1 /* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */ 2 /* 3 * Simple streaming JSON writer 4 * 5 * This takes care of the annoying bits of JSON syntax like the commas 6 * after elements 7 * 8 * Authors: Stephen Hemminger <stephen@networkplumber.org> 9 */ 10 11 #ifndef _JSON_WRITER_H_ 12 #define _JSON_WRITER_H_ 13 14 #include <stdbool.h> 15 #include <stdint.h> 16 #include <stdarg.h> 17 #include <linux/compiler.h> 18 19 /* Opaque class structure */ 20 typedef struct json_writer json_writer_t; 21 22 /* Create a new JSON stream */ 23 json_writer_t *jsonw_new(FILE *f); 24 /* End output to JSON stream */ 25 void jsonw_destroy(json_writer_t **self_p); 26 27 /* Cause output to have pretty whitespace */ 28 void jsonw_pretty(json_writer_t *self, bool on); 29 30 /* Add property name */ 31 void jsonw_name(json_writer_t *self, const char *name); 32 33 /* Add value */ 34 void __printf(2, 0) jsonw_vprintf_enquote(json_writer_t *self, const char *fmt, 35 va_list ap); 36 void __printf(2, 3) jsonw_printf(json_writer_t *self, const char *fmt, ...); 37 void jsonw_string(json_writer_t *self, const char *value); 38 void jsonw_bool(json_writer_t *self, bool value); 39 void jsonw_float(json_writer_t *self, double number); 40 void jsonw_float_fmt(json_writer_t *self, const char *fmt, double num); 41 void jsonw_uint(json_writer_t *self, uint64_t number); 42 void jsonw_hu(json_writer_t *self, unsigned short number); 43 void jsonw_int(json_writer_t *self, int64_t number); 44 void jsonw_null(json_writer_t *self); 45 void jsonw_lluint(json_writer_t *self, unsigned long long int num); 46 47 /* Useful Combinations of name and value */ 48 void jsonw_string_field(json_writer_t *self, const char *prop, const char *val); 49 void jsonw_bool_field(json_writer_t *self, const char *prop, bool value); 50 void jsonw_float_field(json_writer_t *self, const char *prop, double num); 51 void jsonw_uint_field(json_writer_t *self, const char *prop, uint64_t num); 52 void jsonw_hu_field(json_writer_t *self, const char *prop, unsigned short num); 53 void jsonw_int_field(json_writer_t *self, const char *prop, int64_t num); 54 void jsonw_null_field(json_writer_t *self, const char *prop); 55 void jsonw_lluint_field(json_writer_t *self, const char *prop, 56 unsigned long long int num); 57 void jsonw_float_field_fmt(json_writer_t *self, const char *prop, 58 const char *fmt, double val); 59 60 /* Collections */ 61 void jsonw_start_object(json_writer_t *self); 62 void jsonw_end_object(json_writer_t *self); 63 64 void jsonw_start_array(json_writer_t *self); 65 void jsonw_end_array(json_writer_t *self); 66 67 /* Override default exception handling */ 68 typedef void (jsonw_err_handler_fn)(const char *); 69 70 #endif /* _JSON_WRITER_H_ */ 71