X-Git-Url: https://git.tokkee.org/?p=sysdb.git;a=blobdiff_plain;f=src%2Finclude%2Fcore%2Fstore.h;h=6dd7d1ade1ca98b952a4ce05a8b1a4f6bc21fa49;hp=aac884a5d104a72cd747c3db83ffa0f8b478a5c7;hb=7e192f00497c9837856530d2ca5559ec86715502;hpb=045e522816461b58e471a6ccddf4ada51236c478

diff --git a/src/include/core/store.h b/src/include/core/store.h
index aac884a..6dd7d1a 100644
--- a/src/include/core/store.h
+++ b/src/include/core/store.h
@@ -30,8 +30,10 @@
 
 #include "sysdb.h"
 #include "core/object.h"
+#include "core/data.h"
 #include "core/time.h"
-#include "utils/llist.h"
+#include "core/timeseries.h"
+#include "utils/strbuf.h"
 
 #include <stdio.h>
 
@@ -39,50 +41,92 @@
 extern "C" {
 #endif
 
-extern const sdb_type_t sdb_host_type;
-extern const sdb_type_t sdb_attribute_type;
-extern const sdb_type_t sdb_service_type;
+/*
+ * Store object types.
+ */
+enum {
+	SDB_HOST = 1,
+	SDB_SERVICE,
+	SDB_METRIC,
+	SDB_ATTRIBUTE,
+};
+#define SDB_STORE_TYPE_TO_NAME(t) \
+	(((t) == SDB_HOST) ? "host" \
+		: ((t) == SDB_SERVICE) ? "service" \
+		: ((t) == SDB_METRIC) ? "metric" \
+		: ((t) == SDB_ATTRIBUTE) ? "attribute" : "unknown")
 
-typedef struct {
-	sdb_object_t super;
-	sdb_time_t last_update;
-} sdb_store_obj_t;
-#define SDB_STORE_OBJ_INIT(t) { SDB_OBJECT_TYPED_INIT(t), 0 }
-#define SDB_STORE_OBJ(obj) ((sdb_store_obj_t *)(obj))
-#define SDB_CONST_STORE_OBJ(obj) ((const sdb_store_obj_t *)(obj))
+/*
+ * sdb_store_obj_t represents the super-class of any object stored in the
+ * database. It inherits from sdb_object_t and may safely be cast to a generic
+ * object to access its name.
+ */
+struct sdb_store_obj;
+typedef struct sdb_store_obj sdb_store_obj_t;
 
-typedef struct {
-	sdb_store_obj_t super;
+/*
+ * Expressions represent arithmetic expressions based on stored objects and
+ * their various attributes.
+ *
+ * An expression object inherits from sdb_object_t and, thus, may safely be
+ * cast to a generic object.
+ */
+struct sdb_store_expr;
+typedef struct sdb_store_expr sdb_store_expr_t;
+#define SDB_STORE_EXPR(obj) ((sdb_store_expr_t *)(obj))
 
-	char *hostname;
-} sdb_service_t;
-#define SDB_SVC_INIT { SDB_STORE_OBJ_INIT(sdb_service_type), NULL }
-#define SDB_SVC(obj) ((sdb_service_t *)(obj))
-#define SDB_CONST_SVC(obj) ((const sdb_service_t *)(obj))
+/*
+ * Store matchers may be used to lookup hosts from the store based on their
+ * various attributes. Service and attribute matchers are applied to a host's
+ * services and attributes and evaluate to true if *any* service or attribute
+ * matches.
+ *
+ * A store matcher object inherits from sdb_object_t and, thus, may safely be
+ * cast to a generic object.
+ */
+struct sdb_store_matcher;
+typedef struct sdb_store_matcher sdb_store_matcher_t;
+#define SDB_STORE_MATCHER(obj) ((sdb_store_matcher_t *)(obj))
 
-typedef struct {
-	sdb_store_obj_t super;
+/*
+ * A JSON formatter converts a stored object into the JSON format.
+ * See http://www.ietf.org/rfc/rfc4627.txt
+ */
+struct sdb_store_json_formatter;
+typedef struct sdb_store_json_formatter sdb_store_json_formatter_t;
 
-	char *attr_value;
-	char *hostname;
-} sdb_attribute_t;
-#define SDB_ATTR_INIT { SDB_STORE_OBJ_INIT(sdb_attribute_type), NULL, NULL }
-#define SDB_ATTR(obj) ((sdb_attribute_t *)(obj))
-#define SDB_CONST_ATTR(obj) ((const sdb_attribute_t *)(obj))
+/*
+ * Queryable fields of a stored object.
+ */
+enum {
+	SDB_FIELD_NAME = 1,    /* string */
+	SDB_FIELD_LAST_UPDATE, /* datetime */
+	SDB_FIELD_AGE,         /* datetime */
+	SDB_FIELD_INTERVAL,    /* datetime */
+	SDB_FIELD_BACKEND,     /* string */
+};
 
-typedef struct {
-	sdb_store_obj_t super;
+#define SDB_FIELD_TO_NAME(f) \
+	(((f) == SDB_FIELD_NAME) ? "name" \
+		: ((f) == SDB_FIELD_LAST_UPDATE) ? "last-update" \
+		: ((f) == SDB_FIELD_AGE) ? "age" \
+		: ((f) == SDB_FIELD_INTERVAL) ? "interval" \
+		: ((f) == SDB_FIELD_BACKEND) ? "backend" : "unknown")
 
-	sdb_llist_t *attributes;
-	sdb_llist_t *services;
-} sdb_host_t;
-#define SDB_HOST_INIT { SDB_STORE_OBJ_INIT(sdb_host_type), NULL, NULL }
-#define SDB_HOST(obj) ((sdb_host_t *)(obj))
-#define SDB_CONST_HOST(obj) ((const sdb_host_t *)(obj))
+#define SDB_FIELD_TYPE(f) \
+	(((f) == SDB_FIELD_NAME) ? SDB_TYPE_STRING \
+		: ((f) == SDB_FIELD_LAST_UPDATE) ? SDB_TYPE_DATETIME \
+		: ((f) == SDB_FIELD_AGE) ? SDB_TYPE_DATETIME \
+		: ((f) == SDB_FIELD_INTERVAL) ? SDB_TYPE_DATETIME \
+		: ((f) == SDB_FIELD_BACKEND) ? (SDB_TYPE_ARRAY | SDB_TYPE_STRING) \
+		: -1)
 
-/* shortcuts for accessing the sdb_store_obj_t attributes of inheriting
- * objects */
-#define _last_update super.last_update
+/*
+ * sdb_store_clear:
+ * Clear the entire store and remove all stored objects.
+ */
+void
+sdb_store_clear(void);
 
 /*
  * sdb_store_host:
@@ -101,22 +145,28 @@ typedef struct {
 int
 sdb_store_host(const char *name, sdb_time_t last_update);
 
+/*
+ * sdb_store_has_host:
+ * sdb_store_get_host:
+ * Query the store for a host by its (canonicalized) name.
+ *
+ * sdb_store_get_host increments the ref count of the host object. The caller
+ * needs to deref it when no longer using it.
+ */
 _Bool
 sdb_store_has_host(const char *name);
 
-sdb_attribute_t *
-sdb_attribute_create(const char *hostname,
-		const char *name, const char *value);
+sdb_store_obj_t *
+sdb_store_get_host(const char *name);
 
 /*
  * sdb_store_attribute:
  * Add/update a host's attribute in the store. If the attribute, identified by
- * its name, already exists for the specified host, it will be updated
- * according to the specified 'attr' object. If the referenced host does not
- * exist, an error will be reported. Else, a new entry will be created in the
- * store. Any memory required for storing the entry will be allocated and
- * managed by the store itself. The specified attribute-object will not be
- * referenced or further accessed.
+ * its key, already exists for the specified host, it will be updated to the
+ * specified values. If the referenced host does not exist, an error will be
+ * reported. Else, a new entry will be created in the store. Any memory
+ * required for storing the entry will be allocated and managed by the store
+ * itself.
  *
  * Returns:
  *  - 0 on success
@@ -125,20 +175,83 @@ sdb_attribute_create(const char *hostname,
  *  - a negative value on error
  */
 int
-sdb_store_attribute(const sdb_attribute_t *attr);
-
-sdb_service_t *
-sdb_service_create(const char *hostname, const char *name);
+sdb_store_attribute(const char *hostname,
+		const char *key, const sdb_data_t *value,
+		sdb_time_t last_update);
 
 /*
  * sdb_store_service:
- * Add/update a store in the store. If the service, identified by its name,
+ * Add/update a service in the store. If the service, identified by its name,
  * already exists for the specified host, it will be updated according to the
  * specified 'service' object. If the referenced host does not exist, an error
  * will be reported. Else, a new entry will be created in the store. Any
  * memory required for storing the entry will be allocated an managed by the
- * store itself. The specified service-object will not be referenced or
- * further accessed.
+ * store itself.
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a positive value if the new entry is older than the currently stored
+ *    entry (in this case, no update will happen)
+ *  - a negative value on error
+ */
+int
+sdb_store_service(const char *hostname, const char *name,
+		sdb_time_t last_update);
+
+/*
+ * sdb_store_service_attr:
+ * Add/update a service's attribute in the store. If the attribute, identified
+ * by its key, already exists for the specified service, it will be updated to
+ * the specified value. If the references service (for the specified host)
+ * does not exist, an error will be reported. Any memory required for storing
+ * the entry will be allocated and managed by the store itself.
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a positive value if the new entry is older than the currently stored
+ *    entry (in this case, no update will happen)
+ *  - a negative value on error
+ */
+int
+sdb_store_service_attr(const char *hostname, const char *service,
+		const char *key, const sdb_data_t *value, sdb_time_t last_update);
+
+/*
+ * A metric store describes how to access a metric's data.
+ */
+typedef struct {
+	const char *type;
+	const char *id;
+} sdb_metric_store_t;
+
+/*
+ * sdb_store_metric:
+ * Add/update a metric in the store. If the metric, identified by its name,
+ * already exists for the specified host, it will be updated according to the
+ * specified 'metric' object. If the referenced host does not exist, an error
+ * will be reported. Else, a new entry will be created in the store. Any
+ * memory required for storing the entry will be allocated an managed by the
+ * store itself.
+ *
+ * If specified, the metric store describes where to access the metric's data.
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a positive value if the new entry is older than the currently stored
+ *    entry (in this case, no update will happen)
+ *  - a negative value on error
+ */
+int
+sdb_store_metric(const char *hostname, const char *name,
+		sdb_metric_store_t *store, sdb_time_t last_update);
+
+/*
+ * sdb_store_metric_attr:
+ * Add/update a metric's attribute in the store. If the attribute, identified
+ * by its key, already exists for the specified metric, it will be updated to
+ * the specified value. If the references metric (for the specified host)
+ * does not exist, an error will be reported. Any memory required for storing
+ * the entry will be allocated and managed by the store itself.
  *
  * Returns:
  *  - 0 on success
@@ -147,13 +260,416 @@ sdb_service_create(const char *hostname, const char *name);
  *  - a negative value on error
  */
 int
-sdb_store_service(const sdb_service_t *svc);
+sdb_store_metric_attr(const char *hostname, const char *metric,
+		const char *key, const sdb_data_t *value, sdb_time_t last_update);
+
+/*
+ * sdb_store_fetch_timeseries:
+ * Fetch the time-series described by the specified host's metric and
+ * serialize it as JSON into the provided string buffer.
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value else
+ */
+int
+sdb_store_fetch_timeseries(const char *hostname, const char *metric,
+		sdb_timeseries_opts_t *opts, sdb_strbuf_t *buf);
+
+/*
+ * sdb_store_get_field:
+ * Get the value of a stored object's queryable field. The caller is
+ * responsible for freeing any dynamically allocated memory possibly stored in
+ * the returned value. If 'res' is NULL, the function will return whether the
+ * field exists.
+ *
+ * Note: Retrieving the backend this way is not currently supported.
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value else
+ */
+int
+sdb_store_get_field(sdb_store_obj_t *obj, int field, sdb_data_t *res);
+
+/*
+ * sdb_store_get_attr:
+ * Get the value of a stored object's attribute. The caller is responsible for
+ * freeing any dynamically allocated memory possibly stored in the returned
+ * value. If 'res' is NULL, the function will return whether the attribute
+ * exists. If specified, only attributes matching the filter will be
+ * considered.
+ *
+ * Returns:
+ *  - 0 if the attribute exists
+ *  - a negative value else
+ */
+int
+sdb_store_get_attr(sdb_store_obj_t *obj, const char *name, sdb_data_t *res,
+		sdb_store_matcher_t *filter);
+
+/*
+ * sdb_store_expr_create:
+ * Creates an arithmetic expression implementing the specified operator on the
+ * specified left and right operand.
+ *
+ * Returns:
+ *  - an expression object on success
+ *  - NULL else
+ */
+sdb_store_expr_t *
+sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right);
+
+/*
+ * sdb_store_expr_fieldvalue:
+ * Creates an expression which evaluates to the value of the specified
+ * queryable field of a stored object.
+ *
+ * Returns:
+ *  - an expression object on success
+ *  - NULL else
+ */
+sdb_store_expr_t *
+sdb_store_expr_fieldvalue(int field);
+
+/*
+ * sdb_store_expr_attrvalue:
+ * Creates an expression which evaluates to the value of the specified
+ * attribute of a stored object. Evaluates to a NULL value if the attribute
+ * does not exist.
+ *
+ * Returns:
+ *  - an expression object on success
+ *  - NULL else
+ */
+sdb_store_expr_t *
+sdb_store_expr_attrvalue(const char *name);
+
+/*
+ * sdb_store_expr_constvalue:
+ * Creates an expression which evaluates to the specified constant value.
+ *
+ * Returns:
+ *  - an expression object on success
+ *  - NULL else
+ */
+sdb_store_expr_t *
+sdb_store_expr_constvalue(const sdb_data_t *value);
+
+/*
+ * sdb_store_expr_eval:
+ * Evaluate an expression for the specified stored object and stores the
+ * result in 'res'. The result's value will be allocated dynamically if
+ * necessary and, thus, should be free'd by the caller (e.g. using
+ * sdb_data_free_datum). The object may be NULL, in which case the expression
+ * needs to evaluate to a constant value. If specified, only objects matching
+ * the filter will be used during the evaluation.
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value else
+ */
+int
+sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
+		sdb_data_t *res, sdb_store_matcher_t *filter);
+
+/*
+ * sdb_store_isnull_matcher:
+ * Creates a matcher matching NULL values.
+ */
+sdb_store_matcher_t *
+sdb_store_isnull_matcher(sdb_store_expr_t *expr);
+
+/*
+ * sdb_store_isnnull_matcher:
+ * Creates a matcher matching non-NULL values.
+ */
+sdb_store_matcher_t *
+sdb_store_isnnull_matcher(sdb_store_expr_t *expr);
+
+/*
+ * sdb_store_any_matcher:
+ * Creates a matcher iterating over objects of the specified type. It matches
+ * if *any* of those objects match 'm'.
+ */
+sdb_store_matcher_t *
+sdb_store_any_matcher(int type, sdb_store_matcher_t *m);
+
+/*
+ * sdb_store_all_matcher:
+ * Creates a matcher iterating over objects of the specified type. It matches
+ * if *all* of those objects match 'm'.
+ */
+sdb_store_matcher_t *
+sdb_store_all_matcher(int type, sdb_store_matcher_t *m);
+
+/*
+ * sdb_store_lt_matcher, sdb_store_le_matcher, sdb_store_eq_matcher,
+ * sdb_store_ge_matcher, sdb_store_gt_matcher:
+ * Create conditional matchers comparing the values of two expressions. The
+ * matcher matches if the left expression compres less than, less or equal
+ * than, equal to, not equal to, greater or equal than, or greater than the
+ * right expression.
+ */
+sdb_store_matcher_t *
+sdb_store_lt_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
+sdb_store_matcher_t *
+sdb_store_le_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
+sdb_store_matcher_t *
+sdb_store_eq_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
+sdb_store_matcher_t *
+sdb_store_ne_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
+sdb_store_matcher_t *
+sdb_store_ge_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
+sdb_store_matcher_t *
+sdb_store_gt_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
+
+/*
+ * sdb_store_in_matcher:
+ * Creates a matcher which matches if the right value evaluates to an array
+ * value and the left value is included in that array. See sdb_data_inarray
+ * for more details.
+ */
+sdb_store_matcher_t *
+sdb_store_in_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
+
+/*
+ * sdb_store_regex_matcher:
+ * Creates a matcher which matches the string value the left expression
+ * evaluates to against the regular expression the right expression evaluates
+ * to. The right expression may either be a constant value regular expression
+ * or string or a dynamic value evaluating to a string. In the latter case,
+ * the string is compiled to a regex every time the matcher is executed.
+ */
+sdb_store_matcher_t *
+sdb_store_regex_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
+
+/*
+ * sdb_store_nregex_matcher:
+ * Creates a regex matcher just like sdb_store_regex_matcher except that it
+ * matches in case the regular expression does not match.
+ */
+sdb_store_matcher_t *
+sdb_store_nregex_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
+
+/*
+ * sdb_store_matcher_op_cb:
+ * Callback constructing a matcher operator.
+ */
+typedef sdb_store_matcher_t *(*sdb_store_matcher_op_cb)
+	(sdb_store_expr_t *, sdb_store_expr_t *);
+
+/*
+ * sdb_store_parse_matcher_op:
+ * Parse a matcher operator and return a constructor for the respective
+ * matcher.
+ *
+ * Returns:
+ *  - matcher operator constructor on success
+ *  - NULL else
+ */
+sdb_store_matcher_op_cb
+sdb_store_parse_matcher_op(const char *op);
+
+/*
+ * sdb_store_parse_object_type:
+ * Parse the type name of a stored object.
+ *
+ * Returns:
+ *  - the object type on success
+ *  - a negative value else
+ */
+int
+sdb_store_parse_object_type(const char *name);
+
+/*
+ * sdb_store_parse_object_type_plural:
+ * Parse the type name (plural) of a stored object.
+ *
+ * Returns:
+ *  - the object type on success
+ *  - a negative value else
+ */
+int
+sdb_store_parse_object_type_plural(const char *name);
+
+/*
+ * sdb_store_parse_field_name:
+ * Parse the name of a stored object's queryable field.
+ *
+ * Returns:
+ *  - the field id on success
+ *  - a negative value else
+ */
+int
+sdb_store_parse_field_name(const char *name);
+
+/*
+ * sdb_store_dis_matcher:
+ * Creates a matcher matching the disjunction (logical OR) of two matchers.
+ */
+sdb_store_matcher_t *
+sdb_store_dis_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
+
+/*
+ * sdb_store_con_matcher:
+ * Creates a matcher matching the conjunction (logical AND) of two matchers.
+ */
+sdb_store_matcher_t *
+sdb_store_con_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
+
+/*
+ * sdb_store_con_matcher::
+ * Creates a matcher matching the inverse (logical NOT) of a matcher.
+ */
+sdb_store_matcher_t *
+sdb_store_inv_matcher(sdb_store_matcher_t *m);
+
+/*
+ * sdb_store_matcher_matches:
+ * Check whether the specified matcher matches the specified store object. If
+ * specified, the filter will be used to preselect objects for further
+ * evaluation. It is applied to any object that's used during the evaluation
+ * of the matcher. Only those objects matching the filter will be considered.
+ *
+ * Note that the filter is applied to all object types (hosts, service,
+ * metric, attribute). Thus, any object-specific matchers are mostly unsuited
+ * for this purpose and, if used, may result in unexpected behavior.
+ *
+ * Returns:
+ *  - 1 if the object matches
+ *  - 0 else
+ */
+int
+sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_obj_t *obj,
+		sdb_store_matcher_t *filter);
+
+/*
+ * sdb_store_lookup_cb:
+ * Lookup callback. It is called for each matching object when looking up data
+ * in the store passing on the lookup filter and the specified user-data. The
+ * lookup aborts early if the callback returns non-zero.
+ */
+typedef int (*sdb_store_lookup_cb)(sdb_store_obj_t *obj,
+		sdb_store_matcher_t *filter, void *user_data);
+
+/*
+ * sdb_store_scan:
+ * Look up objects of the specified type in the store. The specified callback
+ * function is called for each object in the store matching 'm'. The function
+ * performs a full scan of all objects stored in the database. If specified,
+ * the filter will be used to preselect objects for further evaluation. See
+ * the description of 'sdb_store_matcher_matches' for details.
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value else
+ */
+int
+sdb_store_scan(int type, sdb_store_matcher_t *m, sdb_store_matcher_t *filter,
+		sdb_store_lookup_cb cb, void *user_data);
+
+/*
+ * Flags for serialization functions.
+ *
+ * By default, the full host object will be included in the serialized output.
+ * When specifying any of the flags, the respective information will be left
+ * out. The SKIP_EMPTY flags may be used to skip host objects entirely.
+ */
+enum {
+	SDB_SKIP_ATTRIBUTES         = 1 << 0,
+	SDB_SKIP_SERVICES           = 1 << 1,
+	SDB_SKIP_METRICS            = 1 << 2,
+	SDB_SKIP_SERVICE_ATTRIBUTES = 1 << 3,
+
+	SDB_SKIP_ALL                = (1 << 8) - 1,
+
+	/* skip hosts if they do not reference any services/metrics */
+	SDB_SKIP_EMPTY_SERVICES     = 1 << 8,
+	SDB_SKIP_EMPTY_METRICS      = 1 << 9,
+};
+
+/*
+ * sdb_store_tojson:
+ * Serialize the entire store to JSON and append the result to the specified
+ * buffer. If specified, only objects matching the filter will be included in
+ * the result (see sdb_store_host_tojson for details).
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value on error
+ */
+int
+sdb_store_tojson(sdb_strbuf_t *buf, sdb_store_matcher_t *filter, int flags);
 
-const sdb_service_t *
-sdb_store_get_service(const sdb_host_t *host, const char *name);
+/*
+ * sdb_store_host_tojson:
+ * Serialize a host object to JSON and append the result to the specified
+ * buffer. If specified, only objects matching the filter will be included in
+ * the result. The filter is applied to each object individually and, thus,
+ * should not be of any object-type specific kind. The filter is never applied
+ * to the specified host object; the caller is responsible for this and for
+ * correctly handling skipped hosts.
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value on error
+ */
+int
+sdb_store_host_tojson(sdb_store_obj_t *host, sdb_strbuf_t *buf,
+		sdb_store_matcher_t *filter, int flags);
+
+/*
+ * sdb_store_json_formatter:
+ * Create a JSON formatter writing to the specified buffer.
+ */
+sdb_store_json_formatter_t *
+sdb_store_json_formatter(sdb_strbuf_t *buf);
+
+/*
+ * sdb_store_json_emit:
+ * Serialize a single object to JSON adding it to the string buffer associated
+ * with the formatter object. The serialized object will not include
+ * attributes or any child objects. Instead, call the function again for each
+ * of those objects. All attributes have to be emitted before any other
+ * children types. Use sdb_store_json_emit_full() to emit a full (filtered)
+ * object.
+ *
+ * Note that the output might not be valid JSON before calling
+ * sdb_store_json_finish().
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value else
+ */
+int
+sdb_store_json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj);
+
+/*
+ * sdb_store_json_emit_full:
+ * Serialize a single object including it's attributes and all children to
+ * JSON, adding it to the string buffer associated with the formatter object.
+ * The filter, if specified, is applied to each attribute and child object.
+ * Only matching objects will be included in the output.
+ *
+ * Note that the output might not be valid JSON before calling
+ * sdb_store_json_finish().
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value else
+ */
+int
+sdb_store_json_emit_full(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj,
+		sdb_store_matcher_t *filter);
 
+/*
+ * sdb_store_json_finish:
+ * Finish the JSON output. This function has to be called once after emiting
+ * all objects.
+ */
 int
-sdb_store_dump(FILE *fh);
+sdb_store_json_finish(sdb_store_json_formatter_t *f);
 
 #ifdef __cplusplus
 } /* extern "C" */