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+/*
+ * Copyright (c) 2016 Alexadru Ardelean.
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See COPYING for details.
+ *
+ */
+
+/**
+ * @file
+ * @brief JSON Pointer (RFC 6901) implementation for retrieving
+ * objects from a json-c object tree.
+ */
+#ifndef _json_pointer_h_
+#define _json_pointer_h_
+
+#include "json_object.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Retrieves a JSON sub-object from inside another JSON object
+ * using the JSON pointer notation as defined in RFC 6901
+ * https://tools.ietf.org/html/rfc6901
+ *
+ * The returned JSON sub-object is equivalent to parsing manually the
+ * 'obj' JSON tree ; i.e. it's not a new object that is created, but rather
+ * a pointer inside the JSON tree.
+ *
+ * Internally, this is equivalent to doing a series of 'json_object_object_get()'
+ * and 'json_object_array_get_idx()' along the given 'path'.
+ *
+ * Note that the 'path' string supports 'printf()' type arguments, so, whatever
+ * is added after the 'res' param will be treated as an argument for 'path'
+ * Example: json_pointer_get(obj, "/foo/%d/%s", &res, 0, bar)
+ * This means, that you need to escape '%' with '%%' (just like in printf())
+ *
+ * @param obj the json_object instance/tree from where to retrieve sub-objects
+ * @param path a (RFC6901) string notation for the sub-object to retrieve
+ * @param res a pointer that stores a reference to the json_object
+ * associated with the given path
+ *
+ * @return negative if an error (or not found), or 0 if succeeded
+ */
+JSON_EXPORT int json_pointer_get(struct json_object *obj, const char *path,
+ struct json_object **res);
+
+/**
+ * This is a variant of 'json_pointer_get()' that supports printf() style arguments.
+ *
+ * Example: json_pointer_getf(obj, res, "/foo/%d/%s", 0, bak)
+ * This also means that you need to escape '%' with '%%' (just like in printf())
+ *
+ * Please take into consideration all recommended 'printf()' format security
+ * aspects when using this function.
+ *
+ * @param obj the json_object instance/tree to which to add a sub-object
+ * @param res a pointer that stores a reference to the json_object
+ * associated with the given path
+ * @param path_fmt a printf() style format for the path
+ *
+ * @return negative if an error (or not found), or 0 if succeeded
+ */
+JSON_EXPORT int json_pointer_getf(struct json_object *obj, struct json_object **res,
+ const char *path_fmt, ...);
+
+/**
+ * Sets JSON object 'value' in the 'obj' tree at the location specified
+ * by the 'path'. 'path' is JSON pointer notation as defined in RFC 6901
+ * https://tools.ietf.org/html/rfc6901
+ *
+ * Note that 'obj' is a double pointer, mostly for the "" (empty string)
+ * case, where the entire JSON object would be replaced by 'value'.
+ * In the case of the "" path, the object at '*obj' will have it's refcount
+ * decremented with 'json_object_put()' and the 'value' object will be assigned to it.
+ *
+ * For other cases (JSON sub-objects) ownership of 'value' will be transferred into
+ * '*obj' via 'json_object_object_add()' & 'json_object_array_put_idx()', so the
+ * only time the refcount should be decremented for 'value' is when the return value of
+ * 'json_pointer_set()' is negative (meaning the 'value' object did not get set into '*obj').
+ *
+ * That also implies that 'json_pointer_set()' does not do any refcount incrementing.
+ * (Just that single decrement that was mentioned above).
+ *
+ * Note that the 'path' string supports 'printf()' type arguments, so, whatever
+ * is added after the 'value' param will be treated as an argument for 'path'
+ * Example: json_pointer_set(obj, "/foo/%d/%s", value, 0, bak)
+ * This means, that you need to escape '%' with '%%' (just like in printf())
+ *
+ * @param obj the json_object instance/tree to which to add a sub-object
+ * @param path a (RFC6901) string notation for the sub-object to set in the tree
+ * @param value object to set at path
+ *
+ * @return negative if an error (or not found), or 0 if succeeded
+ */
+JSON_EXPORT int json_pointer_set(struct json_object **obj, const char *path,
+ struct json_object *value);
+
+/**
+ * This is a variant of 'json_pointer_set()' that supports printf() style arguments.
+ *
+ * Example: json_pointer_setf(obj, value, "/foo/%d/%s", 0, bak)
+ * This also means that you need to escape '%' with '%%' (just like in printf())
+ *
+ * Please take into consideration all recommended 'printf()' format security
+ * aspects when using this function.
+ *
+ * @param obj the json_object instance/tree to which to add a sub-object
+ * @param value object to set at path
+ * @param path_fmt a printf() style format for the path
+ *
+ * @return negative if an error (or not found), or 0 if succeeded
+ */
+JSON_EXPORT int json_pointer_setf(struct json_object **obj, struct json_object *value,
+ const char *path_fmt, ...);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif