bartoszek/zephyr
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

lib: json: add JSON_OBJ_DESCR_*_NAMED variants

Browse Source 
The set of valid JSON field names is larger than the set of C
identifiers. This can result in structure field names which pack
decoded JSON values which necessarily differ from the field names in
the JSON.

Support this by adding _NAMED variants to each of the JSON_OBJ_DESCR_*
helper macros. For example, JSON_OBJ_DESCR_PRIM_NAMED allows users to
declare a descriptor field for a primitive type, whose structure field
name is different from the JSON field name.

Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
This commit is contained in:
Marti Bolivar 2017-05-31 11:14:11 -04:00 committed by Anas Nashif
parent a8e08ecdad
commit 44499768a8
1 changed files with 89 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

89
lib/json/json.h
View File

@ -172,6 +172,95 @@ typedef int (*json_append_bytes_t)(const u8_t *bytes, size_t len,
.n_elements = (max_len_), \
}
/**
* @brief Variant of JSON_OBJ_DESCR_PRIM that can be used when the
* structure and JSON field names differ.
*
* This is useful when the JSON field is not a valid C identifier.
*
* @param struct_ Struct packing the values.
*
* @param json_field_name_ String, field name in JSON strings
*
* @param struct_field_name_ Field name in the struct
*
* @param type_ Token type for JSON value corresponding to a primitive
* type.
*
* @see JSON_OBJ_DESCR_PRIM
*/
#define JSON_OBJ_DESCR_PRIM_NAMED(struct_, json_field_name_, \
struct_field_name_, type_) \
{ \
.field_name = (json_field_name_), \
.field_name_len = sizeof(json_field_name_) - 1, \
.offset = offsetof(struct_, struct_field_name_), \
.type = type_, \
}
/**
* @brief Variant of JSON_OBJ_DESCR_OBJECT that can be used when the
* structure and JSON field names differ.
*
* This is useful when the JSON field is not a valid C identifier.
*
* @param struct_ Struct packing the values
*
* @param json_field_name_ String, field name in JSON strings
*
* @param struct_field_name_ Field name in the struct
*
* @param sub_descr_ Array of json_obj_descr describing the subobject
*
* @see JSON_OBJ_DESCR_OBJECT
*/
#define JSON_OBJ_DESCR_OBJECT_NAMED(struct_, json_field_name_, \
struct_field_name_, sub_descr_) \
{ \
.field_name = (json_field_name_), \
.field_name_len = (sizeof(json_field_name_) - 1), \
.offset = offsetof(struct_, struct_field_name_), \
.type = JSON_TOK_OBJECT_START, \
.sub_descr = sub_descr_, \
.sub_descr_len = ARRAY_SIZE(sub_descr_) \
}
/**
* @brief Variant of JSON_OBJ_DESCR_ARRAY that can be used when the
* structure and JSON field names differ.
*
* This is useful when the JSON field is not a valid C identifier.
*
* @param struct_ Struct packing the values
*
* @param json_field_name_ String, field name in JSON strings
*
* @param struct_field_name_ Field name in the struct
*
* @param max_len_ Maximum number of elements in array
*
* @param len_field_ Field name in the struct for the number of elements
* in the array
*
* @param elem_type_ Element type
*
* @see JSON_OBJ_DESCR_ARRAY
*/
#define JSON_OBJ_DESCR_ARRAY_NAMED(struct_, json_field_name_,\
struct_field_name_, max_len_, len_field_, \
elem_type_) \
{ \
.field_name = (json_field_name_), \
.field_name_len = sizeof(json_field_name_) - 1, \
.offset = offsetof(struct_, struct_field_name_), \
.type = JSON_TOK_LIST_START, \
.element_descr = &(struct json_obj_descr) { \
.type = elem_type_, \
.offset = offsetof(struct_, len_field_), \
}, \
.n_elements = (max_len_), \
}
/**
* @brief Parses the JSON-encoded object pointer to by @param json, with
* size @param len, according to the descriptor pointed to by @param descr.