Code

store: Split out common JSON code into a separate helper function.
[sysdb.git] / src / core / store.c
index dba88cd2a03a70e126bf0b409e9d68b6b85e6b25..df5105794ad8f2827323dd81f239f0cdddd818a5 100644 (file)
@@ -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
  * 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 "core/error.h"
+#include "core/store-private.h"
 #include "core/plugin.h"
+#include "utils/error.h"
 #include "utils/llist.h"
 
 #include <assert.h>
  * private variables
  */
 
-static sdb_llist_t *obj_list = NULL;
-static pthread_rwlock_t obj_lock = PTHREAD_RWLOCK_INITIALIZER;
+static sdb_llist_t *host_list = NULL;
+static pthread_rwlock_t host_lock = PTHREAD_RWLOCK_INITIALIZER;
 
 /*
  * private types
  */
 
-static sdb_type_t sdb_store_obj_type;
+static sdb_type_t sdb_host_type;
+static sdb_type_t sdb_service_type;
 static sdb_type_t sdb_attribute_type;
 
-struct store_obj;
-typedef struct store_obj store_obj_t;
-
-struct store_obj {
-       sdb_object_t super;
-       sdb_time_t last_update;
-       store_obj_t *parent;
-};
-#define STORE_OBJ(obj) ((store_obj_t *)(obj))
-#define STORE_CONST_OBJ(obj) ((const store_obj_t *)(obj))
-
-typedef struct {
-       store_obj_t super;
-
-       char *value;
-} sdb_attribute_t;
-#define SDB_ATTR(obj) ((sdb_attribute_t *)(obj))
-#define SDB_CONST_ATTR(obj) ((const sdb_attribute_t *)(obj))
-
-typedef struct {
-       store_obj_t super;
-
-       int type;
-       sdb_llist_t *children;
-
-       sdb_llist_t *attributes;
-} sdb_store_obj_t;
-#define SDB_STORE_OBJ(obj) ((sdb_store_obj_t *)(obj))
-#define SDB_CONST_STORE_OBJ(obj) ((const sdb_store_obj_t *)(obj))
-
-enum {
-       SDB_HOST = 1,
-       SDB_SERVICE,
-       SDB_ATTRIBUTE,
-};
-#define TYPE_TO_NAME(t) \
-       (((t) == SDB_HOST) ? "host" \
-               : ((t) == SDB_SERVICE) ? "service" \
-               : ((t) == SDB_ATTRIBUTE) ? "attribute" : "unknown")
-
-/* shortcuts for accessing the sdb_store_obj_t attributes
- * of inheriting objects */
-#define _last_update super.last_update
-
 static int
 store_obj_init(sdb_object_t *obj, va_list ap)
 {
-       store_obj_t *sobj = STORE_OBJ(obj);
-       sobj->last_update = va_arg(ap, sdb_time_t);
+       sdb_store_obj_t *sobj = STORE_OBJ(obj);
+
+       sobj->type = va_arg(ap, int);
 
+       sobj->last_update = va_arg(ap, sdb_time_t);
+       sobj->interval = 0;
        sobj->parent = NULL;
        return 0;
 } /* store_obj_init */
@@ -112,116 +76,91 @@ store_obj_init(sdb_object_t *obj, va_list ap)
 static void
 store_obj_destroy(sdb_object_t *obj)
 {
-       const store_obj_t *sobj = STORE_OBJ(obj);
+       const sdb_store_obj_t *sobj = STORE_CONST_OBJ(obj);
 
        if (sobj->parent)
                sdb_object_deref(SDB_OBJ(sobj->parent));
 } /* store_obj_destroy */
 
-/* this may not be used as a type on its own but only as helper functions for
- * the derived types; the function accepts a variadic list of arguments to
- * pass to the sub-type's init function */
-static sdb_object_t *
-store_obj_clone(const sdb_object_t *obj, ...)
-{
-       const store_obj_t *sobj = STORE_CONST_OBJ(obj);
-       store_obj_t *new;
-
-       va_list ap;
-
-       va_start(ap, obj);
-
-       new = STORE_OBJ(sdb_object_vcreate(obj->name, obj->type, ap));
-       va_end(ap);
-       if (! new)
-               return NULL;
-
-       new->last_update = sobj->last_update;
-       sdb_object_ref(SDB_OBJ(sobj->parent));
-       new->parent = sobj->parent;
-       return SDB_OBJ(new);
-} /* store_obj_clone */
-
 static int
-sdb_store_obj_init(sdb_object_t *obj, va_list ap)
+sdb_host_init(sdb_object_t *obj, va_list ap)
 {
-       sdb_store_obj_t *sobj = SDB_STORE_OBJ(obj);
+       sdb_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->type = va_arg(ap, int);
-
-       sobj->children = sdb_llist_create();
-       if (! sobj->children)
+       sobj->services = sdb_llist_create();
+       if (! sobj->services)
                return -1;
        sobj->attributes = sdb_llist_create();
        if (! sobj->attributes)
                return -1;
        return 0;
-} /* sdb_store_obj_init */
+} /* sdb_host_init */
 
 static void
-sdb_store_obj_destroy(sdb_object_t *obj)
+sdb_host_destroy(sdb_object_t *obj)
 {
-       sdb_store_obj_t *sobj = SDB_STORE_OBJ(obj);
-
+       sdb_host_t *sobj = HOST(obj);
        assert(obj);
 
        store_obj_destroy(obj);
 
-       if (sobj->children)
-               sdb_llist_destroy(sobj->children);
+       if (sobj->services)
+               sdb_llist_destroy(sobj->services);
        if (sobj->attributes)
                sdb_llist_destroy(sobj->attributes);
-} /* sdb_store_obj_destroy */
+} /* sdb_host_destroy */
 
-static sdb_object_t *
-sdb_store_obj_clone(const sdb_object_t *obj)
+static int
+sdb_service_init(sdb_object_t *obj, va_list ap)
 {
-       const sdb_store_obj_t *sobj = SDB_CONST_STORE_OBJ(obj);
-       sdb_store_obj_t *new;
+       sdb_service_t *sobj = SVC(obj);
+       int ret;
 
-       new = SDB_STORE_OBJ(store_obj_clone(obj, sobj->_last_update, sobj->type));
-       if (! new)
-               return NULL;
+       /* this will consume the first argument (type) of ap */
+       ret = store_obj_init(obj, ap);
+       if (ret)
+               return ret;
 
-       if (sobj->children) {
-               sdb_llist_destroy(new->children);
-               new->children = sdb_llist_clone(sobj->children);
-               if (! new->children) {
-                       sdb_object_deref(SDB_OBJ(new));
-                       return NULL;
-               }
-       }
-       if (sobj->attributes) {
-               sdb_llist_destroy(new->attributes);
-               new->attributes = sdb_llist_clone(sobj->attributes);
-               if (! new->attributes) {
-                       sdb_object_deref(SDB_OBJ(new));
-                       return NULL;
-               }
-       }
+       sobj->attributes = sdb_llist_create();
+       if (! sobj->attributes)
+               return -1;
+       return 0;
+} /* sdb_service_init */
+
+static void
+sdb_service_destroy(sdb_object_t *obj)
+{
+       sdb_service_t *sobj = SVC(obj);
+       assert(obj);
+
+       store_obj_destroy(obj);
 
-       return SDB_OBJ(new);
-} /* sdb_store_obj_clone */
+       if (sobj->attributes)
+               sdb_llist_destroy(sobj->attributes);
+} /* sdb_service_destroy */
 
 static int
 sdb_attr_init(sdb_object_t *obj, va_list ap)
 {
-       const char *value;
+       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 char *);
+       value = va_arg(ap, const sdb_data_t *);
 
-       SDB_ATTR(obj)->value = strdup(value);
-       if (! SDB_ATTR(obj)->value)
-               return -1;
+       if (value)
+               if (sdb_data_copy(&ATTR(obj)->value, value))
+                       return -1;
        return 0;
 } /* sdb_attr_init */
 
@@ -231,112 +170,66 @@ sdb_attr_destroy(sdb_object_t *obj)
        assert(obj);
 
        store_obj_destroy(obj);
-
-       if (SDB_ATTR(obj)->value)
-               free(SDB_ATTR(obj)->value);
+       sdb_data_free_datum(&ATTR(obj)->value);
 } /* sdb_attr_destroy */
 
-static sdb_object_t *
-sdb_attr_clone(const sdb_object_t *obj)
-{
-       const sdb_attribute_t *attr = (const sdb_attribute_t *)obj;
-       sdb_attribute_t *new;
-
-       new = SDB_ATTR(store_obj_clone(obj, attr->_last_update, attr->value));
-       if (! new)
-               return NULL;
-       return SDB_OBJ(new);
-} /* sdb_attr_clone */
-
-static sdb_type_t sdb_store_obj_type = {
-       sizeof(sdb_store_obj_t),
+static sdb_type_t sdb_host_type = {
+       sizeof(sdb_host_t),
+       sdb_host_init,
+       sdb_host_destroy
+};
 
-       sdb_store_obj_init,
-       sdb_store_obj_destroy,
-       sdb_store_obj_clone
+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,
-       sdb_attr_clone
+       sdb_attr_destroy
 };
 
 /*
  * private helper functions
  */
 
-static sdb_store_obj_t *
-sdb_store_lookup_in_list(sdb_llist_t *l, int type, const char *name)
+static sdb_host_t *
+lookup_host(const char *name)
 {
-       sdb_llist_iter_t *iter;
-
-       if (! l)
-               return NULL;
-
-       iter = sdb_llist_get_iter(l);
-       if (! iter)
-               return NULL;
-
-       while (sdb_llist_iter_has_next(iter)) {
-               sdb_store_obj_t *sobj = SDB_STORE_OBJ(sdb_llist_iter_get_next(iter));
-               assert(sobj);
+       return HOST(sdb_llist_search_by_name(host_list, name));
+} /* lookup_host */
 
-               if ((sobj->type == type)
-                               && (! strcasecmp(SDB_OBJ(sobj)->name, name))) {
-                       sdb_llist_iter_destroy(iter);
-                       return sobj;
-               }
-
-               sobj = sdb_store_lookup_in_list(sobj->children, type, name);
-               if (sobj) {
-                       sdb_llist_iter_destroy(iter);
-                       return sobj;
-               }
-       }
-       sdb_llist_iter_destroy(iter);
-       return NULL;
-} /* sdb_store_lookup_in_list */
-
-static sdb_store_obj_t *
-sdb_store_lookup(int type, const char *name)
-{
-       return sdb_store_lookup_in_list(obj_list, type, name);
-} /* sdb_store_lookup */
-
-/* The obj_lock has to be acquired before calling this function. */
+/* The host_lock has to be acquired before calling this function. */
 static int
-store_obj(int parent_type, const char *parent_name,
-               int type, const char *name, sdb_time_t last_update,
-               store_obj_t **updated_obj)
+store_obj(const char *hostname, int type, const char *name,
+               sdb_time_t last_update, sdb_store_obj_t **updated_obj)
 {
-       char *parent_cname = NULL, *cname = NULL;
+       char *host_cname = NULL, *cname = NULL;
 
        sdb_llist_t *parent_list;
-       store_obj_t *old;
+       sdb_store_obj_t *old;
        int status = 0;
 
        if (last_update <= 0)
                last_update = sdb_gettime();
 
-       assert((parent_type == 0)
-                       || (parent_type == SDB_HOST)
-                       || (parent_type == SDB_SERVICE));
        assert((type == 0)
                        || (type == SDB_HOST)
                        || (type == SDB_SERVICE)
                        || (type == SDB_ATTRIBUTE));
 
-       if (parent_type == SDB_HOST) {
-               parent_cname = sdb_plugin_cname(strdup(parent_name));
-               if (! parent_cname) {
-                       sdb_log(SDB_LOG_ERR, "store: strdup failed");
+       assert(hostname || (type == SDB_HOST));
+       assert((! hostname)
+                       || (type == SDB_SERVICE)
+                       || (type == SDB_ATTRIBUTE));
+
+       if (! host_list)
+               if (! (host_list = sdb_llist_create()))
                        return -1;
-               }
-               parent_name = parent_cname;
-       }
+       parent_list = host_list;
+
        if (type == SDB_HOST) {
                cname = sdb_plugin_cname(strdup(name));
                if (! cname) {
@@ -346,79 +239,87 @@ store_obj(int parent_type, const char *parent_name,
                name = cname;
        }
 
-       if (! obj_list) {
-               if (! (obj_list = sdb_llist_create())) {
-                       free(parent_cname);
+       if (hostname) {
+               sdb_host_t *host;
+
+               host_cname = sdb_plugin_cname(strdup(hostname));
+               if (! host_cname) {
+                       sdb_log(SDB_LOG_ERR, "store: strdup failed");
                        free(cname);
                        return -1;
                }
-       }
-       parent_list = obj_list;
-
-       if (parent_type && parent_name) {
-               sdb_store_obj_t *parent;
+               hostname = host_cname;
 
-               parent = sdb_store_lookup(parent_type, parent_name);
-               if (! parent) {
+               host = lookup_host(hostname);
+               if (! host) {
                        sdb_log(SDB_LOG_ERR, "store: Failed to store %s '%s' - "
-                                       "parent %s '%s' not found", TYPE_TO_NAME(type), name,
-                                       TYPE_TO_NAME(parent_type), parent_name);
-                       free(parent_cname);
+                                       "host '%s' not found", SDB_STORE_TYPE_TO_NAME(type),
+                                       name, hostname);
+                       free(host_cname);
                        free(cname);
                        return -1;
                }
 
                if (type == SDB_ATTRIBUTE)
-                       parent_list = parent->attributes;
+                       parent_list = host->attributes;
                else
-                       parent_list = parent->children;
+                       parent_list = host->services;
        }
 
-       /* TODO: only look into direct children? */
-       if (type == SDB_ATTRIBUTE)
-               old = STORE_OBJ(sdb_llist_search_by_name(parent_list, name));
+       if (type == SDB_HOST)
+               old = STORE_OBJ(sdb_llist_search_by_name(host_list, name));
        else
-               old = STORE_OBJ(sdb_store_lookup_in_list(parent_list, type, name));
+               old = STORE_OBJ(sdb_llist_search_by_name(parent_list, name));
 
        if (old) {
                if (old->last_update > last_update) {
                        sdb_log(SDB_LOG_DEBUG, "store: Cannot update %s '%s' - "
                                        "value too old (%"PRIscTIME" < %"PRIscTIME")",
-                                       TYPE_TO_NAME(type), name, last_update, old->last_update);
+                                       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 {
+                       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;
+                       }
                }
 
                if (updated_obj)
                        *updated_obj = old;
        }
        else {
-               store_obj_t *new;
+               sdb_store_obj_t *new;
 
-               if (type == SDB_ATTRIBUTE)
+               if (type == SDB_ATTRIBUTE) {
                        /* the value will be updated by the caller */
                        new = STORE_OBJ(sdb_object_create(name, sdb_attribute_type,
-                                               last_update, NULL));
-               else
-                       new = STORE_OBJ(sdb_object_create(name, sdb_store_obj_type,
-                                               last_update, type));
+                                               type, last_update, NULL));
+               }
+               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) {
                        char errbuf[1024];
                        sdb_log(SDB_LOG_ERR, "store: Failed to create %s '%s': %s",
-                                       TYPE_TO_NAME(type), name,
+                                       SDB_STORE_TYPE_TO_NAME(type), name,
                                        sdb_strerror(errno, errbuf, sizeof(errbuf)));
-                       free(parent_cname);
+                       free(host_cname);
                        free(cname);
                        return -1;
                }
 
-               /* TODO: insert type-aware; the current version works as long as we
-                * don't support to store hierarchical data */
                status = sdb_llist_insert_sorted(parent_list, SDB_OBJ(new),
                                sdb_object_cmp_by_name);
 
@@ -428,15 +329,97 @@ store_obj(int parent_type, const char *parent_name,
                if (updated_obj)
                        *updated_obj = new;
        }
-       free(parent_cname);
+       free(host_cname);
        free(cname);
        return status;
-} /* sdb_store_obj */
+} /* store_obj */
+
+/*
+ * 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)
+{
+       char time_str[64];
+       char interval_str[64];
+
+       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\"", time_str, interval_str);
+} /* store_common_tojson */
+
+/*
+ * 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_llist_t *list, int type, sdb_strbuf_t *buf)
+{
+       sdb_llist_iter_t *iter;
+
+       assert((type == SDB_ATTRIBUTE) || (type == SDB_SERVICE));
+
+       sdb_strbuf_append(buf, "[");
+       iter = sdb_llist_get_iter(list);
+       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);
+       }
+
+       /* 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));
+               assert(sobj);
+               assert(sobj->type == type);
+
+               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);
+               sdb_strbuf_append(buf, "}");
+
+               if (sdb_llist_iter_has_next(iter))
+                       sdb_strbuf_append(buf, ",");
+       }
+
+       sdb_llist_iter_destroy(iter);
+       sdb_strbuf_append(buf, "]");
+} /* store_obj_tojson */
 
 /*
  * public API
  */
 
+void
+sdb_store_clear(void)
+{
+       sdb_llist_destroy(host_list);
+       host_list = NULL;
+} /* sdb_store_clear */
+
 int
 sdb_store_host(const char *name, sdb_time_t last_update)
 {
@@ -445,48 +428,69 @@ sdb_store_host(const char *name, sdb_time_t last_update)
        if (! name)
                return -1;
 
-       pthread_rwlock_wrlock(&obj_lock);
-       status = store_obj(/* parent = */ 0, NULL,
+       pthread_rwlock_wrlock(&host_lock);
+       status = store_obj(/* hostname = */ NULL,
                        /* stored object = */ SDB_HOST, name, last_update,
                        /* updated_obj = */ NULL);
-       pthread_rwlock_unlock(&obj_lock);
+       pthread_rwlock_unlock(&host_lock);
        return status;
 } /* sdb_store_host */
 
 _Bool
 sdb_store_has_host(const char *name)
 {
-       sdb_store_obj_t *host;
+       sdb_host_t *host;
 
        if (! name)
                return NULL;
 
-       host = sdb_store_lookup(SDB_HOST, name);
+       host = lookup_host(name);
        return host != NULL;
 } /* sdb_store_has_host */
 
+sdb_store_obj_t *
+sdb_store_get_host(const char *name)
+{
+       sdb_host_t *host;
+
+       if (! name)
+               return NULL;
+
+       host = lookup_host(name);
+       if (! host)
+               return NULL;
+
+       sdb_object_ref(SDB_OBJ(host));
+       return STORE_OBJ(host);
+} /* sdb_store_get_host */
+
 int
-sdb_store_attribute(const char *hostname, const char *key, const char *value,
+sdb_store_attribute(const char *hostname,
+               const char *key, const sdb_data_t *value,
                sdb_time_t last_update)
 {
        int status;
 
-       store_obj_t *updated_attr = NULL;
+       sdb_store_obj_t *updated_attr = NULL;
 
        if ((! hostname) || (! key))
                return -1;
 
-       pthread_rwlock_wrlock(&obj_lock);
-       status = store_obj(/* parent = */ SDB_HOST, hostname,
+       pthread_rwlock_wrlock(&host_lock);
+       status = store_obj(hostname,
                        /* stored object = */ SDB_ATTRIBUTE, key, last_update,
                        &updated_attr);
 
-       SDB_ATTR(updated_attr)->value = strdup(value);
-       if (! SDB_ATTR(updated_attr)->value) {
-               sdb_object_deref(SDB_OBJ(updated_attr));
-               status = -1;
+       if (status >= 0) {
+               assert(updated_attr);
+               sdb_data_free_datum(&ATTR(updated_attr)->value);
+               if (sdb_data_copy(&ATTR(updated_attr)->value, value)) {
+                       sdb_object_deref(SDB_OBJ(updated_attr));
+                       status = -1;
+               }
        }
-       pthread_rwlock_unlock(&obj_lock);
+
+       pthread_rwlock_unlock(&host_lock);
        return status;
 } /* sdb_store_attribute */
 
@@ -499,99 +503,105 @@ sdb_store_service(const char *hostname, const char *name,
        if ((! hostname) || (! name))
                return -1;
 
-       pthread_rwlock_wrlock(&obj_lock);
-       status = store_obj(/* parent = */ SDB_HOST, hostname,
+       pthread_rwlock_wrlock(&host_lock);
+       status = store_obj(hostname,
                        /* stored object = */ SDB_SERVICE, name, last_update,
                        /* updated obj = */ NULL);
-       pthread_rwlock_unlock(&obj_lock);
+       pthread_rwlock_unlock(&host_lock);
        return status;
 } /* sdb_store_service */
 
-/* TODO: actually support hierarchical data */
 int
-sdb_store_dump(FILE *fh)
+sdb_store_host_tojson(sdb_store_obj_t *h, sdb_strbuf_t *buf, int flags)
+{
+       sdb_host_t *host;
+
+       if ((! h) || (h->type != SDB_HOST) || (! buf))
+               return -1;
+
+       host = HOST(h);
+
+       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);
+       }
+
+       if (! (flags & SDB_SKIP_SERVICES)) {
+               sdb_strbuf_append(buf, ", \"services\": ");
+               store_obj_tojson(host->services, SDB_SERVICE, buf);
+       }
+
+       sdb_strbuf_append(buf, "}");
+       return 0;
+} /* sdb_store_host_tojson */
+
+int
+sdb_store_tojson(sdb_strbuf_t *buf, int flags)
 {
        sdb_llist_iter_t *host_iter;
 
-       if (! fh)
+       if (! buf)
                return -1;
 
-       pthread_rwlock_rdlock(&obj_lock);
+       pthread_rwlock_rdlock(&host_lock);
 
-       host_iter = sdb_llist_get_iter(obj_list);
+       host_iter = sdb_llist_get_iter(host_list);
        if (! host_iter) {
-               pthread_rwlock_unlock(&obj_lock);
+               pthread_rwlock_unlock(&host_lock);
                return -1;
        }
 
-       while (sdb_llist_iter_has_next(host_iter)) {
-               sdb_store_obj_t *host = SDB_STORE_OBJ(sdb_llist_iter_get_next(host_iter));
-               sdb_llist_iter_t *svc_iter;
-               sdb_llist_iter_t *attr_iter;
-
-               char time_str[64];
+       sdb_strbuf_append(buf, "{\"hosts\":[");
 
+       while (sdb_llist_iter_has_next(host_iter)) {
+               sdb_store_obj_t *host = STORE_OBJ(sdb_llist_iter_get_next(host_iter));
                assert(host);
 
-               if (! sdb_strftime(time_str, sizeof(time_str),
-                                       "%F %T %z", host->_last_update))
-                       snprintf(time_str, sizeof(time_str), "<error>");
-               time_str[sizeof(time_str) - 1] = '\0';
-
-               fprintf(fh, "Host '%s' (last updated: %s):\n",
-                               SDB_OBJ(host)->name, time_str);
-
-               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, 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);
+               if (sdb_llist_iter_has_next(host_iter))
+                       sdb_strbuf_append(buf, ",");
+       }
 
-                       if (! sdb_strftime(time_str, sizeof(time_str),
-                                               "%F %T %z", attr->_last_update))
-                               snprintf(time_str, sizeof(time_str), "<error>");
-                       time_str[sizeof(time_str) - 1] = '\0';
+       sdb_strbuf_append(buf, "]}");
 
-                       fprintf(fh, "\tAttribute '%s' -> '%s' (last updated: %s)\n",
-                                       SDB_OBJ(attr)->name, attr->value, time_str);
-               }
+       sdb_llist_iter_destroy(host_iter);
+       pthread_rwlock_unlock(&host_lock);
+       return 0;
+} /* sdb_store_tojson */
 
-               sdb_llist_iter_destroy(attr_iter);
+/* TODO: actually support hierarchical data */
+int
+sdb_store_iterate(sdb_store_iter_cb cb, void *user_data)
+{
+       sdb_llist_iter_t *host_iter;
+       int status = 0;
 
-               svc_iter = sdb_llist_get_iter(host->children);
-               if (! svc_iter) {
-                       char errbuf[1024];
-                       fprintf(fh, "Failed to retrieve services: %s\n",
-                                       sdb_strerror(errno, errbuf, sizeof(errbuf)));
-                       continue;
-               }
+       pthread_rwlock_rdlock(&host_lock);
 
-               while (sdb_llist_iter_has_next(svc_iter)) {
-                       sdb_store_obj_t *svc = SDB_STORE_OBJ(sdb_llist_iter_get_next(svc_iter));
-                       assert(svc);
+       host_iter = sdb_llist_get_iter(host_list);
+       if (! host_iter)
+               status = -1;
 
-                       if (! sdb_strftime(time_str, sizeof(time_str),
-                                               "%F %T %z", svc->_last_update))
-                               snprintf(time_str, sizeof(time_str), "<error>");
-                       time_str[sizeof(time_str) - 1] = '\0';
+       /* 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));
+               assert(host);
 
-                       fprintf(fh, "\tService '%s' (last updated: %s)\n",
-                                       SDB_OBJ(svc)->name, time_str);
+               if (cb(host, user_data)) {
+                       status = -1;
+                       break;
                }
-
-               sdb_llist_iter_destroy(svc_iter);
        }
 
        sdb_llist_iter_destroy(host_iter);
-       pthread_rwlock_unlock(&obj_lock);
-       return 0;
-} /* sdb_store_dump */
+       pthread_rwlock_unlock(&host_lock);
+       return status;
+} /* sdb_store_iterate */
 
 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */