added optional parent token pointer support. Increases parsing speed

jsmn.c

@@ -14,6 +14,9 @@ static jsmntok_t *jsmn_alloc_token(jsmn_parser *parser,
 	tok = &tokens[parser->toknext++];
 	tok->start = tok->end = -1;
 	tok->size = 0;
+#ifdef JSMN_PARENT_LINKS
+	tok->parent = -1;
+#endif
 	return tok;
 }
 
@@ -65,6 +68,9 @@ found:
 		return JSMN_ERROR_NOMEM;
 	}
 	jsmn_fill_token(token, JSMN_PRIMITIVE, start, parser->pos);
+#ifdef JSMN_PARENT_LINKS
+	token->parent = parser->toksuper;
+#endif
 	parser->pos--;
 	return JSMN_SUCCESS;
 }
@@ -92,6 +98,9 @@ static jsmnerr_t jsmn_parse_string(jsmn_parser *parser, const char *js,
 				return JSMN_ERROR_NOMEM;
 			}
 			jsmn_fill_token(token, JSMN_STRING, start+1, parser->pos);
+#ifdef JSMN_PARENT_LINKS
+			token->parent = parser->toksuper;
+#endif
 			return JSMN_SUCCESS;
 		}
 
@@ -137,14 +146,35 @@ jsmnerr_t jsmn_parse(jsmn_parser *parser, const char *js, jsmntok_t *tokens,
 				token = jsmn_alloc_token(parser, tokens, num_tokens);
 				if (token == NULL)
 					return JSMN_ERROR_NOMEM;
-				if (parser->toksuper != -1)
+				if (parser->toksuper != -1) {
 					tokens[parser->toksuper].size++;
+#ifdef JSMN_PARENT_LINKS
+					token->parent = parser->toksuper;
+#endif
+				}
 				token->type = (c == '{' ? JSMN_OBJECT : JSMN_ARRAY);
 				token->start = parser->pos;
 				parser->toksuper = parser->toknext - 1;
 				break;
 			case '}': case ']':
 				type = (c == '}' ? JSMN_OBJECT : JSMN_ARRAY);
+#ifdef JSMN_PARENT_LINKS
+				if (parser->toknext < 1) {
+					return JSMN_ERROR_INVAL;
+				}
+				token = &tokens[parser->toknext - 1];
+				for (;;) {
+					if (token->start != -1 && token->end == -1) {
+						token->end = parser->pos + 1;
+						parser->toksuper = token->parent;
+						break;
+					}
+					if (token->parent == -1) {
+						break;
+					}
+					token = &tokens[token->parent];
+				}
+#else
 				for (i = parser->toknext - 1; i >= 0; i--) {
 					token = &tokens[i];
 					if (token->start != -1 && token->end == -1) {
@@ -165,6 +195,7 @@ jsmnerr_t jsmn_parse(jsmn_parser *parser, const char *js, jsmntok_t *tokens,
 						break;
 					}
 				}
+#endif
 				break;
 			case '\"':
 				r = jsmn_parse_string(parser, js, tokens, num_tokens);

jsmn.h

@@ -37,6 +37,9 @@ typedef struct {
 	int start;
 	int end;
 	int size;
+#ifdef JSMN_PARENT_LINKS
+	int parent;
+#endif
 } jsmntok_t;
 
 /**