2 * Copyright (c) 2009 Nicira Networks.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
29 #include "dynamic-string.h"
35 /* The type of a JSON token. */
36 enum json_token_type {
42 T_NAME_SEPARATOR = ':',
43 T_VALUE_SEPARATOR = ',',
44 T_FALSE = UCHAR_MAX + 1,
54 * RFC 4627 doesn't define a lexical structure for JSON but I believe this to
55 * be compliant with the standard.
58 enum json_token_type type;
61 long long int integer;
67 JSON_LEX_START, /* Not inside a token. */
68 JSON_LEX_NUMBER, /* Reading a number. */
69 JSON_LEX_KEYWORD, /* Reading a keyword. */
70 JSON_LEX_STRING, /* Reading a quoted string. */
71 JSON_LEX_ESCAPE /* In a quoted string just after a "\". */
74 enum json_parse_state {
75 JSON_PARSE_START, /* Beginning of input. */
76 JSON_PARSE_END, /* End of input. */
79 JSON_PARSE_OBJECT_INIT, /* Expecting '}' or an object name. */
80 JSON_PARSE_OBJECT_NAME, /* Expecting an object name. */
81 JSON_PARSE_OBJECT_COLON, /* Expecting ':'. */
82 JSON_PARSE_OBJECT_VALUE, /* Expecting an object value. */
83 JSON_PARSE_OBJECT_NEXT, /* Expecting ',' or '}'. */
86 JSON_PARSE_ARRAY_INIT, /* Expecting ']' or a value. */
87 JSON_PARSE_ARRAY_VALUE, /* Expecting a value. */
88 JSON_PARSE_ARRAY_NEXT /* Expecting ',' or ']'. */
91 struct json_parser_node {
99 /* Lexical analysis. */
100 enum json_lex_state lex_state;
101 struct ds buffer; /* Buffer for accumulating token text. */
107 enum json_parse_state parse_state;
108 #define JSON_MAX_HEIGHT 1000
109 struct json_parser_node *stack;
110 size_t height, allocated_height;
115 char *error; /* Error message, if any, null if none yet. */
118 static struct json *json_create(enum json_type type);
119 static void json_parser_input(struct json_parser *, struct json_token *);
121 static void json_error(struct json_parser *p, const char *format, ...)
125 json_type_to_string(enum json_type type)
156 /* Functions for manipulating struct json. */
159 json_null_create(void)
161 return json_create(JSON_NULL);
165 json_boolean_create(bool b)
167 return json_create(b ? JSON_TRUE : JSON_FALSE);
171 json_string_create_nocopy(char *s)
173 struct json *json = json_create(JSON_STRING);
179 json_string_create(const char *s)
181 return json_string_create_nocopy(xstrdup(s));
185 json_array_create_empty(void)
187 struct json *json = json_create(JSON_ARRAY);
188 json->u.array.elems = NULL;
190 json->u.array.n_allocated = 0;
195 json_array_add(struct json *array_, struct json *element)
197 struct json_array *array = json_array(array_);
198 if (array->n >= array->n_allocated) {
199 array->elems = x2nrealloc(array->elems, &array->n_allocated,
200 sizeof *array->elems);
202 array->elems[array->n++] = element;
206 json_array_trim(struct json *array_)
208 struct json_array *array = json_array(array_);
209 if (array->n < array->n_allocated){
210 array->n_allocated = array->n;
211 array->elems = xrealloc(array->elems, array->n * sizeof *array->elems);
216 json_array_create(struct json **elements, size_t n)
218 struct json *json = json_create(JSON_ARRAY);
219 json->u.array.elems = elements;
221 json->u.array.n_allocated = n;
226 json_array_create_1(struct json *elem0)
228 struct json **elems = xmalloc(sizeof *elems);
230 return json_array_create(elems, 1);
234 json_array_create_2(struct json *elem0, struct json *elem1)
236 struct json **elems = xmalloc(2 * sizeof *elems);
239 return json_array_create(elems, 2);
243 json_array_create_3(struct json *elem0, struct json *elem1, struct json *elem2)
245 struct json **elems = xmalloc(3 * sizeof *elems);
249 return json_array_create(elems, 3);
253 json_object_create(void)
255 struct json *json = json_create(JSON_OBJECT);
256 json->u.object = xmalloc(sizeof *json->u.object);
257 shash_init(json->u.object);
262 json_integer_create(long long int integer)
264 struct json *json = json_create(JSON_INTEGER);
265 json->u.integer = integer;
270 json_real_create(double real)
272 struct json *json = json_create(JSON_REAL);
278 json_object_put(struct json *json, const char *name, struct json *value)
280 shash_add(json->u.object, name, value);
284 json_object_put_string(struct json *json, const char *name, const char *value)
286 json_object_put(json, name, json_string_create(value));
290 json_string(const struct json *json)
292 assert(json->type == JSON_STRING);
293 return json->u.string;
297 json_array(const struct json *json)
299 assert(json->type == JSON_ARRAY);
300 return (struct json_array *) &json->u.array;
304 json_object(const struct json *json)
306 assert(json->type == JSON_OBJECT);
307 return (struct shash *) json->u.object;
311 json_boolean(const struct json *json)
313 assert(json->type == JSON_TRUE || json->type == JSON_FALSE);
314 return json->type == JSON_TRUE;
318 json_real(const struct json *json)
320 assert(json->type == JSON_REAL || json->type == JSON_INTEGER);
321 return json->type == JSON_REAL ? json->u.real : json->u.integer;
325 json_integer(const struct json *json)
327 assert(json->type == JSON_INTEGER);
328 return json->u.integer;
331 static void json_destroy_object(struct shash *object);
332 static void json_destroy_array(struct json_array *array);
334 /* Frees 'json' and everything it points to, recursively. */
336 json_destroy(struct json *json)
339 switch (json->type) {
341 json_destroy_object(json->u.object);
345 json_destroy_array(&json->u.array);
349 free(json->u.string);
367 json_destroy_object(struct shash *object)
369 struct shash_node *node, *next;
371 SHASH_FOR_EACH_SAFE (node, next, object) {
372 struct json *value = node->data;
375 shash_delete(object, node);
377 shash_destroy(object);
382 json_destroy_array(struct json_array *array)
386 for (i = 0; i < array->n; i++) {
387 json_destroy(array->elems[i]);
392 static struct json *json_clone_object(const struct shash *object);
393 static struct json *json_clone_array(const struct json_array *array);
395 /* Returns a deep copy of 'json'. */
397 json_clone(const struct json *json)
399 switch (json->type) {
401 return json_clone_object(json->u.object);
404 return json_clone_array(&json->u.array);
407 return json_string_create(json->u.string);
412 return json_create(json->type);
415 return json_integer_create(json->u.integer);
418 return json_real_create(json->u.real);
427 json_clone_object(const struct shash *object)
429 struct shash_node *node;
432 json = json_object_create();
433 SHASH_FOR_EACH (node, object) {
434 struct json *value = node->data;
435 json_object_put(json, node->name, json_clone(value));
441 json_clone_array(const struct json_array *array)
446 elems = xmalloc(array->n * sizeof *elems);
447 for (i = 0; i < array->n; i++) {
448 elems[i] = json_clone(array->elems[i]);
450 return json_array_create(elems, array->n);
454 json_hash_object(const struct shash *object, size_t basis)
456 const struct shash_node **nodes;
459 nodes = shash_sort(object);
460 n = shash_count(object);
461 for (i = 0; i < n; i++) {
462 const struct shash_node *node = nodes[i];
463 basis = hash_string(node->name, basis);
464 basis = json_hash(node->data, basis);
470 json_hash_array(const struct json_array *array, size_t basis)
474 basis = hash_int(array->n, basis);
475 for (i = 0; i < array->n; i++) {
476 basis = json_hash(array->elems[i], basis);
482 json_hash(const struct json *json, size_t basis)
484 switch (json->type) {
486 return json_hash_object(json->u.object, basis);
489 return json_hash_array(&json->u.array, basis);
492 return hash_string(json->u.string, basis);
497 return hash_int(json->type << 8, basis);
500 return hash_int(json->u.integer, basis);
503 return hash_double(json->u.real, basis);
512 json_equal_object(const struct shash *a, const struct shash *b)
514 struct shash_node *a_node;
516 if (shash_count(a) != shash_count(b)) {
520 SHASH_FOR_EACH (a_node, a) {
521 struct shash_node *b_node = shash_find(b, a_node->name);
522 if (!b_node || !json_equal(a_node->data, b_node->data)) {
531 json_equal_array(const struct json_array *a, const struct json_array *b)
539 for (i = 0; i < a->n; i++) {
540 if (!json_equal(a->elems[i], b->elems[i])) {
549 json_equal(const struct json *a, const struct json *b)
551 if (a->type != b->type) {
557 return json_equal_object(a->u.object, b->u.object);
560 return json_equal_array(&a->u.array, &b->u.array);
563 return !strcmp(a->u.string, b->u.string);
571 return a->u.integer == b->u.integer;
574 return a->u.real == b->u.real;
582 /* Lexical analysis. */
585 json_lex_keyword(struct json_parser *p)
587 struct json_token token;
590 s = ds_cstr(&p->buffer);
591 if (!strcmp(s, "false")) {
592 token.type = T_FALSE;
593 } else if (!strcmp(s, "true")) {
595 } else if (!strcmp(s, "null")) {
598 json_error(p, "invalid keyword '%s'", s);
601 json_parser_input(p, &token);
605 json_lex_number(struct json_parser *p)
607 const char *cp = ds_cstr(&p->buffer);
608 unsigned long long int significand = 0;
609 struct json_token token;
611 bool imprecise = false;
612 bool negative = false;
615 /* Leading minus sign. */
621 /* At least one integer digit, but 0 may not be used as a leading digit for
622 * a longer number. */
628 json_error(p, "leading zeros not allowed");
631 } else if (isdigit(*cp)) {
633 if (significand <= ULLONG_MAX / 10) {
634 significand = significand * 10 + (*cp - '0');
643 } while (isdigit(*cp));
645 json_error(p, "'-' must be followed by digit");
649 /* Optional fraction. */
653 json_error(p, "decimal point must be followed by digit");
657 if (significand <= ULLONG_MAX / 10) {
658 significand = significand * 10 + (*cp - '0');
661 } else if (*cp != '0') {
665 } while (isdigit(*cp));
668 /* Optional exponent. */
669 if (*cp == 'e' || *cp == 'E') {
670 bool negative_exponent = false;
676 } else if (*cp == '-') {
677 negative_exponent = true;
682 json_error(p, "exponent must contain at least one digit");
688 if (exponent >= INT_MAX / 10) {
689 json_error(p, "exponent outside valid range");
692 exponent = exponent * 10 + (*cp - '0');
694 } while (isdigit(*cp));
696 if (negative_exponent) {
704 json_error(p, "syntax error in number");
708 /* Figure out number.
710 * We suppress negative zeros as a matter of policy. */
712 struct json_token token;
713 token.type = T_INTEGER;
715 json_parser_input(p, &token);
720 while (pow10 > 0 && significand < ULLONG_MAX / 10) {
725 while (pow10 < 0 && significand % 10 == 0) {
731 && significand <= (negative
732 ? (unsigned long long int) LLONG_MAX + 1
734 token.type = T_INTEGER;
735 token.u.integer = negative ? -significand : significand;
736 json_parser_input(p, &token);
742 if (!str_to_double(ds_cstr(&p->buffer), &token.u.real)) {
743 json_error(p, "number outside valid range");
746 /* Suppress negative zero. */
747 if (token.u.real == 0) {
750 json_parser_input(p, &token);
754 json_lex_4hex(struct json_parser *p, const char *cp, int *valuep)
759 for (i = 0; i < 4; i++) {
760 unsigned char c = *cp++;
762 json_error(p, "malformed \\u escape");
765 value = (value << 4) | hexit_value(c);
768 json_error(p, "null bytes not supported in quoted strings");
776 json_lex_unicode(struct json_parser *p, const char *cp, struct ds *s)
780 if (!json_lex_4hex(p, cp, &c0)) {
784 if (!uc_is_leading_surrogate(c0)) {
789 if (*cp++ != '\\' || *cp++ != 'u') {
790 json_error(p, "malformed escaped surrogate pair");
794 if (!json_lex_4hex(p, cp, &c1)) {
798 if (!uc_is_trailing_surrogate(c1)) {
799 json_error(p, "second half of escaped surrogate pair is not "
800 "trailing surrogate");
804 ds_put_utf8(s, utf16_decode_surrogate_pair(c0, c1));
809 json_lex_string(struct json_parser *p)
811 struct json_token token;
815 cp = ds_cstr(&p->buffer);
816 if (!strchr(cp, '\\')) {
817 token.type = T_STRING;
819 json_parser_input(p, &token);
824 ds_reserve(&s, strlen(cp));
825 while (*cp != '\0') {
827 ds_put_char(&s, *cp++);
833 case '"': case '\\': case '/':
834 ds_put_char(&s, cp[-1]);
838 ds_put_char(&s, '\b');
842 ds_put_char(&s, '\f');
846 ds_put_char(&s, '\n');
850 ds_put_char(&s, '\r');
854 ds_put_char(&s, '\t');
858 cp = json_lex_unicode(p, cp, &s);
865 json_error(p, "bad escape \\%c", cp[-1]);
870 token.type = T_STRING;
871 token.u.string = ds_cstr(&s);
872 json_parser_input(p, &token);
880 json_lex_input(struct json_parser *p, unsigned char c)
882 struct json_token token;
886 p->column_number = 0;
892 switch (p->lex_state) {
895 case ' ': case '\t': case '\n': case '\r':
899 case 'a': case 'b': case 'c': case 'd': case 'e':
900 case 'f': case 'g': case 'h': case 'i': case 'j':
901 case 'k': case 'l': case 'm': case 'n': case 'o':
902 case 'p': case 'q': case 'r': case 's': case 't':
903 case 'u': case 'v': case 'w': case 'x': case 'y':
905 p->lex_state = JSON_LEX_KEYWORD;
908 case '[': case '{': case ']': case '}': case ':': case ',':
910 json_parser_input(p, &token);
914 case '0': case '1': case '2': case '3': case '4':
915 case '5': case '6': case '7': case '8': case '9':
916 p->lex_state = JSON_LEX_NUMBER;
920 p->lex_state = JSON_LEX_STRING;
925 json_error(p, "invalid character '%c'", c);
927 json_error(p, "invalid character U+%04x", c);
933 case JSON_LEX_KEYWORD:
934 if (!isalpha((unsigned char) c)) {
940 case JSON_LEX_NUMBER:
941 if (!strchr(".0123456789eE-+", c)) {
947 case JSON_LEX_STRING:
949 p->lex_state = JSON_LEX_ESCAPE;
950 } else if (c == '"') {
953 } else if (c < 0x20) {
954 json_error(p, "U+%04X must be escaped in quoted string", c);
959 case JSON_LEX_ESCAPE:
960 p->lex_state = JSON_LEX_STRING;
966 ds_put_char(&p->buffer, c);
972 /* Parses 'string' as a JSON object or array and returns a newly allocated
973 * 'struct json'. The caller must free the returned structure with
974 * json_destroy() when it is no longer needed.
976 * 'string' must be encoded in UTF-8.
978 * If 'string' is valid JSON, then the returned 'struct json' will be either an
979 * object (JSON_OBJECT) or an array (JSON_ARRAY).
981 * If 'string' is not valid JSON, then the returned 'struct json' will be a
982 * string (JSON_STRING) that describes the particular error encountered during
983 * parsing. (This is an acceptable means of error reporting because at its top
984 * level JSON must be either an object or an array; a bare string is not
987 json_from_string(const char *string)
989 struct json_parser *p = json_parser_create(JSPF_TRAILER);
990 json_parser_feed(p, string, strlen(string));
991 return json_parser_finish(p);
994 /* Reads the file named 'file_name', parses its contents as a JSON object or
995 * array, and returns a newly allocated 'struct json'. The caller must free
996 * the returned structure with json_destroy() when it is no longer needed.
998 * The file must be encoded in UTF-8.
1000 * See json_from_string() for return value semantics.
1003 json_from_file(const char *file_name)
1005 struct json_parser *p;
1010 stream = fopen(file_name, "r");
1012 return json_string_create_nocopy(
1013 xasprintf("error opening \"%s\": %s", file_name, strerror(errno)));
1016 /* Read and parse file. */
1017 p = json_parser_create(JSPF_TRAILER);
1019 char buffer[BUFSIZ];
1022 n = fread(buffer, 1, sizeof buffer, stream);
1023 if (!n || json_parser_feed(p, buffer, n) != n) {
1027 json = json_parser_finish(p);
1029 /* Close file and check for I/O errors. */
1030 if (ferror(stream)) {
1032 json = json_string_create_nocopy(
1033 xasprintf("error reading \"%s\": %s", file_name, strerror(errno)));
1040 struct json_parser *
1041 json_parser_create(int flags)
1043 struct json_parser *p = xzalloc(sizeof *p);
1049 json_parser_feed(struct json_parser *p, const char *input, size_t n)
1052 for (i = 0; !p->done && i < n; ) {
1053 if (json_lex_input(p, input[i])) {
1061 json_parser_is_done(const struct json_parser *p)
1067 json_parser_finish(struct json_parser *p)
1071 switch (p->lex_state) {
1072 case JSON_LEX_START:
1075 case JSON_LEX_STRING:
1076 case JSON_LEX_ESCAPE:
1077 json_error(p, "unexpected end of input in quoted string");
1080 case JSON_LEX_NUMBER:
1081 case JSON_LEX_KEYWORD:
1082 json_lex_input(p, ' ');
1086 if (p->parse_state == JSON_PARSE_START) {
1087 json_error(p, "empty input stream");
1088 } else if (p->parse_state != JSON_PARSE_END) {
1089 json_error(p, "unexpected end of input");
1093 assert(p->height == 1);
1094 assert(p->stack[0].json != NULL);
1095 json = p->stack[--p->height].json;
1097 json = json_string_create_nocopy(p->error);
1101 json_parser_abort(p);
1107 json_parser_abort(struct json_parser *p)
1110 ds_destroy(&p->buffer);
1112 json_destroy(p->stack[0].json);
1115 free(p->member_name);
1121 static struct json_parser_node *
1122 json_parser_top(struct json_parser *p)
1124 return &p->stack[p->height - 1];
1128 json_parser_put_value(struct json_parser *p, struct json *value)
1130 struct json_parser_node *node = json_parser_top(p);
1131 if (node->json->type == JSON_OBJECT) {
1132 json_object_put(node->json, p->member_name, value);
1133 free(p->member_name);
1134 p->member_name = NULL;
1135 } else if (node->json->type == JSON_ARRAY) {
1136 json_array_add(node->json, value);
1142 static struct json_parser_node *
1143 json_parser_push(struct json_parser *p,
1144 struct json *new_json, enum json_parse_state new_state)
1146 if (p->height < JSON_MAX_HEIGHT) {
1147 struct json_parser_node *node;
1149 if (p->height >= p->allocated_height) {
1150 p->stack = x2nrealloc(p->stack, &p->allocated_height,
1154 if (p->height > 0) {
1155 json_parser_put_value(p, new_json);
1158 node = &p->stack[p->height++];
1159 node->json = new_json;
1160 p->parse_state = new_state;
1163 json_error(p, "input exceeds maximum nesting depth %d",
1170 json_parser_push_object(struct json_parser *p)
1172 json_parser_push(p, json_object_create(), JSON_PARSE_OBJECT_INIT);
1176 json_parser_push_array(struct json_parser *p)
1178 json_parser_push(p, json_array_create_empty(), JSON_PARSE_ARRAY_INIT);
1182 json_parse_value(struct json_parser *p, struct json_token *token,
1183 enum json_parse_state next_state)
1187 switch (token->type) {
1189 value = json_boolean_create(false);
1193 value = json_null_create();
1197 value = json_boolean_create(true);
1201 json_parser_push_object(p);
1205 json_parser_push_array(p);
1209 value = json_integer_create(token->u.integer);
1213 value = json_real_create(token->u.real);
1217 value = json_string_create(token->u.string);
1226 json_error(p, "syntax error expecting value");
1230 json_parser_put_value(p, value);
1231 p->parse_state = next_state;
1235 json_parser_pop(struct json_parser *p)
1237 struct json_parser_node *node;
1239 /* Conserve memory. */
1240 node = json_parser_top(p);
1241 if (node->json->type == JSON_ARRAY) {
1242 json_array_trim(node->json);
1245 /* Pop off the top-of-stack. */
1246 if (p->height == 1) {
1247 p->parse_state = JSON_PARSE_END;
1248 if (!(p->flags & JSPF_TRAILER)) {
1253 node = json_parser_top(p);
1254 if (node->json->type == JSON_ARRAY) {
1255 p->parse_state = JSON_PARSE_ARRAY_NEXT;
1256 } else if (node->json->type == JSON_OBJECT) {
1257 p->parse_state = JSON_PARSE_OBJECT_NEXT;
1265 json_parser_input(struct json_parser *p, struct json_token *token)
1267 switch (p->parse_state) {
1268 case JSON_PARSE_START:
1269 if (token->type == '{') {
1270 json_parser_push_object(p);
1271 } else if (token->type == '[') {
1272 json_parser_push_array(p);
1274 json_error(p, "syntax error at beginning of input");
1278 case JSON_PARSE_END:
1279 json_error(p, "trailing garbage at end of input");
1282 case JSON_PARSE_OBJECT_INIT:
1283 if (token->type == '}') {
1288 case JSON_PARSE_OBJECT_NAME:
1289 if (token->type == T_STRING) {
1290 p->member_name = xstrdup(token->u.string);
1291 p->parse_state = JSON_PARSE_OBJECT_COLON;
1293 json_error(p, "syntax error parsing object expecting string");
1297 case JSON_PARSE_OBJECT_COLON:
1298 if (token->type == ':') {
1299 p->parse_state = JSON_PARSE_OBJECT_VALUE;
1301 json_error(p, "syntax error parsing object expecting ':'");
1305 case JSON_PARSE_OBJECT_VALUE:
1306 json_parse_value(p, token, JSON_PARSE_OBJECT_NEXT);
1309 case JSON_PARSE_OBJECT_NEXT:
1310 if (token->type == ',') {
1311 p->parse_state = JSON_PARSE_OBJECT_NAME;
1312 } else if (token->type == '}') {
1315 json_error(p, "syntax error expecting '}' or ','");
1319 case JSON_PARSE_ARRAY_INIT:
1320 if (token->type == ']') {
1325 case JSON_PARSE_ARRAY_VALUE:
1326 json_parse_value(p, token, JSON_PARSE_ARRAY_NEXT);
1329 case JSON_PARSE_ARRAY_NEXT:
1330 if (token->type == ',') {
1331 p->parse_state = JSON_PARSE_ARRAY_VALUE;
1332 } else if (token->type == ']') {
1335 json_error(p, "syntax error expecting ']' or ','");
1343 p->lex_state = JSON_LEX_START;
1344 ds_clear(&p->buffer);
1347 static struct json *
1348 json_create(enum json_type type)
1350 struct json *json = xmalloc(sizeof *json);
1356 json_error(struct json_parser *p, const char *format, ...)
1363 ds_put_format(&msg, "line %d, column %d, byte %d: ",
1364 p->line_number, p->column_number, p->byte_number);
1365 va_start(args, format);
1366 ds_put_format_valist(&msg, format, args);
1369 p->error = ds_steal_cstr(&msg);
1375 #define SPACES_PER_LEVEL 2
1377 struct json_serializer {
1383 static void json_to_ds(const struct json *, struct json_serializer *);
1384 static void json_object_to_ds(const struct shash *object,
1385 struct json_serializer *);
1386 static void json_array_to_ds(const struct json_array *,
1387 struct json_serializer *);
1388 static void json_string_to_ds(const char *string, struct ds *);
1390 /* Converts 'json' to a string in JSON format, encoded in UTF-8, and returns
1391 * that string. The caller is responsible for freeing the returned string,
1392 * with free(), when it is no longer needed.
1394 * If 'flags' contains JSSF_PRETTY, the output is pretty-printed with each
1395 * nesting level introducing an additional indentation. Otherwise, the
1396 * returned string does not contain any new-line characters.
1398 * If 'flags' contains JSSF_SORT, members of objects in the output are sorted
1399 * in bytewise lexicographic order for reproducibility. Otherwise, members of
1400 * objects are output in an indeterminate order.
1402 * The returned string is valid JSON only if 'json' represents an array or an
1403 * object, since a bare literal does not satisfy the JSON grammar. */
1405 json_to_string(const struct json *json, int flags)
1407 struct json_serializer s;
1411 json_to_ds(json, &s);
1412 return ds_steal_cstr(&s.ds);
1416 json_to_ds(const struct json *json, struct json_serializer *s)
1418 struct ds *ds = &s->ds;
1420 switch (json->type) {
1422 ds_put_cstr(ds, "null");
1426 ds_put_cstr(ds, "false");
1430 ds_put_cstr(ds, "true");
1434 json_object_to_ds(json->u.object, s);
1438 json_array_to_ds(&json->u.array, s);
1442 ds_put_format(ds, "%lld", json->u.integer);
1446 ds_put_format(ds, "%.*g", DBL_DIG, json->u.real);
1450 json_string_to_ds(json->u.string, ds);
1460 indent_line(struct json_serializer *s)
1462 if (s->flags & JSSF_PRETTY) {
1463 ds_put_char(&s->ds, '\n');
1464 ds_put_char_multiple(&s->ds, ' ', SPACES_PER_LEVEL * s->depth);
1469 json_object_member_to_ds(size_t i, const struct shash_node *node,
1470 struct json_serializer *s)
1472 struct ds *ds = &s->ds;
1475 ds_put_char(ds, ',');
1479 json_string_to_ds(node->name, ds);
1480 ds_put_char(ds, ':');
1481 if (s->flags & JSSF_PRETTY) {
1482 ds_put_char(ds, ' ');
1484 json_to_ds(node->data, s);
1488 json_object_to_ds(const struct shash *object, struct json_serializer *s)
1490 struct ds *ds = &s->ds;
1492 ds_put_char(ds, '{');
1497 if (s->flags & JSSF_SORT) {
1498 const struct shash_node **nodes;
1501 nodes = shash_sort(object);
1502 n = shash_count(object);
1503 for (i = 0; i < n; i++) {
1504 json_object_member_to_ds(i, nodes[i], s);
1508 struct shash_node *node;
1512 SHASH_FOR_EACH (node, object) {
1513 json_object_member_to_ds(i++, node, s);
1517 ds_put_char(ds, '}');
1522 json_array_to_ds(const struct json_array *array, struct json_serializer *s)
1524 struct ds *ds = &s->ds;
1527 ds_put_char(ds, '[');
1533 for (i = 0; i < array->n; i++) {
1535 ds_put_char(ds, ',');
1538 json_to_ds(array->elems[i], s);
1543 ds_put_char(ds, ']');
1547 json_string_to_ds(const char *string, struct ds *ds)
1551 ds_put_char(ds, '"');
1552 while ((c = *string++) != '\0') {
1555 ds_put_cstr(ds, "\\\"");
1559 ds_put_cstr(ds, "\\\\");
1563 ds_put_cstr(ds, "\\b");
1567 ds_put_cstr(ds, "\\f");
1571 ds_put_cstr(ds, "\\n");
1575 ds_put_cstr(ds, "\\r");
1579 ds_put_cstr(ds, "\\t");
1586 ds_put_format(ds, "\\u%04x", c);
1591 ds_put_char(ds, '"');