store: Added a generic JSON formatter.

[sysdb.git] / src / include / core / store.h

diff --git a/src/include/core/store.h b/src/include/core/store.h
index 9ba19b8acbeb6da1ed3513ac9676080b1ba2f0bf..6dd7d1ade1ca98b952a4ce05a8b1a4f6bc21fa49 100644 (file)
--- a/src/include/core/store.h
+++ b/src/include/core/store.h
@@ -88,6 +88,13 @@ struct sdb_store_matcher;
 typedef struct sdb_store_matcher sdb_store_matcher_t;
 #define SDB_STORE_MATCHER(obj) ((sdb_store_matcher_t *)(obj))
 
+/*
+ * 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;
+
 /*
  * Queryable fields of a stored object.
  */
@@ -540,24 +547,26 @@ sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_obj_t *obj,
 /*
  * sdb_store_lookup_cb:
  * Lookup callback. It is called for each matching object when looking up data
- * in the store. The lookup aborts if the callback returns non-zero.
+ * 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, void *user_data);
+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 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 hosts 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.
+ * 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(sdb_store_matcher_t *m, sdb_store_matcher_t *filter,
+sdb_store_scan(int type, sdb_store_matcher_t *m, sdb_store_matcher_t *filter,
                sdb_store_lookup_cb cb, void *user_data);
 
 /*
@@ -611,22 +620,56 @@ sdb_store_host_tojson(sdb_store_obj_t *host, sdb_strbuf_t *buf,
                sdb_store_matcher_t *filter, int flags);
 
 /*
- * sdb_store_iter_cb:
- * Store iterator callback. Iteration stops if the callback returns non-zero.
+ * 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
  */
-typedef int (*sdb_store_iter_cb)(sdb_store_obj_t *obj, void *user_data);
+int
+sdb_store_json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj);
 
 /*
- * sdb_store_iterate:
- * Iterate the entire store, calling the specified callback for each object.
- * The user_data pointer is passed on to each call of the callback.
+ * 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_iterate(sdb_store_iter_cb cb, void *user_data);
+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_json_finish(sdb_store_json_formatter_t *f);
 
 #ifdef __cplusplus
 } /* extern "C" */