2 * Copyright (c) 2009, 2010, 2011, 2012, 2014 Nicira, Inc.
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.
27 #include "dynamic-string.h"
33 /* The type of a JSON token. */
34 enum json_token_type {
40 T_NAME_SEPARATOR = ':',
41 T_VALUE_SEPARATOR = ',',
42 T_FALSE = UCHAR_MAX + 1,
52 * RFC 4627 doesn't define a lexical structure for JSON but I believe this to
53 * be compliant with the standard.
56 enum json_token_type type;
59 long long int integer;
65 JSON_LEX_START, /* Not inside a token. */
66 JSON_LEX_NUMBER, /* Reading a number. */
67 JSON_LEX_KEYWORD, /* Reading a keyword. */
68 JSON_LEX_STRING, /* Reading a quoted string. */
69 JSON_LEX_ESCAPE /* In a quoted string just after a "\". */
72 enum json_parse_state {
73 JSON_PARSE_START, /* Beginning of input. */
74 JSON_PARSE_END, /* End of input. */
77 JSON_PARSE_OBJECT_INIT, /* Expecting '}' or an object name. */
78 JSON_PARSE_OBJECT_NAME, /* Expecting an object name. */
79 JSON_PARSE_OBJECT_COLON, /* Expecting ':'. */
80 JSON_PARSE_OBJECT_VALUE, /* Expecting an object value. */
81 JSON_PARSE_OBJECT_NEXT, /* Expecting ',' or '}'. */
84 JSON_PARSE_ARRAY_INIT, /* Expecting ']' or a value. */
85 JSON_PARSE_ARRAY_VALUE, /* Expecting a value. */
86 JSON_PARSE_ARRAY_NEXT /* Expecting ',' or ']'. */
89 struct json_parser_node {
97 /* Lexical analysis. */
98 enum json_lex_state lex_state;
99 struct ds buffer; /* Buffer for accumulating token text. */
105 enum json_parse_state parse_state;
106 #define JSON_MAX_HEIGHT 1000
107 struct json_parser_node *stack;
108 size_t height, allocated_height;
113 char *error; /* Error message, if any, null if none yet. */
116 static struct json *json_create(enum json_type type);
117 static void json_parser_input(struct json_parser *, struct json_token *);
119 static void json_error(struct json_parser *p, const char *format, ...)
123 json_type_to_string(enum json_type type)
154 /* Functions for manipulating struct json. */
157 json_null_create(void)
159 return json_create(JSON_NULL);
163 json_boolean_create(bool b)
165 return json_create(b ? JSON_TRUE : JSON_FALSE);
169 json_string_create_nocopy(char *s)
171 struct json *json = json_create(JSON_STRING);
177 json_string_create(const char *s)
179 return json_string_create_nocopy(xstrdup(s));
183 json_array_create_empty(void)
185 struct json *json = json_create(JSON_ARRAY);
186 json->u.array.elems = NULL;
188 json->u.array.n_allocated = 0;
193 json_array_add(struct json *array_, struct json *element)
195 struct json_array *array = json_array(array_);
196 if (array->n >= array->n_allocated) {
197 array->elems = x2nrealloc(array->elems, &array->n_allocated,
198 sizeof *array->elems);
200 array->elems[array->n++] = element;
204 json_array_trim(struct json *array_)
206 struct json_array *array = json_array(array_);
207 if (array->n < array->n_allocated){
208 array->n_allocated = array->n;
209 array->elems = xrealloc(array->elems, array->n * sizeof *array->elems);
214 json_array_create(struct json **elements, size_t n)
216 struct json *json = json_create(JSON_ARRAY);
217 json->u.array.elems = elements;
219 json->u.array.n_allocated = n;
224 json_array_create_1(struct json *elem0)
226 struct json **elems = xmalloc(sizeof *elems);
228 return json_array_create(elems, 1);
232 json_array_create_2(struct json *elem0, struct json *elem1)
234 struct json **elems = xmalloc(2 * sizeof *elems);
237 return json_array_create(elems, 2);
241 json_array_create_3(struct json *elem0, struct json *elem1, struct json *elem2)
243 struct json **elems = xmalloc(3 * sizeof *elems);
247 return json_array_create(elems, 3);
251 json_object_create(void)
253 struct json *json = json_create(JSON_OBJECT);
254 json->u.object = xmalloc(sizeof *json->u.object);
255 shash_init(json->u.object);
260 json_integer_create(long long int integer)
262 struct json *json = json_create(JSON_INTEGER);
263 json->u.integer = integer;
268 json_real_create(double real)
270 struct json *json = json_create(JSON_REAL);
276 json_object_put(struct json *json, const char *name, struct json *value)
278 json_destroy(shash_replace(json->u.object, name, value));
282 json_object_put_string(struct json *json, const char *name, const char *value)
284 json_object_put(json, name, json_string_create(value));
288 json_string(const struct json *json)
290 ovs_assert(json->type == JSON_STRING);
291 return json->u.string;
295 json_array(const struct json *json)
297 ovs_assert(json->type == JSON_ARRAY);
298 return CONST_CAST(struct json_array *, &json->u.array);
302 json_object(const struct json *json)
304 ovs_assert(json->type == JSON_OBJECT);
305 return CONST_CAST(struct shash *, json->u.object);
309 json_boolean(const struct json *json)
311 ovs_assert(json->type == JSON_TRUE || json->type == JSON_FALSE);
312 return json->type == JSON_TRUE;
316 json_real(const struct json *json)
318 ovs_assert(json->type == JSON_REAL || json->type == JSON_INTEGER);
319 return json->type == JSON_REAL ? json->u.real : json->u.integer;
323 json_integer(const struct json *json)
325 ovs_assert(json->type == JSON_INTEGER);
326 return json->u.integer;
329 static void json_destroy_object(struct shash *object);
330 static void json_destroy_array(struct json_array *array);
332 /* Frees 'json' and everything it points to, recursively. */
334 json_destroy(struct json *json)
337 switch (json->type) {
339 json_destroy_object(json->u.object);
343 json_destroy_array(&json->u.array);
347 free(json->u.string);
365 json_destroy_object(struct shash *object)
367 struct shash_node *node, *next;
369 SHASH_FOR_EACH_SAFE (node, next, object) {
370 struct json *value = node->data;
373 shash_delete(object, node);
375 shash_destroy(object);
380 json_destroy_array(struct json_array *array)
384 for (i = 0; i < array->n; i++) {
385 json_destroy(array->elems[i]);
390 static struct json *json_clone_object(const struct shash *object);
391 static struct json *json_clone_array(const struct json_array *array);
393 /* Returns a deep copy of 'json'. */
395 json_clone(const struct json *json)
397 switch (json->type) {
399 return json_clone_object(json->u.object);
402 return json_clone_array(&json->u.array);
405 return json_string_create(json->u.string);
410 return json_create(json->type);
413 return json_integer_create(json->u.integer);
416 return json_real_create(json->u.real);
425 json_clone_object(const struct shash *object)
427 struct shash_node *node;
430 json = json_object_create();
431 SHASH_FOR_EACH (node, object) {
432 struct json *value = node->data;
433 json_object_put(json, node->name, json_clone(value));
439 json_clone_array(const struct json_array *array)
444 elems = xmalloc(array->n * sizeof *elems);
445 for (i = 0; i < array->n; i++) {
446 elems[i] = json_clone(array->elems[i]);
448 return json_array_create(elems, array->n);
452 json_hash_object(const struct shash *object, size_t basis)
454 const struct shash_node **nodes;
457 nodes = shash_sort(object);
458 n = shash_count(object);
459 for (i = 0; i < n; i++) {
460 const struct shash_node *node = nodes[i];
461 basis = hash_string(node->name, basis);
462 basis = json_hash(node->data, basis);
469 json_hash_array(const struct json_array *array, size_t basis)
473 basis = hash_int(array->n, basis);
474 for (i = 0; i < array->n; i++) {
475 basis = json_hash(array->elems[i], basis);
481 json_hash(const struct json *json, size_t basis)
483 switch (json->type) {
485 return json_hash_object(json->u.object, basis);
488 return json_hash_array(&json->u.array, basis);
491 return hash_string(json->u.string, basis);
496 return hash_int(json->type << 8, basis);
499 return hash_int(json->u.integer, basis);
502 return hash_double(json->u.real, basis);
511 json_equal_object(const struct shash *a, const struct shash *b)
513 struct shash_node *a_node;
515 if (shash_count(a) != shash_count(b)) {
519 SHASH_FOR_EACH (a_node, a) {
520 struct shash_node *b_node = shash_find(b, a_node->name);
521 if (!b_node || !json_equal(a_node->data, b_node->data)) {
530 json_equal_array(const struct json_array *a, const struct json_array *b)
538 for (i = 0; i < a->n; i++) {
539 if (!json_equal(a->elems[i], b->elems[i])) {
548 json_equal(const struct json *a, const struct json *b)
550 if (a->type != b->type) {
556 return json_equal_object(a->u.object, b->u.object);
559 return json_equal_array(&a->u.array, &b->u.array);
562 return !strcmp(a->u.string, b->u.string);
570 return a->u.integer == b->u.integer;
573 return a->u.real == b->u.real;
581 /* Lexical analysis. */
584 json_lex_keyword(struct json_parser *p)
586 struct json_token token;
589 s = ds_cstr(&p->buffer);
590 if (!strcmp(s, "false")) {
591 token.type = T_FALSE;
592 } else if (!strcmp(s, "true")) {
594 } else if (!strcmp(s, "null")) {
597 json_error(p, "invalid keyword '%s'", s);
600 json_parser_input(p, &token);
604 json_lex_number(struct json_parser *p)
606 const char *cp = ds_cstr(&p->buffer);
607 unsigned long long int significand = 0;
608 struct json_token token;
609 bool imprecise = false;
610 bool negative = false;
613 /* Leading minus sign. */
619 /* At least one integer digit, but 0 may not be used as a leading digit for
620 * a longer number. */
624 if (isdigit((unsigned char) *cp)) {
625 json_error(p, "leading zeros not allowed");
628 } else if (isdigit((unsigned char) *cp)) {
630 if (significand <= ULLONG_MAX / 10) {
631 significand = significand * 10 + (*cp - '0');
639 } while (isdigit((unsigned char) *cp));
641 json_error(p, "'-' must be followed by digit");
645 /* Optional fraction. */
648 if (!isdigit((unsigned char) *cp)) {
649 json_error(p, "decimal point must be followed by digit");
653 if (significand <= ULLONG_MAX / 10) {
654 significand = significand * 10 + (*cp - '0');
656 } else if (*cp != '0') {
660 } while (isdigit((unsigned char) *cp));
663 /* Optional exponent. */
664 if (*cp == 'e' || *cp == 'E') {
665 bool negative_exponent = false;
671 } else if (*cp == '-') {
672 negative_exponent = true;
676 if (!isdigit((unsigned char) *cp)) {
677 json_error(p, "exponent must contain at least one digit");
683 if (exponent >= INT_MAX / 10) {
684 json_error(p, "exponent outside valid range");
687 exponent = exponent * 10 + (*cp - '0');
689 } while (isdigit((unsigned char) *cp));
691 if (negative_exponent) {
699 json_error(p, "syntax error in number");
703 /* Figure out number.
705 * We suppress negative zeros as a matter of policy. */
707 token.type = T_INTEGER;
709 json_parser_input(p, &token);
714 while (pow10 > 0 && significand < ULLONG_MAX / 10) {
718 while (pow10 < 0 && significand % 10 == 0) {
723 && significand <= (negative
724 ? (unsigned long long int) LLONG_MAX + 1
726 token.type = T_INTEGER;
727 token.u.integer = negative ? -significand : significand;
728 json_parser_input(p, &token);
734 if (!str_to_double(ds_cstr(&p->buffer), &token.u.real)) {
735 json_error(p, "number outside valid range");
738 /* Suppress negative zero. */
739 if (token.u.real == 0) {
742 json_parser_input(p, &token);
746 json_lex_4hex(const char *cp, const char *end, int *valuep)
752 return "quoted string ends within \\u escape";
755 value = hexits_value(cp, 4, &ok);
757 return "malformed \\u escape";
760 return "null bytes not supported in quoted strings";
767 json_lex_unicode(const char *cp, const char *end, struct ds *out)
772 error = json_lex_4hex(cp, end, &c0);
775 ds_put_cstr(out, error);
779 if (!uc_is_leading_surrogate(c0)) {
780 ds_put_utf8(out, c0);
784 if (cp + 2 > end || *cp++ != '\\' || *cp++ != 'u') {
786 ds_put_cstr(out, "malformed escaped surrogate pair");
790 error = json_lex_4hex(cp, end, &c1);
793 ds_put_cstr(out, error);
797 if (!uc_is_trailing_surrogate(c1)) {
799 ds_put_cstr(out, "second half of escaped surrogate pair is not "
800 "trailing surrogate");
804 ds_put_utf8(out, utf16_decode_surrogate_pair(c0, c1));
809 json_string_unescape(const char *in, size_t in_len, char **outp)
811 const char *end = in + in_len;
816 ds_reserve(&out, in_len);
820 ds_put_cstr(&out, "quoted string may not include unescaped \"");
824 ds_put_char(&out, *in++);
830 /* The JSON parser will never trigger this message, because its
831 * lexer will never pass in a string that ends in a single
832 * backslash, but json_string_unescape() has other callers that
833 * are not as careful.*/
834 ds_put_cstr(&out, "quoted string may not end with backslash");
838 case '"': case '\\': case '/':
839 ds_put_char(&out, in[-1]);
843 ds_put_char(&out, '\b');
847 ds_put_char(&out, '\f');
851 ds_put_char(&out, '\n');
855 ds_put_char(&out, '\r');
859 ds_put_char(&out, '\t');
863 in = json_lex_unicode(in, end, &out);
871 ds_put_format(&out, "bad escape \\%c", in[-1]);
878 *outp = ds_cstr(&out);
883 json_parser_input_string(struct json_parser *p, const char *s)
885 struct json_token token;
887 token.type = T_STRING;
889 json_parser_input(p, &token);
893 json_lex_string(struct json_parser *p)
895 const char *raw = ds_cstr(&p->buffer);
896 if (!strchr(raw, '\\')) {
897 json_parser_input_string(p, raw);
901 if (json_string_unescape(raw, strlen(raw), &cooked)) {
902 json_parser_input_string(p, cooked);
904 json_error(p, "%s", cooked);
912 json_lex_input(struct json_parser *p, unsigned char c)
914 struct json_token token;
916 switch (p->lex_state) {
919 case ' ': case '\t': case '\n': case '\r':
923 case 'a': case 'b': case 'c': case 'd': case 'e':
924 case 'f': case 'g': case 'h': case 'i': case 'j':
925 case 'k': case 'l': case 'm': case 'n': case 'o':
926 case 'p': case 'q': case 'r': case 's': case 't':
927 case 'u': case 'v': case 'w': case 'x': case 'y':
929 p->lex_state = JSON_LEX_KEYWORD;
932 case '[': case '{': case ']': case '}': case ':': case ',':
934 json_parser_input(p, &token);
938 case '0': case '1': case '2': case '3': case '4':
939 case '5': case '6': case '7': case '8': case '9':
940 p->lex_state = JSON_LEX_NUMBER;
944 p->lex_state = JSON_LEX_STRING;
949 json_error(p, "invalid character '%c'", c);
951 json_error(p, "invalid character U+%04x", c);
957 case JSON_LEX_KEYWORD:
958 if (!isalpha((unsigned char) c)) {
964 case JSON_LEX_NUMBER:
965 if (!strchr(".0123456789eE-+", c)) {
971 case JSON_LEX_STRING:
973 p->lex_state = JSON_LEX_ESCAPE;
974 } else if (c == '"') {
977 } else if (c < 0x20) {
978 json_error(p, "U+%04X must be escaped in quoted string", c);
983 case JSON_LEX_ESCAPE:
984 p->lex_state = JSON_LEX_STRING;
990 ds_put_char(&p->buffer, c);
996 /* Parses 'string' as a JSON object or array and returns a newly allocated
997 * 'struct json'. The caller must free the returned structure with
998 * json_destroy() when it is no longer needed.
1000 * 'string' must be encoded in UTF-8.
1002 * If 'string' is valid JSON, then the returned 'struct json' will be either an
1003 * object (JSON_OBJECT) or an array (JSON_ARRAY).
1005 * If 'string' is not valid JSON, then the returned 'struct json' will be a
1006 * string (JSON_STRING) that describes the particular error encountered during
1007 * parsing. (This is an acceptable means of error reporting because at its top
1008 * level JSON must be either an object or an array; a bare string is not
1011 json_from_string(const char *string)
1013 struct json_parser *p = json_parser_create(JSPF_TRAILER);
1014 json_parser_feed(p, string, strlen(string));
1015 return json_parser_finish(p);
1018 /* Reads the file named 'file_name', parses its contents as a JSON object or
1019 * array, and returns a newly allocated 'struct json'. The caller must free
1020 * the returned structure with json_destroy() when it is no longer needed.
1022 * The file must be encoded in UTF-8.
1024 * See json_from_string() for return value semantics.
1027 json_from_file(const char *file_name)
1032 stream = fopen(file_name, "r");
1034 return json_string_create_nocopy(
1035 xasprintf("error opening \"%s\": %s", file_name,
1036 ovs_strerror(errno)));
1038 json = json_from_stream(stream);
1044 /* Parses the contents of 'stream' as a JSON object or array, and returns a
1045 * newly allocated 'struct json'. The caller must free the returned structure
1046 * with json_destroy() when it is no longer needed.
1048 * The file must be encoded in UTF-8.
1050 * See json_from_string() for return value semantics.
1053 json_from_stream(FILE *stream)
1055 struct json_parser *p;
1058 p = json_parser_create(JSPF_TRAILER);
1060 char buffer[BUFSIZ];
1063 n = fread(buffer, 1, sizeof buffer, stream);
1064 if (!n || json_parser_feed(p, buffer, n) != n) {
1068 json = json_parser_finish(p);
1070 if (ferror(stream)) {
1072 json = json_string_create_nocopy(
1073 xasprintf("error reading JSON stream: %s", ovs_strerror(errno)));
1079 struct json_parser *
1080 json_parser_create(int flags)
1082 struct json_parser *p = xzalloc(sizeof *p);
1088 json_parser_feed(struct json_parser *p, const char *input, size_t n)
1091 for (i = 0; !p->done && i < n; ) {
1092 if (json_lex_input(p, input[i])) {
1094 if (input[i] == '\n') {
1095 p->column_number = 0;
1107 json_parser_is_done(const struct json_parser *p)
1113 json_parser_finish(struct json_parser *p)
1117 switch (p->lex_state) {
1118 case JSON_LEX_START:
1121 case JSON_LEX_STRING:
1122 case JSON_LEX_ESCAPE:
1123 json_error(p, "unexpected end of input in quoted string");
1126 case JSON_LEX_NUMBER:
1127 case JSON_LEX_KEYWORD:
1128 json_lex_input(p, ' ');
1132 if (p->parse_state == JSON_PARSE_START) {
1133 json_error(p, "empty input stream");
1134 } else if (p->parse_state != JSON_PARSE_END) {
1135 json_error(p, "unexpected end of input");
1139 ovs_assert(p->height == 1);
1140 ovs_assert(p->stack[0].json != NULL);
1141 json = p->stack[--p->height].json;
1143 json = json_string_create_nocopy(p->error);
1147 json_parser_abort(p);
1153 json_parser_abort(struct json_parser *p)
1156 ds_destroy(&p->buffer);
1158 json_destroy(p->stack[0].json);
1161 free(p->member_name);
1167 static struct json_parser_node *
1168 json_parser_top(struct json_parser *p)
1170 return &p->stack[p->height - 1];
1174 json_parser_put_value(struct json_parser *p, struct json *value)
1176 struct json_parser_node *node = json_parser_top(p);
1177 if (node->json->type == JSON_OBJECT) {
1178 json_object_put(node->json, p->member_name, value);
1179 free(p->member_name);
1180 p->member_name = NULL;
1181 } else if (node->json->type == JSON_ARRAY) {
1182 json_array_add(node->json, value);
1189 json_parser_push(struct json_parser *p,
1190 struct json *new_json, enum json_parse_state new_state)
1192 if (p->height < JSON_MAX_HEIGHT) {
1193 struct json_parser_node *node;
1195 if (p->height >= p->allocated_height) {
1196 p->stack = x2nrealloc(p->stack, &p->allocated_height,
1200 if (p->height > 0) {
1201 json_parser_put_value(p, new_json);
1204 node = &p->stack[p->height++];
1205 node->json = new_json;
1206 p->parse_state = new_state;
1208 json_destroy(new_json);
1209 json_error(p, "input exceeds maximum nesting depth %d",
1215 json_parser_push_object(struct json_parser *p)
1217 json_parser_push(p, json_object_create(), JSON_PARSE_OBJECT_INIT);
1221 json_parser_push_array(struct json_parser *p)
1223 json_parser_push(p, json_array_create_empty(), JSON_PARSE_ARRAY_INIT);
1227 json_parse_value(struct json_parser *p, struct json_token *token,
1228 enum json_parse_state next_state)
1232 switch (token->type) {
1234 value = json_boolean_create(false);
1238 value = json_null_create();
1242 value = json_boolean_create(true);
1246 json_parser_push_object(p);
1250 json_parser_push_array(p);
1254 value = json_integer_create(token->u.integer);
1258 value = json_real_create(token->u.real);
1262 value = json_string_create(token->u.string);
1271 json_error(p, "syntax error expecting value");
1275 json_parser_put_value(p, value);
1276 p->parse_state = next_state;
1280 json_parser_pop(struct json_parser *p)
1282 struct json_parser_node *node;
1284 /* Conserve memory. */
1285 node = json_parser_top(p);
1286 if (node->json->type == JSON_ARRAY) {
1287 json_array_trim(node->json);
1290 /* Pop off the top-of-stack. */
1291 if (p->height == 1) {
1292 p->parse_state = JSON_PARSE_END;
1293 if (!(p->flags & JSPF_TRAILER)) {
1298 node = json_parser_top(p);
1299 if (node->json->type == JSON_ARRAY) {
1300 p->parse_state = JSON_PARSE_ARRAY_NEXT;
1301 } else if (node->json->type == JSON_OBJECT) {
1302 p->parse_state = JSON_PARSE_OBJECT_NEXT;
1310 json_parser_input(struct json_parser *p, struct json_token *token)
1312 switch (p->parse_state) {
1313 case JSON_PARSE_START:
1314 if (token->type == '{') {
1315 json_parser_push_object(p);
1316 } else if (token->type == '[') {
1317 json_parser_push_array(p);
1319 json_error(p, "syntax error at beginning of input");
1323 case JSON_PARSE_END:
1324 json_error(p, "trailing garbage at end of input");
1327 case JSON_PARSE_OBJECT_INIT:
1328 if (token->type == '}') {
1333 case JSON_PARSE_OBJECT_NAME:
1334 if (token->type == T_STRING) {
1335 p->member_name = xstrdup(token->u.string);
1336 p->parse_state = JSON_PARSE_OBJECT_COLON;
1338 json_error(p, "syntax error parsing object expecting string");
1342 case JSON_PARSE_OBJECT_COLON:
1343 if (token->type == ':') {
1344 p->parse_state = JSON_PARSE_OBJECT_VALUE;
1346 json_error(p, "syntax error parsing object expecting ':'");
1350 case JSON_PARSE_OBJECT_VALUE:
1351 json_parse_value(p, token, JSON_PARSE_OBJECT_NEXT);
1354 case JSON_PARSE_OBJECT_NEXT:
1355 if (token->type == ',') {
1356 p->parse_state = JSON_PARSE_OBJECT_NAME;
1357 } else if (token->type == '}') {
1360 json_error(p, "syntax error expecting '}' or ','");
1364 case JSON_PARSE_ARRAY_INIT:
1365 if (token->type == ']') {
1370 case JSON_PARSE_ARRAY_VALUE:
1371 json_parse_value(p, token, JSON_PARSE_ARRAY_NEXT);
1374 case JSON_PARSE_ARRAY_NEXT:
1375 if (token->type == ',') {
1376 p->parse_state = JSON_PARSE_ARRAY_VALUE;
1377 } else if (token->type == ']') {
1380 json_error(p, "syntax error expecting ']' or ','");
1388 p->lex_state = JSON_LEX_START;
1389 ds_clear(&p->buffer);
1392 static struct json *
1393 json_create(enum json_type type)
1395 struct json *json = xmalloc(sizeof *json);
1401 json_error(struct json_parser *p, const char *format, ...)
1408 ds_put_format(&msg, "line %d, column %d, byte %d: ",
1409 p->line_number, p->column_number, p->byte_number);
1410 va_start(args, format);
1411 ds_put_format_valist(&msg, format, args);
1414 p->error = ds_steal_cstr(&msg);
1420 #define SPACES_PER_LEVEL 2
1422 struct json_serializer {
1428 static void json_serialize(const struct json *, struct json_serializer *);
1429 static void json_serialize_object(const struct shash *object,
1430 struct json_serializer *);
1431 static void json_serialize_array(const struct json_array *,
1432 struct json_serializer *);
1433 static void json_serialize_string(const char *, struct ds *);
1435 /* Converts 'json' to a string in JSON format, encoded in UTF-8, and returns
1436 * that string. The caller is responsible for freeing the returned string,
1437 * with free(), when it is no longer needed.
1439 * If 'flags' contains JSSF_PRETTY, the output is pretty-printed with each
1440 * nesting level introducing an additional indentation. Otherwise, the
1441 * returned string does not contain any new-line characters.
1443 * If 'flags' contains JSSF_SORT, members of objects in the output are sorted
1444 * in bytewise lexicographic order for reproducibility. Otherwise, members of
1445 * objects are output in an indeterminate order.
1447 * The returned string is valid JSON only if 'json' represents an array or an
1448 * object, since a bare literal does not satisfy the JSON grammar. */
1450 json_to_string(const struct json *json, int flags)
1455 json_to_ds(json, flags, &ds);
1456 return ds_steal_cstr(&ds);
1459 /* Same as json_to_string(), but the output is appended to 'ds'. */
1461 json_to_ds(const struct json *json, int flags, struct ds *ds)
1463 struct json_serializer s;
1468 json_serialize(json, &s);
1472 json_serialize(const struct json *json, struct json_serializer *s)
1474 struct ds *ds = s->ds;
1476 switch (json->type) {
1478 ds_put_cstr(ds, "null");
1482 ds_put_cstr(ds, "false");
1486 ds_put_cstr(ds, "true");
1490 json_serialize_object(json->u.object, s);
1494 json_serialize_array(&json->u.array, s);
1498 ds_put_format(ds, "%lld", json->u.integer);
1502 ds_put_format(ds, "%.*g", DBL_DIG, json->u.real);
1506 json_serialize_string(json->u.string, ds);
1516 indent_line(struct json_serializer *s)
1518 if (s->flags & JSSF_PRETTY) {
1519 ds_put_char(s->ds, '\n');
1520 ds_put_char_multiple(s->ds, ' ', SPACES_PER_LEVEL * s->depth);
1525 json_serialize_object_member(size_t i, const struct shash_node *node,
1526 struct json_serializer *s)
1528 struct ds *ds = s->ds;
1531 ds_put_char(ds, ',');
1535 json_serialize_string(node->name, ds);
1536 ds_put_char(ds, ':');
1537 if (s->flags & JSSF_PRETTY) {
1538 ds_put_char(ds, ' ');
1540 json_serialize(node->data, s);
1544 json_serialize_object(const struct shash *object, struct json_serializer *s)
1546 struct ds *ds = s->ds;
1548 ds_put_char(ds, '{');
1553 if (s->flags & JSSF_SORT) {
1554 const struct shash_node **nodes;
1557 nodes = shash_sort(object);
1558 n = shash_count(object);
1559 for (i = 0; i < n; i++) {
1560 json_serialize_object_member(i, nodes[i], s);
1564 struct shash_node *node;
1568 SHASH_FOR_EACH (node, object) {
1569 json_serialize_object_member(i++, node, s);
1573 ds_put_char(ds, '}');
1578 json_serialize_array(const struct json_array *array, struct json_serializer *s)
1580 struct ds *ds = s->ds;
1583 ds_put_char(ds, '[');
1589 for (i = 0; i < array->n; i++) {
1591 ds_put_char(ds, ',');
1594 json_serialize(array->elems[i], s);
1599 ds_put_char(ds, ']');
1603 json_serialize_string(const char *string, struct ds *ds)
1607 ds_put_char(ds, '"');
1608 while ((c = *string++) != '\0') {
1611 ds_put_cstr(ds, "\\\"");
1615 ds_put_cstr(ds, "\\\\");
1619 ds_put_cstr(ds, "\\b");
1623 ds_put_cstr(ds, "\\f");
1627 ds_put_cstr(ds, "\\n");
1631 ds_put_cstr(ds, "\\r");
1635 ds_put_cstr(ds, "\\t");
1642 ds_put_format(ds, "\\u%04x", c);
1647 ds_put_char(ds, '"');