYPE_TO_NAME(attr->parent_type),
+					attr->hostname, attr->parent);
+			status = -1;
+		}
+		else
+			obj.parent_tree = attr->parent_type == SDB_SERVICE
+				? SVC(obj.parent)->attributes
+				: METRIC(obj.parent)->attributes;
+	}
+
+	obj.type = SDB_ATTRIBUTE;
+	obj.name = attr->key;
+	obj.last_update = attr->last_update;
+	obj.interval = attr->interval;
+	obj.backends = attr->backends;
+	obj.backends_num = attr->backends_num;
+	if (! status)
+		status = store_obj(&obj, &new);
+
+	if (! status) {
+		assert(new);
+		/* update the value if it changed */
+		if (sdb_data_cmp(&ATTR(new)->value, &attr->value))
+			if (sdb_data_copy(&ATTR(new)->value, &attr->value))
+				status = -1;
+	}
+
+	if (obj.parent != STORE_OBJ(host))
+		sdb_object_deref(SDB_OBJ(obj.parent));
+	sdb_object_deref(SDB_OBJ(host));
+	pthread_rwlock_unlock(&st->host_lock);
+
+	return status;
+} /* store_attribute */
+
+static int
+store_host(sdb_store_host_t *host, sdb_object_t *user_data)
+{
+	sdb_memstore_t *st = SDB_MEMSTORE(user_data);
+	store_obj_t obj = { NULL, st->hosts, SDB_HOST, NULL, 0, 0, NULL, 0 };
+	int status = 0;
+
+	if ((! host) || (! host->name))
+		return -1;
+
+	obj.name = host->name;
+	obj.last_update = host->last_update;
+	obj.interval = host->interval;
+	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);
+
+	return status;
+} /* store_host */
+
+static int
+store_service(sdb_store_service_t *service, sdb_object_t *user_data)
+{
+	sdb_memstore_t *st = SDB_MEMSTORE(user_data);
+	store_obj_t obj = STORE_OBJ_INIT;
+	host_t *host;
+
+	int status = 0;
+
+	if ((! service) || (! service->hostname) || (! service->name))
+		return -1;
+
+	pthread_rwlock_wrlock(&st->host_lock);
+	host = HOST(sdb_avltree_lookup(st->hosts, service->hostname));
+	obj.parent = STORE_OBJ(host);
+	obj.parent_tree = get_host_children(host, SDB_SERVICE);
+	obj.type = SDB_SERVICE;
+	if (! obj.parent_tree) {
+		sdb_log(SDB_LOG_ERR, "memstore: Failed to store service '%s' - "
+				"host '%s' not found", service->name, service->hostname);
+		status = -1;
+	}
+
+	obj.name = service->name;
+	obj.last_update = service->last_update;
+	obj.interval = service->interval;
+	obj.backends = service->backends;
+	obj.backends_num = service->backends_num;
+	if (! status)
+		status = store_obj(&obj, NULL);
+
+	sdb_object_deref(SDB_OBJ(host));
+	pthread_rwlock_unlock(&st->host_lock);
+	return status;
+} /* store_service */
+
+static int
+store_metric(sdb_store_metric_t *metric, sdb_object_t *user_data)
+{
+	sdb_memstore_t *st = SDB_MEMSTORE(user_data);
+	store_obj_t obj = STORE_OBJ_INIT;
+	sdb_memstore_obj_t *new = NULL;
+	host_t *host;
+
+	int status = 0;
+
+	if ((! metric) || (! metric->hostname) || (! metric->name))
+		return -1;
+
+	if ((metric->store.type != NULL) != (metric->store.id != NULL))
+		return -1;
+
+	pthread_rwlock_wrlock(&st->host_lock);
+	host = HOST(sdb_avltree_lookup(st->hosts, metric->hostname));
+	obj.parent = STORE_OBJ(host);
+	obj.parent_tree = get_host_children(host, SDB_METRIC);
+	obj.type = SDB_METRIC;
+	if (! obj.parent_tree) {
+		sdb_log(SDB_LOG_ERR, "memstore: Failed to store metric '%s' - "
+				"host '%s' not found", metric->name, metric->hostname);
+		status = -1;
+	}
+
+	obj.name = metric->name;
+	obj.last_update = metric->last_update;
+	obj.interval = metric->interval;
+	obj.backends = metric->backends;
+	obj.backends_num = metric->backends_num;
+	if (! status)
+		status = store_obj(&obj, &new);
+	sdb_object_deref(SDB_OBJ(host));
+
+	if (status) {
+		pthread_rwlock_unlock(&st->host_lock);
+		return status;
+	}
+
+	assert(new);
+	if (metric->store.type && metric->store.id)
+		if (store_metric_store(METRIC(new), metric))
+			status = -1;
+	pthread_rwlock_unlock(&st->host_lock);
+	return status;
+} /* store_metric */
+
+sdb_store_writer_t sdb_memstore_writer = {
+	store_host, store_service, store_metric, store_attribute,
+};
+
+/*
+ * store query API
+ */
+
+static sdb_object_t *
+prepare_query(sdb_ast_node_t *ast,
+		sdb_strbuf_t __attribute__((unused)) *errbuf,
+		sdb_object_t __attribute__((unused)) *user_data)
+{
+	return SDB_OBJ(sdb_memstore_query_prepare(ast));
+} /* prepare_query */
+
+static int
+execute_query(sdb_object_t *q,
+		sdb_store_writer_t *w, sdb_object_t *wd, sdb_strbuf_t *errbuf,
+		sdb_object_t *user_data)
+{
+	return sdb_memstore_query_execute(SDB_MEMSTORE(user_data),
+			QUERY(q), w, wd, errbuf);
+} /* execute_query */
+
+sdb_store_reader_t sdb_memstore_reader = {
+	prepare_query, execute_query,
+};
+
+/*
+ * public API
+ */
+
+sdb_memstore_t *
+sdb_memstore_create(void)
+{
+	return SDB_MEMSTORE(sdb_object_create("memstore", store_type));
+} /* sdb_memstore_create */
+
+int
+sdb_memstore_host(sdb_memstore_t *store, const char *name,
+		sdb_time_t last_update, sdb_time_t interval)
+{
+	sdb_store_host_t host = {
+		name, last_update, interval, NULL, 0,
+	};
+	return store_host(&host, SDB_OBJ(store));
+} /* sdb_memstore_host */
+
+int
+sdb_memstore_service(sdb_memstore_t *store, const char *hostname, const char *name,
+		sdb_time_t last_update, sdb_time_t interval)
+{
+	sdb_store_service_t service = {
+		hostname, name, last_update, interval, NULL, 0,
+	};
+	return store_service(&service, SDB_OBJ(store));
+} /* sdb_memstore_service */
+
+int
+sdb_memstore_metric(sdb_memstore_t *store, const char *hostname, const char *name,
+		sdb_metric_store_t *metric_store,
+		sdb_time_t last_update, sdb_time_t interval)
+{
+	sdb_store_metric_t metric = {
+		hostname, name, { NULL, NULL }, last_update, interval, NULL, 0,
+	};
+	if (metric_store) {
+		metric.store.type = metric_store->type;
+		metric.store.id = metric_store->id;
+	}
+	return store_metric(&metric, SDB_OBJ(store));
+} /* sdb_memstore_metric */
+
+int
+sdb_memstore_attribute(sdb_memstore_t *store, const char *hostname,
+		const char *key, const sdb_data_t *value,
+		sdb_time_t last_update, sdb_time_t interval)
+{
+	sdb_store_attribute_t attr = {
+		NULL, SDB_HOST, hostname, key, SDB_DATA_INIT,
+		last_update, interval, NULL, 0,
+	};
+	if (value) {
+		attr.value = *value;
+	}
+	return store_attribute(&attr, SDB_OBJ(store));
+} /* sdb_memstore_attribute */
+
+int
+sdb_memstore_service_attr(sdb_memstore_t *store, const char *hostname,
+		const char *service, const char *key, const sdb_data_t *value,
+		sdb_time_t last_update, sdb_time_t interval)
+{
+	sdb_store_attribute_t attr = {
+		hostname, SDB_SERVICE, service, key, SDB_DATA_INIT,
+		last_update, interval, NULL, 0,
+	};
+	if (value) {
+		attr.value = *value;
+	}
+	return store_attribute(&attr, SDB_OBJ(store));
+} /* sdb_memstore_service_attr */
+
+int
+sdb_memstore_metric_attr(sdb_memstore_t *store, const char *hostname,
+		const char *metric, const char *key, const sdb_data_t *value,
+		sdb_time_t last_update, sdb_time_t interval)
+{
+	sdb_store_attribute_t attr = {
+		hostname, SDB_METRIC, metric, key, SDB_DATA_INIT,
+		last_update, interval, NULL, 0,
+	};
+	if (value) {
+		attr.value = *value;
+	}
+	return store_attribute(&attr, SDB_OBJ(store));
+} /* sdb_memstore_metric_attr */
+
+sdb_memstore_obj_t *
+sdb_memstore_get_host(sdb_memstore_t *store, const char *name)
+{
+	host_t *host;
+
+	if ((! store) || (! name))
+		return NULL;
+
+	host = HOST(sdb_avltree_lookup(store->hosts, name));
+	if (! host)
+		return NULL;
+
+	return STORE_OBJ(host);
+} /* sdb_memstore_get_host */
+
+sdb_memstore_obj_t *
+sdb_memstore_get_child(sdb_memstore_obj_t *obj, int type, const char *name)
+{
+	sdb_avltree_t *children = NULL;
+
+	if ((! obj) || (! name))
+		return NULL;
+
+	if (type & SDB_ATTRIBUTE)
+		children = get_obj_attrs(obj);
+	else if (obj->type == SDB_HOST)
+		children = get_host_children(HOST(obj), type);
+	if (! children)
+		return NULL;
+	return STORE_OBJ(sdb_avltree_lookup(children, name));
+} /* sdb_memstore_get_child */
+
+int
+sdb_memstore_get_field(sdb_memstore_obj_t *obj, int field, sdb_data_t *res)
+{
+	sdb_data_t tmp;
+
+	if (! obj)
+		return -1;
+
+	switch (field) {
+		case SDB_FIELD_NAME:
+			tmp.type = SDB_TYPE_STRING;
+			tmp.data.string = strdup(SDB_OBJ(obj)->name);
+			if (! tmp.data.string)
+				return -1;
+			break;
+		case SDB_FIELD_LAST_UPDATE:
+			tmp.type = SDB_TYPE_DATETIME;
+			tmp.data.datetime = obj->last_update;
+			break;
+		case SDB_FIELD_AGE:
+			tmp.type = SDB_TYPE_DATETIME;
+			tmp.data.datetime = sdb_gettime() - obj->last_update;
+			break;
+		case SDB_FIELD_INTERVAL:
+			tmp.type = SDB_TYPE_DATETIME;
+			tmp.data.datetime = obj->interval;
+			break;
+		case SDB_FIELD_BACKEND:
+			if (! res)
+				return 0;
+			tmp.type = SDB_TYPE_ARRAY | SDB_TYPE_STRING;
+			tmp.data.array.length = obj->backends_num;
+			tmp.data.array.values = obj->backends;
+			return sdb_data_copy(res, &tmp);
+		case SDB_FIELD_VALUE:
+			if (obj->type != SDB_ATTRIBUTE)
+				return -1;
+			if (! res)
+				return 0;
+			return sdb_data_copy(res, &ATTR(obj)->value);
+		case SDB_FIELD_TIMESERIES:
+			if (obj->type != SDB_METRIC)
+				return -1;
+			tmp.type = SDB_TYPE_BOOLEAN;
+			tmp.data.boolean = METRIC(obj)->store.type != NULL;
+		default:
+			return -1;
+	}
+	if (res)
+		*res = tmp;
+	else
+		sdb_data_free_datum(&tmp);
+	return 0;
+} /* sdb_memstore_get_field */
+
+int
+sdb_memstore_get_attr(sdb_memstore_obj_t *obj, const char *name, sdb_data_t *res,
+		sdb_memstore_matcher_t *filter)
+{
+	sdb_memstore_obj_t *attr;
+
+	if ((! obj) || (! name))
+		return -1;
+
+	attr = STORE_OBJ(sdb_avltree_lookup(get_obj_attrs(obj), name));
+	if (! attr)
+		return -1;
+	if (filter && (! sdb_memstore_matcher_matches(filter, attr, NULL))) {
+		sdb_object_deref(SDB_OBJ(attr));
+		return -1;
+	}
+
+	assert(STORE_OBJ(attr)->type == SDB_ATTRIBUTE);
+	if (res)
+		sdb_data_copy(res, &ATTR(attr)->value);
+	sdb_object_deref(SDB_OBJ(attr));
+	return 0;
+} /* sdb_memstore_get_attr */
+
+int
+sdb_memstore_scan(sdb_memstore_t *store, int type,
+		sdb_memstore_matcher_t *m, sdb_memstore_matcher_t *filter,
+		sdb_memstore_lookup_cb cb, void *user_data)
+{
+	sdb_avltree_iter_t *host_iter = NULL;
+	int status = 0;
+
+	if ((! store) || (! cb))
+		return -1;
+
+	if ((type != SDB_HOST) && (type != SDB_SERVICE) && (type != SDB_METRIC)) {
+		sdb_log(SDB_LOG_ERR, "memstore: Cannot scan objects of type %d", type);
+		return -1;
+	}
+
+	pthread_rwlock_rdlock(&store->host_lock);
+	host_iter = sdb_avltree_get_iter(store->hosts);
+	if (! host_iter)
+		status = -1;
+
+	/* has_next returns false if the iterator is NULL */
+	while (sdb_avltree_iter_has_next(host_iter)) {
+		sdb_memstore_obj_t *host;
+		sdb_avltree_iter_t *iter = NULL;
+
+		host = STORE_OBJ(sdb_avltree_iter_get_next(host_iter));
+		assert(host);
+
+		if (! sdb_memstore_matcher_matches(filter, host, NULL))
+			continue;
+
+		if (type == SDB_SERVICE)
+			iter = sdb_avltree_get_iter(HOST(host)->services);
+		else if (type == SDB_METRIC)
+			iter = sdb_avltree_get_iter(HOST(host)->metrics);
+
+		if (iter) {
+			while (sdb_avltree_iter_has_next(iter)) {
+				sdb_memstore_obj_t *obj;
+				obj = STORE_OBJ(sdb_avltree_iter_get_next(iter));
+				assert(obj);
+
+				if (sdb_memstore_matcher_matches(m, obj, filter)) {
+					if (cb(obj, filter, user_data)) {
+						sdb_log(SDB_LOG_ERR, "memstore: Callback returned "
+								"an error while scanning");
+						status = -1;
+						break;
+					}
+				}
+			}
+		}
+		else if (sdb_memstore_matcher_matches(m, host, filter)) {
+			if (cb(host, filter, user_data)) {
+				sdb_log(SDB_LOG_ERR, "memstore: Callback returned "
+						"an error while scanning");
+				status = -1;
+			}
+		}
+
+		sdb_avltree_iter_destroy(iter);
+		if (status)
+			break;
+	}
+
+	sdb_avltree_iter_destroy(host_iter);
+	pthread_rwlock_unlock(&store->host_lock);
+	return status;
+} /* sdb_memstore_scan */
+
+int
+sdb_memstore_emit(sdb_memstore_obj_t *obj, sdb_store_writer_t *w, sdb_object_t *wd)
+{
+	if ((! obj) || (! w))
+		return -1;
+
+	switch (obj->type) {
+	case SDB_HOST:
+		{
+			sdb_store_host_t host = {
+				obj->_name,
+				obj->last_update,
+				obj->interval,
+				(const char * const *)obj->backends,
+				obj->backends_num,
+			};
+			if (! w->store_host)
+				return -1;
+			return w->store_host(&host, wd);
+		}
+	case SDB_SERVICE:
+		{
+			sdb_store_service_t service = {
+				obj->parent ? obj->parent->_name : NULL,
+				obj->_name,
+				obj->last_update,
+				obj->interval,
+				(const char * const *)obj->backends,
+				obj->backends_num,
+			};
+			if (! w->store_service)
+				return -1;
+			return w->store_service(&service, wd);
+		}
+	case SDB_METRIC:
+		{
+			sdb_store_metric_t metric = {
+				obj->parent ? obj->parent->_name : NULL,
+				obj->_name,
+				{
+					METRIC(obj)->store.type,
+					METRIC(obj)->store.id,
+				},
+				obj->last_update,
+				obj->interval,
+				(const char * const *)obj->backends,
+				obj->backends_num,
+			};
+			if (! w->store_metric)
+				return -1;
+			return w->store_metric(&metric, wd);
+		}
+	case SDB_ATTRIBUTE:
+		{
+			sdb_store_attribute_t attr = {
+				NULL,
+				obj->parent ? obj->parent->type : 0,
+				obj->parent ? obj->parent->_name : NULL,
+				obj->_name,
+				ATTR(obj)->value,
+				obj->last_update,
+				obj->interval,
+				(const char * const *)obj->backends,
+				obj->backends_num,
+			};
+			if (obj->parent && (obj->parent->type != SDB_HOST)
+					&& obj->parent->parent)
+				attr.hostname = obj->parent->parent->_name;
+			if (! w->store_attribute)
+				return -1;
+			return w->store_attribute(&attr, wd);
+		}
+	}
+
+	return -1;
+} /* sdb_memstore_emit */
+
+int
+sdb_memstore_emit_full(sdb_memstore_obj_t *obj, sdb_memstore_matcher_t *filter,
+		sdb_store_writer_t *w, sdb_object_t *wd)
+{
+	sdb_avltree_t *trees[] = { NULL, NULL, NULL };
+	size_t i;
+
+	if (sdb_memstore_emit(obj, w, wd))
+		return -1;
+
+	if (obj->type == SDB_HOST) {
+		trees[0] = HOST(obj)->attributes;
+		trees[1] = HOST(obj)->metrics;
+		trees[2] = HOST(obj)->services;
+	}
+	else if (obj->type == SDB_SERVICE)
+		trees[0] = SVC(obj)->attributes;
+	else if (obj->type == SDB_METRIC)
+		trees[0] = METRIC(obj)->attributes;
+	else if (obj->type == SDB_ATTRIBUTE)
+		return 0;
+	else
+		return -1;
+
+	for (i = 0; i < SDB_STATIC_ARRAY_LEN(trees); ++i) {
+		sdb_avltree_iter_t *iter;
+
+		if (! trees[i])
+			continue;
+
+		iter = sdb_avltree_get_iter(trees[i]);
+		while (sdb_avltree_iter_has_next(iter)) {
+			sdb_memstore_obj_t *child;
+			child = STORE_OBJ(sdb_avltree_iter_get_next(iter));
+
+			if (filter && (! sdb_memstore_matcher_matches(filter, child, NULL)))
+				continue;
+
+			if (sdb_memstore_emit_full(child, filter, w, wd)) {
+				sdb_avltree_iter_destroy(iter);
+				return -1;
+			}
+		}
+		sdb_avltree_iter_destroy(iter);
+	}
+	return 0;
+} /* sdb_memstore_emit_full */
+
+/* vim: set tw=78 sw=4 ts=4 noexpandtab : */
+